Introduction: The association between vascular risk factors (VRF) and the development of erectile dysfunction (ED) has been well documented. Radiation therapy (RT) for prostate cancer also has a detrimental effect on erectile function (EF). No data to date has evaluated the impact of VRF on EF after RT. We sought to evaluate the impact of VRF presence on EF after prostate RT.
Methods: We analyzed patients who underwent RT for localized prostate cancer without androgen deprivation therapy. Patients without at least 24 month follow up were excluded. VRF included hypertension, dyslipidemia, diabetes mellitus, coronary artery disease, peripheral vascular disease and history of stroke. Men were grouped by number of VRF for analysis: 0-1 (group 1) vs 2+ VRF (group 2). Patient reported EF outcomes were obtained from International Index of EF erectile function domain (EFD) scores at baseline and in follow up.
Results: 268 patients met all inclusion criteria. Prostate cancer was mostly Gleason 6 (58%) and 7 (35%) and mostly T1c (65%) and T2a (17%). RT was administered as external beam RT (47%), brachytherapy (37%), or a combination (16%). Median EFD score at baseline was 21 (IQR 7, 27) and at 24 months was 12 (IQR 5, 25) (p<0.001). Group 1 contained 192 men and Group 2 contained 76 men. The median number of VRF in both groups was 0 and 2, respectively. Median baseline EFD scores for groups 1 and 2 were 23 and 15.5, respectively (p=0.11). Median EFD score at 24 months for groups 1 and 2 were 13 and 9.5, respectively (p=0.051). On univariate analysis, factors significantly associated with EFD score at 24 months included baseline EFD (p<0.001) and total number of VRF (p<0.001). On multivariable analysis, only baseline EFD remained significantly predictive of EFD at 24 months (p<0.001). Additional analyses were performed to evaluate factors predictive of severe ED (EFD =10) or functional erection (EFD =24) at 24 months. In both cases, univariate analyses showed significant association with baseline EFD (p<0.001 for both) and total number of VRF (p<0.05 for both), but only baseline EFD remained significant on multivariable analysis (p<0.001 for both).
Conclusions: In unadjusted models, the number of VRF in men undergoing RT for prostate cancer was associated with EF preservation. Source of