Topical treatment of cutaneous metastases of malignant melanoma using combined imiquimod and 5-fluorouracil

Background Despite multiple available options, the treatment of cutaneous melanoma metastases is often unsuccessful. Based on the hypothesis that imiquimod and 5-fluorouracil have synergistic antitumor properties, we used this topical combination to treat several patients. Aim Our objective was to investigate the treatment combination in a small cohort of patients with surgically non-resectable melanoma metastases. Methods The lesions of 5 patients with multiple cutaneous metastases were treated topically, 5 days per week, with 5-fluorouracil in the morning and imiquimod at night. Results 45 lesions were treated. A clinical response was seen in 44 lesions, with a complete response in 19 lesions and a partial response in 25. Stable disease was confirmed in the 1 remaining lesion. No patients developed new lesions during treatment. However, one patient had a recurrence 6 months after treatment discontinuation, followed by a partial response when rechallenged. Conclusions The imiquimod and 5-fluorouracil combination is effective. That patients did not develop new, distant lesions suggests the achievement of locoregional control, probably by the induction of antitumor immune response.