Active surveillance and observation are wait-and-see approaches to treatment for prostate cancer. They let you avoid or postpone treatments like surgery and radiation that can cause serious side effects.

• Active surveillance. This means that you'll have regular checkups and tests but you won't have treatment unless the cancer gets worse. This may be an option if cancer hasn't spread outside the prostate (localized prostate cancer). In this case, you may never need treatment. Or you may be able to delay treatment and its side effects until tests show that the cancer is growing more quickly.
• Observation. This means that you'll have regular visits with your doctor but fewer tests. The focus is on treating any symptoms that bother you rather than treating the cancer. This may be a good choice if you are too ill to have (or don't want to have) aggressive treatment, such as surgery.

With either option, you can choose to start treatment at any time.