Treatment Modalities LC Flashcards
drugs that deplete or inhibit proliferation of MDSCs
Liposomal clodronate
Gemcitabine
5-FU
Sunitinib
Docetaxel
Cox 2 inhibitor (SC58236)
KIT-specific Ab
25-Hydroxyvitamin D
CXCR2 antagonist (S-265610)
CXCR4 antagonist (AMD3100)
PROK2-specific Ab
drugs that promote maturation of MDSCs
Zoledronate
ATRA
Docetaxel
Sunitinib
Decitabine
Activated NKT cells
VSSP vaccine
drugs that inhibit recruitment of MDSCs
cFMS kinase inhibitor (GW2580)
NSAIDs
drugs that block interaction of MDSCs
Anti-CD40 Ab
Anti-PD-1/PD-L1 Ab
drugs that block function of MDSCs
Nitroaspirin
Arginase 1 inhibitor (NOHA)
Triterpenoid
Sildenafil
drugs that cause pulmonary fibrosis
Tanovea, bleomycin, gemcitabine, EGFR-directed therapies, MTOR inhibitors, immune checkpoint inhibitors, methotrexate
indications for bone marrow transplant
Hematopoietic Disorders:
Acute leukemias (e.g., acute lymphoblastic leukemia, acute myeloid leukemia) with a high risk of relapse or refractory disease.
Aplastic anemia, where the bone marrow fails to produce adequate blood cells.
Immune-mediated disorders affecting bone marrow function.
lymphoma
risks of bone marrow transplant
Graft-versus-Host Disease (GVHD): A major risk of BMT, where donor immune cells attack the recipient’s tissues, leading to severe inflammation and organ damage.
Infection: Immunosuppression post-transplantation increases the risk of infections, including bacterial, fungal, and viral infections.
Graft Failure: The transplanted bone marrow may fail to engraft and produce sufficient blood cells.
Toxicity: Conditioning regimens and immunosuppressive drugs used in BMT can cause systemic toxicity, including gastrointestinal, hepatic, and renal toxicity.
Secondary Malignancies: Long-term immunosuppression increases the risk of secondary malignancies, including lymphoma and other cancers.
graft vs host disease
allogeneic stem cell transplantation - ~33% of patients in one paper 3/9 dogs
Donor T cells present in the graft recognize alloantigens (foreign antigens) on recipient tissues, such as major histocompatibility complex (MHC) molecules. leads to the activation and expansion of donor T cells.
Activated donor T cells differentiate into effector T cells, including CD4+ T helper cells and CD8+ cytotoxic T cells.
Activated T cells secrete pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), and interferon-gamma (IFN-γ).
These cytokines contribute to tissue inflammation, damage, and recruitment of additional immune cells.
Effector T cells attack and damage recipient tissues, primarily the skin, gastrointestinal tract, and liver.
Skin manifestations include erythematous rash, blistering, and desquamation.
Gastrointestinal manifestations include diarrhea, abdominal pain, and mucosal damage.
Liver involvement can lead to hepatomegaly, jaundice, and hepatic dysfunction.
graft vs host disease acute vs chronic
Acute GVHD typically occurs within the first 100 days after transplantation and is characterized by a rapid onset of symptoms.
Chronic GVHD develops later, usually after day 100 post-transplant, and can persist for months to years. It often resembles autoimmune disorders and can affect multiple organs.
Direct Cytotoxicity: Effector T cells directly attack and kill recipient cells through cytotoxic mechanisms, including perforin and granzyme-mediated apoptosis.
Indirect Pathways: Effector T cells activate macrophages and other immune cells, leading to tissue inflammation and damage.
Antibody-Mediated Damage: B cells activated by donor T cells produce antibodies against recipient tissues, contributing to tissue damage.
prevention and treatment of graft vs host disease
Prevention and Treatment:
GVHD prophylaxis strategies aim to suppress donor T cell activation and function while preserving graft-versus-tumor effects.
Treatment options for established GVHD include immunosuppressive drugs such as cyclophosphamide, corticosteroids, calcineurin inhibitors (e.g., cyclosporine, tacrolimus), and anti-T cell antibodies (e.g., anti-thymocyte globulin).
Severe cases of GVHD may require additional therapies, such as extracorporeal photopheresis or mesenchymal stem cell therapy, to modulate immune responses and reduce tissue damage.
limitations of BMT
Donor Availability: Finding an appropriate donor (allogeneic) or preparing the recipient as its own donor (autologous) can be challenging.
Cost: BMT is an expensive procedure, including pre-transplant workup, conditioning regimens, transplantation, post-transplant care, and potential complications.
Specialized Facilities: BMT requires access to specialized facilities and expertise, including hematologists/oncologists, aphoesis, and specialized laboratories.
Intrinsic Limitations: Some conditions may not be suitable for BMT due to poor prognosis or lack of response to prior chemo treatment
Success Rates of BMT
Success rates for allogeneic BMT in dogs ~89%
Reported success rates for autologous BMT in dogs with lymphoma range from 33 - 40%
allogeneic bmt can cure ~50% more dogs than those treated with autologous
Survival Time: Dogs that successfully undergo BMT may achieve long-term remission or cure, with survival times ranging from months to several years.
Quality of Life: Dogs that undergo successful BMT can regain a good quality of life, with resolution of clinical signs associated with the underlying disease.
Complications: Even in successful cases, dogs may experience complications such as GVHD, infections, and long-term organ toxicities.
aphoresis
Blood Collection: Apheresis begins by drawing blood
Separation Process: The collected blood is then processed through a machine called an apheresis machine. This machine separates the blood into its individual components, such as red blood cells, white blood cells, platelets, and plasma.
Targeted Component Removal: Depending on the purpose of the procedure, specific components of the blood may be removed, such as:
White Blood Cells: Used for patients with certain immune disorders or to reduce the risk of organ rejection in transplant recipients.
Return of Remaining Blood: After the targeted component is removed, the remaining blood components are returned to the body
Filgrastim (G-CSF)
Granulocyte colony-stimulating factor (G-CSF) is used to stimulate the production of neutrophils and accelerate bone marrow recovery after transplantation.
Neupogen
human may not work in dogs
Anti-Thymocyte Globulin (ATG):
ATG is a polyclonal antibody preparation derived from animals (e.g., horse or rabbit) that targets and depletes T cells. It is used as part of the conditioning regimen before BMT to reduce the risk of GVHD
how does Cyclophosphamide work as an immunosuppressant in BMT
inhibiting the function of T and B lymphocytes. only cyclophosphamide and methotrexate can induce apoptosis of alloantigen-activated human T cells. Another unique cyclophosphamide mode of action is upregulation of CD95 expression, which leads to activation-induced apoptosis within 6 days, further preventing T-cell activation
By suppressing the immune system, cyclophosphamide helps prevent rejection of the transplanted bone marrow and reduces the risk of graft-versus-host disease (GVHD).
used to eliminate any remaining cancer cells in the bone marrow and peripheral blood and prevent gvhd.
is often used in combination with other chemotherapy drugs or radiation therapy to maximize its effectiveness in conditioning the recipient
cyclophosphamide dose for BMT
Cyclophosphamide is often administered at high doses, typically ranging from 200 to 400 mg/m^2.
The dose may be given as a single dose or divided into multiple doses over several days.
Some protocols may use higher doses of up to 600 mg/m^2, particularly in aggressive lymphoma protocols.
radiation for BMT
Fractionated total body irradiation involves dividing the total dose into multiple smaller fractions delivered over several days.
Single dose total body irradiation delivers the entire radiation dose in one session.
Typical doses for single dose TBI in dogs range from 8 to 12 Gray (Gy).
Mushroom-Derived Products evidence
Certain mushroom-derived products, such as polysaccharopeptide (PSP) from Coriolus versicolor ( turkey tail) and lentinan from Shiitake mushrooms, have been studied for their potential anticancer properties in both humans and animals.
Sulforaphanes use
Evidence: Sulforaphanes are bioactive compounds found in cruciferous vegetables like broccoli and cauliflower, known for their antioxidant and anti-inflammatory properties.
Effectiveness: Limited studies have investigated the use of sulforaphanes in dogs and cats with cancer. Some research suggests potential anticancer effects by modulating signaling pathways involved in tumor growth and progression.
Yunnan Baiyao:
Evidence: Yunnan Baiyao is a traditional Chinese herbal medicine used for its hemostatic and anti-inflammatory properties.
Hepatoprotectants:
Hepatoprotectants, such as S-adenosylmethionine (SAMe) and milk thistle (silymarin), are commonly used to support liver function in dogs and cats with cancer, especially those undergoing chemotherapy.
Herbal Supplements:
Evidence: Various herbal supplements, such as astragalus, turmeric, and green tea extract, have been studied for their potential anticancer effects in animals.
Effectiveness: While some preclinical studies suggest possible benefits, clinical evidence in dogs and cats with cancer is limited and often inconclusive.
sulforaphane modulating several signaling pathways involved in tumor growth and progression
Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) Pathway:
activate the Nrf2 pathway, regulates the expression of antioxidant and detoxification enzymes.
Activation of Nrf2 leads to increased expression of glutathione S-transferases (GSTs) and NAD(P)H:quinone oxidoreductase 1 (NQO1).
Glutathione helps neutralize reactive oxygen species (ROS) and free radicals, which can damage DNA and promote cancer development.
Anti-Inflammatory Pathways:
inhibiting the production of pro-inflammatory cytokines and enzymes, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS).
reducing chronic inflammation, suppress tumor-promoting processes and inhibit tumor growth
Apoptosis (Programmed Cell Death) Pathway:
upregulate pro-apoptotic proteins Bax and Bak while downregulating anti-apoptotic proteins Bcl-2. activate caspases,
modulate cell cycle progression by arresting cancer cells at different checkpoints, such as the G1/S and G2/M transitions.
Epigenetic Regulation:
inhibit DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), leading to changes in gene expression patterns that may favor tumor suppression.
Angiogenesis Inhibition:
downregulate angiogenic factors like vascular endothelial growth factor (VEGF)
literature evidence of sulforaphane
Clinical Trials:
Study 1: A clinical trial investigated the effects of sulforaphane-rich broccoli sprout extract (BSE) in dogs with lymphoma.
- no clinical response and no adverse events
- affected proteome -14 proteins were significantly downregulated, and 10 proteins were significantly upregulated. Proteins and gene sets impacted by SFN were commonly involved in immunity, response to oxidative stress, gene transcription, apoptosis, protein transport, maturation and ubiquitination.
In Vitro Studies:
Study 1: effects of sulforaphane on canine osteosarcoma cells.
SFN could not induce cell death at potentially physiological concentrations (<50 μM), but significantly diminished cell invasion and downregulation of focal adhesion kinase (FAK) signaling. Modest cell cycle changes were observed in each cell line
Cruciferous Vegetables and Bladder Cancer
Epidemiologic evidence suggests that diets rich in cruciferous vegetables, particularly broccoli, are associated with lower bladder cancer risk
In vitro studies have shown inhibition of bladder cancer cell lines, cell cycle arrest, and induction of apoptosis
research shows dogs can absorb sulforaphane and it has activity
Evaluation of the anti-tumour activity of Coriolus versicolor polysaccharopeptide (I’m-Yunity) alone or in combination with doxorubicin for canine splenic hemangiosarcoma
Dogs treated with PSP alone, female dogs, decreased HCT at diagnosis, and stage III disease associated with poor outcome
Addition of PSP to dox post splenectomy did not improve survival
This study shows the PSP alone does not improve survival compared to splenectomy alone
Single agent polysaccharopeptide effect on metastases and survival in naturally occurring hemangiosarcoma
double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma
2012 - before the paper showing it had no effect
Median time to development or progression of abdominal metastases was significantly delayed in dogs receiving 100 mg/kg/d I’m-Yunity (112 days ) compared with dogs receiving 25 mg/kg/d (30 days), but was not significantly different than in dogs receiving 50 mg/kg/d
maitake (Grifola frondosa) mushroom extract in 15 dogs with intermediate-grade and high-grade lymphoma
extract was well-tolerated and induced no negative effects, no decrease greater than 50% (objective response) in lymph node size occurred in 13 of 15 dogs
protective effects of a combination of S-adenosylmethionine (SAMe) and silybin for lomustine (CCNU)-induced hepatotoxicity
More dogs receiving CCNU alone had an increase in ALT compared with dogs receiving CCNU with Denamarin (84% vs 68%)
using 2 canine B-cell lymphoid cell lines evaluated genistein (4,5,7-trihydroxyisoflavone), a readily available isoflavone found in soy-based products, and genistein-combined polysaccharide (GCP)
genistein and GCP led to cell death via apoptosis, and the treated cells exhibited increased Bax:Bcl-2 ratios.
GCP was also found to inhibit cell proliferation, increase apoptosis, and induce G2/M arrest in 3 human and 4 canine lymphoid cell lines.
in vivo, dose-escalating pharmacokinetic study determined that therapeutic serum levels of genistein were not reached with oral dosing of GCP in normal dogs
study in canine osteosarcoma D-17 cells, treatment with α-mangostin, a xanthone derived from the mangosteen fruit (Garcinia mangostana),
nuclear condensation and fragmentation, typical of apoptosis
Other reported antitumor effects are in human breast and prostate cancer and leukemia
calcitriol and chemotherapy
Calcitriol induces G1/G0 cell-cycle arrest and apoptosis, while down-regulating Bcl-2, decreasing epidermal growth factor, and inhibiting tumor invasion through decreased metalloproteinase (MMP)-2 and metalloproteinase-9 activity.
Calcitriol was synergistic with cisplatin using in vitro canine tumor cells and a phase I clinical study
synergistic, antiproliferative in vitro activity when used with other chemotherapeutics, including CCNU, vinblastine, imatininib, or toceranib
Calcitriol inhibited canine transitional cell carcinoma cells via G0/G1 cell-cycle arrest
Retinoids
A 42%-58% response rate (33% CR) to isotretinoin treatment has been seen in dogs with cutaneous lymphoma, and positive results have been seen with in vitro canine mast cells and osteosarcoma cell lines
25% of dogs experiencing adverse effects that resolve quickly or do not affect quality of life.
selenium supplementation
anticarcinogenic effect by reducing the naturally occurring genotoxic stress within the aging prostate.
In a translational RCCT using 49 intact male elderly beagles, the extent of DNA damage in prostate cells and in peripheral blood lymphocytes was lower among the selenium-supplemented dogs.
recommended to be discontinued during RT since rt works by oxidation
nasal malignant carcinomas were given dietary menhaden oil (DHA and EPA) or soybean oil (control) before radiation therapy (RT)
dogs fed menhaden oil had significantly higher plasma concentrations of DHA (increased by 500%) and EPA (200%), lower tissue inflammatory eicosanoids, and decreased resting energy expenditure (by 20%) compared with controls. Increased plasma DHA was significantly associated (P<.05) with decreased plasma lactic acid and MMPs. This study suggests EPA and DHA may reduce some detrimental inflammatory eicosanoids and metabolic consequences of RT
drug-herb interactions with chemo
likely occur due to altered expression of the functional CYP450 isoenzymes that metabolize chemotherapeutic drugs
Hypericum perforatum, more commonly known as St. John’s Wort (SJW), which interferes with both CYP450 isoenzymes and P-gp - vincristine, vinblastine, and EGFR-TK inhibitors
in Vitro effects of Yunnan Baiyao on canine hemangiosarcoma cell lines after treatment with increasing concentrations of Yunnan Baiyao
herbal supplement did cause dose and time dependent hemangiosarcoma cell death through initiation of caspase-mediated apoptosis
The effect of Yunnan Baiyao on platelet activation, buccal mucosal bleeding time, prothrombin time, activated partial thromboplastin time, and thromboelastography in healthy dogs
no induction of hypercoagulability.
Use of Yunnan Baiyao and epsilon aminocaproic acid in dogs with right atrial masses and pericardial effusion
no side effects attributed to the use of Yunnan Baiyao. The study did not show a significant improvement in survival time from the study dogs compared to the control dogs.
Incompletely excised STS grade II owner cannot afford def RT
– recurrence < 34%, tx with metronomic chemotherapy, hypofract RT
metronomic chemotherapy mechanism
therapeutic target : slowly proliferating tumor endothelium
mechanisms
- inhibition of tumor angiogenesis: possibly though thrombosponin-1 inhibiting vegf and blocking circulating endothelial cells
- activation of anti-tumor immunity: decreases in the number and function of Treg (inhibiting their blocking of NK cell and inhibiting secretion of TGFb/IL10) , dendritic cell activation, and stimulation of tumor-specific cytotoxic T cells
- induction of tumor dormancy AND inhibition of cancer stem cells;
may be able to target CSCs and dormant tumor cells because of the tendency of both cell populations to reside in close proximity to tumor vasculature
function in acidic and hypoxic environments
low doses of paclitaxel to mice with metastatic lung tumors
decrease in Treg number and function without interfering with tumor-specific cytotoxic T cell function
The majority of human studies have paired a conventional chemotherapy drug with a noncytotoxic drug that also targets angiogenesis such as
COX inhibitors, tetracyclines, and thalidomide or those with more direct effects such as bevacizumab
metronomic chemo what pre treatment biomarker (protein) was important
pilot study of MC and celecoxib therapy in 15 dogs with various cancers found low baseline plasma VEGF was predictive of response
side effects of bevacizumab
hypertension, edema, hemorrhage, thromboembolism, proteinuria, intestinal perfo- ration, and impaired wound healing
side effects for TOC
hypertension, protein- uria, dose-dependent gastrointestinal upset, bleeding, myelosup- pression, azotemia, anemia, lethargy, lameness, or disruption of the hypothalamic–pituitary–thyroid axis
metronomic cytoxan causes sterile hemorrhagic cystitis T/F
true
incidence of SHC may be more frequent in metronomic protocols. Recent reports document that cystitis may occur in up to 34% of cases, and SHC risk increases with longer treatment duration
myelopthesis
Combination of Metronomic Chemotherapy
with Other Treatment Modalities
MTD DOX with concurrent metronomic CYC 15 mg/m2 was found to be well tolerated in a recent phase I study - DOX was associated with nonselective depletion of circulating lymphocytes such that any potential benefits of Treg depletion by low- dose CYC would have been lost
pRT plus daily oral piroxicam and thalidomide plus every other day oral CYC significantly longer OST compared with dogs treated with pRT alone (757 vs 286 days, respectively)
RT has been combined with metronomic dosing of lomustine in the treatment of dogs with OSA - no diff in ost
splenic hsa and metronomic chemo
- alternating cytox and etoposide daily with piroxicam let to similar efficacy to dox
- cytox alone vs dox also similar but both were better than splenectomy alone- doxo 4.5 mths, mc ctx 2 mths, splenectomy 1.5 mths. doxo group had higher toxicity.
- splenectomy and six doses of DOX, daily or every other day CYC plus an NSAID had no effect on PFS or OST
administration of lomustine at a daily oral dose of 2.84 mg/m2
high incidence of adverse events occurred and led to the discontinuation of the therapy in nearly 30%
13 dogs with gastrointestinal toxicosis, 4 dogs with thrombocytopenia, 3 dogs with increased alanine transaminase, 1 dog with neutropenia, and 1 dog with progressive azotemia
SE of bisphosphonates
renal tubular damage - azotemia
hypocalcemia
osteonecrosis of the jaw
1 report of allergic rxn
What impact do bisphosphantes have on OSA?
Palliative for pain 28% responded >4months, RT+dox+pam-bloodwork better but owner did not notice;
Another RT+chemo+pam-the RT+pam group did the worst 69days
Aminobisphosphonates bind strongly to hydroxyapatite at which site?
R1 (R2 determines amino-BP (ex. ZOL) vs. nonamino-BP (ex. clodronate))
MOA of zoledronate
binds to HAP via R1. uptake into the osteoclast Synthetic analogs of inorganic pyrophosphate inhibits farnesyl pyrophosphate synthaze preventing conversion of geranyl pp to farnesyl pp
- Induction of osteoclast apoptosis net attenuation of pathologic bone resorption
- Interfere with post translational prenylation of small GTP-binding proteins including Ras, Rho and Rac
Inhibit bone resorption without inhibiting bone mineralization
What effect does ZOL have on expression of chemokine receptors in OSA?
reduced CXCR4 expression by 40% within primary tumor.
cxcr4 is a transmembrane g protein coupled chemokine receptor involved in metastasis and growth
Evaluation of Zoledronate as Treatment for Hypercalcemia
worked
reports prev. Unreported allergic reaction in one dog. Otherwise well tolerated.
Dexrazoxane MOA
Chelation of iron-free radicals, resulting in reduced oxidative damage
also poss dec in ROS
Increased cardiotox secondary to dox function of what?
peak drug level ( within first 30- min) and total cumulative dose
dosing 20 - 30 mg/m2 decreases cardiotox
96 hour infusion is less cardiotox
use of vitamin b6
one study showed protective against Chemotherapy-induced neuropathy - may work against taxane or vinca neuro toxicity
B6 intake from food is also associated with reduced risk of death from stroke, heart disease, and heart failure. B6 may reduce high blood pressure in animals
Pyridoxal phosphate (PLP) is the major coenzyme form, the most abundant in animal tissue, and the cofactor for over 100 enzymes used in amino acid metabolism, including aminotransferases, decarboxylases, racemases, and dehydrases
excess-pyridoxine diet actively influenced cell-mediated immunity via enhanced IFN-γ production and Th1-polarizatio
vit b6 pyridoxine and cisplatin
potentiates intracellular effects intracellularly in vitro
What is the mechanism of action of MESNA (hydrolysis/conjugation in which areas)?
MESNA conjugates with acrolein in the urinary tract in the bladder to render it inactive. - cant work for cisplatin bc it only activates in bladder
Mesna dimerizes to an inactive metabolite in blood so it does not affect the cytotoxicity of cyclophosphamide or ifosfamide
Why are carboplatin and gemcitabine synergistic/what results when given together?
gemcitabine causes decreased NER DNA repair in s phase by inhiting dna polymerase - which is how carboplatin adducts are repaired (induces cell cycle arrest and apoptosis)
Elspar deactivates which chemotherapy?
Methotrexate (can also “rescue” from methotrexate toxicity)
o L-asparaginase depletes the asparagine reserve, and Elspar blocks conversion of MTX to polyglutamates as well as progression into S phase by depletion of asparagine so inhibits MTX action; upreg of MDR
How is MESNA metabolized?
Autooxidation → reduction (by GSHR) → conjugation with acrolein and other urotoxic metabolites in bladder
denamarin + ccnu
dec liver enzyme elevation
84% va 68%
Tavocept
is a water‐soluble disulfide form of mesna
converted to mesna in the kidneys, which then locally inactivates the toxic platinum species - use as protectant form cisplatin
Tavocept decreased the required diuresis time with cisplatin from > 6 hours to 90 minutes, while also decreasing occurrence of azotemia
but may have reduced efficacy of platinum- dogs had worse rr than historic controls
Amifostine
used to protect kidneys from cisplatin
sulfur compound that has the potential to limit severe mucositis caused by RT
reduces neutropenia from cytox
amifostine is not commonly used clinically for a variety of reasons. Clinically, it is difficult to administer, with hypotension being a major side effect.
vinc / lspar together
dose dependent neutropenia
reduce vinc dose
myelosuppressive effects can be additive,
Doxorubicin + Cyclophosphamide
combination has shown synergistic effects, leading to enhanced tumor cell kill, particularly in lymphomas and sarcomas.
Doxorubicin + Cisplatin:
combining them can increase the risk of cardiotoxicity, as both drugs have cardiotoxic effects
RARE
lspar and ccnu
When used together, L-asparaginase and CCNU have shown synergistic effects against lymphoma cells, leading to enhanced tumor cell kill and improved treatment outcomes.
inc rr fro ~50% ccnu alone to 77-87%
what is worse intermittent high dose exposure or chronic low levels of exposure to chemo as the provider
chronic low levels of cytotoxic chemotherapy exposure actually may have increased risk, because cytotoxic effects are less likely to occur with similar mutagenic effects
risks of chemo exposure to people
could harm a fetus, inc risk for other cancers
Human healthcare workers (eg, pharmacy employees, nurses) handling chemotherapeutics have been found to have variably increased chromosomal aberrations compared to the general population, as well as urinary excretion of these drugs or their metabolites, which could lead to similar reproductive complications found in cancer patients treated with cytotoxic drugs
incremental increased risk of infertility and early pregnancy loss with occupational exposure to chemotherapeutics
increased risk was found for the development of multiple myeloma (6 cases out of 12 000), and a decreased risk for lung cancer
things that reduce the risk of chemo exposure
closed-system transfer devices (CSTD)
biologic safety cabinets (BSCs)
personal protective equipment (PPE)
markedly decreases,but does not always eliminate, evidence of drug contamination
PPE recomendations
Chemotherapy-rated (ASTM International [American SocietyTesting Materials]) double-gloving
Long-sleeved coated impermeable gown with back closure
Shoe coverings
Shoe & hair coverings to maintain sterility (if needed)
Eye shield/Face shield if potential for splashing/aerosolization
Respirator (fitted)
closed-system transfer devices (CSTD)
during compounding and administration and methods of preventing aerosol formation and spread of contamination
mechanically prevents the escape of a drug or vapor out of the system into the environment. decrease the risk of needle accidents during administration
adaptor for the drug vial, a piece that attaches to a luerlock syringe (needleless system), and adaptors to allow connection of the needleless syringe to the fluid lines
FDA approved systems:
Chemoclave/Chemolock
Equashield
Onguard
PhaSeal
drawing up chemo
negative-pressure room preferred
compounding aseptic containment isolator - vertical laminar flow, which carries contaminated air away from the operator (horizontal flow only protects the drug and not the worker);
- High-efficiency particulate arrestance filter; 100% ventilation to the outside; and, a continuouslyrunning fan
risk of aerosolization is highest when
during transfer of the drug from the vial to syringe and from the syringe into a fluid line
preparation of chemo
Orders and prescriptions should be independently calculated and verified by at least 2 separate individuals, but ideally including the prescribing clinician, a second person trained in handling
Full PPE should be worn during preparation. A plastic-backed absorbent pad should be placed under the preparation site, and should be replaced at least once daily, or anytime a spill occurs or the pad is contaminated
operations should be done at least 3 inches above the work surface. Fluid bags should be spiked and tubing should be primed with a compatible fluid before adding chemo.
Outer gloves should be removed before final preparation andsurface decontamination. The outside of the container should be wiped with gauze moistened with a deactivating substance before removal
work surface area in the BSC should be decontami-nated and disinfected. A fresh pair of outer gloves should be donned before removing the product
inal product shouldbe clearly labeled as cytotoxic and sealed in a plastic bag that allowsvisualization of the product, then placed into the transport bag orplastic box
Most commonly used cleaning agents for chemo spills
detergent and hypochlorite solution
use of alcohol for primary disinfection will not deactivate chemo and may result in spread of contamination
dont spray chemo directly
disposed of in chemotherapy waste containers
chemo metabolites exerted by the patient
found in urine, feces, saliva, vomitus, and sebum
found in the urine for days to weeks after administration, although concentrations are markedly decreased within 3 days
oral drug excretion for 5–7 days post-administration in the feces
handle excreta from patients that have received injectable chemotherapy as contaminated for a minimum of 48–72 hours post-administration, and as long as 7 days after PO chemotherapy
patient should be allowed to urinate and defecate outside in a separate, designated, sunny low-traffic area - ultraviolet light is believed to inactivate many drugs
what to do if exposed to excreta from a chemo patient
If inadvertent direct contact with chemo or contaminated urine or feces of a patient occurs, the skin should be rinsed with water and washed using dishwashing detergent for a minimum of 5 minutes
recommendation when giving chemo at home
Chemotherapy-rated gloves should be dispensed with any HD for use by the client when giving medications, and hands should be washed after each administration
pet’s medications should not be stored with medications for humans, near food, or where accessible by children
Animals receiving chemotherapy should remain in a controlledenvironment and not be allowed to urinate or defecate in communityareas, areas where children may be exposed, or areas that cannot beeasily cleaned for at least 48 hours after drug administration. Ideally alow-traffic, sunlit area would be preferred for elimination. If excreta arefound in the house, the area should be cleaned, and hands should bewashed afterwards
Cat litter boxes should be cleaned daily and litter should be double-bagged and discarded with household trash.
Any soft items (eg, bedding, towels, toys) should be washed twice, separately from other laundry, after exposure, and ideally bleached
Extracellular vesicular microRNAs as potential biomarker for early detection of doxorubicin-induced cardiotoxicity
Associated cardiac troponin with extracellular vesicle associated microRNAs
Downregulation of miR-502 was detected before significant changes in cTnI concentrations or echocardiographic parameters
VEGF concentrations in the cerebrospinal fluid of dogs with neoplastic or inflammatory central nervous system disorders
Vegf present in 77.8% of neoplastic samples
Vegf present in 92% of inflammatory samples
Only in 20% of normal samples
Targeted sequencing of candidate gene regions for myelofibrosis in dogs
Somatic variants might initiate or perpetuate myelofibrosis in dogs.
findings suggest the occurrence of clonal hematopoiesis in dogs, with increasing incidence with age, as observed in humans
In humans, most primary myelofibrosis cases develop secondary to driver mutations in JAK2, CALR, or MPL.
CDC6: A novel canine tumour biomarker detected in circulating extracellular vesicles
VCO 2021
CDC6 extracellular vesicle may be a non invasive biomarker to diagnose canine tumors in serum
Various tumor types included (epithelial, neuroendocrine, round cell, melanoma, sarcoma)
Extracellular cyclic adenosine monophosphate-dependent protein kinase A auto antibody and C-reactive protein as serum biomarkers for diagnosis of cancer in dogs
There was a significant positive correlation between the neoplastic index, which was developed using ECPKA-Ab and CRP levels, and the presence of cancer in dogs
ECPKA-Ab is a potential serum biomarker for a broad spectrum of cancers.
Combined measurement of CRP and ECPKA-Ab levels in serum improves the sensitivity and accuracy of a diagnosis of cancer in dogs
Canine squamous cell carcinoma: Electrochemotherapy association with surgery and correlation with overall survival
54 SCC: 34 white coat/skin
3 groups sx with wide excision alone, marginal sx + ECT, and ECT alone
Sig. correlation between fur coat color and skin tumors in sun exposure
Animals with sun exposure had longer OST
Sx + ECT resulted in 32% higher survival rate
than Sx alone
ECT with or without SX objective response rate 90.9%
35% of cats overall developed mets
Long-term outcomes of dogs undergoing surgical resection of mast cell tumors and soft tissue sarcomas
surgical margins - 2-3 cm wide and 1 fascial plane deep
Narrowest histologic margin <1 mm in 40 % mct and 37% of sts
4% low grade mct had local recurrence and 6% developed visceral mets
One dog with high grade mct had local recurrence
Not mets or local recurrence in sts
these were mostly low grade tumors** cant make recs for high grade
Incomplete histological margins following planned narrow excision of canine appendicular soft tissue sarcomas and mast cell tumors, using the residual tumor classification scheme
residual tumor classification (“R”) scheme
R1“tumor on ink” - incomplete
R0 all other margin lengths - complete
The R scheme resulted in higher retrospective percentage agreement in histological reporting than defining incomplete histological margin as tumor cells within ≤1 mm of the margin (83% vs 68% agreement)
26% MCT planned narrow excisions and 42% of STS PNEs resulted in R1 margins.
R1 margins were more likely when performing PNE with 0-5 mm LMSM (55%) vs 6-10 mm lateral measured surgical margins (LMSMs) for MCTs (7%), but not STS
Tumors recurred in 3/18 (17%) STSs and 2/18 (11%) MCTs
in conclusion marginal excision of at least 1 cm = better
review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats
Definitions and criteria used to classify and report soft tissue and oncologic surgical complications are often absent, incomplete, or contradictory among studies.
only 7.3% defined the term complication.
Most (58%) reported complications could have been graded with a published veterinary adverse event classification scheme, although common intraoperative complications were notable exceptions.
Preoperative autologous blood donation and transfusion in dogs undergoing elective surgical oncology procedures with high risk of hemorrhage
mandibulectomy, matxillectomy, chest wall retention, liver lobectomy
pre op autologous blood donation was well tolerated and led to uneventful autologous transfusion in 10/12 dogs
Retrospective Study Evaluating Surgical Treatment and Outcome in Dogs with Septic Peritonitis Secondary to Neoplasia
GI LSA and hepatocellular adenoma most common neoplastic cause
No difference in survival compared to non neoplastic causes
having cancer did not increase the risk of complications nor decrease the chance of survival
** CANCER is not a reason to not pursue treatment for septic peritonitis**
Retrospective assessment of the clinical relevance of surgical biopsies of abdominal lymph nodes in cats at the time of exploratory laparotomy
Histology provides more benefit as 5 cats had mets that were not identified on cyto
There were 15 cats with neoplastic disease; LN biopsies confirmed metastatic disease in 10 and ruled out nodal involvement in five.
Bilateral pubic and ischial osteotomy in cats offers good exposure for resection of large vaginal masses with minimal postoperative complications
Bilateral, single-session, laparoscopic adrenalectomy was associated with favorable outcomes in a cohort of dogs
All dogs survived to hospital discharge. Follow-up ranged from 60 to 730 days (median, 264 days)
Intraoperative and postoperative complications of partial maxillectomy for the treatment of oral tumors in dogs
most common intraoperative complication was excessive surgical bleeding 53% - 43 had blood transfusions. significantly associated with tumor size and location, maxillectomy type, and surgical approach
Dogs treated with a dorsolateral combined intraoral surgical approach were more likely to have excessive surgical bleeding [83%] and had a longer mean duration of surgery (106 minutes) than those treated with an intraoral approach [54%] and 77 minutes
post op complications: epistaxis 51%, facial swelling 37%, facial pawing 37%, wound dehiscence 11%, infection 8%
Complications associated with maxillectomy in dogs were generally minor. Aggressive surgical planning, preparedness for hemorrhage and transfusion, careful tissue dissection, and comprehensive pain control are recommended, particularly for dogs with large, caudally located oral tumors requiring extensive excision.
Analysis of risk factors associated with complications following mandibulectomy and maxillectomy in dogs
Overall complication rate of 37.3%, 62.1% minor
Complication & complication rate similar between procedures.
Transfusion is more often needed for maxillectomy.
11.6% fatality with maxillectomy, 4.4% with mandibulectomy.
Increased surgical time associate with increased risk of complication 36% increase/hour
Preoperative RT or chemo associated with increased odds of dehiscence or oral nasal fistula
maxillectomy associated with increased risk for dehiscence or oral nasal fistula
Outcomes of cats treated with maxillectomy:
16.7% intraoperative complication rate, 56.7% post op (hyporexia 20% for avg 7 days, dehiscence 20%)
Local recurrence 18.3% metastatic rate 4.9% (benign tumors included)
1 & 2 year survival really high 94% fibrosarc, 83% SCC, 80% OSA
poor prognostic factors - MI, adjuvant chemo, and local recurrence affected survival
Maxillectomy is a viable treatment
Intraoperative imaging of surgical margins of tumors using optical coherence tomography
IN order of tissue depth from greatest to least light penetration was adipose, skeletal muscle, fascia and sarcoma tissue. Neovascularization was observed in 53.2% sarcoma, and lines of fascia surrounding muscle bundles was present in 93.5% of skeletal muscle images
OCT-guided pathology sections were able to detect incompletely excised MCT near the surgical margin with a sensitivity of 90% and specificity of 56.2%
OCT was able to identify the presence of AGASACA at or within 1 mm of the surgical margin in all areas of interest
OCT of FISS had overall sensitivity and specificity for classification of OCT images by evaluators were 78.9% and 77.6%,
OCT of canine mammary tumors: The sensitivity and specificity for ex vivo images were 83.3% and 82.0% (observer 1) and 70.0% and 67.9% (observer 2). The sensitivity and specificity for in vivo images were 70.0% and 89.3% (observer 1) and 76.7% and 67.9% (observer 2)
for canine sts OCT developed algorithm - accuracy of 97.1% with an excellent sensitivity of 94.3% on the validation set. model showed high sensitivity (0.98) for detecting cancerous tissues and a specificity of 0.97, which means that the misdiagnosis rate of the model for normal tissues was extremely low
Safety and feasibility of short course pre-operative radiation therapy followed by surgical excision for canine solid tumours
Various dermal and/or SQ tumor types treated with short course RT then resected
Acute RT SE in 40%; G1 50%, G2 43%, G3 7%
Surgery complications in 17% mostly infection; 2 required medical intervention, 2 surgical and 1 died
Tumors located on the extremity positive prognostic indicator
overall well tolerated need study about outcome next
Electrochemotherapy in treatment of canine oral malignant melanoma and factors influencing treatment outcome
evaluate treatment effectiveness of ECT in as first line treatment
objective response rate was stage I -100%, stage 2 - 89.5%, stage 3 - 57.7%, and stage 4 - 36.4%,
Only patients in stage I, II and III with partial or complete response improved their quality of life
Bette response if no boney involvement
stage I - PFI 11 mths OST 16,5 mth
stage II- PFI 7 mths OST 9 mths
vs
stage 3/4 - PFI 4 months ST 4.5-7.5 mths
Adjuvant electrochemotherapy with bleomycin and cisplatin combination for canine soft tissue sarcomas: A study of 30 cases
intravenous 20 mg/m2 bleomycin, and the tumor bed and margins were infiltrated with cisplatin at the dose of 0.5 mg/cm2
5 min after the injection of the chemotherapy agents, sequences of eight biphasic pulses lasting 50 + 50 μsec each, were delivered in bursts of 1,300 V/cm using caliper electrodes
second session was performed 2 wk later
treatment was well tolerated and side effects were minimal.
Twenty-six dogs had no evidence of recurrence at the time of manuscript writing; four had recurrence and one of the four recurring dogs died of lung metastases.
Median estimated disease free was 857 d
perivascular wall tumors were not diff in response compared to sts
Treatment of spontaneous canine mast cell tumors by electrochemotherapy combined with IL-12 gene electrotransfer: Comparison of intratumoral and peritumoral application of IL-12.
compare the two IL-12 GET - peritumor vs intra tumoral
local tumor control was significantly better in the ECT + GET i.t. group than in the ECT + GET peri.t. or ECT groups
disease-free interval (DFI) and progression-free survival (PFS) were significantly longer in the ECT + GET i.t. group than in the other two groups
did not observe any unwanted severe or long-lasting side effects
rec response eval 2 months after treatment
Results of Dynamic Contrast-Enhanced Ultrasound Correlate With Treatment Outcome in Canine Neoplasia Treated With Electrochemotherapy and Interleukin-12 Plasmid Electrotransfer.
investigate whether dynamic contrast-enhanced ultrasound (DCE-US) results of subcutaneous tumors differ between tumors with complete response (CR) and tumors without complete response (non-CR) in dogs treated with ECT and GET pIL-12
perfusion and perfusion heterogeneity were lower in CR tumors than in non-CR tumors
Computer simulation of commercial conductive gels and their application to increase the safety of electrochemotherapy treatment
commercial gel having a conductivity of 0.2 S/m when used in combination with effective treatment planning may improve the outcome of electrochemotherapy procedures
Preliminary assessment of electrochemotherapy feasibility in dogs with vesical transitional cell carcinoma
ECT was not able to increase the overall survival of the patients evaluated and should be indicated carefully
sig se - uroabdomen, hematuria
one p had CR but developed tumor emboli and died of renal failure q]
Outcome Following Curative-Intent Electrochemotherapy for Extramedullary Plasmocytoma in Dogs
All dogs developed transitory ulceration and swelling one-week after procedure that completely healed within 30 days post-ECT.
Complete remission was achieved in all cases and lasted for 515 (oral case), 695 (one digit), 90 (another digit case) and 240 (lip) days.
MOA of electrochemotherapy?
electrical pulses lead to Increased membrane permeability allows drug to access cytosol → cell death and activation of APCs
repair pathways
ECT is indicated for ?
primarily for the treatment of incompletely excised cutaneous and subcutaneous tumors, but also for the sole treatment of small primary tumors
some efficacy in the treatment of canine mast cell tumors (MCTs), canine perianal adenomas and adenocarcinomas, canine nasal tumors, canine and feline localized lymphoma, and canine and feline spontaneous soft tissue sarcomas.
recurrence rate
ECT of MCT
mct - 16% - 18% 53-1200 d
64-93% response rate
nasal tumors and ECT
Dogs treated with ECT had significantly better 12- and 32-month survival rates (60% and 30%, respectively) than dogs treated with surgery and chemotherapy (10% and 0%, respectively).
Complications with urethral stent
incontinence (26%–37%), reobstruction (16%), and stent migration (11%), stranguria poststent placement is also a common finding
Stent length diameter and location were NOT associated with incidence of incontinence
urinary stent success
stent placement was found to be rapid, safe, and effective at restoring luminal patency
97 % rr
Evaluation of Temporary Urethral Stents in the Management of Malignant and Nonmalignant Urethral Diseases in Dogs
Temporary stents with red rubber
Placed successfully in all 17 dogs - 9 had cancer
94% caused urinary incontinence - long stent removing all sphincter ability
3/17 dogs had migration
ureteral stent placement
percutaneously gain access into the renal pelvis and place a guide wire across the obstruc- tion in an antegrade fashion. Dilation of a tract through the tumor then occurs from retrograde placement of a sheath and dilator. The ureteral stent is also passed retrograde through the stent and positioned with its pigtails in the renal pelvis and bladder.
ureteral stent outcomes
In dogs with azotemia before stent place- ment, improvements in blood urea nitrogen (BUN) and serum creatinine concentrations were noted in all dogs
improved hydronephrosis and hydroureter
Stenting of malignant obstructions in the gastrointestinal tract has been described for the esophagus and colon in companion animals
all clinical improvement for a short time
Endovascular stenting was used to relieve Budd– Chiari syndrome in three dogs with confirmed or suspected neoplastic obstructions
dogs demonstrated resolution of clini- cal sings and extended survival times ranging from 7 to 20 months
Intraarterial Chemotherapy
greater target organ concentrations of drugs compared with intravenous
requires anesthesia and sx procedure
Side effects and toxicity were minimal - anemia, lethargy, and anorexia were sig- nificantly less likely in the group receiving IA chemotherapy com- pared with that receiving IV chemotherapy
when IA cisplatin is administered with moderate doses of radiation, a high percent tumor necrosis was achieved in osa
in bladder tumors the IA chemotherapy group had a significantly greater decrease in tumor length, length percentage, width percentage, longest unidimen- sional measurement, and longest unidimensional measurement percentage after treatment compared with the IV chemotherapy group
embolism devices
permanent vs temporary
permanent used in cancer: particles (e.g., polyvinyl alcohol beads) and liquid agents (e.g., cyanoacrylate, alcohol, and ethylene vinyl alcohol copolymer)
embolism goal
directly targeting the specific blood supply of the tumor with the purpose of slowing or eliminating blood flow to that tumor
results in ischemic tumor cell death
indications for embolism
(1) treating a tumor primarily by diminishing the blood supply so that tumor death occurs, (2) preoperatively treating a tumor to decrease blood loss during a major surgical resection
main reason for embolization currently in companion animals is as a primary treatment in cases that are deemed to be nonresectable or patients considered to be poor surgical candidates ie liver
Chemoembolization differs from embolization
chemotherapy is simultaneously delivered to a tumor at the time of embolization. This provides the theoretical advantages of IA chemotherapy
After embolization, hypoxia within tumor cells increases vessel permeability, and these factors alter cell membrane function and cause chemotherapy to be sequestered in higher concentrations within tumor cells
reduction of systemic drug exposure and a reported decrease in side effects and toxicity
process of chemoembolization
slurry containing a contrast medium, embolic agent, and a chemotherapy agent
- doxo, epi, cis, mitomycin c decribed in humans - also drug eluting beads
Lipiodol
iodinated poppy seed lipid– based medium that has several proposed benefits: (1) it is radi- opaque and can be used in the slurry to replace contrast medium, (2) it acts as an embolic agent on its own, and (3) it preferentially concentrates in tumor tissue longer than in nontumor tissue
Liver embolization in dogs
Clinical improvement was noted in the dog treated with bland embolization, but the dog died at home approximately 4 months post treatment. Doxorubicin was administered with polyvinyl alcohol particles and lipiodol in the dog treated with chemo- embolization; however, the dog died approximately 3 weeks after treatment as a consequence of an unrelated traumatic event
both dogs demonstrated stable disease at 1 month, but progressive disease at 3 months after treatment
went fine in normal does with temporary embolism
Liver embolization in cat
CT revealed a decrease in tumor size at 71 days posttreatment. Surgical resection was pursued 231 days after embolization and no recurrence was noted at 481 days after tumor removal
Prostatic artery embolization
Experimentally, dogs have undergone PAE in a model of BPH. In this study, four of seven dogs with induced BPH had reduction of prostate size after embolization
Ten dogs with confirmed prostatic carcinoma underwent PAE via a vascular approach in the left carotid artery. Tumor size was evaluated preembolization and approximately 1 month postembolization. In all dogs, prostatic tumor size decreased after embolization, and an improvement in clinical signs was noted based on an owner questionnaire
ethanol ablation
most common chemical ablation
inject directly into lesion
SE = inflammation of the tissue not talked about in Withrow
ethanol ablation use
HCC, parathyroid tumors,
Percutaneous ultrasound-guided ethanol ablation of parathyroid nodules achieves successful resolution of hypercalcemia in 95% of dogs with primary hyperparathyroidism
Percutaneous ethanol ablation of hepatic and renal cysts has been performed without incident in dogs and cats
lingual/sublingual squamous cell carcinoma ethanol ablation in cats
not a viable treatment for feline lingual/sublingual SCC; tumour volume was effectively reduced in some cats, but the simultaneous loss of lingual function was poorly tolerated
Microwave Ablation (MWA)
benefit
(1) Minimally Invasive: MWA requires only a small incision through which a probe is inserted into the tumor. This minimizes trauma to surrounding tissues compared to open surgery.
(2) Precision: MWA precisely targets the tumor, delivering microwave energy to destroy cancerous cells while preserving healthy tissue.
(3) Reduced Recovery Time: Because MWA is minimally invasive, it often leads to shorter hospital stays and quicker recovery times for animals.
(4) Outpatient Procedure: In some cases, MWA can be performed on an outpatient basis, reducing stress for the animal and owner.
(5) Effective for Inoperable Tumors: MWA can be used for tumors that are difficult to access surgically or for animals that are not good candidates for open surgery due to health issues.
(6) does not require grounding pads
(7) Higher intratumoral temperatures and faster ablations with less char and less pain are often achievable with MWA compared with RFA
Microwave Ablation (MWA) risks
- Damage to Surrounding Tissues: While MWA is precise, there is still a risk of damaging nearby tissues, particularly if the tumor is located close to vital structures.
- Incomplete Ablation: In some cases, MWA may not completely destroy the tumor, leading to potential regrowth.
- Post-procedure Pain: Animals may experience some discomfort or pain after the procedure, though this is typically less severe than with traditional surgery.
- Skin Burns: Skin burns can occur at the site of the probe insertion if not carefully managed.
Video-Assisted Surgery - benefit
Improved Visualization: VAS provides better visualization of the surgical site through a camera system, allowing for more precise surgical maneuvers.
Reduced Trauma: VAS typically involves smaller incisions compared to open surgery, resulting in reduced trauma to the patient.
Quicker Recovery: Animals undergoing VAS often experience faster recovery times and reduced post-operative pain compared to traditional open surgery.
Less Blood Loss: Because VAS is minimally invasive, there is generally less blood loss during the procedure.
Less Risk of Infection: Smaller incisions mean a decreased risk of post-operative infections.
down falls of video assisted techniques
- Equipment Costs: VAS requires specialized equipment and training, which can increase the cost of the procedure.
- Learning Curve: Veterinarians need to undergo specific training to perform VAS effectively, and there is a learning curve associated with mastering the technique.
- Limited Accessibility: VAS may not be suitable for all types of tumors or in all locations within the body.
- Risk of Complications: While rare, complications such as organ injury or bleeding can occur during VAS.
microwave ablation
MWA uses electromagnetic energy to cause friction and heat, resulting in coagulative necrosis
liver neoplasia in five dogs, a metastatic pulmonary lesion in one dog, and renal carcinoma in one dog
No procedural complications were encountered
Microwave ablation for the control of bleeding from disintegrated mammary tumours in two dogs
MWA is a feasible and potentially effective palliative treatment modality to stop bleeding from disintegrated mammary tumours in dogs under local anaesthesia
Gilvetmab
first PD-1/PDl1 inhbitor
conditionally approved for melanoma and mct
specifically PD 1 on t cells
how does radiation kill cells
classified as - interphase or proliferative or mitotic death
interphase death: LYMPHS death via apoptosis. DSB leading to apoptosis. High levels of ROS cause oxidative stress, leading to mitochondrial dysfunction, DNA damage, and activation of apoptotic pathways. Radiation can activate p53, which in turn initiates the expression of pro-apoptotic genes. inhibit Bcl. activate death receptor
Factors such as disruption of membrane structure and disorder of cell energy metabolism after irradiation are also important contributors to interphase death
proliferative or mitotic death : all other cells - mitotic catastrophe caused by accumulation of chromosomal aberrations and erroneous repair after radiation induces a DNA double-strand breaks. After one or several division cycles, cells lose their ability to proliferate and begin to die
what type of Rt induced death is associated with efficacy
radiation-induced apoptosis closely correlates with radiosensitivity. A high apoptotic rate is strongly associated with good prognosis in cancer patients treated with radiation therapy
most cell undergo proliferative or mitotic deathafter radiation
TUNEL method
common technique used for detecting DNA fragmentation associated with apoptosis
VRTOG grading of ACUTE SE generalized based on Lauras review
Gr 1 - mild signs ie pain, erythema, cs associated with the organ (gi/urinary etc)
Gr 2 - moderate signs ie intermittent pain, focal/patchy edema or desquamation affecting <50% of the area, moderate signs ass with organ ( cough, regurgitation diarrhea, neuro sx seizures mentally dull etc)
Gr 3 - significant signs requiring intervention ie persistent pain, changes in behavior due to cs, edema or desquamation affecting >50% of the area, obtunded, blepharospasm, hearing loss, exercise intolerance, pericardial effusion, anorexia, 15-20% wt loss
Gr 4 - Severe signs requiring hospitalization, ulceration, necrosis, perforation, O2 req, syncope, obstruction of urinary tract d/t hematuria with clots, wt los >20%
Gr 5 - death
VRTOG grading of LATE SE generalized based on Lauras review
Gr-1 mild cs not changing daily life, pigment changes, subclinical neuro/musc deficits, eye changes, intermittent cough, subclinical ECG, subclinical fibrosis
Gr-2 - moderate cs, fibrosis without impact on function, mental dullness, weakness, intermittent otitis, laryngeal dysfunction, ecg abnormalities requiring medication, intermittent v or diarrhea, chronic pollakiuria, or stranguria; dec tears tx with lubricant
Gr 3 - significant cs that alter day to day life - fibrosis impacting function, ataxia, paresis, ulceration of th eye without depth, incomplete cataract, glaucoma req med, , blepharospasm, tear meds more than lube, hearing loss, coughing interfering with life, bark change, exercise intolerance, ulceration without bone exposure, persistent anorexia/v/d/r, subclinical ulceration or fistula, hydronephrosis
Gr 4 - severe signs requiring hospitalization, necrosis and deep ulceration (skin, airway, brain, gi, bone) fracture, severe kcs, deep corneal ulcer desmetocele, complete cataract, glaucoma causing vision loss, complete stenosis, fistula formation , perforation, CHF, syncope, obstruction
Gr - 5 death
Gray =
1 joule of radiation energy per kg of matter. Unit of absorbed dose that measures the energy produced by ionizing radiation in a unit of mass of matter that is being irradiated
What is a monitor unit?
One monitor unit = 1 cGy of absorbed dose in water under specific calibration conditions for the linac. “Beam on” Charge passing through ionization center
Used to standardize treatment machine within a single radiotherapy center and account for surface distance, scatter, field size
GTV
gross tumor volume
CTV
clinical target volume
PTV
planning target volume - bigger than CTV and accounts for movement, variation in positioning
what kind of cells are resistant to rt
Hypoxic cells are 2-3 x more resistant to radiation than oxic cells (*fractionated RT)
What types of cells typically die an apoptotic death when exposed to radiation?
lymphocytes
haematological cells, epithelial stem cells, hair follicles, gametes.
cells in what phase of the cell cycle are most resistant to rt
s- phase - synthesis phase
Duplicated DNA provide a template for repair
also G0
cells in what phase of the cell cycle are most susceptible to rt
cells in the G2/M-phase are most sensitive to ionizing radiation
law of Bergonie - tumors composed of rapidly multiplying cells, especially those of embryonal type and particularly those of the lymphoid group, are highly susceptible to radiation
5 Rs of radiation
Reoxygenation
DNA repair
radiosensitivity
redistribution in the cell cycle
repopulation
how fast do normal tissue with a high alpha/beta ratio typically repair
within 2-4 weeks following completion of a fractionated RT protocol
what are the risk factors for developing acute toxicity
areas of rapidly dividing cells, fractionated protocols - low chronic dosing
location - oral cavity, colon, eye
typically heal eventually
what are the risk factors for developing late toxicity
high dose per treatment
large field
chemotherapy - doxo
tissues with high rates of cellular turnover (e.g., mucosa, bone marrow) are more susceptible to late effects.
Organs with limited regenerative capacity, such as the brain, eye, spinal cord and salivary glands, are particularly vulnerable to late toxicity.
delays in radiation treatment - prolonged exposure
never heal
IMRT/SRT limit late tox by being precise
When would you expect a radiation-induced tumor to develop?
> 2 years
What is the 2 year local control rate for an incompletely excised, grade 2 mast cell tumor treated with definitive-intent, fractionated radiation?
75%
What percentage of dogs with appendicular osteosarcoma receives significant pain control from palliative-intent radiation therapy
75%
How long does pain control usually last in dogs with appendicular osteosarcoma treated with palliative-intent radiation therapy?
pain releif 2-4 months
survival 4-10 mths
What is the 2-year local tumor control rate of dogs with incompletely excised, grade 2 soft tissue sarcomas treated with definitive-intent fractionated radiation therapy?
85%
Which of the following intranasal tumors in dogs likely has the best prognosis for control following radiation therapy?
A. Non-keratinizing squamous cell carcinoma
B. Adenocarcinoma
C. Chondrosarcoma
B. Adenocarcinoma
chondrosarc - 1-2 years
adeno - 14 mths
scc- 6 mths
what is false ? Nasal tumor SRT – sarcomas do better than carcinomas vs most common side effect oronasal fistula vs IMRT leads to improved ST for stage I-VI Adams
most common SE is mucositis but 10% develop oronasal and cutaneonasal fistulas
What is the approximate complete response rate for oral melanoma treated with hypofractionated radiation therapy?
50-70%
acute responding tissue
high a/b ration (7-20 Gy)
fraction size and overall time both determine the radiation induce effect
acute toxicity increases with higher doses per fraction
skin mucosa
late responding tissue
low a/b ration (0.5-6Gy)
less sensitive to changes in dose per fraction and respond more to higher total dose. time does not effect radiation effect to this tissue
late toxicity increases with higher total doses,
lung, spinal cord, and connective tissues.
α/β Ratio:
used to describe the sensitivity of tissues to changes in radiation dose per fraction. It represents the ratio of the linear (steepness of survival curve) (α) and quadratic (β) components of the linear-quadratic (LQ) model, which is commonly used to estimate the biological effect of radiation.
DNA Repari and rt
Fractionation schedules are designed to allow for repair of normal tissues while minimizing tumor repopulation.
HRR and NHEJ of DSbreaks
repopulation and Rt
increase in cell division of normal and cancer cells after radiation in response to a decreasing number of cells
Accelerated fractionation or hypofractionation schedules may be employed to shorten treatment duration and reduce the opportunity for tumor repopulation
accelerated repopulation phenomenon where, after 4-5 weeks, the growth fraction and doubling time are significantly increased. at each radiotherapy treatment, there are less clonogenic tumour cells (cells that can repopulate). The surviving clonogenic tumour cells increase their rate of proliferation and decrease cell loss, which reduces the radiotherapy treatment effectiveness and introduces resistance.
reoxygenation and rt
Intermittent hypoxia in tumors can reduce radiation effectiveness, so treatment schedules are designed to take advantage of reoxygenation.
Fractionation allows for tumor reoxygenation between treatments, making tumors more sensitive to radiation - center of the tumor is hypo so kill form the outside in
Radiosensitivity and rt
Treatment plans are tailored based on the relative radiosensitivity of tumor and surrounding normal tissues.
Advanced imaging techniques help delineate tumor volumes and critical structures, enabling precise targeting while sparing healthy tissue
radio resistant tissue: myocytes, neurons, connective tissues, conjunctiva.
Tumour cells such as melanoma, renal/pancreatic tumours.
redistribution in the cell cycle
moving from radioresistant s phase to radiosensitive g2/m
Fractionation schedules are designed to exploit redistribution, ensuring that a higher proportion of tumor cells are in the radiosensitive phases during radiation delivery.
give with vincas or taxanes to stop cells int he mitosis phase which keeps them in G2
Fractionating RT you get higher total doses of radiation into the tumor with the same amount of cell kill seen with one single smaller dose of RT, why?
Sublethal damage is repaired so survival curves have shallow shoulder and more reassortment, and repopulation then seen with single high fx
What is the recommend Gy/fx to prevent late effects with RT in perianal region?
<3Gy/fx
tumor evasion
coinhibitory checkpoint molecules
PD-1, CTLA-4, TIM-3, VISTA, BTLA, B7-H3, B7-H4, and LAG3
down regulate t cells
impt to know PD1 is receptor on T cell and pdl1 is the ligand on tumor cells or other cells
costimulatory checkpoint molecules
CD28, OX40, GITR, ICOS, CD137, CD27, CD40L, and CD122
upregulat T cell
how do PDL1 inhibitors work
PD-1 and CTLA-4 are expressed primarily on T cells and NK cells, whereas PD-L1 is expressed by myeloid cells (monocytes, macrophages, and dendritic cells) and by certain tumor cells
by inhibiting this axis you block the normal inhibition by PDL1 of T cells
examples for check point inhibitors
gilvetmab
Yervoy (Ipilimumab) targeting CTLA-4 and Keytruda (pembrolizumab) and Opdivo (nivolumab) targeting PD-1, for treatment of four different cancers (melanoma, head and neck cancer, bladder cancer, and Hodgkin lymphoma)
CD 73
immune suppressive molecule that catalyzes the breakdown of AMP to adenosine
in the TME tumors make a lot of adenosine to be immunosuppressive
cytokine released inflammation which trigger the release of MDSC
granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-3 (IL-3) IL 8?
lead to mdsc release from bone marrow
mdsc action
immune suppression
block NK cells via TGFb and down regulation of IL 12
increase Tregs via TGFb and IL10 - block T cells
block T cells directly via arginine, iNOS, ROS, and cysteine deprivation
inc TAM via IL10 - which then dec NK cells via decreasing IL12 and stimulate tumor angiogenesis and promote metastasis
Block dendritic cells via IDO
differentiate into macrophages or neutrophils and actively suppress the local antitumor immune responses and promote tumor invasion and metastasis via the production of matrix metalloproteinases (MMPs)
chemokine associated with activation of tregs
CCL1binds to CCR8 - CCL1 released by TAMS, CAFs, CSC (helps with treg activation recruitment, angiogenesis, proliferation)
CCL5 binds to ccr 5- released by tams and CAFs to activate tregs and promote growth/proliferation of tumor
● IL-2
o released by T cells after activations and Activates naïve T cells via JAK/STAT, activates Macs, DC, and b cells, and NK cells
o Promotes growth, survival, and differentiation of T-cells
o Increases Bcl-2 and stimulates degradation of p27
o Increased production w IFNy and IL-4 from T-cells
lots of toxicity as therapy in humans - mild gi tox in dogs with lsa but may not be efficacious
made pulmonary mets go away in two dogs. also used in feline fibrosarc and canine melanoma and was safe and effective
● IL-12
o Secreted by DCs and macrophages and B cells, produced in response to TLRs
o Promotes Th1 and NK cells
o Stimulates activation and IFNy secretion
down regulated by MDSC evade immune system
therapeutic use cause sig tox in humans
reduced tumor volume of 9 out of 11 dogs with mast cell tumors and increases in intratumoral IFN-γ and antiangiogenic effects in nine dogs with various cancers, and in six dogs treated with concurrent metronomic chemotherapy- no significant clinical responses were observed in these studies
● IL-10
o Inhibitory/anti-inflammatory/ pro cancer cytokine, secreted by T-regs and MDSC
o IL-10 -> JAK1 and TYK2 to activate STAT3
o Inhibits macs and DCs
o Inhibits IL-12 production
o Inhibits co-stimulators
● Interferons
o IFN alpha, beta, gamma – pro-inflammatory, anti-angiogenic
o IFN gamma- secreted by Ts and NKs – activation of macrophages
o IFN alpha – direct anti-tumor effects - anti-angiogenic, induces TSGs, downregulates oncogenes, inhibits proliferation of tumor cells
Cross-presentation by APCs
Specialized DCs will ingest cells that are infected w virus and present the viral protein to a CD8 T cell
Molecules that help w APC/T-cell recognition and activation
o CD40L on T cells recognizes CD40 on DCs and Macs -> B cell vaccine in dogs- CD40
o IFNy from T cells – activates macs
o Chemokine receptor CCR7 on DCs
NK cells
CD3+/-, CD5, CD4, and CD8+ in dogs, also NKp46
Innate cytotoxic cells – kill by perforin and granzymes and ADCC
Secrete IFNy - activates macrophages
Recognize cells that don’t express MHC I
CD40L
costim mol on T cells binds to CD40 on apcs to enhance IL12 secretion and enhance B7
CD40 is expressed on B cells and interacts with CD40L on T cells to stimulate NFkB and AP1 and B cell proliferation
target of b cell vaccine
rituximab is cd20
● NK activating receptors
o KIRs
o C-type lectins
o CD16 - binds Ag-Ag complexes for Antibody-dependent cellular cytotoxicity
T cell receptors
B7-1 (CD80) and B7-2 (CD86) – expressed on activated APCs, are co-stimulatory bind to ctla4
CD28 – TCR
CD40L on T cells binds to CD40 on APCs for activation
CD4 and CD8 – bind MHC and interact w TCR
ITAMS that are linked to CD3 delta chains – involved w activation
T cells activated by IL-2
IL-12 – promotes T cell differentiation
● B Cell Receptor
Ig Receptor + CD40 costimulator molecule
CD21 – recognizes Ab and activates
Heavy chain – switches isotype
V region – variable – antigen binding
C region – constant region – what switches isotype, effector
CD22 – inhibitor molecule
● Which part of the antibody as the effector action
o C region of the heavy chain
The domains include an antigen-binding fragment (Fab) domain that binds to antigens and a crystallizable fragment (Fc) domain that binds to host sensors that deploy effector functions
● CTLA-4
On T-cells – checkpoint inhibitor that will allow for immune recognition of tumor cells – binds B7 to inhibit T cell activation
More important for CD4+ inhibition
PD1
On T-cells – inhibits activation of effector T cells when binds to PD-L1 on APCs or tumors
More important for CD8+ inhibition
Markers for T regs
Membrane – CD4, CD25
Intracellular – FoxP3
Dendritic cells in dogs
Common myeloid progenitor cell > monocytes > CD1 (Langerhans, Follicular, Myeloid DC) > present to Th1 and Th17
Common myeloid progenitor cell > DC2 (plasmacytoid DC) > present to Th2
Histiocytoma - E-cadherin+
Histiocytic sarcoma (interstitial DCs) - CD1, CD11c, MHCII+
Reactive histiocytosis (activated interstitial DCs) - CD4, Thy1 +
Hemophagocytic HS - CD11d +
bacillus of Calmette and Guerin (BCG) infusion
live attenuated strain of mycobacterium Bovis
infused into bladder to prevent relapse of tcc
recruitment of neutrophils and their ability to promote urothelial cell turnover
VNP20009- attenuated Salmonella typhimurium use
inject into tumors and eat the necrotic and hypoxic cells and induced inflammation
Phase I clinical trial, VNP20009 was administered to dogs with a variety of malignant tumors. In this study, 41 dogs received intravenous infusions of VNP20009 either weekly or biweekly at escalating doses. Fever and vomiting were reported as dose-limiting toxicities. Bacterial colonization was seen in approximately 40% of dogs and significant clinical responses observed in 15% of patients, with an over- all rate of 37% of dogs experiencing either a transient response or stable disease.
muramyl tripeptide-phosphatidylethanolamine (MTP-PE)
main use in people ?
paper in dogs about use vs placebo
paper in dogs about use with cisplatin vs cisplatin alone
other cancers
NOD2 receptor agonist, that when encapsulated in a liposome (L-MTP-PE) can efficiently activate monocytes and macrophages to produce proinflammatory cytokines, such as IL-1α and -β, IL-6, IL-7, IL-8, IL-12 and TNF-α
used in human osa
dogs receiving L-MTP-PE after limb amputation had a median survival time (MST) of 222 days whereas dogs that received placebo had a MST of 77 days.
L-MTP-PE after treatment with cisplatin had a MST of 14.4 months ver- sus 9.8 months in dogs that received cisplatin only. Interestingly, only 73% of dogs receiving L-MTP-PE developed metastatic dis- ease compared with 93% in the cisplatin-only group. However, in a second trial, these investigators saw no significant survival advantage in dogs with OSA that received L-MTP-PE concurrently with cisplatin. cisplatin may have attenuated immune effects
Dogs that received L-MTP- PE with chemotherapy after splenectomy had a MST of 9 months versus 5.7 months seen with dogs receiving chemotherapy alone. In another study only dogs with stage I oral melanoma that received L-MTP-PE had an increased survival over placebo- treated dogs
Bacterial DNA can stimulate the innate immune system how?
CpG oligonucleotides bind to TLR 9 stimulate the immune system largely through induction of NK cell activity and release of IFN-γ
especially when complexed with cationic liposomes - cationic lipid–DNA complexes (CLDCs)
may work as a standalone immune therapy
dogs with osa inc ST compared to historic control
RR in sts 15%
oncolytic viruses
viruses capable of replicating in and lysing tumor cells
Adenoviruses that have undergone genetic modification of their early genes, 1A (E1A) and 1B (E1B), preferentially target rapidly dividing tumor cells and have been used to target canine OSA cells
also looked at pox virus, canine distemper virus, Newcastle disease virus, vesicular stomatitis virus (VSV), that expresses IFN-β and the sodium iodide symporter (NIS)
TLR7 agonist
imiquimod - topical therapy
meningioma with vaccine
cats with scc
IL 15
why’s it better than IL2
- stim Nk cells and promoted T cell proliferation
- in vitro, recombinant IL-15 could expand canine NK cells and could cause expansion of lymphocytes in peripheral blood when administered to dogs intravenously.
better bc:
(1) it does not cause activation-induced cell death of CD4+ T cells after prolonged periods of exposure, but sustains T-cell proliferation
(2) it plays a critical role in CD8+ T cell memory forma- tion and maintenance
(3) unlike IL-2, it does not appear to play a role in the development of Tregs
Tumor antigens
proteins are other molecules that are either unique to cancer cells or significantly more abundant in cancer cells compared with normal cells - oncogenes, oncofetal proteins, and cancer testes antigens
allogeneic vaccine
autologous vaccine
xenogeneic
- made from cell lines with similar tumor types
- made directly from the patients tumor
-made from other species - melanoma vax = huTyr
Whole Tumor Cell vaccine
vs
Tumor lysate vaccines
made by lethally irradiating tumor cells and/or tissues
vs
mechanically disrupting the tumor cells and/or tissues
studies have added hGMCSF as adjuvant to help stem immune system
Allogeneic Anti-tumor Vaccines:
Advantages:
Disadvantages:
AEs:
advantages
1. Off-the-shelf availability
2. Potential for broader immune response
3. Cost-effective
Disadvantages:
1. Risk of rejection: Allogeneic vaccines carry a risk of inducing immune responses against the donor’s tissue, leading to rejection.
2. Limited personalization
3. Efficacy can vary depending on the individual’s immune response and tumor characteristics
Allergic reactions: Management with antihistamines or corticosteroids.
Autoimmune reactions: Treatment with immunosuppressive drugs, such as corticosteroids or TNF-alpha inhibitors.
Autologous Anti-tumor Vaccines:
Advantages:
Disadvantages:
AEs:
Advantages:
1. Personalized therapy
2. Low risk of rejection
3. Potentially higher efficacy
Disadvantages:
1. Time-consuming
2. Costly
3. Limited availability
4. tumor may change so the target may not be functional in the cancer
AEs:
1. Injection site reactions: Typically managed with local measures like ice packs and analgesics.
2. Flu-like symptoms: Managed with supportive care, such as rest, fluids, and over-the-counter pain relievers.
3. Autoimmune reactions: Treated with immunosuppressive agents like corticosteroids or TNF-alpha inhibitors.
Xenogenic Anti-tumor Vaccines:
Advantages:
Disadvantages:
AEs:
Advantages:
1. Wide array of antigens
2. Possibility of overcoming immune tolerance: Since xenogeneic antigens are foreign, they may overcome immune tolerance mechanisms.
3. Availability
Disadvantages:
1. Immunogenicity concerns: Xenogeneic vaccines may induce strong immune responses, potentially leading to adverse reactions.
2. Safety concerns: There’s a risk of cross-species transmission of pathogens or zoonoses.
Adverse Events:
- Immune-related adverse events (irAEs)
- Allergic reactions: Treated with antihistamines or corticosteroids.
- Pathogen transmission: Requires monitoring and appropriate treatment if cross-species transmission of pathogens occurs.
Bacterial Conjugated Bispecific Antibodies:
advantages
disadvantages
aes
advantages:
1. Targeted delivery: Bispecific antibodies conjugated with bacteria can deliver therapeutic agents specifically to tumor cells, minimizing off-target effects.
2. Enhanced tumor penetration: Bacteria can penetrate deep into tumor tissues - into the necrotic hypoxic parts
3. Immune stimulation
Disadvantages:
1. Risk of infection
2. Limited tumor selectivity: While efforts are made to target tumor cells specifically, there’s a risk of non-specific binding to healthy tissues.
3. Immunogenicity: The use of bacteria can induce immune responses, leading to neutralization of the therapeutic effect or adverse reactions.
Indications:
1. Solid tumors: including colorectal, pancreatic, and lung cancers.
Refractory tumors
Adverse Events:
Infections
Allergic reactions
Chemotherapy Conjugated Bispecific Antibodies:
Advantages:
disadvantages
AE
Advantages:
1. Targeted chemotherapy delivery: Bispecific antibodies conjugated with chemotherapy drugs deliver cytotoxic agents directly to tumor cells, sparing healthy tissues.
2. Reduced systemic toxicity
3. Enhanced potency: Conjugation of chemotherapy drugs with bispecific antibodies can enhance their potency against tumor cells.
Disadvantages:
1. Immunogenicity:increase the immunogenicity of chemotherapy drugs.
2. Limited tumor selectivity: There’s a risk of non-specific binding to healthy tissues, leading to off-target effects.
3. Resistance development: Tumors may develop resistance to the chemotherapy drugs used in the conjugates.
Indications:
Solid tumors: including breast, ovarian, and lung cancers.
Refractory tumors:
AEs
Hematologic toxicity:
Gastrointestinal toxicity:
Immunogenic reactions:
Cytokine Conjugated Bispecific Antibodies:
Advantages:
disadvantages
AEs
advantages:
1. Immune stimulation: Cytokine-conjugated bispecific antibodies can stimulate immune responses against tumor cells.
2. Targeted delivery of cytokines: Direct delivery of cytokines to specific tumor sites minimizes systemic toxicity.
3. Enhanced anti-tumor activity
Disadvantages:
1. Cytokine toxicity: Cytokine release syndrome (CRS) and other cytokine-related toxicities can occur.
2. Limited tumor selectivity: There’s a risk of non-specific binding to healthy tissues, leading to off-target effects.
3. Immunogenicity: Conjugation with bispecific antibodies may increase the immunogenicity of cytokines.
Indications:
Solid tumors and hematologic malignancies: including melanoma, renal cell carcinoma, and leukemia.
Immunotherapy-resistant tumors
Adverse Events:
1. Cytokine release syndrome (CRS): Managed with tocilizumab (IL-6 inhibitor) or corticosteroids.
2. Immune-related adverse events (irAEs):
NHS-IL12- targets necrotic areas of the tumor and is linked to IL-12. increased infil- tration of CD8+ T cells
what type of antibody is best
- murine
- chimeric
- humanized
Using humanized antibodies improves antibody-dependent cell-mediated cytotoxicity (ADCC), improves antibody stability, and decreases immunogenicity of the antibody itself
-omab are murine based, -ximab and -zumab are chimeric, and -umab are humanized versions of the antibodies
canonized antibody that targets canine IL-31, which is involved in allergic skin disease and pruritus in dogs - cytopoint
Adoptive T-cell transfer
cells are collected from a cancer patient, expanded, and activated in culture and then transferred back into the patient
enhancement of tumor-specific T cells, it is labor intensive, expensive, and time-consuming; thus its use is limited in both human and veterinary patients
lymphodepletion before ACT may overcome immunosuppression or isolating CD4 only CD4+ T cells are capable of activating both innate immune cells and CD8+ T cells
chimeric antigen receptor (CAR) T cells
CAR-T cells are generated via transfection of antibody genes specific for a tumor target into a T cell
engineered T cells specifically to the tumor tissue. Success with this technol- ogy has been seen in humans with chronic lymphocytic leuke- mia where the T cells target the CD19+ B cells
some new research
lymphokine-activated killer (LAK) cells
culturing PBMCs in high concentrations of IL-2, thus selecting for a population of cells with potent tumor cell lysis ability
limited to studies of cats with FeLV or FIV
not successful in humans
TIL therapy
tumor-infiltrating lymphocytes (TILs), when expanded using IL-2, exhibit potent cytolytic activity that is many folds higher than LAK cells against tumors in both a specific and nonspecific way
considered the best source of T cells for ACT
use in human medicine is limited bc time of isolation, the tumor they were isolated from, and the functional state of the cells when isolated
not used in vet med