Oncology Flashcards
Breed dispositions for cancer-
Pugs, Boston terriers, Boxers–> MCT
Bernese Mountain Dogs–> Histiocytic sarcoma
Boxers, Basset Hounds, Bulldogs–> lymphoma
Belgian Tervurens, chows–> gastric adenocarcinoma
GSD–> hemangiosarcoma, Nodular dermatofibrosis– renal carcinoma and uterine leiomyoma
Intact male dogs are predisposed to what tumor? What about neutered male dogs? What about female dogs?
Male intact is usually perianal adenoma
Neutered males is usually prostatic carcinoma (usually an adenocarcinoma)
Females is usually urinary tumors like TCC
How do P-glycoprotein substrate chemo drugs work and what are some examples?
They are called “immunomodulators” which are used to harness the body’s own immune system to respond to cancer cells with minimal SE as compared to chemotherapy/radiation
they are usually not stand-alone therapies
Examples are: Vincristine, Vinblastine, Vinorelbine, Doxorubicin, +/- Mitoxantrone
Unique SE to 5-Fluorouracil-
Fatal neurotoxicity in cats (and in dogs with very high doses)
Unique SE to Vincristine
peripheral neuropathy – interferes with microtubule formation so interferes with neuron transmission/transduction pathways. Patients may have pins and needle feelings in paws
Unique SE to Cisplatin–
Fatal pulmonary edema in cats
Unique SE to Mechlorethamine-
severe vesicant which means sloughing of the skin when outside of the vein
Unique SE to Cyclophosphamide-
sterile hemorrhagic cystitis because one of the byproducts ends up in urine and is caustic to bladder wall so give in the morning and make sure p is well hydrated
May need to also give Furosemide with it and if you see any cystitis STOP THE DRUGGG
Unique SE to CCNU–
hepatotoxicity and this is one of the ones we need to really watch the neutrophils
Unique SE to Doxorubicin-
Severe vesicant and will slough skin if outside of the vein, Hypersensitivity/anaphylaxis, cumulative cardiotoxic in dogs, arrhythmogenic, cumulative nephrotoxicity in cats
What chemotherapy drugs cross the BBB?
5-FU
Cytosar
Hydroxyurea
CCNU
Procarbazine
Sensitivity to radiation therapy (RT) of cancers in order
Round cell tumor> carcinoma> sarcoma
What is the TOC for LSA and what is the % response rate?
Chemo is the TOC for LSA and there is a 80-90% response rate
Hypercalcemia, mediastinal LN enlargement, and boxers/ wolfhounds/ huskies/ shih tzu’s = ____ cell Lymphoma
T cell Lymphomas
T cell is usually in dogs/cats and B cell is usually in dogs/cats
T cell is usually in dogs and B cell is usually in cats
There is an approx. 60X increase risk of cats getting lymphoma if they are ___ positive and it is usually ___ cell secondary to….
FeLV positive; it is usually T cell secondary to viral integration into the genome
____ has approx. 5x the increased risk in cats who have it for ___ cell LSA secondary to…
FIV; B cell; secondary to immunosuppression
What is acute lymphoid leukemia in cats?
Neoplastic blast cells taking over the bone marrow resulting in pancytopenia (decreased RBCs, WBCs, and platelets)
pancytopenia means…
low RBCs, WBCs and platelets
evans syndrome is…
IMHA and immune-mediated thrombocytopenia
MCT in dogs
do not need chest rads, need FNA of liver and spleen, TOC is surgery and chemotherapy
MCT is the number one most common cutaneous tumor of dogs
MCT in cats
cats get internal MCT and MCT are not as common in cats as they are in dogs, 3 unique variations are cutaneous, splenic/visceral, and intestinal
TOC is splenectomy/sx and chemo
Hepatobiliary tumors in cats are usually ____ but are ____ in dogs
Benign; malignant
50% of canine liver tumors are _____ tumors and usually have no mets if _______
Hepatobiliary; usually no mets if they are massive/solitary
AGASACA
cocker spaniel is the poster child, occurs in females and males but is more common in those that are spayed/neutered, mets are 50-80% of cases and include the LN, liver, spleen, lungs, and bones
LN mets are common at presentation but DISTANT mets are uncommon
TOC is multimodal
Nasal tumors in dogs from most common to lesser commonality
Adenocarcinoma>SCC> Fibrosarcoma> osteosarcoma
Oral tumors in dogs from most common to lesser commonality
Melanoma> SCC> Fibrosarcoma> osteosarcoma
Nasal tumors in cats from most common to lesser commonality
SCC> lymphoma
RT is the TOC like with in dogs, cats have a lot worse of a prognosis
elevated globulins usually point toward what cancer types?
Multiple myeloma and plasma cell tumors
ISS
Injection site sarcomas
4 months to 3 years post vaccine, may be genetic bc higher incidence found in siblings
3-2-1 rule
Still present after 3 months after the vaccine
>2 cm in diameter
still growing 1 month post-vaccination
INCISIONAL biopsy only
locally invasive, non painful, firm, deeper than what we can palpate, slow/late mets but mets to lungs after awhile
TOC is sx and RT +/- chemo if confirmed mets or “hot” tumors which are tumors with high mitotic count, vascular invasion, etc.
Dolichocephalic dogs get this type of brain tumor whereas brachycephalics get this type of brain tumor
Dolichocephalic dogs get meningiomas whereas brachycephalics get this gliomas
Hemangiosarcoma predilection sites
Spleen, right atrium, skin
Hemangiosarcoma notes
Early, aggressive mets
to the liver, lung, mesentery, brain, mets in > 80% of P with HSA on presentation
HSA is the most common tumor to met to the brain, hematogenous spread or can have direct implantation
Sarcoma= cancer of connective tissue cells
Carcinoma= cancer of epithelial cells
Remember, HSA is sarcoma of the conn. tissue around the blood vessels
Double 2/3’s rule
2/3 of splenic masses in dogs are neoplastic
2/3 of those neoplastic masses are hemangiosarcomas
What is definitive diagnosis and TOC for HSA?
Definitive diagnosis is biopsy and TOC is chemo (Doxorubicin aka red death)
Chemo is not a front line but can hopefully slow down any metastatic disease
Prognosis for HSA
-with no tx- days to weeks
-with sx alone 1-3 months because mets get them
-sx for mass and chemotherapy- may double your time so MST 6-8 months
____ % of thyroid tumors are bilateral and bleed a lot so AVOID incisional biopsies
60%
Midline mass on the neck of an older dog is what until proven otherwise?
Thyroid carcinoma until proven otherwise despite what cytology might say
Pheochromocytoma
mets rate is about 40%, they are uncommon and are usually hidden masses with a lot of CS
Hormone testing may find metanephrine which is a break down product of epinephrine and norepinephrine and if it is 4X the normal range means likely has a pheochromocytoma
what is the TOC for pheochromocytoma? What is the prognosis? What is NOT a tx option for them?
sx if adrenal mass is more than 2cm and is causing CS, can also do RT
Will NOT respond to CHEMO; Prognosis is MST 2-3 YEARS with sx resection, otherwise variable to guarded (if tumor is more than 5cm and/or caudal vena cava invasion)
________ , ______ and _____ are cancers that may be very Palladia responsive
thyroid carcinomas; renal adenocarcinomas; and insulinomas
What are the staging tests recommended for oral tumors?
Cytology of both mandibular LN and thoracic radiographs
How do canine oral melanomas differ from SCC and fibrosarcoma in regard to behavior and Tx?
Melanomas that have no pigment resemble sarcomas on histopathology
Requires immunohistochemistry to differentiate the two
Needed because they act different and tx is different- for melanoma, it responds fairly well to definitive curative RT with 4 fractions, and we need systemic disease Tx unlike sarcomas which TOC is surgery
“High/Low” Fibrosarcomas
Golden ret. is the post child, histologically low grade but biologically high grade
usually are on the hard palate between the canine and carnassial teeth
Steps of cleaning- chemo protocol
Step 1 deactivation (bleach/Clorox wipes)
saline/water
Step 2 Deconamination (alcohol, water, peroxide, bleach)
saline/water
Step 3 clean to remove organic debris (bleach/Clorox)
saline/water
Step 4 Disinfecting (Bleach/Clorox, oxidizing agent, phenols, etc.)
uveal melanoma
arises from the anterior segment, is BENIGN in dogs and MALIGNANT in cats
CS are heavy pigmentation (but sometimes tan/white), dyscoria- abn pupil shape, blindness, ocular pain, iris thickening
___ melanoma is ALWAYS benign in dogs and is seen mostly in what breed?
Limbus melanoma; seen in GSD
Lymphoma mets to the eye
via hematogenous spread to the uveal tract, causing anterior uveitis and hyphema (bleeding into the eye), usually stage 5 bc this is mets to distant sites (eyes), more likely to be B-cell and usually presents as nodular lesions within the eye
Histiocytic tumors predisposed breeds
Bernese mtn. dog, flat coated retriever, mini schnauzers
What are the subtypes of histiocytic sarcoma?
Localized- lung, periarticular (stifle and elbow mostly), spleen
Hemophagocytic - rare but bad prognosis, usually has hypocholesterolemia, hypoalbuminemia, thrombocytopenia, regenerative anemia
Disseminated- has affinity for lymphocytic regions like lymphoma (LSA)- liver, spleen, lungs, BM, etc.
CCNU patients need to also be on what supplement?
Denamarin
What characteristic lab work do we see with hemophagocytic histiocytic sarcoma?
hypocholesterolemia, hypoalbuminemia, thrombocytopenia, regenerative anemia
Histiocytoma
Langerhans cells in origin, avoid immunosuppression DO NOT put these p on pred
looks like button ulcer, benign usually in younger dogs and will spontaneously regress
What is a good ddx in a patient that has symptoms that seem out of the normal to the disease esp. if the lesion is in a typical location and a predisposed breed?
Histiocytic sarcoma
Keep what form of cancer on your radar for evans syndrome (where immune system makes antibodies against the body’s own RBC and attacks its own blood cells) or IMHA dogs, remember to look at all bloodwork abnormalities
Hemophagocytic Histiocytic sarcoma
What test is a good GP test to run if you suspect a patient has TCC (recurrent UTI’s and older p/maybe predisposed breed)
BRAF test can also do traumatic catheterization
What is the most common type of renal cancer?
Renal adenocarcinoma
MANY of them express KIT so use Palladia which a receptor kinase inhibitor
What are the top 4 at risk breeds for TCC/UC?
Scottie terrier
Sheltie
Westie
Eskimo dog
Veggies are protective, ayoooo
Why are NSAIDs effective against TCC/UC?
Do chemo indefinitely (do not expect tumor to shrink
why do NSAIDS help?
Because they are COX-2 inhibitors and these tumors way over express COX
What are the pros and cons and limitations of surgery for TCC/UC?
For most cases, exlap and biopsy is the diagnostic test of last resort because super invasive, high risk of seeding and costly since such a major sx
Pros- can do in GP, get histopath, potentially therapeutic if away from the trigone
Cons- anesthesia, INVASIVE, VERRRYYY high risk of seeding, will not usually be curative
what is the general approach to therapy for TCC/UC and general prognosis?
Do BRAF testing (need 40mL free catch urine)
Can do traumatic catheter if in GP
Can scope/biopsy if in referral setting
EXlap/surgery is last resort, very high risk of seeding, major surgical procedure/invasive
Do not have to worry about neutrophil count with what chemo drug? Otherwise, we need neutrophils to be above what level?
Elspar aka L-asparginase; Neutrophils need to be more than 2,000 on CBC
MCT are most common where in dogs and where in cats?
In the skin of dogs (the most common cutaneous mass of dogs), and GI tract of the cat
explain PARR for differentiating lymphoma types
Cancer cells originate along the same cellular line and proliferate so they would all originate from the same cell and that would mean they should all have the same DNA
So with PARR, we are looking to see if this is the same cell line proliferating based off the same origin “monoclonal” = suggestive of a neoplastic process
Dogs with generalized lymphadenopathy rule outs–
Ehrlichia, Blastomycosis, Lymphoma
+/- chronic pyoderma or atopy
What is flow cytometry and how is it used to aid the diagnosis of lymphoma?
Flow cytometry- run all cells through a laser and establish the different sizes and
Regularity. Same as with CBC where the cells are brought into single file line
Through a laser “they FLOW past a laser horizontally/perpendicular to the cells)
And based off the make up inside of the cell, the laser will pick up the size of the cells
And that is how we know WBC which are bigger than RBC which is bigger than a platelet and looks at nucleus inside of WBC to see what type of WBC it is
Lymphocytosis with diffuse lymphadenopathy likely means…
LSA In the bone marrow
Stages of Lymphoma–
Stage 1- single LN
Stage 2- multiple regional LN (on one side of the diaphragm)
Stage 3- generalized lymphadenopathy (both sides of the diaphragm)
Stage 4- spleen and/or liver involvement +/- lymph nodes
Stage 5- bone marrow, ocular, cutaneous, renal, nasal, CNS, GI, anything other than LN/spleen/or liver
Negative prognostic factors of LSA?
T cell, hypercalcemia, substage B (has CS), prolonged prior pred use, young age, hepatosplenic, high stage
“B is bad but T is terrible”
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Remission definition
elimination of all clinically evident disease
Rescue chemo
chemo done after the initial protocol fails to bring the p into remission
T zone lymphoma
Indolent, low grade variant primarily affecting the LN and bone marrow, 85% have lymphadenopathy and more than 50% have lymphocytosis, usually feeling fine but may be slightly off, really good prognosis (MST like 2-3 years)
Darrier’s sign
Palpation of the tumor may cause wide release of Histamine and can double to triple in size, give Benadryl to make it smaller and less irritated looking again. May also see bruising because heparin released from MCT along with histamine, proteolytic enzymes, etc.
Diagnosis of MCT
FNA- can get a diagnosis easily on FNA usually, MCT is a round cell tumor and round cells do exfoliate pretty well
____ dogs are predisposed to MCT but are usually low grade and have better prognosis
Brachycephalic breeds
any dog with one ____ will have a higher risk of more in the future
MCT
Grades of MCT explained…
The lower the grade, the better they do so grade 1 has no to very slow rate of mets (low cellular turnover rate so low mitotic index score). Grade 3 has high mitotic count, growing fast, invading deep tissues, and worse prognosis overall. About 80% of MCT you find in practice will come back as Grade 2, not all grade 2’s are created equal– may be closer to grade 1 or closer to grade 3 which does not help us a ton because in the middle of good and bad prognosis, which is frustrating for tx and future discussion with the owners. Use low grade and high grade two tier/Kiupel to see if it is closer than grade 1 or grade 3 if it is grade 2
TOC for MCT
Surgery is the most important TOC for all MCT of ALL grades!!!
Second best option is chemotherapy because first most common site to mets is all draining LN so radiation therapy (RT) is only good for localized lesions
Where do MCT like to metastasize????
Usually mets to draining LN and then liver and spleen and rarely bone marrow
_____ MCT Are usually LESS aggressive than ____ tumors
Subcutaneous; cutaneous
What anatomical locations of MCT carry a WORSE prognosis???
Subungual (nails), digits, muzzle, oral, preputial/scrotal, GI tract, mouth
haired skin and eye conjunctiva are some locations that have good prognosis
What two long term drugs for p with MCT???
Diphenhydramine and proton pump inhibitors
what is the second most common feline skin tumor?
cutaneous MCT in felines with the head and neck being the most common location
What is the most common cause of feline splenic disease and are usually sick on presentation?
Splenic/Visceral MCT
What is the post child breed for HSA? What is the second runner-up???
Top poster child is GSD and the second runner up is Golden Retriever
If you have a dog with an undiagnosed splenic mass that is causing hemoabdomen, do you autotransfuse the patient after removing the splenic mass even though you do not know if it is a benign splenic mass (splenic hematoma or hemangioma) or malignant (hemangiosarcoma)????
Yes, still transfuse it because likelihood of you causing metastasis is super low bc cells are already in circulation and you will save them and do not have to worry about finding blood that is compatible and do not have to worry about the speed in which you give it because you know the patient is hypovolemic anyway. The downside of autotransfusion is you are only giving back the red blood cells, not the clotting factors or anything like that.
!!!!!!
Throw in some whole blood/plasma if they are going into DIC
What is the difference between SQ and cutaneous/dermal HSA in relation to their different MST????
sun exposure
HSA layers of the skin different prognosis—–
The dermal hemangiosarcoma has a fair prognosis as long as it is removed before it can invade to the subcutaneous tissues. Hemangiosarcomas that develop in the subcutaneous tissue (not on the skin but under it) or spread to the subcutaneous area from the outer skin behave more malignantly.
