MMC assists in preventing recurrence of neoplasia

HONG KONG — The use of adjunctive mitomycin-C in addition to excision provides the best chance for preventing recurrence in localized conjunctival intraepithelial neoplasia, a surgeon said here.

"Mitomycin-C treatment following surgical excision of localized [conjunctival intraepithelial neoplasia] decreases the recurrence rate," James Muecke, MD, said. "It should be considered as adjunctive therapy in the treatment of primary and recurrent disease. It may be used as monotherapy in diffuse disease and fine lesions not amenable to excision, but close, ongoing follow-up is recommended in view of the significant risk of recurrence."

Dr. Muecke presented the data from a prospective, noncomparative case series of 104 patients at the World Ophthalmology Congress. The patients all had localized lesions and were treated over a 9-year period.

The patients were divided into three treatment groups: localized lesions that were either thick or fine, diffuse lesions and recurrent lesions.

Localized thick lesions were excised and treated with cryotherapy and then MMC 0.04% four times a day for 7 days; the cycle was repeated through two courses with 1 week treated and 1 week of rest. Localized fine lesions were treated initially with the same MMC cycle for two to three courses.

Diffuse lesions were treated with the MMC course of treatment over three courses. Recurrent localized lesions were excised, treated with cryotherapy and then treated with three courses of the MMC cycle.

Of the 86 eyes with localized lesions, one eye had a recurrence, for a rate of 1.2%. In the diffuse group, of the 10 eyes, two recurred and two were persistent, for a recurrence rate of 40%. In the already recurrent group of eight eyes, none recurred. "Overall there was a better control of local compared with diffuse disease," Dr. Muecke said. "The best overall control was with excision and mitomycin-C of localized disease."

"I feel like excision remains an important step in this group, but primary excision rate alone has a high recurrence rate," he said.

When MMC is used as an adjunct, he advocated using the highest tolerable concentration with the week-on, week-off course of treatment to minimize toxicity to the healthy cells in the eye.

"Mitomycin-C is also an acceptable alternative for treatment of disease greater than five clock hours," he said.

"There is, however, a higher incidence of persistent or recurrent disease when mitomycin-C is used as monotherapy, as you are treating a larger tumor load."

Dr. Muecke said there were no major complications, but there was a high incidence of allergy.