33 Treatment of Therapy Complications
The management of prostate cancer has evolved rapidly over the last few decades. The focus of this section is on the complications associated with definitive treatment of the primary disease with surgery or radiation therapy (RT). Both of these modalities can have significant effects on urinary continence and erectile function. Generally, the functional side effects of surgery are immediate and improve with time, whereas the long-lasting side effects of RT can gradually worsen over time. A recent report of quality of life outcomes in men undergoing both primary modalities in the Prostate Cancer Outcomes Study (PCOS) indicate similar rates of urinary and erectile complaints at 15 years (1).
Urinary incontinence can be seen after both prostatectomy and RT. The physical removal of the prostate gland and associated trauma invariably alter flow dynamics of the bladder outlet. Injury to the external urinary sphincter and loss of the constrictive effect created by the prostate and bladder neck paves the way for stress urinary incontinence (SUI). RT can alter the outlet through gradual fibrosis and potential for urethral stricture formation. Both surgery and RT can alter detrusor muscle function and lead to or unmask irritative voiding symptoms, such as urinary urgency and frequency.
34Systematic reviews of postprostatectomy data have shown that the rates of SUI after surgery are highly variable and depend on many factors, both patient and surgeon related. The incidence of SUI has been reported to range from 7% to 40% after open surgery and 4% to 31% after robotic intervention (2). Irritative symptoms affect up to 25% or more of men who receive prostate RT, but long-term urinary irritative symptoms are less common, affecting 5% to 10% of men. Studies show that the rates of urethral scarring are quite close when comparing brachytherapy and external beam radiation therapy (EBRT). Current data show that stricture rates stand at 1.8% and 1.7%, respectively (3). Alongside strictures, bladder dysfunction has also been observed in patients receiving EBRT. Studies have shown that scatter radiation can reduce bladder filling capacity (4), which can impair bladder compliance and induce urinary frequency and hyperreflexia.
The irritative symptoms can often be managed with dietary and lifestyle modifications, followed by medical therapy such as anticholinergic agents. Stress incontinence can be mitigated with Kegel exercises and pelvic floor therapy. If stress incontinence persists beyond 12 months after surgery and is bothersome, surgical interventions are available, including urethral bulking agents, urethral sling placement, and artificial urinary sphincter prosthesis placement (5). In the case of posttherapy urethral stricture disease that affects a patient’s emptying, surgical options include urethral dilation, endoscopic visual urethrotomy, or urethroplasty reconstructive surgery (6).
One of the biggest concerns for men after prostatectomy is erectile dysfunction. The prostate facilitates ejaculation, removing the ability for emission of seminal fluid after surgery. Additionally, the cavernosal nerves that provide autonomic regulation of erections travel in the fascial layers on the lateral aspect of the prostate gland and are at risk of injury with surgery or any energy delivery modality such as radiation or ablation. Significant data have been reported on the predictors and mechanisms of erectile dysfunction; however, vast variation exists and definitive conclusions are hard to reach. An extensive literature review indicates that rates of complete erectile dysfunction after surgery 35(refractory to all medical therapy) range from 26% to 100% and rates of partial erectile dysfunction range from 16% to 48% (7). Data demonstrate that it can take on average up to 24 months to fully recover erectile function after surgery, and RT can cause continued fibrosis and loss of function with time. Some recent data have shown that patients have reported a greater magnitude of erectile dysfunction with EBRT compared to brachytherapy (8), but this subject continues to warrant further investigation.
Surgical technique has undergone refinements with a better understanding of preservation of the neurovascular bundle. During nerve sparing surgery, emphasis is placed on careful dissection and maintenance of three neurologic focal points: proximal neurovascular plate, predominant neurovascular bundle, and accessory neural pathways (9). Literature shows that in major academic centers, erectile function recovery occurs at rates ranging from 60% to 85%. Currently, many surgeons have instituted programs of postsurgical penile rehabilitation, to include use of phosphodiesterase type 5 (PDE-5) inhibitors and other methods, as a means of improving the time to recovery (10). Management of erectile dysfunction proceeds stepwise from oral medication (PDE-5 inhibitors), to intra-urethral medication and intra-cavernosal injections, and finally to penile prosthesis placement.
Impotence also remains an important pathological consequence of radiotherapy. Scatter radiation has potential to affect pelvic nerve bundles and diminish erectile function as well as to damage local tissue that is important in both erection and ejaculation.