Theraputic Oncology - Part 2 Flashcards
What type of therapy boosts the body’s natural defenses to fight cancer?
Immunotherapy
What are used an nonspecific tumor immunotherapy?
Interferons/interleukins (immunomodulators)
How are monoclonal antibodies used in immunotherapy ?
Lab made AB’s designed to block abnormal proteins in a cancer cell or attach to specific proteins on cancer cells —> flag the cells so the immune system will destroy it
What is T-cell therapy??
T cells removed, modified with receptors to allow those T cells to recognize cancer cells
—> cells growth in large numbers in the lab —> returned to patient —> seek out/destroy cancer cells
What is oncolytic virus therapy?
Genetically modified viruses to kill cancer cells
What is the MOA of oncept canine melanoma vaccine?
Conventional vaccines stimulate an immune response direct against foreign proteins
—> tyrosinase is present on melanoma cells (required for melanin synthesis, but is not targeted by dogs immune system)
—> vaccine made with human tyrosinase, immune response to this also induces immune response to tyrosinase on melanoma cells
What is Pipeline (OSA)?
Listeria-based antigen delivery system —> vaccine is a freeze-dried formulation of a modified-live, attenuated Listeria strain that activates cytotoxic T cells
—> listeria strain expresses a tumor-associated antigen —> activated T cells are directed to fight cancer cells
Your client wants to used turkey tail mushroom in their dog with a hemangiosarcoma. Would you recommend this treatment? How does it work?
Contains polysaccharide (PSP) which causes cell -cycle arrest and G1/S checkpoint with alterations in apoptogenic and extracellular signaling proteins
Net result = a reduction in proliferation and an increase in apoptosis in cancer cells
This has shown to delay progression of metastasis in dogs with HSA, why not give it a try!
What is yunnan Baiyao? Is it useful in treatment of cancers?
Herbal extract
Shown to improve clotting and enhance platelet function
Panax notoginseng root extract
Anecdotally reported to prolong survival times in dogs with HSA
What different forms can radiation therapy come in?
Photons (X-ray and Gamma rays)
Subatomic particles (electrons, alpha particles, protons, and neutrons)
What is the MOA of radiation therapy?
Energy is deposited within the medium —> leads to DNA damage —> cellular death
Interacts with cells through transfer of energy
-dose is therefore measured in using of energy deposited per mass of tissue
What are the effects of radiation on tissue?
Dependent on dose
Early responding tissue = epithelial layers of skin or mucosa and bone marrow (+/- organs)
-> effects are seen within weeks of exposure to RT, appear like sunburn
Late responding tissue = nervous tissue and bone
-> effects are seen within months or years (can lead to neoplasm)
How can you maximize radiation therapy to tumors while reducing effects on normal tissues?
Fractionation Precise tumor localization Planned multimodality therapy Computer treatment planning Positioning Instrumentation Sensitizers/protectants
What are the “big 3” variables that dictate the response to tissues to radiation?
Total dose: related to both tumor response and toxicity. Increased dose —> increase response —> increased side effects
Fraction size: larger fraction size -> higher probability of a LATE effect. When larger fractions are used the total dose has to be decreased to avoid increasing the probability of a late irreversible effect of radiation.
Duration of treatment: longer protocol = fewer/milder ACUTE effects BUT increases opportunity for tumor to repopulate during treatment
What is the standard dosing for radiation?
40 GY (Gy = 1joule/kg) over 20 daily fractions
=> 2Gy/fractions
Classic treatment for incompletely excised soft tissue sarcoma
