Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.
Han D, Zager JS, Shyr Y. Clinicopathologic Predictors of Sentinel Lymph Node Metastasis in Thin Melanoma. Published online before print November 4, 2013, doi: 10.1200/JCO.2013.50.1114 JCO December 10, 2013 vol. 31 no. 35 4387-4393