Loss of some sexual function is a common concern among men undergoing radiation therapy for prostate cancer. In this type of therapy, high-energy beams of radiation or radioactive seeds are used to eliminate tumors. Recent advances in the precision of radiation therapy have reduced the risk for complications, but side effects such as erectile dysfunction (ED) are still an issue for many men.
According to results from a recent multicenter study, however, the use of an oral erectile function medication before, during, and after radiation therapy for prostate cancer may help reduce side effects related to sexual dysfunction. Memorial Sloan Kettering radiation oncologist Michael J. Zelefsky presented the findings of the prospective trial at the annual American Society for Radiation Oncology (ASTRO) meeting in Boston on October 29, and the results are being submitted for publication in the coming months.
“This is a good first step in an effort to help patients find ways to improve their quality of life after treatment,” Dr. Zelefsky says.
A Multicenter Trial
In the clinical trial, 290 men treated at Memorial Sloan Kettering and three other New York–area hospitals were randomly assigned to receive either a placebo pill or a 50 milligram daily dose of sildenafil citrate (Viagra®) for three days before radiation treatment and continued daily for six months after treatment. Following the six months, the pill was taken on an as-needed basis. Men in the study had cancer confined to the prostate, and had not received previous treatment (including hormone therapy).
The participants were also asked to complete a set of questionnaires to assess their sexual function, which included questions about erectile function, ability to orgasm, sexual desire, satisfaction with intercourse, and overall sexual satisfaction. Their feedback was recorded before the first radiation therapy treatment, and at six, 12, and 24 months after treatment.
In total, 144 patients completed the questionnaires. An analysis of their responses showed that those who were prescribed Viagra before, during, and after treatment reported better overall sexual function, erectile function, sexual desire, and intercourse satisfaction after therapy. The most significant improvements were seen at the six- and 12-month marks, with a slight drop in improvement at the 24-month mark.
Continuing to Improve Sexual Health for Patients
Dr. Zelefsky, along with urologic surgeon John P. Mulhall, director of the Male Sexual and Reproductive Medicine Program, and colleagues, points out that additional randomized trials will be needed to corroborate the findings and better define how long men should take the drug.
“A drop at the 24-month mark suggests that future trials should be conducted to demonstrate whether giving the drug for a longer period of time can further improve patient outcomes,” says Dr. Zelefsky. “In the meantime, we encourage physicians to discuss with their patients the potential benefit of this approach, which could be used to lessen the degree of erectile function loss that may occur after radiotherapy.”