Efficacy of 2-cm surgical margins for intermediate-thickness melanomas (1 to 4 mm). Results of a multi-institutional randomized surgical trial.

BACKGROUND: A prospective, multi-institutional, randomized surgical trial involving 486 localized melanoma patients was conducted to determine whether excision margins for intermediate-thickness melanomas (1.0 to 4.0 mm) could be safely reduced from the standard 4-cm radius.

METHODS: Patients with 1- to 4-mm-thick melanomas on the trunk or proximal extremities were randomly assigned to receive either a 2- or 4-cm surgical margin.

RESULTS: The median follow-up time was 6 years. The local recurrence rate was 0.8% for 2-cm margins and 1.7% for 4-cm margins (p value not significant [NS]). The rates of in-transit metastases were 2.1% and 2.5%, respectively (p = NS). Of the six patients with local recurrences, five have died. Recurrence rates did not correlate with surgical margins, even among stratified thickness groups. The overall 5-year survival rate was 79.5% for the 2-cm margin patients and 83.7% for the 4-cm margin patients (p = NS). The need for skin grafting was reduced from 46% with 4-cm surgical margins to 11% with 2-cm surgical margins (p < 0.001). The hospital stay was shortened from 7.0 days for patients receiving 4-cm surgical margins to 5.2 days for those receiving 2-cm margins (p = 0.0001). This reduction was largely due to reduced need for skin grafting, since the hospital stay for those who had a skin graft was 2.5 days longer than that for those who had a primary wound closure (p < 0.01).

CONCLUSION: Margins of excision can be safely reduced to 2 cm for patients with intermediate-thickness melanomas. The narrower margins significantly reduced the need for skin grafting and shortened the hospital stay.