Watchful waiting is based on the premise that localized prostate cancer may advance so slowly that it is unlikely to cause men any problems during their lifetime.

The most obvious candidates for watchful waiting are older men whose tumors are small and slowgrowing, and who typically have no symptoms

Men who choose watchful waiting are urged to schedule regular checkups, and to immediately report any new symptoms to their doctor. Many who choose this approach live for years with no signs of the disease.

The obvious advantage of watchful waiting is that it spares a man with localized prostate cancer the pain and possible side effects of surgery or radiation. Treatments for prostate cancer may also improve with the passage of time.

A potential disadvantage -- in a society which has been educated to seek treatment early -- is the worry of living with untreated cancer. And watchful waiting also decreases the chance of controlling the disease before it spreads.

But a number of studies have found that for older men, the life expectancy of those who take the watchful waiting approach to prostate cancer is not substantially different from those who choose surgery or radiation.