Improved Survival After Lymphadenectomy for Nodal Metastasis From an Unknown Primary Melanoma

Purpose No primary lesion is identified in 10% to 20% of patients presenting with palpable evidence of regional metastatic melanoma. Because the prognostic significance of unknown primary melanoma (MUP) is unclear, we compared clinical outcomes of patients with MUP and known primary melanoma (MKP) with regional nodal metastases. Patients and Methods We reviewed our 13,000-patient prospective melanoma database (1971 through 2005) to identify patients managed with regional lymphadenectomy for palpable nodal metastases from MUP or MKP. Multivariate analysis identified prognostic factors significant for survival. MUP and MKP were then matched by significant covariates. Overall survival (OS) was estimated by Kaplan-Meier method and compared by log-rank analysis. Results Multivariate analysis of data from 1,571 study patients identified four significant covariates associated with worse prognosis: age ≥ 60 years (hazard ratio [HR] = 1.294; P = .0017), male sex (HR = 1.335; P = .0004), nodal tumor burden ≥ one (H...