Significance of multiple nodal basin drainage in patients with truncal melanoma

1687 Objectives The aim of this study was to assess whether an association exists between drainage to multiple basins and lymphatic metastasis in patients with truncal melanoma (TM). Methods The study included 260 patients with primary TM (163 men; median age 56.5 y/o) with a cN0 M0, who underwent a sentinel lymph node scintigraphy, followed by a sentinel lymph node biopsy. The tumour thickness (TT) was 4 mm in 21%, 44%, 25% and 10%, respectively, with a median TT of 1.51 mm. The majority of the patients had a Clark Level IV (58.8%), without ulceration (87.3%). Results 103 patients (39.6%) showed more than one basin; of these, 95 patients had 2 basins, 6 had 3 basins, and 2 had 4 basins of drainage. Nodal histology was positive for metastatic disease in 65 patients (25%), of whom, 40 had 1 basin, 24 had 2 basins and 1 had 3 basins of drainage. Of the 195 node-negative patients, 116 had 1 basin, 70 had 2 basins, 5 had 3 basins, and 2 had 4 basins of drainage (P= 0.89). In a median follow-up time of 36 months, 26 patients showed progressive disease (PD), of whom 15 had 1 basin and 11 had 2 basins of drainage (P=0.76). 20 patients died, of whom 11 had 1 basin and 9 had 2 basins of drainage (P=0.75). Conclusions There is no significant association between the number of drainage basins and sentinel node positivity or further progress of the disease in patients with TM.