Oncology Flashcards
T/F: With oncology, it is always better to wait and see
False
What is the difference between staging and grading a tumor?
Grade is the histopathological scoring by the pathologist.
Staging is determined by the clinician with tests that rank the extent of the body affected
How do you stage lymph nodes and why?
Sample both normal and enlarged, since normal may have mets and enlarged may just be reactive.
What direction do the lymph nodes drain?
Towards the heart
What are some tests to run to determine the staging of a cancer?
Diagnostic imaging: CT, rads, MRI, nuclear scintigraphy
What are the advantages of cytology for neoplasm?
Least invasive, inexpensive, safe, and quick
What are the disadvantages of cytology for neoplasm?
Cannot grade it histologically, false positives/negatives
What are the indications of using a non-aspiration technique for cytology?
Your first attempt, fewer lysed cells, less blood.
For lymph nodes, round cell tumors, highly vascularized tumors
What are the indications of using an aspiration technique for cytology?
Second attempts if non-aspiration doesn’t yield good results, hard/firm lesions, very small lesions where you cannot redirection the needle
What do you monitor when performing an FNA?
the needle hub to make sure the sample doesn’t fill and dilute with blood
What is the goal when applying the cytology sample onto the slide?
A monolayer of cells onto the slide
What are some biopsy techniques?
Needle core, punch, jamshidi bone, incisional, excisional
What are the indications for an incisional biopsy?
When the type of treatment, the extent of resection is determined by the type of tumor
What are some potential issues with excisional biopsy?
The blade can seed the tumor to other areas, and the owner may think you fixed the issue and may not want further treatment
What are some features that determine the grading scheme of tumors?
Cellular differentiation, degree of necrosis, invasion, and stromal tissue reaction, and the mitotic index
What does a clinician need to provide for the pathologist when submitting a sample for a tumor?
History and anatomical location, submission of all tissue removed and fixated, inking the tissue, request for 2nd opinions
What are some properties of epithelial tumors?
Adenoma/Carcinoma
Exfoliate easily, cellular
Sheets, clusters, acinar
Round, cuboidal, polyhedral
Vacuolated
What are some properties of mesenchymal tumors?
Sarcomas
Exfoliate poorly
Individual
spindle, stellate, round
What are some properties of round cell neoplasia?
Exfoliate easily, highly cellular
Individual
Round/oval
What are the three cellular criteria of malignancy?
Anisocytosis, macrocytosis, pleomorphism
What cancer treatment is useful to control local recurrence or progression of certain tumors?
Radiation
What cancer treatment is used to suppress cancer cells for some time, but has low cure rates?
Chemotherapy
What cancer treatment is used to cure more cancer than the other treatments?
Surgery
If a cure is not possible, what other reasons would you want to treat a cancer patient?
Pain control, supportive care (palliative)
What types of cancer are highly responsive to chemotherapy?
Hematopoietic (lymphoma, leukemia, myeloma)
Why is it “imperative” to establish a diagnosis with cancer?
To determine the appropriate therapy
When would you perform chemotherapy?
As an adjuvant therapy, palliate metastatic cancer, to downstage a tumor before definitive therapy, to sensitize tissue for radiation
What is the Goldie Coldman Hypothesis?
Tumors are clinically detectable after 30 doublings (1 billion tumor cells, 1 gram/cm3)
What is expected, in terms of treatment, if a tumor has reached 1 million cells?
Chemotherapy will probably not work
What does the Gompertezian growth show?
That tumor growth rate is not constant, and that is grows exponentially at early stages
When is chemotherapy most effective when looking at the Goldie Coldman hypothesis and Gompertezian growth chart?
Early when cancer is quickly proliferating
T/F: It is better to use one single form of chemotherapy to avoid summation of symptoms
False. Combination chemotherapy exert effort through different mechanisms, maximizing the killing of cancer cells, and decreases chance of resistance
What is BAG toxicity?
Bone marrow, alopecia, GI side effects
What can you do if the patient is responding really poorly to chemotherapy?
Remove the specific drug, reduce the specific drug, stop chemotherapy all together
Which chemotherapies are a high risk for dogs with the MDR1 gene mutation?
Vincristine, vinblastine, doxorubicin, mitoxantrone
What are the three areas of safety concern with chemotherapy?
The staff, the patient, and the owners
What is the most dangerous way the staff can be affected by the chemotherapy drug?
Aerosolization
T/F: You cannot split/open chemotherapy tablets and capsules
True
What type of syringe (not needle) do you want to use when dealing with chemo drugs?
Luer locks
How are most chemotherapy drugs eliminated from the body?
Urine or feces
What are some examples of alkylating agents for chemotherapy?
Cyclophosphamides, Chlorambucil, Melphalan, CCNU, Ifosfamide
What are the toxic effects of alkylating chemotherapy agents?
BAG
What are some examples of antimetabolic chemotherapies?
Cytosine arabinoside, 5-fluorouracil, methotrexate, gemcitabine
How does alkylating chemotherapies work?
Alkylate DNA bases, induces apoptosis
How do antimetabolites work?
Interrupt DNA synthesis by mimicking nucleoside analogs
What are some examples of antitumor antibiotics?
Doxorubicin, Mitoxantrone, Epirubicin
What is the mechanism of antitumor antibiotics?
Inhibits topoisomerase II leading to production of free radicals, killing tumor cells
What are some toxic side effects of Antitumor antibiotics?
BAG
What are the toxic effects of doxorubicin specifically?
Irreversible cardiotoxicity in dogs, nephortoxicity in cats, tissue damage if outside the vein, colitis
What are some examples of spindle toxin: vinca alkaloid toxins?
Periwinkle, vincristine, vinblastine
What is the mechanism of spindle toxins?
Binds to the tubulin to interfere with mitosis
What are some examples of Platinum dugs?
Cisplatin, Carboplatin
What is the mechanism of platinum drugs?
Binds to DNA causing cross links
What can platinum toxicity do to cats?
Fatal idiosyncratic pulmonary edema
What do NSAIDs do to aid in cancer treatment?
Chemoprevention, over-expression of cyclo-oxygenase II, mostly unknown mechanism
What are the common NSAIDs used for cancer treatment in dogs?
Carprofen, prioxicam
What are examples of passive immunotherapy?
Anti-tumor antibodies, activated lymphocytes, cytokines
What are examples of active immunotherapy?
Tumor vaccines, gene therapy
How does canine melanoma vaccine work?
It leads to production of DNA that codes for non-canine tyrosinase, leading to a strong immune response and acting against the melanoma
What drug is currently being studied to target genetic mutations?
Gleevec (Imatinib mesylate-Gleevec)
What cancer drug is a tyrosine kinase inhibitor and used to treat mast cell tumors but also other head and neck tumors?
Palladia (toceranib)
What cancer treatment is anti-angiogenic and antimetastatic?
Low Dose Continuous Chemotherapy (cyclophosphamide).
Suppresses T cells leading to blood vessel inhibition
What are the three radiation margins with RT?
GTV = gross tumor volume CTV = clinical target volume PTV = planning target volume
What is the main target of photons and electrons from radiation therapy?
DNA, but also get cell membranes
T/F: Radiation therapy targets only cancer cells
False. Cancer and normal
What are the 4 R’s of radiation therapy?
Repair, repopulation, redistribution, reoxygenation, radiosensitive
Which of the 4 R’s is considered good for tumor cells
Redistribution, reoxygenation, radiosensitive
What of the 4 R’s is desired among normal cells?
Repair, repopulation
T/F: the larger the tumor, the higher the dose of radiation needed
True
T/F: Acute radiation toxicity is generally irreversible
False.
What is acute radiation toxicity dependent on?
Dose, dose rate, and dose per fraction. TOTAL DOSE
What is late radiation toxicity dependent on?
VERY dependent on dose per fraction. FRACTION SIZE
T/F: Late radiation toxicity is usually progressive and irreparable
True
What is the protocol for definitive RT?
Large # of fractions with low doses. Long term control with expected acute side effects, but limited late toxicity
What is the protocol for palliative RT?
Fewer # of fractions but higher doses. Few acute side effects but higher risk of late toxicity
What is the difference between SRS and SRT?
SRS is radiosurgery with usually only 1 treatment, SRT is radiotherapy with several.
What is used for systemic radiation therapy?
Iodine-131
Samarium-153
What is another term for strontium therapy?
Plesiotherapy
What are the indications for strontium therapy?
Small, superficial tumors
Feline MCT, dermal SCC
Canine limb SCC, melanoma
What are external beam radiation and strontium therapy primary used for?
Local or locoregional disease
With cancer, what is cryotherapy used for?
Superficial lesions ONLY
ex: MCT
(<1.5 cm)
What is the proposed mechanism of electrochemotherapy?
Opens channels in cells to allow drug to enter them.
