behavior-based dietary intervention in treating patients with hormone-refractory prostate cancer

Conditions: Prostate Cancer

Summary: rationale: a low-fat, high-fiber diet that includes soy protein may prevent disease progression in patients with hormone-refractory prostate cancer. nutrition counseling may help motivate patients to follow this diet. purpose: randomized phase i trial to study the effectiveness of behavior-based dietary interventions, such as receiving nutrition counseling, in helping patients who have hormone-refractory prostate cancer follow a low-fat, high-fiber, soy-supplemented diet.

objectives: * determine whether a behavior-based dietary intervention can motivate patients with hormone-refractory prostate cancer to adopt and maintain a dietary pattern that includes \ 25 g of fiber, and 80 g of soy protein powder. * compare bioavailable levels of testosterone in patients treated with a behavior-based dietary intervention vs observation only. * determine whether this dietary intervention decreases or stabilizes a rising serum prostate-specific antigen level in these patients. * determine whether this dietary intervention improves disease-specific survival, mediated by reduced bioavailable levels of testosterone, in these patients. * determine the impact of a positive intervention outcome on androgen receptors in patients treated with this dietary intervention. outline: this is a randomized, controlled, pilot, multicenter study. patients are randomized to 1 of 2 treatment arms. all patients receive nutritional counseling on a healthy diet. patients also keep a food diary during study participation. * arm i (dietary intervention): patients receive dietary intervention comprising nutritional counseling on a low-fat, high-fiber, soy supplemented diet and behavior-based activities, such as goal-setting, contracting, and stimulus control, once weekly for 6 weeks, every 3 weeks for 33 weeks, and then at weeks 44, 48, and 52. treatment continues in the absence of disease progression or unacceptable toxicity. * arm ii (observation): patients undergo observation every 6 weeks for 36 weeks and then every 8 weeks for 18 weeks. projected accrual: a total of 92 patients (46 per treatment arm) will be accrued for this study.

Eligibility criteria:
disease characteristics: * histologically confirmed adenocarcinoma of the prostate * no small cell component * no histologically confirmed and/or demonstrable metastatic or locally recurrent disease by bone scan, chest x-ray, computed tomography (ct) scan, or transrectal ultrasound * no clinical symptoms within the past 90 days * documented biochemical failure after radical prostatectomy * prostate-specific antigen must have initially nadired to an undetectable level (\< 0.1 ng/ml) after prostatectomy and is currently rising (0.3-40.0 ng/ml) * serum testosterone \> 100 ng/dl patient characteristics: age * any age performance status * zubrod 0-1 life expectancy * at least 1 year hematopoietic * not specified hepatic * not specified renal * not specified other * no known allergic reactions to milk or soy products prior concurrent therapy: biologic therapy * not specified chemotherapy * more than 1 year since prior chemotherapy endocrine therapy * more than 1 year since prior hormonal therapy radiotherapy * not specified surgery * see disease characteristics

Keywords: stage i prostate cancer stage ii prostate cancer adenocarcinoma of the prostate