Oncology Flashcards
Treating Cancer
Sx, Radiation, Meds
Cytotoxic: Drugs that kill cells directly, most common and widespread toxicities; can’t differentiate good from bad cells = side effects
Hormone and hormone antagonists: Balance hormonal effects with cancer growth
Biologic Response Modifiers: Immunomodulators
Targeted Drugs: Bind specific molecules that promote cancer
General Rules
Chemotherapy drugs are more toxic to tissues that have a high growth fraction than to those with low growth fraction; hair, epithelial, gi, bone marrow
SOLID TUMORS (BREAST, LUNG, PROSTATE, COLON) DON’T respond well to chemo only.
High growth fraction rate responds well to chemo alone (testes, blood)
True early detection is rare; usually advanced before ID’d
Toxicity to normal cells
Chemo drugs, especially in high growth lack selectivity.
Toxicities are often dose-limiting, so the max TOLERATED dose may not be adequate.
Cure requires 100% cancer cell eradication; hard to tell, takes a long time at high doses, very little help from host defenses.
Major Toxicities of Chemotherapeutic Drugs
Bone Marrow Suppression: decreased PMN, PLT, RBCs
Neutropenia: Scary. Increases risk, incidence, and severity of infection. Fever. Need broad spectrum ABX
Thrombocytopenia: Increases risk of serious bleeding, PLT infusions are the main treatment
Anemia from reduced RBCs: Much less common, treated with blood transfusion or erythropoietin
More Major Toxicities of Chemo
Digestive Tract Injury: Stomatitis; inflammation of oral mucosa, can be severe and inhibit eating. Use magic mouthwash. N/V/D common and reduced with premedication.
Alopecia: 7-10 days after 1st treatment, peaks at 1-2 months, regeneration 1-2 months after last course
Alkylating Agents
MOA: Inhibits DNA synthesis, alkylates DNA leading to single and dsDNA cross-linking = cell death
ADR: Cyclophosphamide; Hemorhagic cystitis, pyelitis, ureteritis, and hematuria (BLADDER) from excretion of metabolites in urine. Bendamustine: Infusion related rxns
Platinum Compounds
Carboplatin, Cisplatin, Oxaliplatin
MOA: Inhibits DNA synthesis, alkylates DNA
ADR: Highly emetogenic, peripheral neuropathy, ototoxicity. Cisplatin: Severe renal toxicity, ototoxicity up to full hearing loss. Oxaplatin: Worst for peripheral neuropathy, exacerbated by cold drinks!
Antimetabolites
MTX, Pemetrexed, Fluorouracil, Gemcitibine
MOA: Structural analogs of important natural metabolites; disrupt critical metabolic processes.
ADR: MTX: Tons of box warnings. 5-FU (fluorouracil): Palmar-plantar syndrome (skin rxns)
Hypomethylating Agents
Azacitidine, Decitibine
MOA: Inhibit DNA Methyltransferase. Alters gene expression. Alters DNA expression, leading to tumor suppression and cell differentiation for destruction
ADR: CNS depression
Anti-tumor ABX (Anthracyclines)
MOA: DNA/RNA synthesis
ADR: Cardiotoxicity, leading to heart failure proportional to cumulative exposure 1-20% incidence in doses 300mg/m -500. Can be acute changes but can become long term/chronic (heart failure). Extravasation; severe local tissue injury and necrosis, needs a nurse to stay and watch
Anti-tumor NONanthracyclines (Bleomycin)
IND: Inhibits RNA production
ADR: Pulmonary toxicity; pneumonitis/fibrosis. Very low chance of bone marrow suppression
Vinca Alkaloids
Vincristine, Vinblastine, Vinorelbine
MOA: Stop mitosis by blocking microtubule assembly; stops cell division.
ADR: Vincristine: Peripheral neuropathy, decreased sensation etc. Vinorelbine: Can rarely cause Interstitial Pulmonary damage and adult respiratory distress syndrome (ARDS), usually presents within 1 week of initiation and unfortunately is typically fatal.
Taxanes
Docetaxel, Paclitaxel
MOA: Inhibits cell replication by stabilizing existing microtubules and inhibits disassembly
ADR: Significant hypersensitivity rxn risk (tree). Docetaxel: fluid retention, particularly in pts with poor liver function
Topoisomerase Inhibitors
Etoposide, Irinotecan, Topotecan
MOA: Inhibit topoisomerase; prevent DNA/RNA synthesis and repair
ADR: Irinotecan: Early (24hrs of infusion) excessive cholinergic stimulation of GI tract. Fix with IV or SubQ atropine. Late (past 24 hrs) = diarrhea
