Immunotherapy for Cancer: How It Works and What to Expect

Immunotherapy is a category of treatments that boost or redirect the immune system rather than directly killing cancer cells. Checkpoint inhibitors block proteins that cancer cells use to hide from immune attack, while other forms train or engineer immune cells to target cancer specifically.

If immunotherapy is an option, your team will likely test your tumour for relevant biomarkers first. Knowing what side effects to watch for and reporting them early helps your care team manage them effectively.

Biomarker tests on tumour tissue, such as PD-L1 immunohistochemistry or microsatellite instability testing, help estimate likely benefit. Baseline blood work and imaging establish a reference point to monitor treatment response and side effects.

Immunotherapy is approved for melanoma, non-small cell lung cancer, kidney cancer, bladder cancer, some head and neck cancers, Hodgkin lymphoma, and tumours with specific genetic features such as microsatellite instability, among others.

Checkpoint inhibitors are given by infusion on a set schedule, sometimes alongside chemotherapy. Other immunotherapy approaches, including CAR-T cell therapy, involve collecting and modifying a patient's own immune cells before reinfusion.