Prostate Cancer - Vitamin E, Soy and Selenium

Source:J Clin Oncol, May 2, 2011. [Epub ahead of print].

Research: High-grade prostatic intraepithelial neoplasia (HGPIN) is a putative precursor of invasive prostate cancer (PCa) and preclinical evidence suggests vitamin E, selenium and soy protein may prevent the progression of HGPIN to PCa. This hypothesis was tested among 300 men in a randomized phase III double-blind study of daily soy (40 grams), vitamin E (800 IUs) and selenium (200 μg) consumption versus placebo. Treatment was administered daily for 3 years. Follow-up prostate biopsies occurred at 6, 12, 24 and 36 months post-randomization.

Results: For all patients, the median age was 63 years. The median baseline prostate-specific antigen (PSA; n = 302) was 5.41 ug/L; total testosterone (n = 291) was 13.4 nmol/L. Invasive PCa developed among 26% of patients. Gleason score distribution was similar in both groups, with 83.5% of cancers graded Gleason sum of 6. Baseline age, weight, PSA and testosterone did not predict for development of PCa. The supplement was well tolerated with flatulence reported more frequently (27% vs. 17%) among men receiving micronutrients. According to researchers, this trial does not support the hypothesis that combination vitamin E, selenium and soy prevents progression from HGPIN to PCa.