Responses to Topical Diphenylcyclopropenone as an Adjunct Treatment for In-Transit Melanoma: A Tertiary Referral Center Experience

BACKGROUNDIn-transit cutaneous metastases occur in 5% to 10% of patients with melanoma. Recently, topical diphenylcyclopropenone (DPCP) has been described as a treatment option. OBJECTIVETo evaluate efficacy of DPCP in treatment of in-transit cutaneous melanoma. METHODSThe authors retrospectively reviewed the records of 13 consecutive patients with in-transit metastases treated with topical DPCP between March 1, 2013, and January 31, 2017. The authors recorded the response of in-transit cutaneous melanoma lesions treated with DPCP measured by clinical examination. RESULTSAmong the 13 patients, 9 patients completed at least a 1-month course of DPCP treatment. Of these 9 patients, 6 (66.7%) maintained either stable disease or had a partial or complete regression, and 3 (33.3%) had progressive disease. Patients with less burden of disease (e.g., 25 lesions or plaques). Both patients who received DPCP alone had progression of their cutaneous lesions. One patient who did not become sensitized to DPCP died within 2 months, and his anergy likely reflecting immense burden of disease. CONCLUSIONTopical DPCP is a low-cost, patient-applied treatment option for in-transit melanoma, most effective for patients with relatively low tumor burden and localized disease.