Abstract 3617: Fat intake after prostate cancer diagnosis and risk of lethal prostate cancer and total mortality.

Abstract

Abstract Context and Objective: Although prostate cancer is the 2nd leading cause of cancer death in the US, few studies have evaluated the effect of diet after diagnosis on prostate cancer progression and all-cause mortality. We examined fat intake after prostate cancer diagnosis in relation to risk of lethal prostate cancer and all-cause mortality. Methods: This was a prospective study of 1,019 men diagnosed with prostate cancer between 1982 and 2000 in the Physicians’ Health Study. Men completed a dietary food frequency questionnaire a median of 5.1 years after diagnosis. We examined post-diagnostic intake of saturated, monounsaturated, polyunsaturated, and trans fats, as well as animal and vegetable fats. Cases were confirmed by medical record review. The main outcomes were lethal prostate cancer, defined as prostate cancer-specific death or metastasis to bone, and all-cause mortality. Multivariate Cox proportional hazards regression was used to estimate the relative risk of lethal prostate cancer and all-cause mortality. Models were adjusted for age at diagnosis, time since diagnosis, clinical T-stage, Gleason Score, prostate cancer treatment, BMI, smoking status, intake of alcohol and protein, total calories, and other fats. Results: We observed 87 lethal prostate cancer events and 395 total deaths over a median follow-up after diagnosis of 13.9 years. There was a suggestion of a positive relation between saturated fat intake and lethal prostate cancer that failed to reach statistical significance. The hazard ratio (HR) for lethal prostate cancer associated with a 5% increase in energy from saturated fat was 1.97 (0.89, 4.36; p=0.10). In addition, saturated fat intake after diagnosis was associated with increased risk of all-cause mortality (HR per 5% energy: 1.49; 95%CI: 1.02, 2.16; p=0.04) while vegetable fat was associated with reduced risk of all-cause mortality (HR per 10% energy: 0.63; 95%CI; 0.46, 0.88; p=0.007). Conclusions: Among men diagnosed with prostate cancer, replacing calories from carbohydrates with saturated fat after diagnosis may increase risk of all-cause mortality, while replacing calories from carbohydrates with vegetable fat may reduce risk of all-cause mortality. Citation Format: Stacey A. Kenfield, Erin L. Richman, Howard D. Sesso, Jing Ma, Meir J. Stampfer, Jorge E. Chavarro. Fat intake after prostate cancer diagnosis and risk of lethal prostate cancer and total mortality. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3617. doi:10.1158/1538-7445.AM2013-3617