Targeted Therapy

Chemotherapy affects many dividing cells. A targeted drug is chosen because the tumour has a specific feature. Familiar examples include HER2-directed treatment in some breast cancers, EGFR-directed tablets in some lung cancers, and PARP inhibitors in some ovarian cancers with a BRCA-related weakness. Using the drug without that match exposes a person to side effects without a reason to expect benefit.

Many of these medicines are tablets taken at home. Others are infusions. A tablet is still a cancer medicine. Missed doses, food rules, and interactions with ordinary drugs can change how much of it reaches the cancer. Blood tests continue even when you feel well.

Testing is most useful when the result could change treatment. The useful panel depends on the cancer type and stage. A variant of unknown significance is not a target. A blood test for tumour DNA can help when a biopsy is hard to repeat, and it can miss a change that is present in the tumour. Bring any report you already have so the same test is not repeated without a reason.

When a drug matches, scans may show shrinkage or a period of stability. That is control, not a promise of cure. The cancer can later become resistant. Side effects depend on the drug: rash, diarrhoea, high blood pressure, liver changes, or effects on the heart. Report them. Do not stop or double a dose on your own. A consultation is where the report, the goal, and the monitoring plan are set.