Can diet in conjunction with stress reduction affect the rate of increase in prostate specific antigen after biochemical recurrence of prostate cancer?

PURPOSE: Epidemiological and laboratory evidence indicates that a Western diet is associated with an increased incidence of prostate cancer. Specific components of the diet, such as high saturated fat, low fiber and high meat content, may have greatest clinical significance in the later stages of tumor promotion and progression. However, departure from the conventional diet is difficult to initiate and maintain. Therefore, we combined the well-known Mindfulness-Based Stress Reduction (MBSR) program with a low saturated fat, high-fiber, plant-based diet to determine the effect on the rate of change in prostate specific antigen (PSA) in patients with biochemical recurrence after prostatectomy. MATERIALS AND METHODS: We enrolled 10 men and their partners in a 4-month group-based diet and MBSR intervention. A pre-study post-study design in which each subject served as his own control was used to compare the rate of increase in and doubling time of PSA before and after intervention. RESULTS: The rate of PSA increase decreased in 8 of 10 men, while 3 had a decrease in absolute PSA. Results of the signed rank test indicated a significant decrease in the rate of increase in the intervention period (p = 0.01). Estimated median doubling time increased from 6.5 months (95% confidence interval 3.7 to 10.1) before to 17.7 months (95% confidence interval 7.8 to infinity) after the intervention. CONCLUSIONS: Our small study provides evidence that a plant-based diet delivered in the context of MBSR decreases the rate of PSA increase and may slow the rate of tumor progression in cases of biochemically recurrent prostate cancer. Larger-scale randomized studies are warranted to explore further the preventive and therapeutic potential of diet and lifestyle modification in men with prostate cancer.

Diet and risk for breast cancer recurrence and survival.

Dietary factors may influence the risk for breast cancer and also the prognosis following diagnosis and treatment. The aim of this study was to assess whether self-reported prediagnosis diet or other patient factors associated with breast cancer incidence were predictive of recurrence and survival. Patients (n = 149) diagnosed with primary breast cancer between 1989 and 1991 were followed for five or more years. Total energy (hazard ratio (HR) = 1.58, 95%, confidence interval (CI) = 1.05, 2.38) as well as total (HR = 1.46, 95% CI = 1.05, 2.01), saturated (HR = 1.79, 95% CI = 1.05, 3.04), and monounsaturated (HR = 1.65, 95% CI = 1.09, 2.49) fat intakes were associated with increased risk, and energy-adjusted bread and cereal consumption (HR = 0.55, 95% CI = 0.33, 0.93) with decreased risk of recurrence. Both total energy (HR = 1.58, 95% CI = 1.03, 2.43) and polyunsaturated fat (HR = 1.84, 95% CI = 1.09, 3.13) intakes were associated with an increased risk of death. All associations between dietary fat and recurrence and survival attenuated following energy adjustment. Oral contraceptive use (HR = 1.28, 95% CI = 1.03, 1.60), lymph node positive status (HR = 2.36, 95% CI = 1.01, 5.49), and tumor stage (HR = 2.22, 95% CI = 1.02, 4.81) were associated with increased risk of recurrence. Tumor stage (HR = 4.96, 95% CI = 1.86, 13.23), lymph node positive status (HR = 3.31, 95% CI = 1.38, 7.95), and estrogen receptor negative status (HR = 2.46, 95% CI = 1.02, 5.94) were associated with increased risk, and arm muscle circumference (HR = 0.27, 95% CI = 0.09, 0.86) and mammographic utilization (HR = 0.77, 95% CI = 0.61, 0.98) with decreased risk of death. Higher levels of energy, fat intakes, and selected patient characteristics (particularly disease stage and anthropometric indicators of adiposity) appear to increase risk of recurrence and/or shortened survival following the diagnosis of breast cancer.

Carotenoids, vitamin A, and estrogen receptor status in breast cancer.

Among patients with breast cancer, tumors that contain estrogen receptors (ER) are associated with improved survival and better response to hormone therapy than those not expressing these receptors. The purpose of these case comparison studies was to examine the relationship between carotenoids, vitamin A, and the tumor ER status in women at diagnosis of primary breast cancer. The focus of the first study was the relationship between dietary intake and ER status, and the focus of the second study was the relationship between ER status and the plasma carotenoid, retinol, and tocopherol concentrations. We evaluated tumor ER status and self-reported dietary intake in 142 women and plasma concentrations of carotenoids, retinol, and tocopherols in 149 women, at diagnosis of breast cancer, before any medical or surgical treatment. In the first study the overall odds of ER-positive status were increased in relation to number of mammograms in the past five years, number of breast-fed babies, dietary carotenoid intake, and more frequent intake of yellow and green vegetables. Overall odds of ER-positive status were decreased in relation to years of oral contraceptive use and preformed vitamin A intake. In the second study older women, women with higher plasma lutein concentration, and women not using beta-carotene supplements were more likely to be ER positive, when data were adjusted for body mass index and factors that may influence breast cancer risk or hormonal status. Significant independent relationships between plasma retinol or tocopherol concentrations and ER status were not observed. The strong and independent relationships between carotenoid intake, plasma lutein concentration, and ER status may relate to observations linking a carotenoid-rich diet with improved prognosis after diagnosis of breast cancer.