[1] European Inst Oncol IRCCS, Prevent Gynecol Unit, I-20141 Milan, Italy
[2] Univ Sassari, Dept Biomed Sci, I-07100 Sassari, Italy
[3] European Inst Oncol IRCCS, Div Epidemiol & Biostat, I-20141 Milan, Italy
[4] Univ Udine, Obstet & Gynecol Specializat Sch, I-33100 Udine, Italy