Erectile dysfunction after prostate cancer
Erectile dysfunction occurs most often when prostate cancer is treated surgically.
At a glance
- Erectile dysfunction (ED) occurs more frequently when prostate cancer is treated surgically rather than medically.
- Phosphodiesterase type 5 inhibitors are often used initially for ED following radical prostatectomy.
- Address the medical and psychological issues of ED in conjunction with treatment options early in the disease course.
- Reasons for not seeking treatment include embarrassment, financial instability and threatened masculinity.
With the diagnosis of a localized tumor, many patients choose complete eradication of the cancer by means of radical prostatectomy. In fact, it is generally recognized as the favored treatment for localized prostate cancer in young, otherwise healthy men with high probability of significant life expectancy.4 While this treatment reduces mortality, distant metastasis, and tumor recurrence, it is also associated with possible lifelong side effects. Although it is essential that men with prostate cancer are effectively treated, primary-care providers must keep in mind the possible complications and preservation of function after treatment.
Pathology and epidemiology
Erectile dysfunction (ED) is one of the most devastating long-term obstacles following treatment of prostate cancer, regardless of the management chosen by the patient. ED occurs more frequently when prostate cancer is treated surgically rather than medically.5 Even seven years postoperatively, more than 75% of men struggle with problems related to ED.6 The rate of ED following radical prostatectomy is unpredictable because of such variables as time of assessment, baseline function, and use of pharmacologic or surgical treatments.7 With the increasing use of radical prostatectomy to eradicate localized prostatic carcinoma, providers need to be more aware of this common and distressing adverse effect. It was proposed in a landmark trial that the basis of ED was damage to the cavernous nerves that transmit autonomic neuroregulatory function to the proximal penis and deep pelvis.8 Vascular and smooth-muscle damage during surgery plays a role in pathogenesis as well.9 Despite efforts to reduce incidence (e.g., bilateral nerve-sparing prostatectomy), most men battle with ED after prostatectomy.10
Easy-to-use and inexpensive, phosphodiesterase type 5 (PDE-5) inhibitors are often prescribed following radical prostatectomy. A trial of sildenafil (Viagra) is a sound initial choice for prostate-cancer survivors presenting with ED after surgical treatment. In men treated with the nerve-sparing prostatectomy procedure, sildenafil and other oral PDE-5 inhibitors have been effective.11 Unfortunately, these agents are less effective in prostate-cancer patients following non-nerve-sparing surgical intervention.10 More aggressive management may be needed. Increased dosages of PDE-5 inhibitors have not been found to improve the desired effect of an erection.12 Propionyl-L-carnitine and acetyl-L-carnitine have parallel mechanisms of action to the PDE-5 inhibitors and can be added to sildenafil to increase its effectiveness.12
More invasive treatments such as penile-injection therapy, vacuum devices, and penile-prosthetic surgery have better efficacy in assisting production of erections.10 Penile-injection therapy consists of the introduction of such vasoactive substances as prostaglandins and phentolamine via intracavernosal injection.13 A small study found that penile injections improved not only sexual function in terms of erection after prostatectomy, but satisfaction with the sexual relationship and sexual confidence as well.13 Success rates of penile injections lie within the 75% to 80% range.13
Vacuum devices and penile implants allow anywhere from 90% to 100% of patients to achieve successful sexual intercourse.14 Early use of vacuum-constriction devices after radical prostatectomy allows quicker return to sexual activity.15 Studies have shown early return of erectile function in patients undergoing both nerve-sparing and non-nerve-sparing intervention.11 The penile prosthesis was introduced in the early 1970s by Brantley Scott.16 The basis for Scott's implant is still in use today, with increased reliability, longevity, and improved surgical outcomes attributable to its modifications.
The receptiveness toward more invasive treatments is less than that of oral PDE-5 inhibitors.10 Many prostate-cancer survivors consider vacuum devices and implants unnatural.17 For these men, the recently introduced sural-nerve grafting has shown promising results. Unfortunately, nerve grafting is a technically difficult procedure and has varied reproducibility.18 This surgical procedure employs the concept of a neural conduit to improve the recovery of erectile function.19
Unilateral loss of neurovasculature with subsequent sural-nerve grafting allowed a 78% chance of recovery of erectile function; bilateral neurovasculature loss with sural-nerve grafting procedure allowed a 58% chance.18 Such invasive procedures are not usually within the scope of primary care but are available options to discuss with patients presenting with persistent ED (Table 1).
Providers must realize that ED may be a lifelong complication following prostate-cancer treatment, despite the availability of acceptable management options. After radical prostatectomy, almost 60% of men are unable to maintain firmness for intercourse, and about 44% are completely unable to have erections.1 Providers need to address the medical and psychological issues of ED in conjunction with treatment options early in the disease course. Successfully coping with diagnosis, treatment, and adverse effects can drastically alter personal aspects of quality of life for patients.
From a primary-care standpoint, patient education plays a large part in the treatment and management of a prostate-cancer patient. A survey of prostate-cancer survivors indicated a need for more information concerning the side effects of the cancer itself and its treatments.20 Patients surveyed also placed an importance on sexual function postoperatively. The fact that information concerning management of ED ranked seventh on a list of top unmet needs shows that the side effect and its treatment were not sufficiently presented to a significant number of patients.20 ED might be included on a list of side effects presented to patients in the preoperative period, but discussion of the side effect itself and options for its treatment are often not readily explored.