Background: Lymphovascular invasion (LVI) is considered a high-risk pathologic feature in resected non-small cell carcinoma (NSCLC). The ability to stratify stage I patients into risk groups may permit refinement of adjuvant treatment recommendations. We performed a systematic review and meta-analysis to evaluate whether the presence of LVI is associated with disease outcome in stage I NSCLC patients.
Methods: A systematic search of the literature was performed (1990 to December 2012 in MEDLINE/EMBASE). Two reviewers independently assessed the quality of the articles and extracted data. Pooled hazard ratios (HRs) and 95% confidence intervals (CI) were estimated with a random effects model. Two end points were independently analyzed: recurrence-free survival (RFS) and overall survival (OS). We analyzed unadjusted and adjusted effect estimates, resulting in four separate meta-analyses.
Results: We identified 20 published studies that reported the comparative survival of stage I patients with and without LVI. The unadjusted pooled effect of LVI was significantly associated with worse RFS (HR, 3.63; 95% CI, 1.62 to 8.14) and OS (HR, 2.38; 95% CI, 1.72 to 3.30). Adjusting for potential confounders yielded similar results, with RFS (HR, 2.52; 95% CI, 1.73 to 3.65) and OS (HR, 1.81; 95% CI, 1.53 to 2.14) both significantly worse for patients exhibiting LVI.
Conclusions: The present study indicates that LVI is a strong prognostic indicator for poor outcome for patients with surgically managed stage I lung cancer. Future prospective lung cancer trials with well-defined methods for evaluating LVI are necessary to validate these results.
Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.