BENEFIT OF ELECTIVE LYMPH-NODE DISSECTION IN SUBGROUPS OF MELANOMA PATIENTS - RESULTS OF A MULTICENTER STUDY OF 3616 PATIENTS

Background. The benefit of elective lymph node dissection (ELND) for t he treatment of the nonmetastasized malignant melanoma has been assess ed differently until today. Methods. Nine medical centers with a diffe rent ELND practice but comparable standards regarding diagnosis, excis ion of the primary tumors, classification, and follow-up, have collect ed their data (primarily ascertained prospectively) of 3616 patients o f the tumor categories pT2 to pT4N0M0 to produce an unbiased analysis of the prognostic benefit of ELND, and to find the indications for its application. The data are based on patients 70 years of age and young er with a primary melanoma of the skin, who have been followed for at least 4 years (median, 9.6 years). The stratification (according to pT category alternatively, tumor thickness!, sex, anatomic site) was in accordance with the results of the multivariate risk analysis (Cox ha zard model). Imbalances of other criteria such as ulceration, type, an d age were excluded by chi-square tests of the individual strata. The results are based on the observed survival rates according to Kaplan-M eier analysis of the different strata. Results. A prognostic benefit o f the ELND group (improvement of the 5-year survival rate of about 20% ) can be claimed for male patients with axial and acral melanomas (exc luding lentigo maligna melanoma LMM! and ulcerated tumors) of the cat egories pT3a up to pT4a (tumor thickness of > 1.5-4.5 mm, respectively ) (P < 0.001). As to the rest of the nonulcerated tumors of male patie nts, only those of the categories pT3b and 4a benefited from ELND (P < 0.01). A benefit from ELND for women was statistically verified (impr ovement of the 5-year survival rate of about 5%-10%) only for the subg roup with a tumor thickness > 2.5-5 mm, excluding LMM) (P = 0.016). Co nclusions. This retrospective study strongly suggests the efficacy of ELND in subgroups of melanoma patients.