Abstract 4443: Body weight status predicts pre-treatment risk of PSA failure in men with clinically localized prostate cancer

Abstract

Abstract Introduction and Objective: Obesity/excessive adiposity in men with clinically organ-confined prostate cancer is of growing concern, because it associates with an increased risk of cancer recurrence after definitive therapy based on post-treatment prognostic parameters. The objective of this study was to evaluate whether body weight status associates with pre-treatment predictors of cancer recurrence in this patient population. Methods: We performed a cross-sectional study of body weight status and pre-treatment risk of PSA failure in 119 men awaiting radical prostatectomy for clinically localized prostate cancer in four urologic clinics in the Chicago area. Body weight status was assessed using the body mass index (BMI) and dual-energy x-ray absorptiometry (DXA). D'Amico risk scores, which are based on clinical tumor stage, biopsy Gleason sum, and pre-treatment PSA, were used to rank each patient's 5-year risk of PSA failure as low, intermediate, or high. Ordinal logistical regression analyzed the association between BMI quartile and D'Amico risk scores after accounting for age, race, total grams of body fat, and study site. Results: The risk of PSA failure increased with increasing quartile of BMI. Relative to the lowest BMI quartile, the cumulative odds of an intermediate or higher D'Amico risk score vs. a low risk score (the “cumulative odds ratio”) for patients in the second BMI quartile (mean BMI = 27.8 kg/m2) was 3.51 (95% CI = 1.07 to 11.5, p = .038). For patients in the third quartile (mean BMI = 32.0 kg/m2) and forth quartile (mean BMI = 37.0 kg/m2), the cumulative OR was 6.52 (95% CI = 1.72 to 24.6, p = .0057) and 7.74 (95% CI = 1.18 to 50.9, p = .033), respectively (OR trend = 1.98, 95% CI = 1.09 to 3.59, p = .0254). Conclusions: Body weight status predicts pre-treatment risk of PSA failure in men with clinically localized prostate cancer. This provides further support for a mechanistic link between body weight status, which reflects energy balance, and prostate cancer prognosis. The results also highlight the potential for using body weight status and other lifestyle-related factors pertinent to prostate cancer to identify men who are at high risk for unfavorable treatment outcomes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4443. doi:1538-7445.AM2012-4443