title: Prognostic significance of peritoneal tumour cells identified at surgery for colorectal cancer.
abstract: BACKGROUND
  The prognostic significance of intraperitoneal tumour cells (IPCs) in colorectal cancer is not clear. This study aimed to determine whether detection of IPCs could be used a prognostic marker for selecting patients at high risk of recurrence.
  
  
  METHODS
  The study included 226 patients with colorectal cancer who underwent elective resection. Clinical variables, including the presence of IPCs, were analysed for their prognostic significance.
  
  
  RESULTS
  Thirty-three patients (14.6 per cent) were positive for IPCs. Univariable analysis indicated that the presence of IPCs was a significant prognostic factor in patients with stage III colorectal cancer; the 5-year disease-specific survival rate was 14 per cent in IPC-positive patients versus 79 per cent in those without IPCs (P < 0.001). Multivariable analysis showed that IPC positivity was the most robust prognostic factor in stage III disease (hazard ratio 2.2; P = 0.003), whereas nodal category (N1 or N2) showed no significant association with prognosis. In addition, IPCs were associated with haematogenous recurrence (P = 0.004) rather than peritoneal or local recurrence (P = 0.077) in patients with stage III disease.
  
  
  CONCLUSIONS
  The presence of IPCs is a significant prognostic factor in patients with stage III colorectal cancer.
authors.affiliation: Department of Surgery, Kitasato University Hospital, Kitasato 1-15-1, Sagamihara 228-8555, Kanagawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Katoh
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Ozawa
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging / Q000379:methods; D010533:Peritoneal Lavage; D010534:Peritoneal Neoplasms / Q000473:pathology* / Q000556:secondary; D011379:Prognosis; D012307:Risk Factors; D055815:Young Adult