Sentinel lymph node (SLN) biopsy provides valuable prognostic information for patients with thick (T4) melanoma.
Post hoc analysis of data from a prospective, randomized trial.
Academic and private hospitals.
Data of 240 patients with melanoma thicker than 4 mm were analyzed. Patients with tumor-positive SLNs underwent completion lymphadenectomy. Disease-free and overall survival were evaluated by Kaplan-Meier analysis. Univariate and multivariate analyses were performed to evaluate factors predictive of tumor-positive SLNs and disease-free and overall survival.
Median thickness of melanoma was 5.6 mm, and patients were followed up for a median of 50 months. The SLNs were tumor positive in 100 patients (41.7%); 18% of these had additional positive nodes on completion lymphadenectomy. Extremity tumor location (risk ratio, 1.66; 95% confidence interval, 1.24-2.24; P = .001), Clark level (1.95; 1.33-2.87; P = .02), and lymphovascular invasion (1.57; 1.13-2.17; P = .01) were associated with a greater risk of tumor-positive SLNs. The patients with tumor-negative SLNs had significantly better median disease-free survival (46.5 vs 31.0 months; P = .04) and overall survival (55.5 vs 43.0 months; P = .004) compared with patients with tumor-positive SLNs. On multivariate analysis, male sex (risk ratio, 1.59; 95% confidence interval, 1.05-2.50; P = .02), increasing Breslow thickness (1.58; 1.10- 2.30; P = .03), ulceration (1.73; 1.18-2.59; P = .02), and tumor-positive SLNs (1.68; 1.17-2.43; P = .009) were associated with worse overall survival.
The SLN biopsy provides useful prognostic information for patients with T4 melanoma.