Prognostic significance of pretreatment elevated platelet count in patients with colorectal cancer: a meta-analysis

BACKGROUND The prognostic effect of pretreatment elevated platelet count remains controversial in colorectal cancer patients. We conducted this meta-analysis to evaluate the prognostic impact of it in these patients. METHODS PubMed, EMBASE and Cochrane Library were searched and studies on the prognostic significance of pretreatment elevated platelet count in colorectal patients were identified. We performed the meta-analysis, using overall survival and disease-free survival as outcomes and presenting data with hazard ratio and its 95% confidence interval. Heterogeneity among studies and publication bias were also evaluated. RESULTS Thirty studies were included in the meta-analysis. Compared with normal platelet count, pretreatment elevated platelet count was associated with poorer overall survival (Hazard ratio = 1.837, 95% confidence interval, 1.497 to 2.255, p = 0.000) and poorer disease-free survival (Hazard ratio = 1.635, 95% confidence interval, 1.237 to 2.160, p = 0.001) in patients with colorectal cancer. In subgroup analyses, pretreatment elevated platelet count was also associated with poorer overall survival and disease-free survival in most subgroups. CONCLUSION Pretreatment elevated platelet count was an independent prognostic factor of overall survival and disease-free survival in colorectal cancer patients. Large-scale prospective studies and a validation study are warranted.