D2-40 lymphatic marker for detecting lymphatic invasion in thin to intermediate thickness melanomas: association with sentinel lymph node status and prognostic value-a retrospective case study.

Abstract

Sentinel lymph node (SLN) status is the greatest prognostic factor of morbidity in melanoma. D2-40 antibody specifically marks lymphatic endothelium and has been used for identifying lymphatic invasion (LI) in multiple cancers. We sought to determine the relationship between melanoma lymphatic invasion (as detected using D2-40 on primary melanoma biopsies/excisions) and the presence or absence of melanoma in subsequent SLN biopsy. We retrospectively evaluated LI using D2-40 on primary biopsies/excisions from patients with thin to intermediate thickness (Breslow thickness: ≤2.0 mm) melanomas, who underwent lymphatic mapping and SLN biopsy, and whose SLN status was known. Sixty-four cases met the criteria and were available for analysis. We analyzed patient age, patient sex, mitotic rate, ulceration, tumor depth, and D2-40 detected LI as predictors of SLN status. Lymphatic invasion detection increased from 3.1% using hematoxylin and eosin only to 21.9% using D2-40. Twelve of 14 patients with D2-40 LI were SLN positive (positive predictive value, 85.7%). D2-40 LI was detected in the primary biopsy specimen of 12 of 18 patients with a positive SLN (sensitivity 66.7%). Of 50 patients without D2-40 LI, 44 were SLN negative (negative predictive value, 88.0%). Of 46 SLN-negative patients, 44 did not have D2-40 LI (specificity, 95.7%). Results are retrospective and limited to SLN biopsy performed at one institution. On univariate and multivariate analysis, D2-40-detected LI was the most significant predictor of SLN status. D2-40 antibody staining to detect lymphatic invasion should be incorporated in routine melanoma biopsy evaluation.