Long-term results of a multi-institutional randomized trial comparing prognostic factors and surgical results for intermediate thickness melanomas (1.0 to 4.0 mm)

Background: Ten- to 15-year survival results were analyzed from a prospecti ve multi-institutional randomized surgical trial that involved 740 stages I and II melanoma patients with intermediate thickness melanomas (1.0 to 4.0 mm) and compared elective (immediate) lymph node dissection (ELND) with cl inical observation of the lymph nodes as well as prognostic factors that in dependently predict outcomes. Methods: Eligible patients were stratified according to tumor thickness, an atomical site, and ulceration, and then prerandomized to either ELND or nod al observation. By using Cox stepwise multivariate regression analysis, the independent predictors of outcome were tumor thickness (P < .001), the pre sence of tumor ulceration (P < .001), trunk site (P = .003), and patient ag e more than 60 years (P = .01). Results: Overall 10-year survival was not significantly different for patie nts who received ELND or nodal observation (77% vs. 73%; P = .12). Among th e prospectively stratified subgroups of patients, 10-year survival rates fa vored those patients with ELND, with a 30% reduction in mortality rate for the 543 patients with nonulcerated melanomas (84% vs. 77%; P = .03), a 30% reduction in mortality rate for the 446 patients with tumor thickness of 1. 0 to 2.0 mm (86% vs. 80%; P = .03), and a 27% reduction in mortality rate f or 385 patients with limb melanomas (84% vs. 78%; P = .05). Of these subgro ups, the presence or absence of ulceration should be the key factor for mak ing treatment recommendations with regard to ELND for patients with interme diate thickness melanomas. Conclusions: These long-term survival rates from patients treated at 77 ins titutions demonstrate that ulceration and tumor thickness are dominant pred ictive factors that should be used in the staging of stages I and II melano mas, and confer a survival advantage for these subgroups of prospectively d efined melanoma patients.