Prognostic significance of microscopic tumor burden in sentinel lymph node in patients with cutaneous melanoma.

BACKGROUND/AIM Sentinel lymph node (SLN) biopsy provides useful prognostic information for patients with melanoma. The present study sought to determine the prognostic value of SLN tumor burden on overall survival (OS) and disease-free survival (DFS). We also assessed its association with non-sentinel lympth node (NSLN) involvement. PATIENTS AND METHODS We conducted a retrospective review of 138 patients with cutaneous melanoma, who were found to have positive SLNs from 2000 to 2011. SLN tumor burden was measured in the maximum diameter of the largest tumor focus. OS and DFS were assessed by the Kaplan-Meier method and Cox proportional hazard regression model. A logistic regression model was used to evaluate the association between SLN tumor burden and NSLN positivity. RESULTS On multivariable analysis, SLN tumor burden was significantly associated with OS (hazard ratio (HR)>1 vs. ≤ 1 mm=5.15; 95% confidence interval (CI)=2.32-11.44; p<0.0001) and DFS rate (HR>1 vs. ≤ 1 mm=3.02; 95% CI=1.37-6.67; p=0.0064). On univariate analysis, SLN tumor burden was significantly associated with NSLN positivity (OR>1 vs. ≤ 1 mm=3.41; 95% CI=1.03-11.27; p=0.04). CONCLUSION SLN tumor burden, by measuring the maximum diameter of the largest tumor focus, is significantly associated with OS, DFS and NSLN involvement.