Improved long-term survival in patients with intermediate thickness primary melanoma managed by sentinel node biopsy

8576 Background: Although improved disease-free survival (DFS) with sentinel node biopsy (SNB) for clinically localized melanoma was observed at the interim analysis from the first Multicenter Selective Lymphadenectomy Trial (MSLT-I) there was not yet an improvement in overall survival (OS). We hypothesize this was due to the few observed early deaths. To investigate this we simulated the MSLT-1 protocol using our institutional database. Methods: 3,800 patients undergoing wide excision with or without SNB were matched by primary stage/ulceration/site and patient demographics. Patients with positive sentinel nodes (SN) underwent immediate completion lymphadenectomy (CLND) whereas non-SNB patients managed by nodal observation underwent delayed CLND at nodal recurrence. Survival was determined by the Kaplan-Meier method. Significance was determined using log-rank and Cox regression analysis. Results: Among matched pairs of SNB and non-SNB patients with 1.2–3.5 mm primaries, projected 10-year OS was 76% with ...