Study Suggests Smaller Melanoma Excision Margins May Be Option for Some Patients

Adapted from the NCI Cancer Bulletin.

A randomized controlled trial of patients with stage IIA–C cutaneous melanoma thicker than 2-mm found that a 2-cm surgical resection margin is sufficient and is as safe for patients as a 4-cm margin in terms of overall survival, according to a report published online October 21, 2011 in The Lancet.

The study, which took place from 1992 to 2004 in nine European clinics, assigned 936 patients to receive treatment with either a 2-cm or a 4-cm resection margin. After a median follow-up of 6.7 years, 181 patients in the 2-cm margin group and 177 in the 4-cm group had died. Both groups had a 5-year overall survival rate of 65 percent.

Controversies and discussions about optimal surgical excision margins for patients with thick melanomas have lasted many years, according to the study's authors, led by Peter Gillgren, M.D., of the Karolinska Institute in Sweden. Wide excisions can lead to poor cosmetic results, lymphedema, long hospital stays, frequent need for skin grafts, or complicated skin flap reconstructions. "A trade-off exists between a wide excision, with consequent surgical difficulties, and the relapse risk with a narrow excision, which could compromise disease-free survival or, worse, overall survival," the researchers noted.

Several recent studies and a meta-analysis by the Cochrane Collaboration have found no significant differences in the rate of local recurrence or in overall survival with smaller excision margins for melanoma. However, prior to the current study "no randomised controlled trial of equal size has been done comparing surgical excision margins of 2-cm and 4-cm for patients with cutaneous melanoma thicker than 2-mm," the researchers wrote.

In an accompanying editorial, John Thompson, M.D., of the Melanoma Institute Australia and David Ollila, M.D., of the University of North Carolina at Chapel Hill noted that the current study's conclusions about the comparability of 2-cm versus 4-cm excision widths "need to be tempered by the knowledge that the originally planned equivalence trial design had a target accrual of 2,000 patients, yet fewer than 1,000 were enrolled."

As a result, they explained, the trial lacked the statistical power to prove the two treatment options are equivalent. Instead, the study showed that a 2-cm margin was not inferior to a 4-cm margin. The editorialists also noted that a new clinical trial is being planned to test whether a 1-cm margin is equivalent or noninferior to a 2-cm margin.