Do Abiraterone or Enzalutamide Increase Risk for Metabolic and Cardiovascular Events?

Although androgen deprivation therapy (ADT) is the cornerstone for the systemic management of advanced prostate cancer, there is an associated elevated risk for both metabolic syndrome and major cardiovascular events. Abiraterone and enzalutamide are widely used in advanced prostate cancer based on evidence of survival benefit. To examine their safety in routine practice, investigators assessed the occurrence of metabolic and cardiovascular events in a random sample of 20% of Medicare beneficiaries from 2010–2017.

The primary outcome was a composite measure of major metabolic and cardiac events, defined as an emergency room visit or hospitalization associated with a primary diagnosis of diabetes, hypertension, or cardiovascular disease. A secondary endpoint, minor metabolic or cardiac events, was defined as an outpatient visit associated with those same diagnoses. For both endpoints, individuals were excluded from the analysis if they had the relevant diagnostic codes within the prior 12 months.

Both abiraterone and enzalutamide were associated with increased risk of major metabolic or cardiovascular events (hazard ratios, 1.77 and 1.22, respectively). Patients treated with abiraterone had 1 additional major cardiovascular event for each 29 patients treated. Abiraterone was associated with an increased risk of minor events, whereas enzalutamide was not. In analyses of individual minor events, abiraterone was associated with new diagnosis of diabetes (HR, 1.37), while enzalutamide was associated with reduced risk of diabetes (HR, 0.66).