Correlation of lymphovascular invasion with clinicopathological factors in invasive breast cancer: a meta-analysis.

Objectives: Lymphovascular invasion (LVI) has been associated with a poor outcome in patients with breast cancer, but it is not included in international TNM staging system and molecular subtype criterion. The current studies have reported the relation between LVI and the tumor size (T), the status of axillary lymph node (ALN), age, histological grade in invasive breast cancer, but the results were debatable. So the meta-analysis was conducted to confirm the relation between LVI and the four clinicopathological factors.

Methods: Literature was searched by entering the terms: breast AND (neoplasm OR cancer OR carcinoma) AND (lymphovascular OR "lymphatic vessel" OR "vascular vessel" OR "blood vessel" OR "lymph vessel") AND (invasion OR "carcinoma embolus") AND (lymph node OR grade OR size OR clinicopathological) in PubMed, The merged odds ratio (OR) and 95% confidence interval (CI) were estimated using fixed-effect or random-effect model, RevMan 5.3 was used to analyze the relation between LVI and tumor size, status of ALN, age, histological grade in invasive breast cancer respectively. The fail-safe number was used to estimate publication bias.

Results: The analysis included 6 studies, LVI positive rate was significant lower in T≤2 cm, ALN negative, age >50 y and histological grade 1 groups statistically. The OR and 95% CI were 0.53 [0.46, 0.61], 0.23 [0.15, 0.35], 1.62 [1.42, 1.85], 0.36 [0.17, 0.77] respectively.

Conclusions: LVI was significantly correlated with the expression status of the tumor size, status of ALN, age, histological grade in invasive breast cancer, and was consistent with adverse features of the four factors.