Management of erectile dysfunction after radical treatment of prostate cancer

Abstract

There has been a great evolution in the field of male erectile dysfunction after the establishment of factors that play major roles in the penile erectile physiology. Any disorder affecting these factors which include vessels, smooth muscle, neurotransmitters and hormones may alter the erections of a healthy man. Erectile dysfunction caused by any cancer treatment modality has a great impact on quality of life. Preservation of potency remains a primary concern in patients' decision for different treatment options in localized disease. Therefore, preoperative patient counseling should be one of the most important goals of the physician to reach satisfactory results in terms of quality of life. In this article, management of erectile dysfunction after treatment with curative intent in prostate cancer has been summarized and current knowledge on this topic has been reviewed. The primary goal of the treatment modalities in early stage prostatic carcinoma is to achieve a curable state for the disease. On the other hand, post-prostatectomy or post-radiotherapy impotence has been a major detrimental issue on quality of life of patients who undergo one of those treatment modalities. Before the pioneering study of Walsh and Donker in 1982, nearly all patients were impotent after radical prostatectomy (1). With the help of studies revealing precise localization of nerves responsible for erections in man, it has been possible to maintain potency in many patients undergoing radical prostatectomy (1-4). Although these encouraging results give insights into the etiology, clinical studies have also suggested that up to 50% of patients impotent after a nerve sparing radical prostatectomy have a vasculogenic etiology (5-6) which further creates question marks about the exact etiology of erectile dysfunction in this patient population. Interestingly, Breza et al. found in a series of meticulous anatomical dissections that there is great variation in penile arterial supply (7). There are also some additional factors that play important roles in the recovery of erections after radical prostatectomy. It has been demonstrated in different studies that patient age has a great impact on the recovery of potency after radical prostatectomy (8-9). This finding may be due to age-associated poorer cavernous nerve regeneration and atherosclerosis (8) and/or due to the presence of extensive disease in older patients which may further prevent the preservation of cavernous nerves (10). The recovery of sexual function also correlates inversely with the extension of the disease so that advanced pathologic disease has a negative impact on erectile function after radical prostatectomy (11). It has been reported in the literature that radiotherapy-associated impotence occurs in 14 to 50% of treated prostate cancer patients (12-15), Unfortunately, there is not enough data to explain the mechanism that causes impotence after irradiation. Goldstein et al. have suggested that underlying mechanism of radiation associated impotence may be secondary to endarteritis of the branches of the internal pudendal and penile arteries (15). Functional changes in the pudendal nerve or endocrine secretions were also considered as causative events (16). All these data suggest that there is a strong need for the research regarding erectile dysfunction after radiation therapy. It is obvious that despite improvements in the surgical technique and development of better delivery systems for radiation therapy, there will still be patients suffering from treatment-related impotence. Giving the appropriate information to the patient regarding the erectile dysfunction after radical prostatectomy or radiation therapy should be one of the primary concerns of the phycision to reach the expectations of both the patient and the partner.