Lymphovascular invasion as a poor prognostic indicator in thoracic esophageal carcinoma: a systematic review and...

The ability to further stratify patients with esophageal carcinoma (EC) in the same stage into high-risk patients by the presence of lymphovascular invasion (LVI) may permit refinement of multi-modality therapy. However, the role of LVI in the prognosis of EC is not definite. A meta-analysis was conducted to investigate the relationship between LVI and EC prognosis. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for studies on the association between LVI and prognosis of EC. Only studies with patient survival data related to LVI were included. The effect size for this analysis was the hazard ratio (HR) with 95% confidence intervals (CI) for overall survival (OS) and recurrence-free survival (RFS). Thirty-five studies with 9876 patients were included according to the defined inclusion and exclusion criteria. LVI was a poor indicator for the OS (HR = 1.64, 95% CI: 1.44-1.87, P < 0.001) and RFS (HR = 1.79, 95% CI: 1.38-2.34, P < 0.001). However, the heterogeneity was medium in OS (I2 = 61.2%, P < 0.001) and extreme in RFS (I2 = 77.5%, P < 0.001). In subgroup analysis, heterogeneity was originated from the staining method and proportion of early disease (stage (I + II)). We concluded that LVI was a poor prognostic indicator in patients with EC, especially in those studies with the IHC staining method and a high proportion of early disease (stage (I + II)).