3372 - Erectile Dysfunction Severity as a Vascular Biomarker Predicting Cardiovascular Mortality in Patients with Prostate Cancer
Presenter(s)
M. Sayan1, G. S. Miric2, R. W. Galbreath3, R. W. Fiano3, K. Wallner4, S. Moningi5, A. C. Smart6, J. E. Leeman7, M. T. King6, and P. F. Orio III8; 1Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, New Brunswick, NJ, 2Bethany College, Bethany, WV, 3Urologic Research Institute, Sarasota, FL, 4Department of Radiation Oncology, University of Washington, Seattle, WA, 5Cleveland Clinic, Cleveland, OH, 6Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 7Department of Radiation Oncology, Mass General Brigham, Harvard Medical School, Boston, MA, 8Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA
Purpose/Objective(s): Erectile dysfunction (ED) may represent early systemic vascular disease due to small-vessel atherosclerosis. We hypothesized that baseline ED severity independently predicts cardiovascular-specific mortality following definitive prostate radiation therapy and functions as a clinically accessible vascular biomarker.
Materials/Methods: We analyzed 2,445 consecutive patients treated with low-dose-rate brachytherapy (2001–2018) who completed a pretreatment IIEF-6 questionnaire without pharmacologic or mechanical support. ED severity was classified as severe (1–10), moderate/mild (11–24), or normal (25–30). The primary endpoint was cardiovascular-specific mortality. Secondary endpoints included overall mortality (OM), biochemical failure, and prostate cancer–specific mortality (PCSM). Cox regression evaluated OM, and competing risk regression (Fine and Gray) assessed cardiovascular death. Multivariable models adjusted for age, PSA, Gleason group, ADT, EBRT, hypertension, diabetes, tobacco use, cardiovascular disease, and comorbidity burden.
Results: At a median follow-up of 10 years, severe ED independently predicted worse OM (vs normal function HR 0.68, p<0.001). The association between ED severity and OM was significant in patients aged 60–69 and =70, but not in those =59 years. In competing risk analysis, ED severity was strongly associated with cardiovascular mortality (overall p<0.001). Compared with severe ED, normal erectile function was associated with a 65% relative reduction in cardiovascular death (HR 0.35, p<0.001), independent of established cardiovascular disease and risk factors. ED severity was not associated with biochemical failure (p=0.682) or PCSM (p=0.649).
Conclusion: Baseline ED severity independently predicts cardiovascular mortality—but not prostate cancer–specific death—after definitive radiation therapy. These findings support ED as a readily available vascular biomarker within oncology practice. Incorporating ED severity into routine assessment may identify patients at increased cardiovascular risk and create an opportunity for earlier preventive intervention.