Preserving Erectile Function after Prostate Cancer Treatment

From the American Society of Andrology

CHICAGO—Sildenafil (Viagra) and other phosphodiesterase type 5 (PDE-5) inhibitors may help treat erectile dysfunction (ED) in men who have been treated with surgery or radiation for prostate cancer, said John Mulhall, MD, of Cornell Medical Center/Memorial Sloan Kettering Cancer Center, New York City, at the 31st annual conference of the American Society of Andrology. Additional strategies, such as penile rehabilitation, may also help maintain erectile function.

Dr Mulhall noted that the 2 most frequently used treatments for prostate cancer, radical prostatectomy and postoperative radiation therapy, can often lead to ED. In an effort to preserve erectile function, investigators have been evaluating nerve-sparing surgery and medications such as PDE-5 inhibitors.

The response to sildenafil in men who have had prostate surgery appears to depend on the type of surgery. In a study of 174 patients who began treatment with sildenafil at a mean of 3 months after radical prostate surgery, erectile function varied by nerve-sparing procedure. The best response to sildenafil was in men who had bilateral nerve-sparing prostate surgery, with 76% reporting some response. Among men who underwent unilateral nerve-sparing surgery, 53% said they had some response to sildenafil. Response to this medication among men who had surgery that was not nerve-sparing was notably smaller, at only 14%.

“Regular erections following surgery can protect erectile tissue, and chronic PDE-5 treatment has been shown to have some benefit.”

—John Mulhall, MD

J Sex Med

The effects of sildenafil after radiation treatment may be about the same. Dr Mulhall presented data from a nonrandomized trial of 132 men who had functional preoperative erections before undergoing radical prostate surgery for prostate cancer (. 2005;2:532-540). Participants who decided to use medications for regular erectile function postoperatively were given oral sildenafil or intracavernosal injection therapy 2 to 3 times weekly (rehabilitation group); this group was compared with men who opted against such a structured program (the non-rehabilitation group). After 18 months of treatment, men in the rehabilitation group reported significantly better erectile function than those in the nonrehabilitation group.

IMWR.

Dr Mulhall noted that there are a number of strategies that can reduce the likelihood of ED following radical prostatectomy. “Regular erections following surgery can protect erectile tissue, and chronic PDE-5 treatment has been shown to have some benefit,” he told

Additional post–radical prostatectomy treatments for ED that are currently being evaluated include neuromodulatory drugs, such as tacrolimus (Prograf) and erythropoietin (Procrit).

Dr Mulhall stressed the pathophysiologic similarities responsible for ED in men who have undergone radical prostatectomy for prostate cancer and in men who have diabetes. In both cases, injury to nerves, blood vessels, and erectile tissue can all lead to erectile problems. This implies that similar treatments may work for men with ED caused by either process. Dr Mulhall answered the question “Can we extrapolate the data on erectile function protection and preservation in radical prostatectomy to the man with diabetes?” affirmatively, pointing the way for further research in men who have diabetes and ED.