title: Increased risk of ischemic bowel complications during treatment with bevacizumab after pelvic irradiation: report of three cases.
abstract: OBJECTIVE
  To assess the rate of severe bowel complications during treatment with the anti-vascular endothelial growth factor monoclonal antibody bevacizumab.
  
  
  METHODS
  We performed a retrospective evaluation of bevacizumab-associated severe intestinal adverse events from our institutional database.
  
  
  RESULTS
  A total of 33 patients started treatment with bevacizumab at our institution during the first 6 months after its approval in Germany. Three patients (9%) presented with severe bowel complications: two with acute ischemic colitis and one with gastrointestinal perforation with a fatal outcome. All 3 patients had undergone radiotherapy directed to the pelvis before treatment with bevacizumab. None of the 30 patients without bowel complications had been pretreated with infradiaphragmatic irradiation. Histologic evaluation of bowel biopsies and resection specimens revealed severe ischemic bowel damage as the pathophysiologic background of the clinical findings.
  
  
  CONCLUSIONS
  This report contributes to the pathophysiologic clarification of bevacizumab-induced bowel complications and points to a potentially increased risk of severe ischemic damage during treatment with bevacizumab in patients who have undergone previous radiotherapy.
authors.affiliation: Third Department of Internal Medicine (Hematology/Medical Oncology), Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany. f.lordick@lrz.tum.de
authors.forename: Florian
authors.initials: F
authors.lastname: Lordick
authors.forename: Hans
authors.initials: H
authors.lastname: Geinitz
authors.forename: Joerg
authors.initials: J
authors.lastname: Theisen
authors.forename: Andreas
authors.initials: A
authors.lastname: Sendler
authors.forename: Mario
authors.initials: M
authors.lastname: Sarbia
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D001859:Bone Neoplasms / Q000532:radiotherapy / Q000556:secondary; D002292:Carcinoma, Renal Cell / Q000532:radiotherapy / Q000556:secondary; D002429:Cecal Diseases / Q000139:chemically induced*; D017091:Colitis, Ischemic / Q000139:chemically induced*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007416:Intestinal Perforation / Q000139:chemically induced*; D007680:Kidney Neoplasms; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000628:therapy; D012189:Retrospective Studies
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab