Evaluation of a short-term topical interferon α-2b treatment for histologically proven melanoma and primary acquired melanosis with atypia.

OBJECTIVE: To evaluate the efficiency of series of 6-week treatments with brief intervals (6-week = 1 cycle) of topical Interferon α-2b (IFNα-2b) treatment in primary acquired melanosis (PAM) with atypia and melanoma of the conjunctiva. PATIENTS AND METHODS: Five patients with biopsy-proven PAM with atypia and seven patients with melanoma of the conjunctiva, treated with topical IFNα-2b (1 million units/ml, 5 times daily), were included in the study. All patients had colour photographs and the tumour area was measured manually for each patient before and after treatment.
RESULTS: The median age of 12 patients at initiation of treatment was 61.5 years (range 39-75 years). The mean therapy duration was 2.4 cycles (range 1-6 cycle). Compared to pretreatment lesion dimension, the mean decrease in tumour size were after the first cycle 66% (range 18-98%; p = 0.004; n = 10 patients), after the second cycle 55% (range 10-100%; p = 0.016; n = 7 patients), and after the third cycle 74% (range 23-100%; n = 3 patients). In one patient 6 cycles of topical IFNα-2b were needed. The decrease in size was 22% after the 4(th) cycle, 34% after the 5(th) cycle, and 98% after the 6(th) cycle.
CONCLUSION: Our clinical experience demonstrates promising results of topical IFNα-2b treatment for PAM with atypia and melanoma of the conjunctiva without any local or systemic side effects. However, future multicenter prospective studies are recommended to confirm the efficiency and safety of topical IFNα-2b treatment.