Sentinel lymph node status is the most important prognostic factor for thick (≥ 4 mm) melanomas

Background: The value of the status of the sentinel lymph node (SLN) in patients with thick melanomas (Breslow thickness ≥ 4 mm) is controversial. Patients and Methods: Using Kaplan‐Meier estimates and Cox regression models, we studied 152 patients with primary melanomas ≥ 4 mm thickness who underwent sentinel lymph node excision (SLNE) at the university hospitals of Hannover and Göttingen, Germany, between 1998 and 2006. Results: The median tumor thickness was 5.2 (4–18) mm; 58.5% of primary melanomas were ulcerated. Micrometastasis to a SLN was found in 48.7%. The patients with positive SLNs were significantly younger than those with negative SLN (p = 0.01). Of the complete lymph node dissections, 32% contained positive non‐SLN. The estimated 5 year recurrence‐free survival was 42.5 ± 5% (± standard error) (26.3 ± 6.6% after positive SLNE, 58.7 ± 7.1% after negative SLNE). The 5 year overall survival rate was 53.2 ± 5.4% (37.5 ± 8.1% after positive SLNE, 67.6 ± 6.7% after negative SLNE). By multivariate analysis, the SLN was a highly significant predictor for overall survival (p = 0.007, relative risk 2.3, 95%, confidence interval 1.2–4.2). The overall survival was significantly associated with penetration of nodal metastases into the SLN > 0.3 mm (p = 0.001). Other parameters such as tumor thickness, ulceration, age and sex were not significant. In the subgroup of patients with negative SLN, neither tumor thickness nor ulceration was significant. Conclusions: The status of the SLN represents the most important prognostic parameter in patients with thick melanomas, whereas other parameters such as tumor thickness and ulceration loose their prognostic value.