The short answer
Active surveillance is close monitoring with exams, PSA tests and biopsies, with treatment given only if test results change.
Active surveillance is close monitoring with treatment starting if the cancer begins to grow, and is different from watchful waiting, which treats symptoms when they appear.
In the ProtecT trial at 15 years, prostate-cancer-specific survival was about 97% across active monitoring, surgery, and radiotherapy.
Metastases were more common with monitoring (9.4%) than after surgery (4.7%) or radiotherapy (5.0%), which is the honest trade-off.
About a quarter of men in the ProtecT monitoring arm were alive with no prostate cancer treatment at all at the end of follow-up.
On this page
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The whole article, with every detail and caution.
This page is for men with low-risk prostate cancer who are weighing active surveillance. It covers what it involves, the evidence behind it, and what can prompt a switch to treatment.
Active surveillance is not doing nothing
Active surveillance is a structured monitoring program. NCI defines it as "closely following a patient's condition without giving any treatment unless there are changes in test results." The aim is to catch signs of progression early.
It is different from watchful waiting. With watchful waiting, the cancer is monitored without treatment until symptoms appear, and treatment is then given to relieve symptoms. With active surveillance, treatment begins when the cancer starts growing. So confirm which one your team is describing.
Why it exists
Surgery and radiation carry real risks. NCI lists erectile dysfunction, urine or stool leakage after surgery, and urinary problems after radiation. Active surveillance is one way to put off those side effects while the cancer is being watched.
The ProtecT trial studied men with localized prostate cancer. It randomly assigned them to active monitoring, surgery, or radiotherapy. At 15 years, prostate-cancer-specific survival was about 97% in all three groups. There were 17 deaths in the monitoring arm, 12 after prostatectomy, and 16 after radiotherapy. Metastases were more frequent with monitoring: 9.4%, versus 4.7% after surgery and 5.0% after radiotherapy. About a quarter of men in the monitoring arm were still alive without any prostate cancer treatment at the end of follow-up.
That is the honest trade-off. Deferring treatment did not increase the chance of dying from prostate cancer over 15 years. It did roughly double the chance of developing metastatic disease. And it spared many men treatment side effects entirely. Reasonable people weigh those differently.
Who is generally considered
Whether active surveillance fits depends on the details of your cancer, your health and your preferences. Your care team is the right place to find out whether it is an option for you.
What the monitoring looks like
NCI says active surveillance involves regular exams, including a digital rectal exam, PSA tests and biopsies. Programs vary between centers, so ask for the written schedule.
What triggers a change
NCI describes treatment as starting when test results change and the cancer starts growing. Ask your team exactly which findings would prompt a treatment discussion for you. You can also raise treatment yourself at any time.
Living with it
The demands are real. There are appointments and repeat tests. And you hold a cancer diagnosis without treating it. If the monitoring is causing you worry, tell your team.
Worth asking
- Am I being offered active surveillance or watchful waiting?
- Can I have the written protocol: what tests, how often, and for how long?
- What specific findings would trigger treatment?
- Which tests are part of my program?
- What happens to my treatment options if I defer for several years?
Sources
Common questions
Is active surveillance the same as watchful waiting?
No. NCI describes active surveillance as close follow-up with tests such as PSA, exams and biopsies, with treatment starting if the cancer begins to grow. Watchful waiting means monitoring without treatment until symptoms appear, then treating to relieve symptoms. Confirm which your team means.
Am I taking a risk by not treating now?
There is a real trade-off. In ProtecT, deferring treatment did not increase prostate cancer death over 15 years, and it roughly doubled the chance of developing metastatic disease, while sparing many men treatment side effects entirely. Reasonable people weigh those differently, and it is your call to make with your team.
What would make me switch to treatment?
NCI describes active surveillance as following the condition closely without treatment unless there are changes in test results. Ask your team which results (such as PSA, exam or biopsy findings) would prompt a treatment discussion for you.
Can I stop surveillance if the anxiety is too much?
Tell your team. Living with a cancer diagnosis without treating it can be stressful, and your team can talk through your options, including treatment, with you.
Questions to ask your doctor
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Written by: Cancer ExplainedSources last checked: 2026-07-30 what this meansLast updated: 2026-10-16Next planned review: 2027-01-30
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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