In a follow-up study spanning almost 20 years, researchers found that surgery does not decrease mortality outcomes in patients with localized prostate cancer. In fact, the results showed that surgery is associated with a higher frequency of adverse events, such as infection, urinary incontinence, and erectile dysfunction.

The study, “Follow-up of Prostatectomy versus Observation for Early Prostate Cancer,” was published in The New England Journal of Medicine.

Previously, the team of researchers at Washington University School of Medicine, led by the Minneapolis Veterans Administration Health Care System, had found no significant differences in mortality when they compared men with localized prostate cancer who underwent surgery with those who received observation only. Now, researchers extended their analysis to evaluate surgery effects in terms of nonfatal health outcomes and long-term mortality.

In one of the largest trials conducted with cancer patients, the Prostate Cancer Intervention Versus Observation Trial (PIVOT, NCT00007644) researchers randomly assigned 731 men with localized prostate cancer to radical prostatectomy or observation. The observation group was treated only if they developed symptoms, including urinary difficulty or bone pain, which may indicate cancer progression.

Patients, all less than 75 years of age, were followed during 19.5 years and in this period researchers registered a death toll of 61.3 percent (223 of 364 men) in the group assigned to surgery and 66.8 percent (245 of 367) in the observation group. The analysis showed there was no statistical significant difference in mortality between the groups.

The number of deaths due to prostate cancer reached 7 percent (27 men) in the surgery group, while this number was 11 percent (42 men) in the observation group, but this difference, once again, was not significant statistically.

Surgery, researchers found, may carry benefits relative to observation in men with intermediate-risk prostate cancer but not for those with low-risk disease. PSA scores of 10-20 ng/ml and a Gleason score of seven (a system of grading prostate cancer tissue based on how it looks under a microscope) constitute an intermediate risk.

It would be a disservice to dismiss surgery as a viable option for patients with intermediate-risk prostate cancer,” study co-author Gerald L. Andriole, MD, director of Washington University’s Division of Urologic Surgery, said in a press release. “For these patients, and for some men with high-risk prostate cancer, surgery is often beneficial, as are other treatments such as radiation,” said Andriole, who is the School of Medicine’s Robert K. Royce Distinguished Professor of Urologic Surgery.

Treatment for disease progression was less frequently required in the surgery group than the observational group, but urinary incontinence and erectile and sexual dysfunction were more prevalent in the surgery group when compared to controls.

“The benefits of surgery also need to be balanced against the negative long-term consequences of surgery that occur early and often,” said study lead author Timothy Wilt, MD, a physician-researcher with the Center for Chronic Disease Outcomes Research at the Minneapolis VA Health Care System and a professor of medicine at the University of Minnesota.

“Our results demonstrate that for the majority of men with localized prostate cancer, selecting observation for their treatment choice can help them live a similar length of life, avoid death from prostate cancer and prevent harms from surgical treatment,” Wilt added. “Physicians can use information from our study to confidently recommend observation as the preferred treatment option for men with early prostate cancer.”