The benefit of a sentinel lymph node biopsy and adjuvant therapy in thick (>4 mm) melanoma: multicenter, retrospective study of 291 Japanese patients.

The benefit of a sentinel lymph node (SLN) biopsy and adjuvant therapy for patients with thick (>4 mm) melanoma has not been well studied in the Asian population. We examined the benefit of an SLN biopsy and adjuvant therapy on prognosis in Japanese patients with thick melanoma. A review of the melanoma database collected from 26 institutions in Japan identified 291 patients with thick melanoma between 2005 and 2010. Univariate and multivariate analyses were performed to evaluate the factors predictive of the overall survival (OS) and the disease-free survival (DFS). Of the 242 patients with thick melanoma who underwent an SLN biopsy, the results for 96 (40%) were positive. On multivariate analysis, increased Breslow thickness (relative risk, 1.11; 95% confidence interval, 1.05-1.17; P=0.0002) and SLN metastasis (2.14; 1.04-4.43; P=0.040) were associated with a poor OS. Increased Breslow thickness (1.11; 1.04-1.18; P =0.0018), ulceration (3.11; 1.25-7.72; P=0.014), satellitosis (3.89; 1.62-9.31; P=0.0023), and SLN metastasis (2.24; 1.16-4.36; P=0.017) were associated with DFS. Adjuvant chemotherapy had no impact on either OS or DFS. Adjuvant use of a monthly dermal injection of interferon-β (IFN-β) was associated with a improvement in both OS (0.34; 0.17-0.67; P=0.0022) and DFS (0.42; 0.20-0.86; P=0.018). An SLN biopsy provided useful prognostic information and the adjuvant use of IFN-β improved both OS and DFS in Japanese patients with thick melanoma. These results were consistent with those of previous studies carried out on a white population. Therefore, we suggest that an SLN biopsy and adjuvant IFN should be considered for patients with thick melanoma irrespective of the Breslow thickness or ethnicity.