Influence of vascular comorbidities and race on erectile dysfunction after prostate cancer radiotherapy

Introduction: Vascular comorbidities (VC) (hypertension, diabetes, and hyperlipidemia) are known factors related to erectile dysfunction (ED) in men. However, no data are yet available for the effects of VC on ED incidence after prostate cancer radiotherapy (XRT).

Aim: To investigate the influence of VC on post-XRT ED incidence and to further characterize ED incidence by racial groups.

Main outcome measures: ED incidence.

Methods: We reviewed 732 charts of patients (267 Caucasian and 465 African American [AA]) who received prostate XRT (external beam radiotherapy and/or brachytherapy) with or without hormone therapy between 1999 and 2010. The number of pre-XRT VC (0, 1, 2, or 3) was determined by medical history and medication list. ED (defined by use of erectile aids or by documentation of moderate or high sexual dysfunction on patient history) was determined pre-XRT as well as 1, 2, and 4 years post-XRT.

Results: ED incidence progressively increased from 22% pre-XRT to 58% 4 years post-XRT (P < 0.01). Additionally, ED incidence significantly increased with number of VC-4-year incidence between patients with 1 vs. 0 (P = 0.02), 2 vs. 0 (P < 0.01), 3 vs. 0 (P < 0.01), 3 vs. 1 (P < 0.01), and 3 vs. 2 (P = 0.04) VC (2 vs. 1 VC was nonsignificant). Compared with the Caucasian patients, ED incidences were slightly higher for the AA group with 0, 1, 2, and 3 comorbidities at 4 years follow-up (but statistically nonsignificant).

Conclusions: The number of VCs have a significant effect on development of post-XRT ED. Pre- and post-XRT ED appear to be independent of race when number of VCs are considered. Our results can be used to guide physicians in counseling patients on the incidence of ED by number of VC and as preliminary data for prospective efforts aimed at reducing post-XRT ED.