Needle before Scalpel: Considering the Role of Intratumoral Therapy in Melanoma

Advanced melanoma and nonmelanoma skin cancer or cutaneous metastases not amenable to surgery often require alternate therapy. Although surgery is first-line treatment for early-stage melanoma, it can be challenging with multifocal disease, sites with high morbidity, large lesions such as lentigo maligna on the head and neck, and patients with comorbidities that add surgical risk. Intratumoral therapy is a safe method of treating advanced melanoma which avoids the toxicities of systemic therapies. Our review examined the overall response rates and adverse effects of the following experimental and standard intralesional agents: ipilimumab, rose bengal (PV-10), cathelicidin LL37, SD-101, coxsackie A21 V937, and talimogene laherparepvec. Injection of oncolytic virus, immune-modulating drugs, cytotoxic agents, or studied combinations was well-tolerated and effective alternative treatments for advanced melanoma and cutaneous metastases. Response to treatment was observed in both injected and noninjected lesions demonstrating systemic antitumor effects of these intralesional therapies. Further utility of intralesional agents can be explored as neoadjuvant treatment of large lentigo maligna lesions or those in cosmetically sensitive areas. Intralesional therapy should be developed further for morbidity reduction in challenging melanoma cases.