[1] Milano Bicocca Univ, S Gerardo Hosp, Dept Surg, Monza, Italy
[2] S Raffaele Univ, Dept Surg, Milan, Italy
[3] European Inst Oncol, Dept Abdomino Pelv Surg, Milan, Italy
[4] Gen Hosp, Dept Surg, Prato, Italy
[5] Ist Nazl Tumori, Unit Stat & Biometry, I-20133 Milan, Italy