B. Sometimes surgery isn't straightforward. Brain cancer 2. Solution for tumor that can't be totally removed is to take out main bulk of tumor. Then do radiation and chemotherapy. When primary tumor gets removed, secondary tumors grow faster.
Dividing cells are the usual target.
A. Chemicals that kill dividing cells. Methotrexate prevents synthesis of DNA by blocking an enzyme needed for that. A cell that starts to replicate DNA and can't finish will die. Cyclophosphamide binds to DNA and the primary effect is inhibiting DNA replication B. Chemical could attack organelles called microtubules. Microtubules move chromosomes and if microtubules don't work, the cell tries to divide but it can't and it dies.