Prognostic significance of lymphovascular invasion in radical cystectomy on patients with bladder cancer: A systematic review and meta-analysis

Abstract

Purpose: The objective of the present study was to conduct a systematic review and meta-analysis of published literature to appraise the prognostic value of lymphovascular invasion (LVI) in radical cystectomy specimens. Materials and Methods: Following the PRISMA statement, PubMed, Cochrane Library, and SCOPUS database were searched from the respective dates of inception until June 2013. According to inclusion criteria, 21 articles were included from the 389 articles initially identified. Methodological assessment for the included studies was performed. The log-Hazard Ratios (HR) and their 95% Confidence intervals (CI) were obtained from each study and the meta-analysis was performed subsequently using a random-effect model. Subgroup analyses were performed to examine if our pooled estimate of the prognostic value was influenced by data parameters. Sensitivity analyses were performed by removing one study at a time. A test of heterogeneity of the combined HRs was carried out using the Chi-square test and Higgins I-squared statistic. Publication bias was evaluated using the funnel plot. Results: A total of 21 articles met the eligibility criteria for this systematic review, which included a total of 12,527 patients ranging from 57 to 4,257 per study. LVI was detected in 34.6% in radical cystectomy specimens. LVI was associated with higher pathological T stage and tumor grade, as well as lymph node metastasis. The pooled HR was statistically significant for recurrence-free survival (pooled HR, 1.61

95% CI, 1.26?2.06), cancer-specific survival (pooled HR, 1.67

95% CI, 1.38?2.01), and overall survival (pooled HR, 1.84

95% CI, 1.27?2.66), despite the heterogeneity among included studies. On sensitivity analysis, the pooled HRs and 95% CIs were not significantly altered when any one study was omitted. The funnel plot for overall survival demonstrated a certain degree of asymmetry, which showed slight publication bias. Conclusions: This meta-analysis indicates that LVI is significantly associated with poor outcome in patients with bladder cancer who underwent radical cystectomy. Adequately designed prospective studies are required to provide the precise prognostic significance of LVI in bladder cancer.