A new study shows that prostate-cancer surgery, which often leaves men impotent or incontinent, does not appear to save the lives of men with early-stage disease, who account for most cases, and many of these men would do just as well to choose no treatment.

The findings were based on the largest clinical trial comparing surgical removal of the prostate to a strategy known as "watchful waiting."

They add to growing concerns that prostate-cancer detection and treatment efforts in the past 25 years, particularly in the United States, have been woefully misguided, rendering millions of men impotent, incontinent and saddled with fear about a disease that was unlikely to ever kill them. About 100,000 to 120,000 radical prostatectomy surgeries are performed in the United States each year.

The research, published in the new edition of The New England Journal of Medicine, is unlikely to settle the debate about the best course of prostate-cancer care.

An editorial accompanying the report said the study of 731 men is too small to draw definitive conclusions about the relative benefits of radical prostatectomy.

The study included only men with early-stage disease. The findings are not relevant to men with more advanced disease, who may benefit from aggressive treatment, one expert said.

About 28,000 die of prostate cancer each year, the second-biggest cancer killer of men after lung cancer.