SURGICALMARGINS OF MELANOMA

• There were no significant differences between 2-cm and 4-cm excision groups in overall or melanoma-specific survival at a median of 19.6 years.
• For melanoma-specific death, absolute rates per 100 person-years were 3.9 vs 4.1.

In a nearly 20-year follow-up of a Scandinavian trial reported in The Lancet, Utjés et al found no difference in survival outcomes with 2-cm vs 4-cm surgical excision margins for primary localized cutaneous melanoma with a thickness > 2 mm. The previous report from the trial showed no difference in melanoma-specific or overall survival between the two approaches after a median follow-up of 6.7 years.
The trial included 936 patients with primary disease on the trunk or upper or lower extremities from 53 sites in Sweden, Denmark, Estonia, and Norway. They had a median age of 59 to 60 years at baseline.
Patients were randomly assigned between January 1992 and May 2004 to a 2-cm excision margin (n = 471) or a 4-cm excision margin (n = 465). The co-primary outcomes in the current extended follow-up were overall survival and melanoma-specific survival in the intent-to-treat populations.
Overall and Melanoma-Specific Survival
At a median follow-up of 19.6 years, there were 621 deaths, including 304 (49%) in the 2-cm group and 317 (51%) in the 4-cm group (unadjusted hazard ratio [HR] = 0.98, P = .75). For overall mortality, absolute rates per 100 person-years were 6.1 vs 6.3.
A total of 397 deaths were attributed to melanoma, consisting of 192 (48%) in the 2-cm excision margin group and 205 (52%) in the 4-cm excision margin group (unadjusted HR = 0.95, P = .61). For melanoma-specific death, absolute rates per 100 person-years were 3.9 vs 4.1. In multivariate analysis, adjustment for prognostic factors did not change the hazard ratios for the 2-cm excision margin group vs the 4-cm excision margin group.
For overall survival, probabilities of survival for the 2-cm vs 4-cm groups were 65% vs 64% at 5 years, 50% vs 51% at 10 years, 40% vs 40% at 15 years, 35% vs 33% at 20 years, and 25% vs 26% at 25 years.
The investigators concluded, “A 2-cm excision margin was safe for patients with thick (> 2 mm) localized cutaneous melanoma at a [median] follow-up of 19.6 years. These findings support the use of 2-cm excision margins in current clinical practice.”