title: Free intraperitoneal tumor cells and outcome in gastric cancer patients: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Despite continuously improving therapies, gastric cancer still shows poor survival in locally advanced stages with local recurrence rates of up to 50% and peritoneal recurrence rates of 17% after curative surgery. We performed a systematic review with meta-analyses to clarify whether positive intraperitoneal cytology (IPC) indicates a high risk of disease recurrence and poor overall survival in gastric cancer.
  
  
  METHODS
  Multiple databases were searched in December 2014 to identify studies on the prognostic significance of positive intraperitoneal cytology in gastric cancer, including: Medline, Biosis, Science Citation Index, Embase, CCMed and publisher databases. Hazard ratios (HR) and associated 95% confidence intervals (CI) were extracted from the identified studies. A meta-analysis was performed using a random-effects model on overall survival, disease-free survival and peritoneal recurrence free survival.
  
  
  RESULTS
  A total of 64 studies with a cumulative sample size of 12,883 patients were included. Cytology, quantitative real time polymerase chain reaction (PCR) or both were performed in 35; 21 and 8 studies, respectively. Meta analyses revealed free intraperitoneal tumor cells (FITC) to be associated with poor overall survival in univariate (HR 3.27; 95% CI 2.82 - 3.78]) and multivariate (HR 2.45; 95% CI 2.04 - 2.94) analysis and poor peritoneal recurrence free survival in univariate (4.15; 95% CI 3.10 - 5.57) and multivariate (3.09; 95% CI 2.02 - 4.71) analysis. Subgroup analysis showed this effect to be independent of the detection method, Western or Asian origin or the time of publication.
  
  
  CONCLUSIONS
  FITC oder positive peritoneal cytology is associated with poor survival and increased peritoneal recurrence in gastric cancer.
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Pecqueux
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Fritzmann
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Mariam
authors.initials: M
authors.lastname: Adamu
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Kristian
authors.initials: K
authors.lastname: Thorlund
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kahlert
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Reißfelder
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Weitz
authors.affiliation: Department for Visceral, Thoracic and Vascular Surgery, University of Dresden, Dresden, Germany.
authors.forename: Nuh N
authors.initials: NN
authors.lastname: Rahbari
mesh_terms: D000818:Animals; D006652:Histological Techniques / Q000379:methods*; D006801:Humans; D010537:Peritoneum / Q000473:pathology*; D011379:Prognosis; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: free intraperitoneal tumor cells; gastric cancer; peritoneal lavage; prognosis