Elderly men who are treated for localized prostate cancer survive significantly longer than peers who are not treated, according to an article in the December 13 issue of the Journal of the American Medical Association.

The widespread adoption of prostate-specific antigen (PSA) screening has led to an increasing proportion of men being diagnosed with early-stage and low- or intermediate-grade prostate cancer. Studies have demonstrated the slow-developing nature of low- and intermediate-grade prostate cancer, making management options controversial, with uncertain outcomes.

The lack of clarity regarding whether or how to treat men who are older than 65 years persists because of a lack of information from randomized trials. When randomized controlled trial data are not available, observational studies can provide insight into important clinical questions, according to background information in the article.

In an observational study, Yu-Ning Wong, MD, of the University of Pennsylvania, Philadelphia, and colleagues evaluated the association of active treatment (radiation or prostatectomy) versus observation on overall survival in a large sample of elderly men treated for low- or intermediate-risk localized prostate cancer. The researchers used data from the nationwide US Surveillance, Epidemiology, and End Results (SEER) Medicare database, a registry encompassing approximately 14 percent of the U.S. population.

This study included data on 44,630 men age 65 to 80 years who were diagnosed between 1991 and 1999 with prostate cancer and who had survived more than a year after diagnosis. Patients were followed until death or study end, December 31, 2002. Patients were classified as having received treatment (32,022 patients) if they had claims for radical prostatectomy or radiation therapy during the first 6 months after diagnosis. They were classified as having received observation (12,608 patients) if they did not have claims for radical prostatectomy radiation or hormonal therapy. Patients who received only hormonal therapy were excluded.

The researchers found that patients who received treatment had a 31-percent lower risk of death during the 12-year follow-up. In the observation group, 4,643 patients died (37 percent) compared with 7,639 patients (23.8 percent) in the treatment group. Active treatment was associated with a significant improvement in survival in the study overall. A benefit associated with treatment was seen in all subgroups examined, including older men (age 75-80 years at diagnosis), black men, and men with low-risk disease.

"In summary, even though prostate cancer commonly is considered an indolent [slow to develop and painless] disease, this observational study suggests a reduced risk of mortality associated with active treatment for low- and intermediate-risk prostate cancer in the elderly Medicare population examined. Because observational data can never be free of concerns about selection bias and confounding, these results must be validated by rigorous randomized controlled trials of elderly men with localized prostate cancer before the findings can be used to inform treatment decisions," the authors concluded.

In an accompanying editorial, Mark S. Litwin, MD, and David C. Miller, MD, University of California, Los Angeles, commented on the findings:

"Improvement in the quality of care for men with prostate cancer may best be achieved not by treating more patients but by treating them more discerningly. Clinicians must remain steadfast in their efforts to reduce over-treatment and under-treatment by thoughtfully defining each patient's unique balance between the natural history of prostate cancer and that individual patient's life expectancy."

"The reported association between treatment and improved survival for older men with low- and intermediate-risk prostate cancer will be confirmed or refuted by the results of ongoing randomized controlled trials … Until then, physicians should apply these provocative findings judiciously and continue their concerted efforts to help patients make informed treatment decisions based not only on survival predictions but also on health status, functional concerns, and-most importantly-personal preference," they wrote.