Every year more than 160,000 men in the U.S. are diagnosed with prostate cancer. For those whose disease is caught early, that diagnosis may come with a decision: Should the disease be treated right now, or is it safe to monitor it and treat it only if it starts to grow?

The latter approach is called active surveillance. It's based on the fact that prostate cancer often grows slowly. So immediate treatment may not always be necessary.

Men who choose active surveillance typically see their doctor about every six to 12 months for digital rectal exams, prostate-specific antigen (PSA) tests and prostate biopsies. These tests are used to monitor the cancer, and treatment—such as radiation or surgery—begins only if the cancer changes or starts to grow.

One potential benefit of active surveillance is that it can help a man avoid or delay potential side effects of treatment, including sexual difficulties and incontinence.

One risk is that the cancer could grow in between tests. Also, the prostate biopsies that are part of this approach can be uncomfortable.

Active surveillance is considered safe. According to experts, men who choose this option usually have a good prognosis, but it isn't for everyone. Active surveillance is more likely a possibility for men with small, slow-growing tumors. Many of these men are also older.

A pathology report can help determine if a man is a candidate for active surveillance based on specific details about his prostate tumor. Doctors also look at other factors, including the cancer's stage and the man's personal and family health history. Of course, preference is also part of the choice—some men, for instance, may not feel comfortable delaying treatment.

The bottom line: Men who think they may want to try active surveillance for prostate cancer should discuss the pros and cons of the plan with their doctor.

Sources: American Society for Clinical Oncology; American Urological Association