NCT01437826 2011-09-21Antioxidant Supplement and Reduction of Metachronous Adenomas of the Large Bowel: a Double Blind Randomized TrialIRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, ItalyPhase 3 Terminated411 enrolled