Patients matched on propensity to receive androgen deprivation therapy did not show an association between ADT use and cardiovascular mortality, report researchers from the University of California, San Francisco.
"This suggests that potential unmeasured variables affecting treatment selection may confound the relationship between ADT use and cardiovascular risk," wrote the authors, who published their findings online in the Journal of Clinical Oncology (Aug. 15, 2011).
In their study, 7,248 men in the CaPSURE registry were analyzed. Treatment was categorized as local only, primary ADT monotherapy, local treatment plus ADT, and watchful waiting/active surveillance. Competing hazards survival analysis was performed for prostate cancer-specific mortality, cardiovascular mortality, and all-cause mortality. A propensity score-adjusted and a propensity-matched analysis were undertaken to adjust for imbalances in covariates among men receiving various treatments.
The results showed that patients treated with ADT or active surveillance had a higher likelihood of prostate cancer-specific mortality than those treated with local therapy alone. Patients treated with primary ADT had an almost twofold greater likelihood of cardiovascular mortality (HR, 1.94; 95% CI, 1.29 to 2.97) than those treated with local therapy alone; however, patients treated with watchful waiting had a greater than two-fold increased risk of cardiovascular mortality (HR, 2.46; 95% CI, 1.53 to 3.95). A propensity-matching algorithm in a subset of 1,391 patients was unable to find a significant difference in cardiovascular mortality between those who did or did not receive ADT.