[1] Univ Athens, Sch Med, Laikon Gen Hosp, Dept Surg 1, GR-10679 Athens, Greece
[2] Metaxa Canc Hosp, Dept Med Oncol 2, Piraeus, Greece
[3] Univ Athens, Sch Med, Arete Hosp, Dept Surg 2,Oncol Unit, GR-10679 Athens, Greece
[4] Univ Athens, Sch Med, Laikon Gen Hosp, Propedeut Clin,Dept Internal Med 1,Oncol Unit, GR-10679 Athens, Greece
[5] Theagen Canc Hosp, Dept Med Oncol 2, Thessaloniki, Greece
[6] Gen Hosp Nikea, Med Dpt 2, Piraeus, Greece
[7] Univ Athens, Sch Med, Laikon Gen Hosp, Dept Pathophysiol,Oncol Unit, GR-10679 Athens, Greece
[8] Univ Athens, Sch Med, Laikon Gen Hosp, Dept Pathophysiol,Gastroenterol Unit, GR-10679 Athens, Greece
[9] G Gennimatas Gen Hosp, Dept Surg 3, Athens, Greece
[10] Univ Athens, Sch Med, Attiko Hosp, Dept Surg 3, GR-11527 Athens, Greece