Tumor thickness as a guide to surgical management of clinical stage I melanoma patients

An analysis of failure to control locally recurrent or metastatic melanoma was used to substantiate the value of thickness as a guide to surgical management. There were no local recurrences in patients with melanomas less than 0.76 mm in thickness, regardless of the skin margins excised. The three year actuarial incidence of subsequent regional metastases in patients initially treated by wide local excision (WLE) of their melanoma was directly correlated with tumor thickness (p = <0.001); it was 0% for lesions <0.76 mm, 25% for 0.76 to 1.50 mm lesions, 51% for 1.50 to 3.99 mm lesions and 62% for lesions >4.0 mm in thickness. At five years, patients with melanomas of 1.50 to 3.99 mm thickness who had WLE plus elective regional node dissection (RND) had a calculated 15% incidence of distant metastases and an actuarial survival rate of 83%, while patients with melanomas of the same thickness who had WLE alone as their initial surgical treatment had a 78% incidence of distant metastases and a 37% survival rate (p = 0.001 and 0.01, respectively). In patients with melanomas exceeding 4.0 mm in thickness, the potential benefits of RND were less apparent because of a high risk (>70%) of distant metastases at the time of initial diagnosis. Based upon this analysis, our initial surgical management of melanomas <0.76 is a WLE using a 2.0 cm margin of skin, while thicker lesions are excised using a 3 to 5 cm skin margin. Elective RND is not indicated for lesion <0.76 mm in thickness, but it is considered for 0.76 to 1.50 mm lesions in selected patients and is employed for virtually all patients with lesions exceeding 1.5 mm in thickness. The rationale of elective RND is improved survival in patients with intermediate thickness lesions (0.76 to 3.99 mm) while it is justifiable as a staging procedure for lesions exceeding 4.0 mm thickness. Cancer 43:883–888, 1979.