title: A systematic review of the accuracy and utility of peritoneal cytology in patients with gastric cancer.
abstract: BACKGROUND
  There is lack of uniformity in the utilization of peritoneal cytology in gastric cancer management. The identification of intraperitoneal free cancer cells (IFCCs) is believed to confer poor prognosis. However, while some of these patients are palliated, others may undergo more aggressive therapies. In this review, we aimed to identify and synthesize findings on the use of peritoneal cytology in predicting peritoneal recurrence and overall survival in curative gastric cancer patients.
  
  
  METHODS
  Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We determined the accuracy, sensitivity, and specificity of peritoneal cytology in predicting peritoneal recurrence based on four techniques-conventional cytology, immunoassay, immunohistochemistry, and reverse transcriptase-polymerase chain reaction. Recurrence rates and overall survival rates for curative patients were determined, based on positivity or negativity for IFCCs.
  
  
  RESULTS
  Twenty-eight articles were included. All four techniques showed wide variations in accuracy, sensitivity, and specificity in predicting peritoneal recurrence. Recurrence rates for patients positive for IFCCs ranged from 11.1 to 100%, while those negative for IFCCs had recurrence rates of 0-51%. Overall survival was significantly reduced for patients with positive IFCCs. Short follow-up periods and possible duplication of results may limit result interpretation.
  
  
  CONCLUSIONS
  The presence of IFCCs appears to increase the risk of peritoneal recurrence and is associated with worse overall survival in gastric cancer patients. Further incorporation of peritoneal cytology in clinical decision-making in gastric cancer depends on the development of a consistently accurate and rapid IFCC detection method.
authors.affiliation: Department of Surgery, University of Toronto, Toronto, ON, Canada.
authors.forename: Pierre-Anthony
authors.initials: PA
authors.lastname: Leake
authors.forename: Roberta
authors.initials: R
authors.lastname: Cardoso
authors.forename: Rajini
authors.initials: R
authors.lastname: Seevaratnam
authors.forename: Laercio
authors.initials: L
authors.lastname: Lourenco
authors.forename: Lucy
authors.initials: L
authors.lastname: Helyer
authors.forename: Alyson
authors.initials: A
authors.lastname: Mahar
authors.forename: Corwyn
authors.initials: C
authors.lastname: Rowsell
authors.forename: Natalie G
authors.initials: NG
authors.lastname: Coburn
mesh_terms: D003657:Decision Making; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D010529:Peritoneal Cavity / Q000166:cytology / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology; D013534:Survival; D013997:Time Factors