ATLANTA – At 15 years after treatment, disease-related quality of life measures appear similar in men with prostate cancer, regardless of whether they had radical prostatectomy or external radiation beam therapy.
The significant differences in sexual, urinary, and bowel function that were apparent in the first 5 years, largely disappeared as time advanced, Dr. Matthew Resnick reported, based on a new subanalysis of men in the Prostate Cancer Outcomes Study.
The convergence of outcomes may not have so much to do with treatment type as it does advancing age, he said at the annual meeting of the American Urologic Association. This is especially apparent in erectile dysfunction, according to Dr. Resnick, a urologic surgeon at Vanderbilt University Medical Center, Nashville, Tenn.
"Age really is the most significant determinant of decline in erectile function over time," he said. "About 50% of men older than 70 have erectile dysfunction."
The Prostate Cancer Outcomes Study (PCOS) enrolled patients from six Surveillance, Epidemiology, and End Results (SEER) tumor registries to examine long-term functional outcomes in men who were diagnosed with prostate cancer between 1994 and 1995.
This subanalysis included 1,655 men aged 55-74 years, who underwent either external beam radiation or radical prostatectomy during that period. They filled out quality of life surveys at baseline, and at 6 months and 1, 2, 5, and 15 years after their diagnosis. Since younger, healthier men may be more likely to have surgery, the authors used a propensity score analysis in an attempt to control for age. Most of the group (70%) underwent radical prostatectomy; 30% had radiation therapy.
Overall, men who had surgery were significantly more likely to experience urinary and sexual dysfunction, while the radiation group was significantly more likely to experience bowel dysfunction.
The differences were most obvious early in the follow-up period. At 2 and 5 years after treatment, men in the surgery group were significantly more likely to report erectile dysfunction than those were those treated with radiation. (odds ratio, 3.46 and 1.96 respectively). By 15 years, this difference had disappeared, however.
Men who had surgery were also significantly more likely to report having no sexual activity at 2 years (OR, 1.83), but at 5 and 15 years, there were no significant differences between the groups.
The surgical group was more likely to report urinary dysfunction compared with the radiation-treated cohort. Having no urinary control was significantly more likely at 2 and 5 years (OR, 6.2 and 5.1 respectively), but not at 15 years. Urine leakage was also significantly more likely in the surgery group at 2 and 5 years (OR, 13.0 and 5.5, respectively), but not at 15 years.
The need for pads to stay dry was significantly more likely at both 2 and 5 years for the surgery group (OR, 26 and 12, respectively). The surgery group was still significantly more likely to need pads at 15 years, although the difference was somewhat attenuated (OR, 4.5).
Not surprisingly, Dr. Resnick said, men in the surgery group were also significantly more likely to report being bothered by their urinary problems at 2 and 5 years, (OR, 6 and 7, respectively), but not at 15 years.
Finally, patients who underwent radiation therapy were more likely to be bothered by bowel dysfunction throughout the follow-up period; by 15 years after treatment, bowel issues were 3.4 times more common among this group.
While more studies on long-term functional outcomes are needed, Dr. Resnick said this information can be helpful in pretreatment decision-making – a time when patients need to weigh the risks of impaired function associated with each treatment paradigm.
"In terms of evaluating the patient up-front, we can use this information to elicit their preferences [for treatment]. That is an important piece of the plan."
The study was funded by the National Cancer Institute. Dr. Resnick had no financial disclosures.
*Headline was revised 07/12/12.