Chemotherapy Flashcards
Log Cell Kill Theory
A given dose of chem drugs will kill a constant percent of cancer cells per dose rather than a constant number of cells.
Use a log plot to represent killing strategies and outcomes where the down arrows represent killing upon admin and the upward arrows represent log growth of remaining cells in btwn doses.
Induction chemotherapy
- Initial chemotherapy (anticancer drugs)
- Goal is cytoreduction (decrease in tumor cell volume) and remission
- Graph arrow steadily zigzags downwards
Complete response to chemotherapy
-Disappearance of disease for at least 1 month. remission
Partial response
-Reduction in tumor volume by at least 50%
Stable disease
-Reduction of tumor volume by less than 50% and no new disease sites for at least 30days
Prgression
An increase in tumor volume of 25 % or move and evidence of new disease sites.
Maintenance of Chemontherapy
- Prolonged low dose chemotherapy
- Goal is too achieve cure (disease eradication) or prolonged remission.
- Graph steadily declines downward like intro and zig zag horizontally to convey steady state of disease.
Adjuvant Chemotherapy
- Given after disease reduction or eradication via surgery or radiation.
- Reduce microscopic disease and prevent local recurrence
- Graph is a SHARP vertical line followed by steady downward zig zags
Neoadjuvant Chemotherapy
- Given prior to surgery or radiation to reduce tumor volume and improve efficacy of treatment.
- Graph is at first steady zigzag downwards then sharp vertical decline followed by steady zig zag downwards
Palliative or Salvage therapy
- Given after the failure of other therapies to control disease, prolong life and reduce cancer related symtoms.
- Graph is just zig zag horizontally following the sigmoidal log solid tumor growth line.
Chemotherapy Agents are classified by their
Chemical structure
Mechanism of action
Cell cycle Specificity
Chemincal compounds
1. Platinum compounds (cisplatin) forms platinum cross links btwn adjacent guanines and adenines. Forms DNA adducts which inhibits replication and transcription. 2. Nitrogen mustards, Nitrosurea alkylating agents forms DNA adducts prevent relication 3. Anthracyclines 4. Camptothecins 5. Antimetabolites 6. Taxanes 7. Vinca alkaloids
MOA
- Drugs affecting biosynthesis of nucleic acids
- Mercaptopurine inhibits purine synthesis) and thioguanine (inhibits DNA synthesis) - Drugs disrupting DNA structure and function
- 5-FLU (inhibit thymidylate synthesis) - Antimetabolites (block DHFR andpurine synthesis)
- Alkylating agents ( forms adducts with DNA)
- TOPO-I
- Antitumor antibiotics (
- Drugs that alter cell signalling and progression
Cel Cycle Specificity
CCS: cell cycle specific act only on dividing cells
CCNS: cell cycle no specific targets both dividing and non dividing cells
-Follow CCNS tx with CCS agent
aADECommon
- Cytotoxic effects on ALL rapidly dividing cells
- Affects regenerating cells
1. Bone marrow
2. Blood cells
3. Gastric mucosa
4. Follicular cells
5. Gametes