Real-life data of adjuvant IFN-α2b and MMC in conjunctival melanocytic lesions

Purpose We herein compare topical interferon alpha 2b (IFN-alpha 2b) to topical mitomycin C (MMC) in the adjuvant management after excision of primary acquired melanosis with atypia (PAM) and melanoma of the conjunctiva/cornea (CM). Methods We included 25 tumors from 25 patients (six with PAM and 19 with CM). After surgical excision, four patients started with adjuvant IFN-alpha 2b (two in combination with radiotherapy), 19 with MMC, and two with radiotherapy alone. Five patients were switched from initial MMC/radiotherapy to IFN-alpha 2b during follow-up. Efficacy was assessed via time to tumor recurrence and initial therapy response. Results With initial IFN-alpha 2b, three patients (3/4, two with additional radiotherapy) showed complete remission (follow-up: 1478-1750 days) and one recurrence (1/4) was noted after 492 days. With initial MMC, no recurrence was recorded in 15 of the 19 patients (follow-up: 99-4732 days). Five patients were switched from MMC or radiotherapy to IFN-alpha 2b: two patients showed complete remission (2/5), while another two (2/5) experienced recurrences and remained without recurrence after repeated courses of IFN-alpha 2b (follow-up: 1798 and 1973 days). Only one patient showed incomplete response. Adverse effects were recorded in five patients, all received MMC. Conclusion Topical IFN-alpha 2b (arguably together with radiotherapy) may be a viable alternative to MMC in PAM and CM. We observed fewer side effects at similar response rates. However, when response to MMC was poor, IFN-alpha 2b may also be of limited utility.