[1] Cisanello Hosp, Div Thorac Surg, Pisa, Italy
[2] European Inst Oncol, Div Epidemiol & Biostatist, Milan, Italy
[3] European Inst Oncol, Thorac Surg Div, Via Ripamonti 435, I-20141 Milan, Italy
[4] European Inst Oncol, Div Gen Surg, Unit Minimally Invas Surg, Milan, Italy
[5] Univ Milan, Fdn Granda Policlin Mangiagalli, Inst Urol, Milan, Italy
[6] Univ Milan, Milan, Italy