Observation or Active Surveillance for Prostate Cancer

Not all prostate cancers are the same. Some can grow quickly, but others tend to grow very slowly. Some men with slow-growing prostate cancers, especially men who are older or have other serious health problems, might never need treatment. Instead, their doctors may recommend active surveillance or observation (sometimes called watchful waiting).

What is the difference between active surveillance and observation?

The difference between active surveillance and observation is usually in how many tests are done. No matter which term your doctor uses, it’s very important for you to understand exactly what they mean when they refer to it.

Active surveillance usually means monitoring the cancer closely, with a plan to treat it if tests show that it's starting to grow faster. Usually, this approach includes doctor visits with:

• A prostate-specific antigen (PSA) blood test about every 3 to 6 months
• A digital rectal exam (DRE) about once a year

Sometimes other tests are done, including:

• Prostate biopsies and imaging tests every 1 to 3 years
• Imaging with multiparametric MRI (mpMRI), which can sometimes reduce how often biopsies are needed

How often tests are done can be adjusted based on your situation and preferences. If your test results change, your doctor will then talk to you about treatment options to try to cure the cancer.

Observation (watchful waiting) is a less intensive type of follow-up. It involves fewer tests and relies more on noticing changes in symptoms to decide whether treatment is needed. This is more often a good option for men who are older or have other serious health problems.

When are these options used?

Your doctor might recommend one of these approaches, or offer it as an option, if your cancer:

• Isn’t causing any symptoms
• Is small and confined to the prostate
• Is expected to grow slowly, because it’s in the very low-, low-, or favorable intermediate-risk group, and/or based on results from a molecular test of the cancer cells. To learn more, see Risk Groups and Lab Tests to Help Determine Risk from Localized Prostate Cancer.

These approaches are not likely to be good options if you have a fast-growing cancer or if the cancer is likely to spread outside the prostate.

The main advantage of active surveillance and observation is that some men with slow-growing cancers can avoid, or at least delay, treatments like surgery or radiation, which can cause bothersome side effects. Many of these men will never need treatment. If they do eventually need treatment, the delay is unlikely to affect how long they live.

What are the risks of active surveillance and observation?

In some cases, biopsies may later show the cancer is growing faster than first thought. This might happen because the initial biopsy missed a faster-growing part of the cancer, or because the cancer changed over time and became more aggressive. In either case, the cancer might be harder to cure than if it had been treated right away.

These approaches also require lifelong doctor visits and tests to monitor the cancer, especially with active surveillance. These visits and tests can be time-consuming, and waiting for test results can cause anxiety.

Some men may also feel uncomfortable knowing they have cancer in their body, even if it’s unlikely to ever cause problems. This concern is sometimes the reason people choose treatment instead of active surveillance or observation, even if the treatment will likely cause effects and is unlikely to help them live longer.

Comparing active surveillance and treatment

We don’t have results from large studies directly comparing active surveillance with treatment for slow-growing prostate cancer. But some studies have compared slightly different groups.

For example, studies have compared observation (with less intense follow-up than active surveillance) versus treatment. Some of these studies also included men who would now be considered at higher risk, and therefore likely wouldn’t be offered active surveillance today.

Based on the studies done so far, it doesn’t appear that men who are treated right away are likely to live any longer than men who choose active surveillance.

Improvements in active surveillance

There are still some questions about active surveillance. But in recent years, it’s become easier for doctors to decide who might benefit from it. This is because of recent advances including:

• The development of risk groups and molecular tests
• Improved imaging tests, such as multiparametric MRI (mpMRI)

Doctors also continue to refine the best ways to monitor men who are on active surveillance, so they get the necessary tests to look for cancer progression while not being tested too often.