[1] Univ Hosp Essen, West German Canc Ctr, Dept Med Oncol, Essen, Germany
[2] Alfried Krupp von Bohlen & Halbach Hosp, Dept Med 1, Essen, Germany
[3] Prosper Hosp, Dept Med 1, Recklinghausen, Germany
[4] Hosp Essen Werden, Dept Hematol & Med Oncol, Essen, Germany
[5] Grp Practice Hematol Oncol, Cologne, Germany
[6] Catholic Hosp, Dept Hematol & Med Oncol, Essen, Germany
[7] Univ Hosp Essen, West German Canc Ctr, Inst Pathol, Essen, Germany
[8] Elisabeth Hosp, Dept Gen Visceral & Trauma Surg, Essen, Germany
[9] Univ Hosp Essen, West German Canc Ctr, Dept Gen Visceral & Transplantat Surg, Essen, Germany
[10] Univ Hosp Essen, West German Canc Ctr, Dept Gastroenterol & Hepatol, Essen, Germany