Five years after surgery for prostate cancer, African-American men reported better sexual and urinary function than non-Latino white men-yet they were also more dissatisfied with problems related to their sexual function, according to researchers from the Keck School of Medicine of the University of Southern California and colleagues.
Investigators report the latest results from the expansive Prostate Cancer Outcomes Study (PCOS), a National Cancer Institute-supported study encompassing nearly 3,500 prostate cancer patients, in the Oct. 15 issue of the Journal of Clinical Oncology. The study is one of the nation's largest and most representative on quality of life after prostate cancer.
The six-center research team followed up on men from six cancer registries across the country who were diagnosed with prostate cancer between 1994 and 1995. Researchers interviewed the men about their lives at regular intervals after diagnosis.
In this section of the study, researchers studied 1,475 non-Latino white, 321 African-American and 279 Latino prostate cancer patients who were treated through prostate surgery (prostatectomy) or radiation therapy. They asked the men about changes in their urinary, bowel and sexual function in the years after diagnosis; they also asked how much of a problem such changes in function posed in the men's lives.
"We found that African-American men had significantly higher sexual and urinary function five years after prostatectomy than non-Latino white men," says Ann S. Hamilton, Ph.D., assistant professor of preventive medicine at the Keck School and the study's senior author. However, when researchers asked how much patients' change in sexual function bothered them, Hamilton says, "The African-American men indicated slightly more bother. We couldn't really explain why that might be."
Although several studies, including PCOS, have examined the prevalence of sexual, urinary and bowel problems after prostate cancer surgery, radiation therapy and other treatments, this study is the first to look at such issues within ethnic groups.
Because African-American men have tended to have worse outcomes after prostate cancer treatment, researchers suspected they might have reduced function, as well. Results were surprising.
Researchers found that five years after surgery, nearly 44 percent of African-American men had erections firm enough for sexual intercourse; only about 22 percent of their non-Latino white prostatectomy counterparts could say the same. However, nearly 38 percent of African-American men reported that their sexual function was a moderate-to-big problem, compared to 35 percent of non-Latino white men.
The team controlled for many factors that might affect results, such as secondary treatments, income level and age, but differences among ethnic groups persisted. Terri Kang Johnson, doctoral student in biostatistics at the Keck School, was the study's first author and conducted these complex analyses. Other members of the USC research team include Frank Gilliland, M.D., Ph.D., David Penson, M.D., M.P.H., and Dennis Deapen, Dr.P.H.
"There may be differences among ethnic groups in their perceptions of function," Hamilton proposes.
The researchers also found that while about 28 percent of Latino men who underwent prostatectomy reported having erections firm enough for sexual intercourse, more than 54 percent of them reported sexual function as a moderate-to-big problem.
Researchers say results indicate that significant side effects continue to affect men long after treatment. "In the end, what might be important is actually how the therapy affects each man," Hamilton says. "In terms of counseling men for side effects, perhaps there may be additional care that could be taken in discussing sexual side effects."
Interestingly, men from different ethnic and racial groups who were treated through radiation therapy experienced no significant differences in their recovery of sexual, urinary or bowel function after treatment, Hamilton says. The radiation therapy group included those who had received external beam radiation therapy, as well as those who underwent brachytherapy-the use of radioactive "seeds." Researchers caution, though, that their sample size might not have been large enough to discern differences among ethnic groups in those receiving radiotherapy.
Hamilton notes that among African-American men, more patients tend to opt for radiation therapy. "There is a perception that enters into the choice of radiotherapy-that it will have less effect on sexual function," she says.
Yet men in PCOS who underwent prostate cancer surgery reported worsened sexual function six months after surgery, but then experienced gradually recovering sexual function through the five-year mark. Men who received radiation therapy actually saw their sexual function gradually decline throughout the five years following surgery.