Primary treatment of ocular surface squamous neoplasia with topical interferon alpha-2b: Comparative analysis of outcomes based on original tumor configuration

PURPOSE: The aim of this study was to evaluate tumor control of OSSN with topical IFNα2b alone based on tumor configuration (flat versus (vs.) dome-shaped). METHODS: Retrospective, nonrandomized, interventional cohort study on 64 consecutive tumors in 63 patients with OSSN treated with topical IFNα2b. Topical IFNα2b (1 million international units/cc) was compounded and provided by the Thomas Jefferson University Hospital Pharmacy to be refrigerated and applied 4 times daily until biomicroscopic evidence of tumor resolution was observed. RESULTS: The tumor configuration was flat (n = 15, 23%) or dome-shaped (n = 49, 77%). A comparison (flat vs. dome-shaped) revealed dome-shaped with older mean patient age at presentation (62 vs. 70 years, P = 0.04), greater patient history of smoking (13% vs. 42%, P = 0.04), greater corneal involvement (7% vs. 82%, P < 0.001), larger mean basal diameter (5.5 vs. 12.4 mm, P = 0.001) and mean thickness (1.9 vs. 4.3, P = 0.002), and longer mean duration IFNα2b therapy (3.7 vs. 6.3 months, P = 0.002). There was no difference in mean follow-up time (22.2 vs 23.1 months) or time to complete response (5.0 vs. 6.1 months). There was no difference in achievement of complete tumor control with IFNα2b alone (93% vs. 96%). There were no cases with metastasis or death. CONCLUSION: Topical IFNα2b alone shows excellent overall tumor control of 95% with no difference in efficacy based on tumor configuration.