How Will I Know — Chemotherapy Is Working?

These are the four RECIST categories. A complete response means no measurable tumour can be detected on imaging. A partial response means the tumour has reduced in size by a meaningful amount. Stable disease means the tumour has not grown significantly — which is considered a positive outcome for many advanced cancers. Progressive disease means the tumour has grown, or new sites have appeared. Your oncologist will explain which category your result falls into and what that means for your next steps.

Yes, in many situations. For an advanced or widespread cancer, stopping the disease from progressing is a meaningful outcome. It is not the same as shrinkage, but it can mean the cancer is being held in check, which may translate into more time and better quality of life. Whether stable disease is a satisfying result depends on your starting point, your cancer type, and what you and your oncologist are aiming for. Ask your oncologist to explain what it means specifically for you.

Not necessarily, and the answer also depends on which marker and which cancer. Tumour markers can fluctuate for reasons unrelated to tumour response, and some markers temporarily rise when cancer cells are dying and releasing their contents. The marker result is always read alongside your scans and the full clinical picture — not as a standalone answer. If a change in your markers is worrying you, ask your oncologist to explain what the trend means in the context of everything else they are seeing.

Tell your team what has changed, and do not wait for your next scheduled visit if something feels wrong. But do not assume worsening symptoms mean the cancer is growing — chemotherapy causes its own symptoms, including fatigue, pain from mouth sores or nerve changes, and digestive effects, which are separate from tumour activity. New or changing symptoms always deserve reporting, because your team cannot monitor what they do not know about. The rule is simple: any new symptom, or any existing symptom that has changed, is worth a call.

Your oncologist will review the result in the context of your full picture and discuss the options with you. Those may include switching to a different drug regimen, adjusting the current approach, or seeking a second opinion. A result showing that the current chemotherapy is not responding as expected is not the end of options — it is information that redirects the treatment plan. Ask what the alternatives are and what each one aims to achieve. Your oncologist should be able to answer both questions directly.

There is no action that directly changes how the drug acts on the tumour itself. What you can do is protect your body's capacity to complete the planned cycles at the planned doses — which is the most important factor in your care. That means eating as well as you are able, reporting side effects early so they can be managed, staying hydrated, and checking with your team before taking any supplement or herbal preparation, as some interact with chemotherapy in ways that are not obvious. Your team's job is to help you complete the course.