Among men, prostate cancer is the most commonly diagnosed nonskin cancer; each year about 200,000 men are diagnosed with the disease. Despite its prevalence, doctors still don't know how best to treat the disease, such as whether surgery or radiation therapy is a better treatment. The Prostate Cancer Outcomes Study, initiated by the National Cancer Institute a decade ago with participants from around the country, is one of the best sets of data about the long-term outcomes of men with prostate cancer. Researchers from the NCI used the data to determine the effects of surgery versus radiation years after treatment.

What they wanted to know: How do the side effects of prostatectomy compare with radiation therapy five years after treatment?

What they did: Out of the 3,500 men who participated in the Cancer Institute's study, the researchers used information from about 1,200 who were between the ages of 55 and 79, were treated with either a radical prostatectomy or external beam radiotherapy, and returned a follow-up survey sent out by the researchers five years after the men were initially diagnosed. Participants were asked about their urinary, bowel, and sexual functioning as well as about their perception of their condition.

What they found: Neither of the procedures was a clear-cut favorite, with both showing negative side effects. Patients who had a prostatectomy were more likely to report urinary incontinence, and trouble achieving erection, but patients who had radiation therapy were more likely to report bowel problems (though neither group was very concerned about bowel problems). There is some nuance to these results, however; fewer men were incontinent after radiation therapy but more reported difficulty urinating. In addition, men who had undergone radiation therapy were much more likely to report impotence in the five-year follow-up than they were in the two-year, while impotence declined during that period of time for prostatectomy patients..

What it means to you: There's still no clear advantage to one treatment over another, and patients should discuss their options with doctors and families. Overall, after treatment, less than half of the participants were bothered by urinary and bowel side effects, and just over 50 percent were frustrated by sexual side effects five years after treatment—which isn't bad, considering they'd had prostate cancer.

Caveats: When the researchers sent out the questionnaires, they got back fewer responses from young men who had radiation treatment than from older men. So, because these men would be less likely to have certain dysfunctions than older men, it could have skewed the results for problems from radiation therapy. In addition, these patients were all treated between 1994 and 1995; treatments have improved since then and side effects may be different now.

Find out more: The National Cancer Institute has a Web page with information about treatment options for prostate cancer.

The NCI conducted the Prostate Cancer Outcomes Study, the source of data in this article, and has more information on its website: http://www.cancer.gov/newscenter/pcos

Read the article: Potosky, A.L. et al. "Five-Year Outcomes After Prostatectomy or Radiotherapy for Prostate Cancer: The Prostate Cancer Outcomes Study." Journal of the National Cancer Institute. Sept. 15, 2004, Vol. 96, No. 18, pp. 1358-1367.

Abstract online: http://jncicancerspectrum.oupjournals.org