Prognostic significance of red blood cell distribution width in gastrointestinal cancers: A meta-analysis.

Background: Many publications showed red blood cell distribution width (RDW) might associate with the prognosis of gastrointestinal (GI) cancers, however, the agreement has not been reached because of controversial results. This meta-analysis aimed to explore the prognostic value of RDW in GI cancers. Methods: Four common databases were comprehensively searched to look for relevant studies. The meta-analyses for overall survival (OS) and disease-free survival were performed using hazard ratio (HR) and 95% confidence interval (CI), and the meta-analyses for clinical parameters were conducted using odd ratio and 95% CI. Results: A total of 13 studies involving with 3,509 patients with GI cancers were included into this study. The results showed, compared to patients with low RDW, patients with high RDW tended to have shorter OS (HR = 1.75, 95%CI = 1.57-1.94,P < .01) and disease-free survival (HR = 1.67, 95%CI = 1.39-2.00,P < .01). High RDW was associated with larger tumor size (P < .01), worse differentiation (P = .02), deeper invasion (P < .01), earlier lymph node metastasis (P < .01), more advanced clinical stage (P < .01) and higher carcinoembryonic antigen level (P < .01) when compared to low RDW. Conclusion: High RDW was significantly associated with worse prognosis of GI cancers, which could be regarded as a prognostic biomarker for GI cancers. More prospective studies with large sample size and long follow-up period should be carried out to determine the prognostic significance of RDW in GI cancers in future.