Soy Bread Diet Intervention on Immune Function in Men with Prostate Cancer

Principal Investigator: Steve Clinton


We have developed novel soy bread which will be tested against wheat bread in this study of 60 men with prostate cancer who are initiating hormone therapy. This trial is designed to evaluate relevant immune biomarkers including myeloid derived suppressorcells (MDSC) systemically in the blood. Importantly, we will also be able to establish whether or not immune biomarkers in blood are correlated with the level of isoflavones or their metabolites. Participants in this trial will be seen in clinic at their usual Medical Oncology clinic visits for all study visits. Study materials and the bread will be distributed at each visit. Any subject who does not have adequate freezer space to accommodate the quantity of study bread required can choose to have bread mailed to him twice between weeks 8 and 20, or he can pick up the bread from our laboratory. Benefits relative to improving cancer outcomes are speculative and unknown. Benefits in terms of reducing tumor grade or stage are speculative in spite of in vitro and animal model studies. It is our experience that patients participating in diet and nutritional studies derive significant emotional and psychological benefits from participating in the study, which include feelings of self-empowerment and pride in contributing to scientific knowledge. The risks are minimal as the soy bread has not been associated with significant toxicity and persons with a soy allergy will not be enrolled. The risks of the alternate treatment (wheat bread) are essentially nonexistent. Our highly integrated and collaborative multi-disciplinary research team will conduct this important clinical trial in men with prostate cancer. This work will provide critical insight regarding the impact of dietary soy phytochemicals on reversing the ability of prostate cancer to evade immunosurveillance and immune therapy. In addition to prevention strategies, future efforts will employ dietary soy to enhance immune based prostate cancer therapies, many of which are in development.