Thrombocytosis predicts poor prognosis of Asian patients with colorectal cancer: A systematic review and meta-analysis

Background: There is no study analyzing and evaluating the prognostic role of thrombocytosis in Asian patients with colorectal cancer (CRC). Methods: A systematic search of articles (PubMed, Embase, and the Cochrane Library) was performed to identify studies using the terms Platelet count, Thrombocytosis, Thrombocytoses, Thrombocythemia or Thrombocythemias with colon, colonic, rectal, rectum, colorectal and prognostic, prognosis, survival or outcome. Results: Thirteen eligible studies with 3964 patients were included. Thrombocytosis was associated with a poorer overall survival (HR of 1.88 [95% CI: 1.24-2.85; P = .003] with univariate analyses, HR of 2.07 [95% CI: 1.2-3.56; P = .008] with multivariate analyses), disease-free survival (HR of 2.58 [95% CI: 1.87-3.57; P < .00001] with multivariate analyses) and cancer specific survival (HR of 2.55 [95% CI: 1.68-3.85; P < .00001]) in Asian patients with CRC. Thrombocytosis had a significant association with female gender, tumor location in the colon, higher pathological T-stage, pathological positive N-stage, but not with lymphatic involvement and venous involvement. Conclusion: The present meta-analysis demonstrates that thrombocytosis is a potentially useful tool for predicting poor survival in Asian patients with CRC, especially for overall survival.