Sentinel lymph node biopsy in patients with thick (=4 mm) melanoma: a single-centre experience

Background and objective Lymphatic mapping/sentinel lymph node biopsy (LM/SLNB) have become routine techniques for staging the regional lymph nodes in early stage melanoma, yet their role in the management of thick (= 4 mm) melanoma is debated. The aim of the present study is to review our experience with LM/SLNB in a series of patients with thick primary melanoma, to evaluate its utility in this melanoma subset. Patients and methods Thirty patients (18 men and 12 women; mean age 70.6 years; median 75 years) with thick primary melanoma underwent LM/SLNB, using both radioisotope and blue dye. The statistical tests were performed by using SAS software for Windows, version 8.2. Results The primary tumour sites were head/neck (n = 5; 16.6%), trunk (n = 10; 33.3%), and extremities (n = 15; 50%). Tumour thickness ranged from 4 to 17 mm (mean 5.14 mm; median 4.5 mm). Ulceration was observed in 23 (76.6%) tumours. Eleven patients (36.6%) had at least a positive sentinel lymph node (SLN). The mean follow-up was 27.3 months (median 26 months; range 5-63 months). Patients without SLN metastases had a 5-year disease-free survival rate of 78.9%, vs. 18.2% for patients with SLN metastases (P = 0.0121 by log rank test). The 5-year overall survival rate for patients without SLN metastases was 89.5%, whereas patients with SLN metastases had a 5-year overall survival rate of 36.4% (P = 0.0272 by log rank test). Conclusion Our retrospective analysis indicates that the SLN status is predictive of recurrence and survival in patients with thick melanoma, and LM/SLNB should be routinely performed in this subset of melanoma patients.