By: Dan Sperling, MD
Weyne et al. (2015) observe that since Patrick Walsh’s development of nerve-sparing radical prostatectomy (RP), “…a large proportion of men still suffer from erectile dysfunction (ED) as a complication of prostatectomy.”[i] To illustrate how large, this article summarizes data from recently published research on the incidence of post-RP ED.
It is a fact of life that the organic risk of ED unrelated to prostate cancer (PCa) or PCa treatment increases as men age. Johannes et al. (2000) described their longitudinal study of 847 men with no self-reported ED at baseline (study entry point, age range 40-69 years old).[ii] They found that the annual incidence rate of new cases increased with each decade. Incidence was reported as number of new cases per 1,000 man-years as follows:
Age 40-49 12.4 cases per 1,000 man-years
Age 50-59 29.8 cases per 1,000 man-years
Age 60-69 46.4 cases per 1,000 man-years
They also found that the age adjusted risk of erectile dysfunction was greater for men with lower education, diabetes, heart disease and hypertension.
Patients diagnosed with localized PCa are routinely evaluated regarding their baseline erectile function before treatment in order to assess the side effect rates compared with baseline, and the duration of ED from recovery onward. An Australian prostate cancer-specific study by Ong, et al. (2015) evaluated baseline rates of ED prior to brachytherapy for localized PCa.[iii] Patients who took the International Index of Erectile Function (IIEF) questionnaire before treatment were included in their data. The men were classified according to their IIEF scores:
No ED 335 men (48%)
Mild ED 129 men (17%)
Mild-moderate ED 42 men (6%)
Moderate ED 37 men (5%)
Severe ED 165 men (24%)
As in the first study, the authors discuss age, diabetes, and hypertension as increased risk factors. It is reasonable to assume that these pretreatment ED rates are representative of the whole population of men between the ages of 40-70 who are diagnosed with prostate cancer. It is also expectable that in longitudinal studies with follow-up greater than 5 years, post-RP ED may involve additional factors besides the impact of the surgery on nerve function: aging, co-existing medical conditions that naturally diminish sexual function, post-treatment psychological or emotional factors, etc. Even allowing for such influences, however, the reported numbers of post-RP ED are less than encouraging regardless of surgical technique (open RP, laparoscopic RP, robotic RP).
Schiavina et al. (2014) presented long-term follow-up (5-10 years) on 112 patients who had nerve-sparing radical retropubic prostatectomy at their institution.[iv] “Of the 112 patients who underwent nerve-sparing RRP, 22 (19.6%) were fully potent without aids (P0), 13 (11.6%) were potent with assumption of PDE-5 inhibitors[v] (P1) and 77 (68.8%) experienced erectile dysfunction (P2).”
Rates even greater than 68.8% were calculated at 12 months post-RP by Haglind et al. (2015) with a large study population of 2431 patients.[vi] While the purpose of their study was to compare robotic RP with open RP, the end point of self-reported sexual function at one year post-treatment is illuminating. In their experience, 1200 post-robotic RP patients (70.4%) had ED compared with 531 post-open RP patients (74.7%). While the difference between robotic and open surgery ED rates was not significantly significant, it is important to note that the similar ED rates suggest that up to three quarters of surgery patients will be faced with ED as a side effect.
A very large study with a median of 12 year follow-up by Carlsson et al. (2015) involved data from 3937 patients who were matched with 459 non-prostate cancer patients as controls.[vii] This is an important piece of research due to the number of cases, the inclusion of matched controls, and the duration of follow-up. Patients were < 70 years old at diagnosis, and a validated self-report questionnaire was used to gather patient data on sexual function. At 12 years following diagnosis, 87% of men had ED or were sexually inactive, compared with 62% of the control group who did not have PCa. The authors used the term “substantial” to describe the long-term impact on sexual function after treatment.
It is no wonder that there is growing interest in partial gland prostate cancer treatment approaches as a way to preserve sexual function. Aside from active surveillance, which has no impact on potency, the trend toward ever-more targeted treatments, such as focal laser ablation, provides a rational middle ground between radical vs. no treatment, one that preserves quality of life while controlling the cancer.
[i] Weyne E, Castiglione F, Van der Aa F et al. Landmarks in erectile function recovery after radical prostatectomy. Nat Rev Urol. 2015 May;12(5):289-297. doi: 10.1038/nrurol.2015.72. Epub 2015 Apr 14.
[ii] Johannes CB, Araujo AB, Feldman HA et al. Incidence of erectile dysfunction in men 40 to 69 years old: longitudinal results from the Massachusetts male aging study. J Urol. 2000 Feb;163(2):460-3.
[iii] Ong WL, McLachlan H, Millar JL. Prevalence of Baseline Erectile Dysfunction (ED) in an Australian Cohort of Men with Localized Prostate Cancer. J Sex Med. 2015 May;12(5):1267-74. doi: 10.1111/jsm.12867. Epub 2015 Apr 1.
[iv] Schiavina R, Borghesi M, Dababneh H et al. Survival, Continence and Potency (SCP) recovery after radical retropubic prostatectomy: a long-term combined evaluation of surgical outcomes. Eur J Surg Oncol. 2014 Dec;40(12):1716-23. doi: 10.1016/j.ejso.2014.06.015. Epub 2014 Jul 18.
[v] PDE-5 inhibitors are a class of drugs that include Viagra®, Cialis® and Levitra®.
[vi] Haglind E, Carlsson S, Stranne J et al. Urinary Incontinence and Erectile Dysfunction After Robotic Versus Open Radical Prostatectomy: A Prospective, Controlled, Nonrandomised Trial. Eur Urol. 2015 Mar 11. pii: S0302-2838(15)00194-3. doi: 10.1016/j.eururo.2015.02.029. [Epub ahead of print]