Patterns of failure following the excision of in-transit lesions in melanoma and the influence of excisional margins

Background and ObjectivesTo describe the patterns of failure in patients with in-transit (IT) melanoma undergoing surgical excision. MethodsA retrospective review of patients who underwent their first IT lesion(s) resection between May 2005 and September 2014. Cumulative incidence of local failure (new lesion within 2cm of IT resection) was estimated. Associations between clinicopathologic characteristics, local failure, and any recurrence were analyzed. ResultsOne hundred and thirty patients presented to our institution with IT disease over the study period and met the inclusion criteria. The 2-year cumulative incidence of local failure was 19.5%. Twenty-four patients developed disease within 2cm of the resected IT disease; however, only eight were isolated local events. Cumulative incidence of local failure and of any disease differed with respect to less than 1 year disease-free interval (DFI) from primary melanoma to first IT event, and having greater than 1 IT lesion at presentation. Incidence of local failure was not found to differ with respect to gross margin greater than 5mm, after adjusting for DFI and greater than 1 IT lesions. ConclusionsPatients with greater than 1 IT lesion and a DFI less than 1 year are at a higher risk of failure after surgical excision of a first IT event. Very few failures were isolated local disease within 2cm of the IT resection scar, regardless of IT excision margin.