Weinstock takes exception to the conclusion advanced by Barnhill and myself that the choice of a resection margin greater than 1 cm for primary melanomas of any thickness has no factual basis. He bases his objection principally on the data of the randomized, prospective World Health Organization study1,2 of wide (3-cm) vs narrow (1-cm) resection margins, wherein the application of a 1-cm margin for melanomas of 1 mm to 2 mm in thickness was associated with 4 cases of local recurrence (Table).
On statistical analysis, these instances, as compared with no local recurrences in the subset of patients with 3-cm resection margins, approached the threshold of significance, but there was notably no corresponding trend to a difference in survival outcomes between the 2 arms of the study. To Weinstock, however, these data are nevertheless suggestive that the wider margin offers a protective effect against the hazard of local recurrence.