Lymphovascular invasion as a prognostic factor in melanoma.

The prognostic significance of lymphovascular invasion (LVI) in melanoma remains controversial. Clinicopathologic data from a prospective trial of patients with melanoma were analyzed with respect to LVI. Disease-free survival and overall survival (OS) were evaluated by Kaplan-Meier (KM) analysis. Univariate and multivariate analyses were performed to evaluate factors predictive of tumor-positive sentinel nodes (SLN) and survival. A total of 2183 patients were included in this analysis; 171 (7.8%) had LVI. Median follow-up was 68 months. Factors associated with LVI included tumor thickness, ulceration, and histologic subtype (P < 0.05). LVI was associated with a greater risk of SLN metastasis (P < 0.05). By KM analysis, LVI was associated with worse OS (P = 0.0009). On multivariate analysis, age, gender, thickness, ulceration, anatomic location, and SLN status were predictors of OS; however, LVI was not an independent predictor of OS. Among patients with regression, the 5-year OS rate was 49.4 per cent for patients with LVI versus 81.1 per cent for those with no LVI (P < 0.0001). LVI is associated with a greater risk of SLN metastasis. Although LVI is not an independent predictor of OS in general, it is a powerful predictor of worse OS among patients who have evidence of regression of the primary tumor.