Aim: Recently, several studies have reported that thrombocytosis may be associated with the poor prognosis of colorectal cancer (CRC). Nevertheless, their conclusions were still controversial. Results & methodology: We searched PubMed, Embase, Cochrane Library and Web of Science up to April 2016. A total of 30 studies including 9129 patients were included in this meta-analysis. Thrombocytosis had a close relationship with the poor overall survival of CRC compared with normal platelet counts, with the pooled hazard ratios being 1.89 (95% CI: 1.45-2.47; p < 0.00001) and 1.83 (95% CI: 1.33-2.53; p = 0.0002), with univariate and multivariate analyses, respectively.
Discussion & conclusion: This meta-analysis indicated that thrombocytosis may be a cost-effective and noninvasive indicator for poor prognosis of patients with CRC, especially for overall survival.
Keywords: colorectal cancer; meta-analysis; platelet counts; prognosis; thrombocytosis.