Prognostic significance of tumor length in patients with esophageal cancer undergoing radical resection A PRISMA-compliant meta-analysis

Background: The prognostic significance of tumor length in esophageal cancer (EC) remains controversial. Hence, we conducted a meta-analysis to quantitatively assess the prognostic significance of tumor length in EC patients. Method: A systematic literature search was conducted in the PubMed, EMBASE, and Web of Science. Hazard ratios (HRs) with their 95% confidence intervals (CIs) were used to assess the prognostic significance of tumor length for overall survival (OS), and disease-free survival (DFS) in EC patients. Results: A total of 21 articles with 22 eligible studies involving 9271 patients were included in this meta-analysis. The results of our pooling analyses demonstrated that tumor length was an independent prognostic parameter for OS (HR=1.38, 95% CI: 1.24-1.54, P<. 01) and DFS (HR= 1.29, 95% CI: 1.11-1.50, P<. 01) in EC patients. Moreover, our subgroup analysis and sensitivity analysis showed that the pooled HRs assessing the prognostic significance of tumor length did not significantly fluctuated, suggesting our pooling analyses were stable and reliable. Conclusion: The results of this meta-analysis demonstrated that long tumor is an independent risk of poor OS and DFS in EC patients, suggesting that it may provide additional prognostic information and thus contribute to a better stratification of EC patients, especially for those with no lymph node metastasis. However, more well-designed prospective clinical studies with large sample size are needed to strength our conclusion due to several limitations in this meta-analysis.