To characterize the impact of androgen-deprivation therapy (ADT) on the incidence of cardiovascular events (CE) in prostate cancer patients treated with radiotherapy (RT).
2211 patients with localized prostate cancer were treated with RT from 1988-2008 at our institution. 991 patients (44. 8%) received ADT at the time of RT for a median of 6. 1 months. Salvage ADT was initiated prior to CE in 365 men (16. 5%) at a median of 5. 5 years (range, 0. 6 to 18. 4 years) after RT and continued for a median of 4. 3 years. A nomogram was constructed to predict the 10-year risk of CE post-RT.
Patients receiving ADT at the time of RT exhibited significantly higher 10-year incidence of CE (19. 6%, 95% CI 17. 0-22. 6%) than those not receiving ADT (14. 3%, 95% CI 12. 2%-16. 7%, P = . 005). On multivariate analysis, both ADT at the time of RT (P= . 007) and the time of salvage (P = . 0004) were associated with increased CE risk, as were advanced age (P = . 02), smoking (P = . 0007), history of diabetes (P = . 0007), and history of CE before RT (P < . 0001). A nomogram using patient age, smoking status, history of pre-RT CE, history of diabetes, and ADT use at the time of RT predicted the rate of 10-year CE with a C-index of 0. 81 (95% CI, 0. 72-0. 88).
While ADT is often an essential part of prostate-cancer treatment, patients should be counseled regarding increased risks of CE and prophylactic efforts should be considered to mitigate that risk.
Urology. 2015 Oct 14 [Epub ahead of print]
Zachary A Kohutek, Emily Steinberger, Xin Pei, Weiji Shi, Zhigang Zhang, Marisa A Kollmeier, Michael J Zelefsky
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. , Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY. Electronic address: zelefskym@mskcc. org.