[1] Univ Munich, Dept Med Informat Biometry & Epidemiol IBE, Munich Canc Registry, Klinikum Grosshadern,Munich Canc Ctr, D-81377 Munich, Germany
[2] Tech Univ Munich, Dept Surg, Klinikum Rechts Isar, D-81675 Munich, Germany
[3] CHIR Net Munich, D-81675 Munich, Germany
[4] Tech Univ Munich, Munchner Studienzentrum MSZ, Klinikum Rechts Isar, D-81675 Munich, Germany
[5] Univ Munich, Klinikum Grosshadern, LMU, D-81377 Munich, Germany
[6] Stadt Klinikum Munchen Neuperlach, Dept Surg, D-81737 Munich, Germany
[7] Stadt Klinikum Munchen Bogenhausen, Dept Gastroenterol Hepatol & Gastrointestinal Onc, D-81925 Munich, Germany
[8] Stadt Klinikum Munchen Neuperlach, Dept Gastroenterol, D-81737 Munich, Germany
[9] Klin Bad Trissl, Dept Internal Med, D-83080 Oberaudorf, Germany
[10] Tech Univ Munich, Fac Med, D-81675 Munich, Germany