prostate studies

The study involved about 700 men from Sweden, Finland and Iceland diagnosed early prostate cancer while in their 60s on average.

Half were assigned a radical prostatectomy and half were given a passive "watchful waiting" approach in which they were not immediately given surgery. Later treatment depended on changes in their condition.

After tracking them for an average of about 11 years, 13.5 percent of men in the surgery group died from prostate cancer, compared to 19.5 percent of men in the watchful waiting group.

Dr. Lars Holmberg of the Kings College Medical School in London, who helped lead the research, said that in this study in order to avert one man's death from prostate cancer, about 20 men must undergo radical prostatectomy.

With an estimated 254,000 men dying from prostate cancer annually, it is the sixth leading cause of cancer death in men worldwide, according to the American Cancer Society.

Surgery and other types of treatment such as radiation or hormone therapy pose their own risks and side effects, including urinary, erectile dysfunction and other problems.

The Scandinavian Prostate Cancer Group study was launched in 1989 with hopes of clarifying whether the best way to deal with prostate cancer is patience or aggressive treatment.

The researchers previously published findings after tracking the men for an average of eight years, also seeing a survival benefit for the men who got surgery.

"The gain in terms of prostate cancer mortality from radical prostatectomy still holds out 10 to 15 years after the operation," Holmberg, whose findings appear in the Journal of the National Cancer Institute, said in a telephone interview.

Because the study covered years when many men did not get regular prostate cancer screening using the prostate-specific antigen, or PSA, blood test, Holmberg said the results do not directly address the question of the value of PSA screening.

Studies looking into whether PSA screening saves lives are still ongoing. Some experts note that such screening often can detect tumors that may never threaten the life of the man, and lead to surgery and other treatment that is not necessary.