Selenium and Vitamin E for Prostate Cancer - Justifications for the SELECT Study

There are several studies that relate oxidative damage as possible mechanism for many cancers. Manystudies have also shown that anti-oxidants like selenium and vitamin E decrease the risk for prostate cancer.The main objective of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) study was to look forthe benefits of selenium and vitamin E supplementation on prostate cancer. The study had a large sample size,stringent experimental conditions, very long duration, standardized laboratories for biochemical analysesand other factors that contribute to high external validity. The SELECT study failed to show any significantrisk reduction for prostate cancers ascribable to selenium and vitamin E supplementations. Because of theseconflicting results, many researchers argue about the methods used, supplementations administered (seleniumand vitamin E) and indicators used for assessing levels of supplementations. We reviewed many epidemiologicalstudies, clinical trials, and pre-clinical studies. With corroborative evidences we justify that SELECT study hasa sound methodology and rationale. In lieu of the contrary results of the select study, researchers should focuson the probable mechanisms for these contrary findings and continue their search for newer and effective agentsfor prevention of prostate cancer.