Metastasis of melanoma to regional lymph nodes is readily identified by sentinel lymph node (SLN) biopsy. Sentinel lymph node biopsy in patients with melanoma, while clearly not improving survival in patients with negative SLNs,1 offers other noteworthy advantages that justify the minor increase in morbidity over wide excision alone. These include superior staging and prognostication1,2; improved relapse-free survival, with more patients alive and free from relapse at 5 years postoperatively1; improved regional control and potentially less morbidity compared with node dissection performed because of palpable metastases3; and, perhaps, improved survival in patients with positive SLNs.1 Another underappreciated value of SLN biopsy is enhancement of our understanding of the metastatic process. Available prognostic factors, based on clinical parameters and histologic findings in the primary tumor, are limited in their ability to reliably determine which patients will manifest SLN metastasis or disseminated disease, indicating the presence of missing links in our understanding of how melanomas metastasize.4 There is an unmet clinical need for improved predictive biomarkers of metastasis in clinically localized primary melanomas. These new biomarkers can be derived only from improved understanding of melanoma biology and the inherent variations in the host response to the tumor.
Sondak VK, Messina JL. LymphangiogenesisHost and Tumor Factors in Nodal Metastasis. Arch Dermatol. 2008;144(4):536–537. doi:10.1001/archderm.144.4.536