Five mechanism classes, five ways to disrupt dividing cells
Conventional chemotherapy works largely by interfering with cell division, which is why rapidly dividing tissues (tumor, but also bone marrow, gut lining, and hair follicles) bear the brunt of both effect and toxicity. The diagram groups the major agents by mechanism. Alkylating agents add chemical groups that crosslink DNA and block replication. Antimetabolites mimic the building blocks of DNA and RNA, jamming synthesis.
Anthracyclines intercalate into DNA and poison topoisomerase II, breaking strands during replication. Taxanes stabilize microtubules so the mitotic spindle cannot disassemble, freezing cells in division. Platinum agents crosslink DNA much like alkylators through a distinct chemistry. Regimens often combine classes so that several pathways are hit at once and resistance is harder to develop.
Why grouping by mechanism is useful
Knowing the class predicts characteristic side effects and which drugs are sensible to combine. Anthracyclines carry cumulative cardiac risk, platinums can damage nerves and kidneys, and most classes suppress the bone marrow. Combining drugs with non-overlapping toxicities lets clinicians press the antitumor effect without compounding one organ's damage.
Interpreting the log-kill curve
This is general educational information, not medical advice. Specific drugs, doses, and combinations are matched to the cancer and the individual by an oncology team; the classes here describe biology, not a prescription.