Sentinel lymph node staging of cutaneous melanoma: predictors and outcomes

BackgroundThe authors updated their experience with sentinel lymph node (SLN) biopsy of clinically node negative (N0) melanoma to clarify indications, predictive factors, and outcomes.MethodsA review of patients from the authors' institution's prospective database (n = 397) was performed; survival statistics were obtained from the institutional tumor registry.ResultsThe SLN-positive (SLN+) rate was 16% (47 of 282) for lesions >1 mm thick; only 2 of 105 T1 lesions were SLN+. Thickness >2 mm, upper extremity primary, and ulceration predicted SLN+ status. Most SLN+ patients underwent completion node dissection; 12% had additional positive nodes. The false-negative SLN biopsy rate was 4.0%; the majority involved lower extremity and head and neck primaries. The overall complication rate was 26%; all were minor and resolved within 6 months. Overall 5-year survival rates were 73% and 92% for SLN+ and SLN-negative patients, respectively. SLN status was the most significant predictor of survival.ConclusionsSLN status, the most important determinant of outcome for clinically N0 melanoma, correlated with T stage, ulceration, and site. Staging of T1 lesions had low yield. A minority of completion node dissections yielded additional positive nodes.