title: Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis.
abstract: BACKGROUND
  There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.
  
  
  METHODS
  We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.
  
  
  RESULTS
  A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.
  
  
  CONCLUSIONS
  Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.
authors.affiliation: Medical Oncology Unit, Oncology Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Fausto
authors.initials: F
authors.lastname: Petrelli
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Berenato
authors.affiliation: Surgical Oncology Unit, Surgery Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Turati
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Mennitto
authors.affiliation: Surgical Oncology Unit, Surgery Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Steccanella
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Caporale
authors.affiliation: Surgical Oncology Unit, Surgery Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Dallera
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: de Braud
authors.affiliation: Pathology Unit, Oncology Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Ezio
authors.initials: E
authors.lastname: Pezzica
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Di Bartolomeo
authors.affiliation: Surgical Oncology Unit, Surgery Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sgroi
authors.affiliation: Hepatobiliopancreatic Surgery Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Mazzaferro
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Pietrantonio
authors.affiliation: Medical Oncology Unit, Oncology Department, ASST Bergamo Ovest, Treviglio (BG), Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Barni
keywords: Gastric cancer (GC); Lauren classification; diffuse histology; meta-analysis; prognostic factor