Risk factors for in-transit metastasis in patients with cutaneous melanoma

BackgroundIn-transit metastases have been associated with the presence of various negative prognostic factors in patients with cutaneous melanoma. It has recently been suggested that sentinel lymph node biopsy (SLNB) may lead to an increase in the incidence of this particular type of metastasis. In this study, we analyzed risk factors for the appearance of in-transit metastasis and its potential association with the use of SLNB.Material and methodsA prospective study was undertaken in a cohort of 404 patients with cutaneous melanoma seen in the melanoma unit of Hospital San Cecilio in Granada, Spain. Statistical analysis was performed with SPSS 15.0 and Epidat 3.1 using the χ² and Fisher exact tests.ResultsOut of 93 (23%) patients with recurrence at any time, 28 (6.9%) had in-transit metastases. The occurrence of in-transit metastasis was associated with age greater than 50 years, greater Breslow depth and Clark level, the presence of ulceration, positive SLNB, and the presence of other types of recurrence (local recurrence, lymph node metastasis, or distant metastasis). There was no relationship between surgical treatment or performing SLNB and the presence of in-transit metastasis.ConclusionsThe risk factors for in-transit metastasis are the same as those for any type of recurrence and coincide with factors linked to poor prognosis. Given that in-transit metastases are much more common in patients with positive SLNB, while the technique itself is not linked to their occurrence, these findings suggest that the appearance of in-transit metastasis is linked to biological characteristics of the tumor cells rather than an influence of the surgical technique.