Interim analysis of a prospective randomized trial of dietary carbohydrate restriction for men with a rising PSA after failed primary treatment: Carbohydrate and Prostate Study 2 (CAPS2).

382Background: Nearly one third of men treated with curative intent for localized prostate cancer (PC) will develop a rising PSA. The rate of PSA rise (PSA doubling time aka PSASDT) is a predictor metastases and PC death. In laboratory mice, an extreme low carbohydrate diet slows PC growth. We tested whether this diet could slow PSADT in men with recurrent PC. Methods: We are conducting a 6-month multi-center randomized phase II trial of dietary carbohydrate restriction vs. no diet intervention control. Men had to have a BMI ≥24 kg/m2, received radical prostatectomy or definitive local radiation for PC, had a PSA 0.4-20.0 ng/ml (3-20 if prior radiation therapy) within the past 3 months, and current PSADT 3-36 months. The intervention arm was instructed to eat < 20 grams/carbs/day with no other limits. The control arm was told to make no diet. In this interim analysis, we present the efficacy of the dietary intervention with regards to weight loss. Arms were compared using rank-sum. Total anticipated enrol...