title: Postoperative intra-abdominal infection and colorectal cancer recurrence: a prospective matched cohort study of inflammatory and angiogenic responses as mechanisms involved in this association.
abstract: BACKGROUND
  Anastomotic leakage is associated with higher rates of recurrence after surgery for colorectal cancer. However, the mechanisms responsible are unknown. The aim was to investigate the inflammatory and angiogenic responses in patients undergoing surgery for colorectal cancer who had postoperative intra-abdominal infection, and to compare the results with patients without complications.
  
  
  METHODS
  Consecutive patients undergoing surgery for colorectal cancer with curative intent were included. Patients who had an anastomotic leak or intra-abdominal abscess were included in the infection group and matched with patients who had an uncomplicated postoperative course. IL-6 and VEGF were measured in serum and peritoneal fluid.
  
  
  RESULTS
  Serum concentration of IL-6 was higher in the infection group (n = 30) compared with the control group (n = 30) on day 4 (infection: 42.3 [27.6-1473.2] versus control: 0.6 [0.6-17.1] pg/ml; p = 0.008). IL-6 in peritoneal fluid was higher in the infection group at 48 h and day 4 (infection: 1000.2 [995.4-1574.0] versus control: 90.3 [35.2.6-106.1] pg/ml; p = 0.001). Serum VEGF was higher in the infection group on day 4 (infection: 1128.6 [427.3-10000.0] versus control: 438.3 [214.1-677.6] pg/ml; p = 0.001). Peritoneal VEGF concentration was higher in the infection group at 48 h and day 4 (infection: 10000.0 [2563.0-10000.0] versus control: 477.8 [313.5-814.4] pg/ml; p = 0.001). Two-year recurrence rate was higher in patients with infection (infection: 30% versus control: 4%; p = 0.001).
  
  
  CONCLUSIONS
  Intra-abdominal infection increases IL-6 and VEGF after surgery for colorectal cancer. Amplification of inflammation and angiogenesis might be one of the mechanisms responsible for the higher recurrence rate observed in patients with anastomotic leakage or intra-abdominal abscess.
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain; Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Department of Surgery, Universidad Autónoma de Barcelona, Bellaterra, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Alonso
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain; Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Department of Surgery, Universidad Autónoma de Barcelona, Bellaterra, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pascual
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain; Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Salvans
authors.affiliation: Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Mayol
authors.affiliation: Consulting Service on Methodology for Biomedical Research, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Mojal
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Gil
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain; Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Department of Surgery, Universidad Autónoma de Barcelona, Bellaterra, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Grande
authors.affiliation: Section of Colon and Rectal Surgery, Hospital del Mar, Barcelona, Spain; Colorectal Cancer Research Group, Cancer Program, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Department of Surgery, Universidad Autónoma de Barcelona, Bellaterra, Spain. Electronic address: mpera@hospitaldelmar.cat.
authors.forename: M
authors.initials: M
authors.lastname: Pera
mesh_terms: D018784:Abdominal Abscess / Q000097:blood* / Q000209:etiology / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical / Q000009:adverse effects; D057868:Anastomotic Leak / Q000209:etiology; D001202:Ascitic Fluid / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000601:surgery*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism; D011446:Prospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000097:blood* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D042461:Vascular Endothelial Growth Factor A
keywords: Angiogenesis; Colorectal cancer; Inflammation; Postoperative intra-abdominal infection; Recurrence