Background: The traditional surgical treatment for primary malignant melanoma has often been a wide excision with a margin of about 5 cm. Since the risk of local recurrences is dependent on tumor thickness, thin tumors (<1 mm) have routinely been excised with a narrow margin. For thick tumors, the optimal resection margin is controversial, and can be determined only by prospective, randomized trials.
Methods: The Swedish Melanoma Study Group performed a prospective, randomized multicenter study to evaluate an excision margin of 2 versus 5 cm for patients with cutaneous malignant melanoma with tumor thickness > 0.8 and < or = 2.0 mm. The trial includes 769 patients. Patients with melanomas of the skin of the head, neck, hands, feet, or vulva were not included in the trial. In the event of an excision biopsy for diagnosis, radical surgery was completed within 6 weeks. The median follow-up time was 5.8 years for estimation of survival and 4.0 years for diagnosis of recurrent disease.
Results: No significant differences have been observed between the treatment groups regarding local or regional recurrences or survival.
Conclusions: We recommend an excision with a margin of 2 cm for cutaneous malignant melanoma with a tumor thickness > 0.8 and < or = 2.0 mm.