Immunotherapy

Your immune system is remarkably good at detecting and eliminating abnormal cells — but cancer cells can be deceptive, disguising themselves so that immune cells pass them by or actively suppressing immune activity. Immunotherapy works by disrupting those disguises and suppression mechanisms, or by giving your immune system a more powerful toolkit to identify and destroy cancer cells more effectively.

There are several types of immunotherapy used in cancer care. Checkpoint inhibitors are drugs that block proteins cancer cells use to 'hide' from immune cells, effectively taking the brakes off the immune response. Monoclonal antibodies are lab-engineered proteins that can target specific markers on cancer cells, flagging them for immune destruction or delivering toxic agents directly to the tumor. In some cases, a patient's own immune cells are extracted, genetically engineered to target cancer, and infused back into the body — an approach called CAR-T cell therapy. Cancer vaccines are another emerging area. The right type of immunotherapy depends on the cancer type, its molecular profile, and your overall health.

In breast cancer specifically, immunotherapy has shown the most benefit in triple-negative breast cancer, an aggressive subtype that lacks the hormone receptors and HER2 protein targeted by other treatments. Checkpoint inhibitors have been approved for certain triple-negative breast cancer cases, both in early-stage and metastatic settings. Ongoing clinical trials are exploring immunotherapy combinations across other breast cancer subtypes as well.

Immunotherapy represents one of the most exciting frontiers in cancer medicine, and for women with certain breast cancer subtypes — particularly triple-negative breast cancer — it has already expanded treatment options in meaningful ways. If your oncologist mentions immunotherapy as part of your treatment plan, it means your cancer has characteristics that make your immune system a potential ally in fighting it.

Immunotherapy side effects differ from chemotherapy side effects because they stem from immune system activation rather than broad cell damage. Common effects include fatigue, rash, and inflammation in various organs. While most side effects are manageable, some can be serious, so open communication with your care team about any new or changing symptoms is important. Asking about clinical trials is also worthwhile — immunotherapy research is moving quickly, and participation in a trial may give you access to promising new approaches while contributing to knowledge that will help future patients.