Resolution of primary acquired melanosis with atypia after treatment with topical mitomycin C and interferon alfa-2b

Toxicity and efficacy of type I interferons on the ocular surface: in vitro, animal, and clinical studies

PURPOSE

To investigate the toxicity of type I interferons (IFNs) on the ocular surface and assess their efficacy in ocular surface tumors.

METHODS

We examined the effects of IFN-α2a, IFN-α2b and IFN-β on corneal epithelial cells and stromal fibroblasts in vitro as well as the impact of IFN-α2a on the ocular surface in mice. Additionally, we analyzed the therapeutic and adverse effects of topically administered IFN-α2a and IFN-α2b in patients with ocular surface tumors. Risk factors contributing to side effects were explored.

RESULTS

IFN-α2a, IFN-α2b or IFN-β reduced cell viability and induced pro-inflammatory cytokines in corneal epithelial cells and stromal fibroblasts. Furthermore, IFNs enhanced the expression of major histocompatibility complex class II and CD40 in corneal epithelial cells. In mice, subconjunctival IFN-α2a injection did not induce corneal epithelial defects or opacity, nor did it reduce aqueous tears or conjunctival goblet cells. In patients, topical IFN-α2a or IFN-α2b administration decreased tumor size and prevented recurrence; however, it was associated with mild side effects, including corneal epitheliopathy and conjunctival hyperemia. These complications were associated with longer IFN use, the presence of underlying ocular surface disease and concurrent use of mitomycin C or anti-glaucoma eye drops.

CONCLUSION

Although type I IFNs cause direct toxicity on corneal cells, they do not induce significant side effects on the healthy ocular surface. Considering its therapeutic and preventive effects, topical type I IFN is safe and effective for treating ocular surface tumors. The potential for ocular side effects should be considered in eyes with identified risk factors.

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

PURPOSE

We herein compare topical interferon alpha 2b (IFN-α2b) 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-α2b (two in combination with radiotherapy), 19 with MMC, and two with radiotherapy alone. Five patients were switched from initial MMC/radiotherapy to IFN-α2b during follow-up. Efficacy was assessed via time to tumor recurrence and initial therapy response.

RESULTS

With initial IFN-α2b, 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-α2b: two patients showed complete remission (2/5), while another two (2/5) experienced recurrences and remained without recurrence after repeated courses of IFN-α2b (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-α2b (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-α2b may also be of limited utility.

Use of interferon alpha 2b to manage conjunctival primary acquired melanosis and conjunctival melanoma

Primary acquired melanosis (PAM) is acquired conjunctival pigmentation that can give rise to conjunctival melanoma (CM), a malignant tumor of the bulbar and palpebral conjunctiva or the caruncle. Surgical excision is the treatment of choice for this neoplasm. Topical chemotherapy is also used for patients with PAM with atypia or CM, hand in patients with recurrent or extensive disease, this may be an important option. Of the several chemotherapeutic drugs used, topical interferon alpha 2b (IFN-α2b) has become popular because of its low toxicity. Clinical evidence from case reports and case series supports the efficacy of IFN-α2b as the preferred adjuvant treatment for PAM and CM. In addition, topical IFN-α2b has been successfully applied to melanocytic tumors refractory to other treatments, such as cryotherapy and topical mitomycin C. In patients with locally advanced CM, the combination of IFN-α2b and systemic immunotherapy may serve as an alternative to exenteration. Given the low frequency of CM, long-term multicenter studies are needed to demonstrate the efficacy of IFN-α2b for preventing local recurrence and distant metastasis.

Ocular surface complications of local anticancer drugs for treatment of ocular tumors

Local chemotherapy is increasingly used, either in combination with surgery or as monotherapy, for management of ocular tumors. Yet many of the local chemotherapeutic agents used for ocular tumors are cytotoxic drugs that are frequently associated with toxicities in normal ocular tissues. Understanding and managing these side effects are important because they affect treatment tolerability, outcome and quality of vision. Herein, we review local anticancer drugs administered for the treatment of ocular tumors, with an emphasis on their toxicities to the ocular surface, adnexa and lacrimal drainage system. We provide the underlying mechanisms and management strategies for the ocular side effects. Recent innovations in anticancer immunotherapy and ocular drug delivery systems also are discussed as new potential therapeutic modalities for alleviation of side effects.

Resolution of conjunctival melanoma with topical interferon alpha 2b in a patient with mitomycin C intolerance

OBJECTIVE

To describe the clinical and histological resolution of a case of an inexcisable conjunctival melanoma using topical interferon alpha 2b (INFα2b) in a patient with mitomycin C (MMC) intolerance.

CASE REPORT

Conjunctival melanoma is a rare, but potentially sight- and life-threatening, tumour. In cases of multiple lesions, or when surgical excision is not possible, topical combination chemotherapy with MMC and INFα2b has been described as first line therapy. The case is presented of a 77 year-old woman with a multifocal conjunctival in situ melanoma, who was intolerant to initial treatment with MMC and was switched to long-term INFα2b therapy, with a good outcome.

CONCLUSIONS

When topical MMC is given as chemotherapy treatment for primary acquired melanosis with atypia or in situ melanoma is not well tolerated, switching to INFα2b seems to be a good option. This approach could replace surgical management of pigmented tumours, especially the larger ones, with potential benefits that include less dependence on surgical margins. This report prompts a need for prospective studies designed to examine the role of INFα2b as primary treatment for heavily pigmented conjunctival tumours avoiding the ocular surface toxicity caused by MMC.

Pharmacotherapy and Immunotherapy of Conjunctival Tumors

Conjunctiva and cornea tumors represent a large spectrum of conditions ranging from benign lesions to aggressive and life-threatening malignancies. Topical pharmacotherapies and immunotherapies have recently acquired a relevant role in the management of conjunctival tumors and, in the past 2 decades, there has been a shift from surgery alone toward the use of these agents, both as a sole therapy or as adjunct to surgery (before or after surgery). The 3 main agents that have been used for topical medical treatment of conjunctival tumors are mitomycin-C, 5-fluorouracil, and interferon-α2b. Advantages of topical pharmacotherapies and immunotherapies include the ability to treat the entire ocular surface and prevention of surgical side effects and complications. The aim of this review is to summarize the current use of topical pharmacotherapy and immunotherapy in the management of conjunctival tumors.