Topical and Intralesional Treatments for Skin Metastases and Locoregionally Advanced Melanoma

Cutaneous melanoma is a malignant neoplasm with local and distant metastatic potential. When feasible, surgery is the first line of treatment in locoregionally advanced disease. Topical and intralesional treatments can be an alternative second-line treatment. The aim of this article was to perform a narrative review of the most widely used topical and intralesional treatments for locoregionally advanced melanoma. Diphenciprone, imiquimod and 5-florouracil were included as topical treatments and bacillus Calmette-Guerin, interleukin 2, rose bengal, talimogene laherparepvec and electrochemotherapy were included as intralesional treatments. Brief comments on other alternatives in development such as interferon-alpha, interleukin-12, ipilimumab and intralesional daromun are presented. Topical treatments generally have higher response rates in epidermal metastases than in deeper metastases. In addition, the larger the lesions, the worse they tend to respond to local treatments. Some reports show that combining certain systemic treatments and topical or intralesional therapies can improve response rates. It has also been described in a few papers that non-injected lesions may respond after the application of a local therapy in distant skin-metastases. Many of these intralesional treatments are being combined in different investigations with systemic immunotherapies, with the aim of obtaining synergic responses in those patients with refractory disease.