The pretreatment thrombocytosis as one of prognostic factors for gastric cancer: A systematic review and meta-analysis

Background & aims: At present, increasing reports have shown that pretreatment platelet count was associated with the prognosis of many types of cancer. We performed rounded analysis to comprehensively analyze and evaluate the prognostic significance of pretreatment thrombocytosis for patients with gastric cancer. Methods: We identified relevant studies by searching database including PubMed, Embase, Cochrane Library and Web of Science. The relative risk (RR) with its 95% confidence interval (CI) was used to assess the correlation between thrombocytosis and overall survival (OS) of gastric cancer patients. We also conducted subgroup analysis and sensitivity analysis for the prognostic effect of thrombocytosis on OS. The analysis was performed and assessed using Review Manager 5.2. Results: A total of nine studies including 7158 participants were included in this systematic review. Analysis results showed that pretreatment thrombocytosis had a close relationship with 1, 3 and 5 years survival of gastric cancer, with the pooled RRs being 0.80 (95% CI 0.71-0.90; P=0.0004), 0.65 (95% CI 0.45-0.92; P=0.02) and 0.64 (95% CI 0.47-0.87; P=0.004) respectively. Conclusions: The present rounded analysis suggests that pretreatment thrombocytosis may have significant association with poor survival of patients with gastric cancer.