Post-prostate cancer treatment erectile dysfunction incidence higher than claimed

August 15, 2008

Studies in the field of sexual dusfunction suggest urologists don't know as much as they think they do about Peyronie's disease and that incidence of erectile dysfunction has other implications.

Key Points

Urologists show gaps in basic knowledge of Peyronie's disease, and often manage this condition by observation or oral medications.

A Weill Cornell Medical College survey of 639 urologists (67% private practice, 33% academic) found significant gaps in respondents' understanding of Peyronie's disease therapy. Of those surveyed, 72% said they used oral agents as first-line treatment and 5% used transdermal agents.

"The definitive therapy for Peyronie's disease is surgery," he concluded.

Other noteworthy findings were that 40% of urologists considered themselves experts in sexual medicine, but only 9% were members of the Sexual Medicine Society of North America (SMSNA).

"We are getting fewer and fewer younger doctors involved in erectile dysfunction and sexual medicine. You can count the members of the SMSNA who perform surgery for sexual dysfunction who are under age 40 on two hands. It does not bode well for sexual medicine," Dr. Mulcahy said.

A high incidence of ED follows Peyronie's disease surgery. The amount of preoperative curvature, type of procedure, patient age, and presence of pre-operative venous leak are risk factors for post-op ED.

Another study, also from Cornell, found that up to 50% of men undergoing plaque incision and grafting for Peyronie's disease can expect to experience some degree of ED following the procedure. Of 56 men undergoing the procedure, 46% exhibited at least a six-point drop in their scores on the International Index of Erectile Function (IIEF) questionnaire. The predictors of this decrease in scores were degree of preoperative curvature (>60 degrees), type of plaque incision (Egydio technique), patient age (>55 years), and baseline venous leak.

Dr. Mulcahy said that many sur geons suggest and many men choose plaque incision and grafting on the assumption that it will not shorten the penis as much as plication techniques will.

"The problem is that there are many urologists who recommend the incision and graft technique, but who do not own up to the fact that there is considerable ED following the procedure," he explained. "They say it is around 10%. This study shows it is around 50%, and the greater the curve, the greater the risk of ED."

Decreased sexuality is common following prostate cancer brachytherapy. Erectile function appears to deteriorate over time, with as many as 71% of men experiencing some form of ED 4 years after the procedure.

ED following brachytherapy for prostate cancer is far more prevalent than oncologists may think or state, this French study indicates. The study of 406 men undergoing brachytherapy found that the percentage of men with severe to mild-moderate ED increased from 32% before therapy to 71% at a mean follow-up of 4 years. Among the patients who had a pretreatment IIEF-5 score higher than 12 (mild-moderate ED), 11% became sexually inactive after treatment, 25% deteriorated by one IIEF category, and 42% declined by two or more categories. Only 2% of men showed improvement.

"I have had oncologists tell me that the rate of ED is low, sometimes less than 5%. They say it is because they have tight control over the [radiation] field. That just is not so. With radical prostatectomy, ED appears immediately. With brachytherapy, it just takes longer to develop. I think this study's data are much closer to the truth," Dr. Mulcahy said.

Initial sexual function and early recovery of postoperative continence indicate sexual function outcomes following nerve-sparing radical prostatectomy.

Two studies looked at predictors of return to sexual function following nerve-sparing radical prostatectomy. One study found that the lower the baseline IIEF score is at 3 months post-op, the less likely the return to full sexual function is. The authors also concluded that while functional erections may return at 9 to 12 months postoperatively, they remain below the starting point. The second study found that the shorter the time to recovery of urinary continence is following prostatectomy, the higher the probability of a return of sexual function is.

"Essentially, [these studies] found that if there is any ED prior to the operation, the chances of having an erection afterward are slim. Some doctors wait until 18 months post-op before treating ED. The study indicates that if erections do not return in 9 to 12 months, they are not going to return,"Dr. Mulcahy said.

"The second study said that the chances of the return of sexual function are much better in men who have an early return of continence."