cancer chemo Flashcards
what is the cancer cell biology
- she’d of cell surface antigens
- expression of tumour associated antigens
- excretion of lytic enzymes
- growth factor synthesis
what is the cell cycle of cancer
- g1
- dna sysnethesis
- cdk
- mitosis
- s phase
- g2
anti metabolic
these inhibit enzymes involved in dna/rna synthesis and its similar to the natural structures
methotrexate
- these inhibit DIHYDROFOLATE REDUCTASE
theses are used for solid tumours (luekimia)
5 F U
this inhibits THYMIDYLATE SYNTHASE which disrupts dna synthesis
Term: Alkylating Agents
Examples: Cyclophosphamide, Melphalan, Ifosfamide, Carmustine
Mechanism of Action: Covalently interact with DNA base residues, disrupting DNA synthesis and damaging DNA
Cyclophosphamide
Most commonly used alkylating agent for various cancers
Inactive until metabolized by P450 in the liver
Metabolites include aldophosphamide, acrolein, and phosphoramide mustard
Side effects: Toxic bladder (acrolein), myelosuppression, nausea, vomiting
Mechanism of Action of Platinum Compounds
platinum compounds like Cisplatin covalently bind DNA, forming a highly reactive species inside cells. Cross-linking occurs between guanine molecules in DNA, preventing replication.
Cisplatin Toxicity
Clearance via kidneys (nephrotoxicity)
Can cause ototoxicity, neuropathies
Low myelotoxicity
Major toxic effect on kidneys
Hydration recommended as part of chemo regimen
Resistance to Chemotherapeutic Drugs
Two types: Inherent resistance, Acquired resistance
Tumor cells adapt to drugs, less affected
Cancer Screening
Early diagnosis for better prognosis
Screening identifies early stages and asymptomatic patients
Benefits and disadvantages of screening
Tumour Markers
Some tumors secrete substances into the bloodstream
Useful for diagnosis, monitoring, detection of recurrence
Examples: PSA, CEA, CA 125, hCG
CEA (Carcinoembryonic Antigen)
Carcinoembryonic antigen
Raised in smokers, patients with Crohn’s Disease
Normal level: Less than 2.5 nanograms/ml
