1 or 2 cm margins of excision for T2 melanomas: do they impact recurrence or survival?

NCCN guidelines recommend 1 or 2 cm margins for melanomas 1-2 mm (T2 melanomas) in depth; however, no head-to-head comparison has been performed. We hypothesized 1- or 2-cm margins would have similar local recurrence (LR) and overall survival (OS).

An institutional database was queried for patients with 1.0-2.0 mm melanomas treated from July 1995 to January 2011. All had wide excision and sentinel lymph node biopsy. Patients without documented surgical margins or follow-up were excluded. Clinicopathologic and recurrence data were reviewed. Univariate and multivariate analyses were performed.

Of 2,118 patients, 1,225 met study criteria. Of these, 576 had complete data: 224 (38.9%) had 1 cm margins and 352 (61.1%), 2 cm margins. Median follow-up was 38 months. Mean age was 52.6 years (range 11.3-86.7). Mean thickness was 1.27 and 1.48 mm (1 and 2 cm, respectively, p<0.001) with ulceration more common in the 2 cm group (12.3 and 21.3%, respectively; p=0.009). LR was 3.6 and 0.9% in the 1 cm versus 2 cm group, respectively (p=0.044). OS was 29.1 months with 1 cm and 43.7 months in the 2 cm group. On multivariate analysis, only head and neck location and nodal status were associated with overall survival.

In this series, 1 cm margins were associated with a small increase in LR that did not impact OS. This is concordant with the NCCN recommendations; however, a prospective, randomized trial would be optimal.