Staging of Regional Lymph Nodes in Melanoma: A Case for Including Nonsentinel Lymph Node Positivity in the American Joint Committee on Cancer Staging System

IMPORTANCE Survival varies widely in patients with stage III melanoma. The existence of clinical significance for positive nonsentinel lymph node (NSLN) status would warrant consideration for incorporation into the American Joint Committee on Cancer staging system and better prediction of survival. OBJECTIVE To evaluate whether disease limited to sentinel lymph nodes (SLNs) represents different clinical significance than disease spread into NSLNs. DESIGN, SETTING, AND PARTICIPANTS The database of the John Wayne Cancer Institute at Saint John’s Health Center, Santa Monica, California, was queried for all patients with SLNs positive for cutaneous melanoma who subsequently underwent completion lymph node dissection. MAIN OUTCOMES AND MEASURES Disease-free survival, melanoma-specific survival (MSS), and overall survival. RESULTS A total of 4223 patients underwent SLN biopsy from 1986 to 2012. Of these patients, 329 had a tumor-positive SLN. Of the 329, 250 patients (76.0%) had no additional positive nodes and 79 (24.0%) had a tumor-positive NSLN. Factors predictive of NSLN positivity included older age (P = .04), greater Breslow thickness (P