Understanding Treatment Response: What Your Scan Results Mean

Response, stable disease, progression-free survival and remission explained in plain language — and the questions to ask your oncologist at each review.

2026-10-086 min readMy Body Healer Editorial Team
Understanding Treatment Response: What Your Scan Results Mean

During treatment with an oral cancer medicine, your oncologist will regularly check how the cancer is responding, usually with scans and blood tests every few months. The words used to describe the results can be confusing. This guide explains the most common terms.

How response is measured

Oncologists usually compare the size of measurable tumours on CT or MRI scans with earlier scans. Blood tests, tumour markers for some cancers and how you are feeling are also taken into account. One scan is rarely judged on its own; the trend over time matters most.

Common terms

  • Complete response: no sign of the measurable cancer on the scan. It does not always mean the cancer has gone permanently, so follow-up continues
  • Partial response: the measurable cancer has shrunk by a meaningful amount
  • Stable disease: the cancer has not grown or shrunk significantly. With targeted therapies, keeping the cancer stable is often an important goal
  • Progression: the cancer has grown or spread. Your oncologist may then discuss changing treatment
  • Remission: a general term meaning signs and symptoms of cancer have reduced (partial) or disappeared (complete)

Why "stable" can be good news

Many targeted therapies, such as tyrosine kinase inhibitors, work mainly by slowing or stopping cancer growth rather than shrinking it quickly. Stable disease on these medicines can mean the treatment is doing its job. Your oncologist will explain what the result means in your situation.

Terms you may hear about treatment trials

  • Progression-free survival (PFS): how long people in a study lived without the cancer growing
  • Overall survival (OS): how long people in a study lived, from the start of treatment

These figures describe groups of patients in research studies. They cannot predict exactly what will happen to one person, because every patient's cancer, health and treatment history are different.

Questions to ask at your review

  • Is the cancer responding, stable or growing?
  • Should we continue the same medicine and dose?
  • When is my next scan and blood test?
  • Are my side effects being managed as well as they can be?

Bring a family member if you can, and write down the answers. It is always reasonable to ask your oncologist to explain a result again.

Important: This article is general information, not medical advice. Always follow the instructions of your oncologist and the patient information leaflet supplied with your medicine. Do not start, stop or change any treatment on the basis of this article.
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