Managing in-transit melanoma metastases in the new era of effective systemic therapies for melanoma

Introduction: Melanoma in-transit metastases (ITMs) occur between the primary tumor site and the regional node field. Most patients with ITMs have a poor prognosis. The treatment of ITMs can be simple if surgical excision is possible, but challenging when ITMs are advanced, multiple or recurrent and impacting quality of life. Areas covered: The management of ITM is still evolving. Patients who are disease-free after surgical excision of ITMs are today candidates for adjuvant systemic treatment to reduce recurrence risk. Some who have multiple or advanced ITMs may achieve long-term survival or disease control with systemic therapies alone. Those who do not remain candidates for the numerous locoregional therapies used to treat ITMs, including electrocautery, intralesional injection, topical therapy, electrochemotherapy, isolated limb infusion, isolated limb perfusion, radiation therapy and, rarely, amputation. Relevant publications identified in Pubmed and MEDLINE databases are reviewed. Expert opinion: Patients with multiple ITMs can benefit from use of systemic therapies as primary treatment, in the adjuvant setting and in neoadjuvant trials. Multiple alternative treatment modalities exist for patients unsuitable for systemic therapies or in whom systemic therapies have failed. Trials assessing combined systemic and locoregional therapies for ITMs are in progress.