Mitomycin C or interferon as adjuvant therapy to surgery for ocular surface squamous neoplasia: comparative study

BACKGROUND: Traditionally, surgical excision has been the treatment of choice for ocular surface squamous neoplasia (OSSN). Recurrences after surgery are high. To reduce the risk of recurrence, adjuvant therapies have been increasingly used. PURPOSE: We compared recurrences and complications of 3 forms of treatment for OSSN: surgical excision (group A), surgical excision plus adjuvant topical mitomycin C (MMC) (group B), and surgical excision plus subconjunctival interferon-α-2b (IFN-α-2b) (group C). METHODS: A retrospective comparative study was conducted between January 2006 and March 2016 at the Ocular Oncology Service of the Catholic University of Rome. Seventy-nine patients with a confirmed histological diagnosis of OSSN were included: 43 were treated with surgical excision (group A), 16 underwent surgical excision plus topical MMC (group B), and 20 underwent surgical excision plus adjuvant subconjunctival IFN-α-2b (group C). RESULTS: The recurrences were different in the 3 groups. Thirty-one recurrences (72%) were seen in group A, 5 (31%) were found in group B, and 3 (15%) were seen in group C. Eight (50%) patients who received MMC 0.02% complained of ocular discomfort, 10 (62.5%) presented conjunctival hyperemia, while conjunctival chemosis and corneal epitheliopathy were noticed in 2 (13%) and 2 (13%) patients, respectively. All patients treated with subconjunctival IFN-α-2b reported flu-like symptoms. Two patients (10%) complained of ocular discomfort. CONCLUSIONS: Our study revealed that OSSN is not always manageable with simple excision. Adjuvant chemotherapy is strongly advisable after surgery to reduce recurrences. Interferon injections and MMC drops are effective in preventing recurrences and should be administered after surgery.