(387) Evaluating Bias Against Prostate Cancer Survivors in Clinical Trials for Erectile Dysfunction

Abstract

Abstract Introduction Approximately 250,000 men are diagnosed with prostate cancer every year in the United States with 90,000 radical prostatectomies (RP) performed yearly. Erectile dysfunction (ED) is a common side effect following prostate cancer therapies. The estimated incidence of erectile dysfunction (ED) varies in the literature after RP, however some studies have reported percentages as high as 75%. It is unclear whether there is exclusion bias among clinical trials evaluating erectile dysfunction therapies against prostate cancer survivors. We were interested to determine if clinical trials for ED had specific criteria that would exclude prostate cancer survivors. Objective To investigate how previous and current clinical trials evaluating ED interventions exclude prostate cancer survivors from enrollment. Methods We reviewed all registered trials under the category of “Erectile Dysfunction” on the website “clinicaltrials.gov”. Studies were excluded if an intervention for ED was not tested or if evaluation of ED was not a primary outcome. Exclusion criteria were examined for radical prostatectomy, androgen deprivation, pelvic radiotherapy for prostate cancer, or a history of prostate cancer whether treated or not. Results A total of n = 545 trials were reviewed. 169 trials were excluded because the primary end point did not assess ED outcomes. Thus, 376 trials were analyzed further for relevant exclusion criteria. Of the 376 trials, 48 (12.8%) were specifically for patients undergoing or status post radical prostatectomy, 8 (2.1%) for post-radiation prostate cancer survivors, 1 (0.3%) for after any intervention for prostate cancer including radical prostatectomy, radiation, and hormonal therapy, and 1 (0.3%) was for men with prostate cancer more generally. Among the 317 studies not specifically for prostate cancer survivors, 126 (39.7%) studies specifically excluded patients who had undergone RP and 167 trials (52.7%) had at least one exclusion criteria pertaining to prostate cancer history or treatment. 150 trials (47.3%) had no exclusions regarding prostate cancer interventions. A chi-square test of independence was performed to examine the relationship between exclusion criteria for prostate cancer history/therapies and intervention type. The relation between these variable was significant, χ2(7, N=317)=37.33, p=0.00. Prostate cancer related exclusions were more likely to be present than no-prostate cancer related exclusions among the examined trials not specifically designed for prostate survivors. Conclusions While erectile dysfunction is a common problem for prostate cancer survivors, over half of registered general erectile dysfunction intervention trials exclude patients with prostate cancer or who have had a therapeutic intervention for prostate cancer. Almost half of these clinical trials specifically exclude patients who have had a radical prostatectomy. Disclosure No