Veterans with cardiovascular disease or diabetes have slightly longer survival when treated with enzalutamide vs abiraterone for metastatic castration-resistant prostate cancer (mCRPC), a new study finds.
In a retrospective study of 5822 veterans treated for mCRPC during 2014-2017, 43% initially received enzalutamide, an androgen receptor inhibitor, and 57% initially received abiraterone, which inhibits androgen production. Overall, veterans receiving enzalutamide first had significantly longer median overall survival (OS) compared with veterans receiving abiraterone first: 24.2 vs. 22.1 months, Martin W. Schoen, MD, MPH, of Saint Louis Veterans Affairs Medical Center in Missouri, and colleagues reported in Prostate Cancer and Prostatic Diseases. They found a survival benefit among men aged 75 years and older (21.2 vs 18.4 months) and those with a Charlson Comorbidity Index of 4 or more vs less than 4 (21.5 vs 18.2 months), respectively.
Among the 5822 veterans, 4207 had cardiovascular disease or diabetes. In this subgroup, median treatment duration was significantly longer with enzalutamide than abiraterone (11.4 vs 8.6 months) with longer median OS (23.2 vs. 20.5 months), the investigators reported.
After propensity score matching by age and cardiac comorbidities, enzalutamide was significantly associated with a 10% decreased mortality risk compared with abiraterone.
Men who started with enzalutamide vs abiraterone were older (mean age 75.8 vs 75.0 years) with higher mean Charlson comorbidity index (4.4 vs. 4.1) and higher rates of cardiovascular disease or diabetes (74.2% vs 70.6%).
“By focusing on patients who are older and/or who have comorbid illnesses, our analyses give potentially actionable information from real-world data to guide treatment decisions,” Dr Schoen’s team wrote.
After androgen axis targeted treatment, 52.4% of veterans received subsequent therapies.
The study is limited by its retrospective design. Future studies are needed to assess enzalutamide and abiraterone and survival among men with metastatic hormone-sensitive prostate cancer.
Schoen MW, Carson KR, Eisen SA, et al. Survival of veterans treated with enzalutamide and abiraterone for metastatic castrate resistant prostate cancer based on comorbid diseases. Prostate Cancer Prostatic Dis. Published online September 14, 2022. doi:10.1038/s41391-022-00588-5