Surgical Margins in Cutaneous Melanoma (2 cm versus 5 cm for Lesions Measuring Less than 2.1-mm Thick)
K hayat et al. 1 reported the results of the French Melanoma Group's randomized trial examining excision margins in cutaneous melanoma (2 cm vs. 5 cm for melanomas Ͻ 2.1 mm thick). This work is a noteworthy contribution to the body of knowledge regarding surgical margins in the treatment of primary cutaneous melanoma, but it also raises several important issues in this controversial area.{FNO} Four randomized trials have assessed the effect of the width of excision margins on melanoma recurrence and survival. 2 Pooled analysis of the 10-year overall mortality data from the French, Intergroup, and Swedish trials (which involved 1783 patients total) demonstrated no statistically significant difference in overall mortality between patients treated with narrow margins and patients treated with wide margins (odds ratio, 1.06; 95% confidence interval, 0.79 -1.42; P ϭ 0.23).
The results from the French trial are compatible with the results from the other three trials. Our analysis provides additional support for the view that the extent of excision margins for melanomas Ͻ 2 mm in thickness has no influence on survival. Thus, we support the conclusion of Khayat et al. 1 that excision margins Ͼ 2 cm are unnecessary for the majority of melanomas Ͻ 2 mm in thickness.
Nonetheless, current evidence is not sufficient to address the issue of optimal surgical margins for all melanomas. There is a broad international consensus that 1 cm margins are adequate for thin melanomas (Յ 1 mm thick). In contrast, there is still debate regarding the safety of 1 cm margins for melanomas measuring 1-2 mm in Breslow thickness (especially those that are ulcerated), and our analysis only provides data in support of 2 cm excision margins.
Only the Intergroup trial investigated excision margins in melanomas Ͻ 2 mm thick; however, there is insufficient evidence from randomized trials to determine which margins are acceptable in 2-4 mm thick melanomas, although 2 cm margins are believed to be appropriate. 3 To our knowledge, there are no published data on thicker melanomas (Ͼ 4 mm thick). Disclosure of the results of the UK Melanoma Study Group/British Association of Plastic Surgeons randomized trial comparing 1 cm and 3 cm excision margins for melanoma measuring Ն 2 mm in Breslow thickness is awaited.
Further research is required to establish the appropriate local treatment not only for thick melanomas but also for specific types of melanoma (e.g., lentigo maligna melanoma, acral lentiginous melanoma, and desmoplastic melanoma) and for some subgroups of patients.