Adjuvant and Neoadjuvant — Targeted Therapy Explained

Adjuvant comes from a Latin root meaning 'to help'. In oncology, it describes any treatment given after the primary treatment — usually surgery — to reduce the risk of the cancer returning. Adjuvant targeted therapy means targeted therapy given after surgery, with the specific aim of treating cancer cells that surgery could not detect or remove. Receiving adjuvant therapy is standard practice in many cancer types, not a sign that something went wrong in surgery.

Neoadjuvant targeted therapy is most commonly given before surgery to shrink the tumour, making the operation safer or less extensive. A smaller tumour can allow surgeons to remove the cancer more completely and, in some cases, preserve more surrounding tissue. Giving the drug before surgery also lets your oncologist see how your cancer responds — information that can guide decisions about what comes after surgery. In rare situations, shrinking is needed before surgery becomes possible at all.

The duration varies considerably depending on your cancer type and the specific drug. NCCN and ASCO guidelines set the recommended duration for each cancer type and drug combination, and your oncologist will give you a planned timeline before treatment begins. The length is decided at the start — you are not weighing it up month by month. Ask your team for the full expected timeline so you can plan around it from the beginning.

Neoadjuvant targeted therapy does not usually replace surgery — it is designed to prepare for it. In a small number of cases, a tumour shrinks so completely that no residual cancer is found when surgery is performed; this is called a pathological complete response. Even then, surgery still goes ahead in most cancers, because imaging alone cannot confirm that all cancer cells have gone. Whether a watch-and-wait approach might ever apply to your situation is a specific question for your oncologist.

No. Both are given after surgery to reduce the risk of recurrence, but they work differently. Chemotherapy affects all rapidly dividing cells, which is why it causes side effects in hair, gut lining, and bone marrow. Targeted therapies work on specific molecular changes present in your tumour, so the side-effect profile is different. Whether you receive one, both, or neither depends on your cancer type, the molecular profile of your tumour, and your overall fitness.

Not exactly. Surgery aims to remove all visible cancer, and in most cases it does. But even after a complete operation, microscopic cancer cells can remain that neither imaging nor pathology can detect. Adjuvant therapy treats that possibility — it is a precautionary step based on what is known about your cancer type, not evidence that visible cancer was left behind. In many cancers, adjuvant treatment is planned before surgery even happens, as a standard part of the overall treatment pathway.

Yes, and for some cancer types this combination is standard. You might receive targeted therapy before surgery to shrink the tumour, then continue with the same or a different drug after surgery to consolidate the response. The post-surgery decision often depends on how the tumour responded to the pre-surgery course — a good response may support continuing the same drug; a poor response may prompt a switch. Your oncologist will explain the plan at both stages, so you know what to expect throughout.

Targeted therapy is administered as day care at CION centres. If adjuvant or neoadjuvant targeted therapy is part of your plan, your oncologist will confirm which centre is appropriate for you. Response-assessment scans — such as PET-CT used to evaluate how neoadjuvant therapy is working — are coordinated with partner imaging centres. CION does not provide CAR-T or cell therapy; if that is being considered for your situation, you would be referred to a centre that does.