The Prognostic Significance of Nonsentinel Lymph Node Metastasis in Melanoma
We hypothesized that metastasis beyond the sentinel lymph nodes (SLN) to the nonsentinel nodes (NSN) is an important predictor of survival.
Materials and methods
Analysis was performed of a prospective multi-institutional study that included patients with melanoma ≥1.0 mm in Breslow thickness. All patients underwent SLN biopsy; completion lymphadenectomy was performed for all SLN metastases. Disease-free survival (DFS) and overall survival (OS) were computed by Kaplan–Meier analysis; univariate and multivariate analyses were performed to identify factors associated with differences in survival among groups.
A total of 2335 patients were analyzed over a median follow-up of 68 months. We compared 3 groups: SLN negative (n = 1988), SLN-only positive (n = 296), and both SLN and NSN positive (n = 51). The 5-year DFS rates were 85.5, 64.8, and 42.6% for groups 1, 2, and 3, respectively (P < 0.001). The 5-year OS rates were 85.5, 64.9, and 49.4%, respectively (P < 0.001). On univariate analysis, predictors of decreased OS included: SLN metastasis, NSN metastasis, increased total number of positive LN, increased ratio of positive LN to total LN, increased age, male gender, increased Breslow thickness, presence of ulceration, Clark level ≥ IV, and axial primary site (in all cases, P < 0.01). When the total number of positive LN and NSN status were evaluated using multivariate analysis, NSN status remained statistically significant (P < 0.01), while the total number of positive LN and LN ratio did not.
NSN melanoma metastasis is an independent prognostic factor for DFS and OS, which is distinct from the number of positive lymph nodes or the lymph node ratio.
KeywordsOverall Survival Sentinel Lymph Node Sentinel Lymph Node Biopsy Sentinel Lymph Node Metastasis Breslow Thickness
The authors would like to sincerely thank Deborah Hulsewede, Sherri Matthews, Wanda Greenwell, Pam Harlan, Alex Scroggins, and Ivan Deyahs for their dedication and hard work in managing the Sunbelt Melanoma Trial. We also express gratitude to Advertek, Inc., for their expert data management. Finally, we thank all of the patients, centers, and investigators who participated in the trial. This work is supported by a grant from Schering Oncology-Biotech. Schering Oncology-Biotech had no access to data, no input into the analysis of the data, and has not participated in the preparation or review of this manuscript.
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