The case for wide local excision and regional node dissection for high-risk cutaneous melanoma.

For melanomas less than 1 mm thick, a 1-cm margin is considered adequate by most authors. For melanomas 1 to 4 mm thick, the results of the Intergroup Melanoma Trial in the United States suggest that a 2-cm margin is adequate. European studies indicate that a 1-cm margin may be satisfactory for all melanomas 2 mm thick or less. Elective node dissection is not indicated for melanomas less than 1 mm thick. Survival benefit has not been shown in two prospective studies, although retrospective studies suggest that elective node dissection improves the survival of patients with intermediate melanomas 1 to 4 mm thick. Elective dissection is more likely to benefit patients at high risk of harboring microscopic disease in the regional nodes, such as men with melanomas 1 to 4 mm thick or women with 2- to 4-mm lesions. For melanomas thicker than 4 mm, elective dissection is generally not indicated, except for staging purposes in the context of a protocol because the predominant mode of dissemination in this group is hematogenous. Therapeutic dissection is indicated in all patients with clinically suspicious regional nodes and no evidence of distant dissemination. In doubtful cases, a biopsy of the node may be done, to be followed, if the results are positive, with the definitive procedure. Although the majority of these patients relapse, the surgical treatment offers appreciable 5-year survival rates which cannot, at present, be attained by other modalities. Some evidence suggests that prompt detection of palpable regional nodes and thorough dissection improve the survival rates.