title: Are clinical trials the "gold standard" for cancer prevention research?
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kristal
mesh_terms: D035843:Biomedical Research / Q000639:trends*; D002986:Clinical Trials as Topic; D006801:Humans; D009369:Neoplasms / Q000517:prevention & control*; D012107:Research Design; D012643:Selenium / Q000494:pharmacology; D013997:Time Factors; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D014810:Vitamin E; D012643:Selenium