Clinicopathological factors and gastric cancer prognosis in the iranian population: a meta-analysis.

BACKGROUND: Gastric cancer is the most common cancer in the Iranian population. The aim of this study was to determine the effect of clinicopathological factors on prognosis by meta-analysis. MATERIALS AND METHODS: A literature search was conducted using MEDLINE, EMBASE and Cochrane library and extensive literature search using the Persian databases until February 2011. Prospective follow up studies with multivariate analysis of overall survival of the patients with gastric cancer were included in this review. The data were analyzed by CMA.2. Publication bias are checked by funnel plot and data are shown as Forest plots. RESULTS: From a total of 63 articles, 14 retrospective studies which examined 5 prognostic factors and involving 10,500 patients were included. Tumor size (>35mm) was the main significant factor predicting an unfavorable prognosis for the patients with gastric cancer (RR=1.829 , p<0.001) followed by presence of distant metastases (RR=1.607 , p<0.001), poor differentiation (RR=1.408 , p<0.001) and male sex (RR=1.194, p<0.001). Lymph node metastases (RR=1.058, p=0.698) and moderate differentiation (RR=0.836, p=0.043) were not statistically significant as prognostic factors. CONCLUSIONS: This meta-analysis suggests that tumor size>35mm, poor differentiation, presence of distant metastasis and male gender are strongly associated with a poor prognosis in Iranian patients with gastric cancer.