Clinicopathological Characteristics Predicting Further Recurrence and Survival Following Resection of In-Transit Melanoma Metastases

Background In-transit metastases (ITMs) affect approximately 4% of patients with cutaneous melanoma. This study sought to identify clinical and pathological characteristics that predict further recurrence and survival following resection of ITMs. Patients and Methods Patients ( n = 573) who underwent surgical resection of their first presentation of ITM following previous surgical treatment of an American Joint Committee on Cancer (AJCC) stage I–II melanoma between 1969 and 2017 were identified from an institutional database. Clinicopathological predictors of patterns of recurrence and survival following ITM resection were sought. Results The median time of ITM development was 2.4 years after primary melanoma resection. ITMs were most frequently located on the lower limb (51.0%). The most common melanoma subtype associated with ITM development was nodular melanoma (44.1%). After surgical resection of a first ITM, 65.4% of patients experienced recurrent disease. Most recurrences were locoregional (44.7%), with distant metastasis occurring in 23.9% of patients. Lower limb ITMs were more frequently associated with subsequent ITMs [odds ratio (OR) 2.41, p = 0.0002], and the lowest risk of distant metastasis ( p < 0.0001) compared with other primary sites. Primary melanomas and ITM on head and neck, as well as the presence of ulceration, were associated with worse survival. Conclusions Recurrence after surgical resection of a first ITM was common. Patterns of recurrence differed according to anatomical site; further ITM recurrences were more likely for lower limb ITMs, which were also associated with longer distant recurrence-free survival. Distant metastasis was more common for ITM on the head and neck, with worse survival.