[1] Univ Klin Erlangen, Endocrinol Dept, Gastroenterol & Hepatol, Erlangen, Germany
[2] Tech Univ Munich, Inst Pathol, Munich, Germany
[3] Klinikum St Marien Amberg, Onkol Zentrum, Amberg, Germany
[4] Zentralklin Bad Berka, Dept Internal Med Gastroenterol & Endocrinol, Bad Berka, Germany
[5] Univ Klinikum Bonn, Dept Haematol & Oncol, Bonn, Germany
[6] Univ Klinikum Hamburg Eppendorf, Ctr Internal Med, Hamburg, Germany
[7] Klinikum Nurnberg, Ctr Oncol Haematol, Clin Internal Med, Nurnberg, Germany
[8] Univ Klin Magdeburg, Dept Gastrointestinal Oncol, Magdeburg, Germany
[9] AIO Studien gGmbH, Project Management Sponsor, Berlin, Germany
[10] Natl Ctr Tumor Dis NCT Heidelberg, Dept Med Oncol, Heidelberg, Germany