A study comparing outcomes among prostate cancer patients treated with surgery versus radiation therapy found differences in urinary, bowel and sexual function after short-term follow-up—but those differences were no longer significant 15 years later.
The study, led by first author Dr. Matthew Resnick, instructor in urologic surgery at Vanderbilt School of Medicine, was published in the Jan. 31 issue of the New England Journal of Medicine.
From Oct. 1, 1994, through Oct. 31, 1995, investigators enrolled men diagnosed with localized prostate cancer in the Prostate Cancer Outcomes Study (PCOS). For the current study, investigators followed 1,655 men between the ages of 55 and 74.
“At the two- and five-year time points, men who underwent prostatectomy were more likely to suffer from urinary incontinence and erectile dysfunction than men who received radiation therapy,” says Resnick. “While treatment-related differences were significant in the early years following treatment, those differences became far less pronounced over time.” Surgery patients were more likely to wear incontinence pads throughout the 15-year follow-up period.
Despite early and intermediate-term data revealing differences in patterns of sexual dysfunction, after five years both groups had a gradual decline in sexual function. At 15 years erectile dysfunction was nearly universal, with 87 percent in the prostatectomy group and 93.9 percent in the radiotherapy group reporting sexual difficulties. Age may have played a role, as shown in unrelated studies.
Some patients also experienced problems with bowel function in the years following treatment. The radiotherapy group reported significantly higher rates of bowel urgency than the prostatectomy group at two years and five years. At 15 years, though, researchers found no significant difference.
Median life expectancy after treatment for prostate cancer is 13.8 years.
“Patients need to be aware that all aggressive therapies for prostate cancer have significant side effects, and perhaps these data make an argument for active surveillance [avoiding aggressive treatment and closely following the cancer] in certain cases,” says Dr. David Penson, the Paul V. Hamilton, M.D. and Virginia E. Howd Chair in Urologic Oncology and director of the Vanderbilt Center for Surgical Quality and Outcomes Research, the senior study author.
Research funding was supported by a grant from the National Cancer Institute. Resnick was supported by the Veterans Affairs National Quality Scholars Program and the T.J. Martell Foundation.