ABSTRACT
INTRODUCTION: Obesity in prostate cancer survivors may increase mortality. Better characterization of this effect may allow better counseling on obesity as a targetable lifestyle factor to reduce mortality in prostate cancer survivors. The purpose of this study was to determine whether pre- and post-diagnostic obesity and weight change affect all-cause mortality, cardiovascular disease specific mortality, and prostate cancer specific mortality in patients with nonmetastatic prostate cancer. PATIENTS AND METHODS: We performed a retrospective cohort analysis of 5,077 patients diagnosed with localized prostate cancer from 1997 to 2017 with median follow-up of 15.5 years. The Utah Population Database linked to the Utah Cancer Registry was used to identify patients at a variety of treatment centers. RESULTS: Pre-diagnosis obesity was associated with a 62% increased risk of cardiovascular disease specific mortality and a 34% increased risk of all-cause mortality (HR 1.62, 95% CI 1.05-2.50; HR 1.34, 95% CI 1.07-1.67, respectively). Post-diagnosis obesity increased the risk of cardiovascular disease specific mortality (HR 1.83, 95% CI 1.31-2.56) and all-cause mortality (HR 1.37, 95% CI 1.16-1.64) relative to non-obese men. We found no association between pre-diagnostic obesity or post-diagnostic weight gain and prostate cancer specific mortality. CONCLUSION: Our study strengthens the conclusion that pre-, post-diagnostic obesity and weight gain increase cardiovascular disease and all-cause mortality but not prostate cancer specific mortality compared to healthy weight men. An increased emphasis on weight management may improve mortality for prostate cancer survivors who are obese.