Topical chemotherapy agents similarly effective against ocular surface squamous neoplasia

This study compared the effectiveness of topical 5-fluorouracil 1% (5FU) versus interferon alfa-2b (IFN) eye drops as primary treatment modalities for ocular surface squamous neoplasia (OSSN).

Study design

The authors retrospectively identified all patients with ocular surface squamous neoplasia (OSSN) who were treated with either 5-FU or IFN 1 MIU/mL over a 3.5-year period. After exclusion criteria were applied, the study included records from 54 patients who exclusively received topical 5-FU and 48 patients who exclusively received topical IFN. Demographics, phenotypic appearance, clinical stage and pathologic results, if available, were extracted while primary outcomes measures were frequency of resolution and time to recurrence.

Outcomes

Univariate analysis revealed a higher rate of clinical resolution among patients treated with 5-FU versus IFN drops, but the drugs performed similarly on multivariate analysis. The overall response to medical therapy was 7.7-fold greater among Hispanic than non-Hispanic patients. There were no statistically significant differences in time to resolution, frequency of recurrence or long-term complications between groups.

Limitations

The study's retrospective nature made it impossible to control for factors such as treatment compliance and follow up. The treatment groups varied slightly in ethnicity and tumor location. Also, details about pathologic grading and tumor genetics were not available for all patients.

Clinical significance

Interferon alfa-2b has gained popularity as a medical therapy for OSSN. While it has an appealing side effect profile, cost remains an issue. The authors show that 5-FU, a cheaper and established alternative, should remain a viable treatment option given that it offers a  similar effectiveness and recurrence rate as IFN.