Improved staging of node-negative patients with intermediate to thick melanomas (>1 mm) with the use of lymphatic mapping and sentinel lymph node biopsy

Background: Elective lymph node dissection (ELND) may contribute to a survival benefit in certain stratified subsets of melanoma patients. We hypothesized that lymphatic mapping and sentinel lymph node (SLN) biopsy (with complete node dissection if metastases are present) may improve both staging and survival of patients with clinically negative nodes, without subjecting all patients to the morbidity associated with complete ELND. Methods: We reviewed the data for all 14,914 NO patients of the AJCC Melanoma Staging Database to determine the effect of SLN biopsy and ELND on staging and survival. Results: Retrospective analysis revealed that there was an apparent statistically significant survival advantage to SLN biopsy in patients with melanomas > 1 mm (n = 9024; 68.5% and 26.2% reduction in mortality compared with patients staged to be NO by clinical exam and ELND, respectively; P < .0001). Five-year survivals were 90.5%, 77.7%, and 69.8%, respectfully, for patients staged by SLN biopsy (n = 2552), ELND (n = 2014), and clinical examination alone (n = 5192). The survival advantage of SLN biopsy was statistically significant for each T-stage category (T2, T3, and T4) and ulceration status. There was no advantage to SLN biopsy in patients with melanomas < 1 mm (n = 5890). Conclusions: SLN biopsy provides more accurate staging and may contribute to a survival benefit in populations of patients with melanoma.