Efficacy of an elective regional lymph node dissection of 1 to 4 mm thick melanomas for patients 60 years of age and younger

Abstract

Objective: A prospective multi-institutional randomized surgical trial involving 740 stage I and II melanoma patients was conducted by the Intergroup Melanoma Surgical Program to determine whether elective (immediate) lymph node dissection (ELND) for intermediate-thickness melanoma (1-4 mm) improves survival rates compared with clinical observation of the lymph nodes. A second objective was to define subgroups of melanoma patients who would have a higher survival with ELND.

Methods: The eligible patients were stratified according to tumor thickness, anatomic site, and ulceration, and then were prerandomized to either ELND or nodal observation. Femoral, axillary, or modified neck dissections were performed using standardized surgical guidelines.

Results: The median follow-up was 7.4 years. A multifactorial (Cox regression) analysis showed that the following factors independently influenced survival: tumor ulceration, trunk site, tumor thickness, and patient age. Surgical treatment results were first compared based on randomized intent. Overall 5-year survival was not significantly different for patients who received ELND or nodal observation. However, the 552 patients 60 years of age or younger (75% of total group) with ELND has a significantly better 5-year survival. Among these patients, 5-year survival was better with ELND versus nodal observation for the 335 patients with tumors 1 to 2 mm thick, the 403 patients without tumor ulceration, and the 284 patients with tumors 1 to 2 mm thick and no ulceration. In contrast, patients older than 60 years of age who had ELND actually had a lower survival trend than those who had nodal observation. When survival rates were compared based on treatment actually received (i.e., including crossover patients), the patients with significantly improved 5-year survival rates after ELND included those with tumors 1 to 2 mm thick, those without tumor ulceration, and those 60 years of age or younger with tumors 1 to 2 mm thick or without ulceration.

Conclusion: This is the first randomized study to prove the value of surgical treatment for clinically occult regional metastases. Patients 60 years or age or younger with intermediate-thickness melanomas, especially with nonulcerative melanoma and those with tumors 1 to 2 mm thick, may benefit from ELND. However, because some patients still are developing distant disease, these results should be considered an interim analysis.