Lymphatic mapping and sentinel lymphadenectomy for melanoma: past, present, and future

Intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL) is a minimally invasive technique to determine whether a primary melanoma has metastasized to the sentinel node in the regional drainage basin. The sentinel node is the first node that receives lymph from any primary solid neoplasm whose drainage pattern is determined by its anatomical site and by the normal variations in lymphatic anatomy. Data from an ongoing multicenter phase III trial indicate that LM/SL for melanoma is accurate and reproducible when undertaken after a 30-case learning phase during which LM/SL is followed by complete lymphadenectomy. Although the optimal postoperative management of patients with sentinel node micrometastases identified by immunohistochemical staining has not been determined, adjuvant vaccine immunotherapy is a promising nontoxic approach that takes advantage of melanoma's intrinsic immunogenicity. Among the current adjuvant immunotherapy trials is a multicenter phase III study of CancerVax vaccine, an allogeneic polyvalent melanoma cell vaccine; results will indicate whether this vaccine should become standard therapy after complete surgical resection of melanoma metastatic to sentinel nodes.