Sentinel node studies in truncal melanoma: does an increased number of draining basins correlate with an increased risk of lymph metastasis?

Abstract

Objectives: To assess whether an association exists between drainage to multiple basins and lymphatic metastasis in patients with truncal melanoma. Methods: We retrospectively reviewed 227 patients with primary malignant melanoma between January 2006 and December 2009. All patients received an intradermal injection of 99mTc-nanocolloid and lymphoscintigraphy followed by sentinel node biopsy. Pre-staging histology with Breslow thickness from excision biopsy was also obtained. Results: 82/227 (36%) patients with primary truncal melanoma were identified. Nodal histology was positive for metastatic disease in 27/82 (32.9%) patients. Of these 27, 15 had 1 basin of drainage, 7 had 2 basins of drainage and 5 had 3 basins of drainage. Of the 55 node-negative patients, 35 had 1 basin, 18 had 2 basins and 2 had 3 basins of drainage. We found no significant correlation with sentinel node positivity and those that had ≥2 drainage basins. Breslow thickness was available in 65/82(79.2%) patients. Sentinel node biopsy was positive in 6/28 patients who had <1.5 mm thickness, 8/14 who had a 1.5–3.9 mm thickness and 9/23 who had ≥4 mm thickness. There was a significant correlation between Breslow thickness of ≥4 mm and nodal positivity (P = 0.03). Conclusion: This study demonstrates no association between multiple drainage basins and sentinel node histology. Sentinel lymph node status did correlate with Breslow thickness.

Prognostic Value of Multiple Draining Lymph Node Basins in Melanoma: A Matched-Pair Analysis Based on the John Wayne Cancer Institute Experience

“…Had patients not been matched by stage, a disproportionate distribution of stage I/II and stage III cases could have biased survival and recurrence data. While multivariable analysis, and not matching, may be the standard method of retrospectively evaluating two groups to correct for confounders and population heterogeneity, all previous studies of MBD have used these methods with conflicting results ( 3 – 6 , 8 , 9 , 20 ). Given the inconsistent conclusions found with multivariable analysis, we hope to bring a new perspective to this clinical scenario by using the alternative statistical method of base pair matching to add to the understanding of the true prognostic value of MBD when found on lymphoscintigraphy.…”