Treatment with androgen deprivation therapy (ADT) does not significantly increase the risk of cardiovascular mortality according to evaluation of mortality data in a large registry of men treated for prostate cancer.
ADT is commonly used to treat prostate cancer. Some studies have shown that it may increase the risk of cardiovascular disease, but other studies have not confirmed the association and it remains controversial. The authors of the recent study tried to explore the evidence further by analyzing the patients registry CAPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor), which includes men with confirmed prostate cancer recruited from 40 mostly community-based US urological practices.
Men who are diagnosed with localized prostate cancer between 1995 and 2007 were included in the analysis, and in order to try to control for factors that may confound the relationship between ADT and cardiovascular death, patients who used and did not use ADT were matched by their propensity to receive ADT. These patients were categorized into three groups: primary ADT monotherapy, local treatment plus ADT, and watchful waiting/active surveillance (WW/AS). Initial outcomes were associations between treatment and cardiovascular cause, prostate cancer, and other causes. Study investigators assessed cause of death using death certificates.
At the point of data capture, there were 13,887 men in the registry, of whom 7,248 were eligible for the analysis. The majority (71.3%) received local treatment only, 6.7% received local treatment plus ADT, 15% received primary ADT, and 7 percent WW/AS. It was found that 21.7% received AFT at some point. Nine hundred seventy six of these men died during the study period, 1.4% from prostate cancer, 2.7% from cardiovascular disease, and 9.4 percent due to other causes. Patients treated with ADT or WW/AS had a higher likelihood of death due to prostate cancer than those treated just with local therapy.
The largest risk of cardiovascular death was in those treated with WW/AS compared to those only receiving local therapy. The difference for those treated with local therapy plus ADT was not significant.
The authors’ conclusion is that the increased rate of cardiovascular death in the WW/AS group compared to the ADT group suggests that there are possibly unmeasured variables that affect treatment selection and that confound the association between ADT and cardiovascular death. The research team notes that when patients were match on propensity to receive ADT, there was no significant association. The limitation so the study included the relatively small number of deaths in some groups, and the assignment of cause of death from death certificates.