« Classical » chemotherapy targets cell division and therefore all the proteins involved in cell division, or indeed DNA itself.
Unfortunately, such treatments counter not only cancer cells but also healthy cells that are naturally fast-dividing. This causes side effects such as a decrease in white cells, hair loss or digestive troubles for instance.
… OR TARGETED CHEMOTHERAPY?
Targeted chemotherapy specifically attacks cancer cells by targeting exclusively the altered proteins particular to them.
Several cancers are caused by a mutation that is well-known in the world of precision medicine: BRAF V600E. If BRAF V600E is identified in a tumour, then the patient can be offered targeted chemotherapy. Why?