Reduced Cardiorespiratory Fitness and Increased Cardiovascular Mortality After Prolonged Androgen Deprivation Therapy for Prostate Cancer

BACKGROUND: Prolonged androgen deprivation therapy (ADT) is favored over short-term use in patients with localized high-risk prostate cancer (PC). OBJECTIVES: This study sought to compare cardiorespiratory fitness (CRF) and cardiovascular (CV) mortality among patients with PC with and without ADT exposure and to explore how duration of ADT exposure influences CRF and CV mortality. METHODS: Retrospective cohort study of patients referred for exercise treadmill testing (ETT) after a PC diagnosis. PC risk classification was based on Gleason score (GS): high risk if GS ≥8; intermediate risk if GS = 7; and low risk if GS <7. CRF was categorized by metabolic equivalents (METs): METs >8 defined as good CRF and METs ≤8 as reduced CRF. ADT exposure was categorized as short term (≤6 months) versus prolonged (>6 months). RESULTS: A total of 616 patients underwent an ETT a median of 4.8 years (interquartile range: 2.0, 7.9 years) after PC diagnosis. Of those, 150 patients (24.3%) received ADT prior to the ETT; 99 with short-term and 51 with prolonged exposure. 504 patients (81.8%) had ≥2 CV risk factors. Prolonged ADT was associated with reduced CRF (odds ratio [OR]: 2.71; 95% confidence interval [CI]: 1.31 to 5.61; p = 0.007) and increased CV mortality (hazard ratio [HR]: 3.87; 95% CI: 1.16 to 12.96; p = 0.028) in adjusted analyses. Although the association between short-term ADT exposure and reduced CRF was of borderline significance (OR: 1.71; 95% CI: 1.00 to 2.94; p = 0.052), there was no association with CV mortality (HR: 1.60; 95% CI: 0.51 to 5.01; p = 0.420) in adjusted Cox regression models. CONCLUSIONS: Among patients with PC and high baseline CV risk, prolonged ADT exposure was associated with reduced CRF and increased CV mortality.