The prognostic value of separate lymphatic invasion and vascular invasion in oesophageal squamous cell carcinoma: a meta-analysis and systematic review

Abstract

Abstract Background Lymphovascular invasion (LVI) is a factor correlated with a poor prognosis in oesophageal squamous cell carcinoma (ESCC). Lymphatic invasion (LI) and vascular invasion (VI) should be reported separately because they may indicate a difference in prognosis. The prognostic role of LI and VI in ESCC patients remains controversial. A meta-analysis was conducted to resolve this question. Methods We searched the PubMed, EMBASE, Web of Science, Scopus and Cochrane Library databases for studies on the association between LI and VI and the prognosis of patients with ESCC. The PICOs (Participant, Intervention, Comparison, Outcome) strategy were selected for the systematic review and meta-analysis. The effect size (ES) was the hazard ratio (HR) or relative ratio (RR) with 95% confidence intervals (CI) for overall survival (OS) and recurrence-free survival (RFS). Results A total of 27 studies with 5740 patients were included. We calculated the pooled results from univariate and multivariate analysis using the Cox proportional hazards method. The heterogeneity was acceptable in OS and RFS. According to the pooled results of multivariate analysis, both LI and VI were correlated with a worse OS. VI was a negative indicator for RFS, while the p value of VI was greater than 0.05. The prognostic role was weakened in subgroup analysis with studies using haematoxylin–eosin staining method. Conclusions Both LI and VI were indicators of a worse OS outcome. LI was a more significant indicator in predicting a worse RFS. More larger sample studies with immunohistochemical staining and good designs are required to detect the prognostic value of separate LI and VI in ESCC.