Absence of second echelon involvement in melanoma patients with limited Breslow thickness and low sentinel node tumor load

Abstract

9060 Background: The sentinel node (SN) procedure has become a widely used staging procedure for stage I/II melanoma. Most melanoma patients with a positive SN undergo completion lymph node dissection and, as a consequence, frequently experience associated morbidity. However, only approximately 20% of these patients have second echelon metastases. The aim of the present study therefore was to predict the absence of second echelon metastases in patients with a positive SN based on primary melanoma features, depth of SN invasion and SN tumor load. Methods: Of 70 SN positive patients, 18 had second echelon metastases. Penetrative depth of metastatic cells into the SN and SN tumor load (largest diameter and total tumour area) were assessed with morphometry. Primary tumour features concerned Breslow thickness, Clark level and ulceration. Results: None of the patients with a Breslow thickness <2.5 mm and a SN tumor load <0.3 mm2 had second echelon metastases. Similarly, none of the patients with a Breslow thickness <2.5 mm and SN depth of invasion <200 μm had second echelon metastases. Lastly, none of the patients with a Breslow thickness <2.5 mm and a diameter of the largest SN deposit <40 μm had second echelon metastases. Conclusions: A combination of limited Breslow thickness and low SN tumour load predicts absence of second echelon metastases in melanoma with a positive SN. We therefore propose that this subgroup may be spared completion lymph node dissection. No significant financial relationships to disclose.