A retrospective comparison of surgical removal and subsequent CO2 laser ablation versus topical administration of mitomycin C as therapy for equine corneolimbal squamous cell carcinoma.

This research compares the effectiveness and complications of using mitomycin C therapy with CO2 laser ablation in the treatment of eye cancer in horses. It suggests that mitomycin C therapy can achieve similar results and may have fewer complications when applied just after re-epithelialization of the surgical site.

Research Methodology

• The study is a retrospective one, meaning it makes use of existing data rather than new observations or experiments.
• It focuses on 25 horses that had equine corneolimbal squamous cell carcinoma (SCC), a type of eye tumor.
• The medical records of these horses were reviewed, specifically those that had undergone surgery for the removal of this tumor followed by either topical mitomycin C (MMC) therapy or CO2 laser ablation between 2004 and 2010.
• The success of each treatment method was gauged by the rate of nonrecurrence, i.e., the rate at which the tumor did not reappear.
• The treatments were further compared based on complications faced, and for the MMC therapy, subgroups were created based on when the medication was applied relative to the surgery.

Research Findings

• The researchers found that the use of MMC therapy, applied topically, achieved a nonrecurrence rate similar to that of CO2 laser ablation, with rates of 82.4% and 85.7% respectively.
• Applying MMC therapy after the epithelialization of the surgical site (or the reformation of the protective surface layer), specifically a mean of 15 days post-surgery, did not result in higher tumor recurrence rates compared to immediate postoperative treatment.
• There was a tendency for severe complications that could threaten vision or the anatomy of the eye itself to occur more frequently when MMC was applied immediately after surgery, with 5 out of 6 major complications occurring in this setting.
• Only 1 out of 6 major complications occurred when MMC was applied following the epithelialization of the surgical site.

Conclusions

• The research concludes that horses that received topical MMC therapy were no more likely than horses with CO2 laser ablation to experience tumor recurrence.
• Initiating two to three rounds of MMC after the epithelialization of the surgical site resulted in fewer major complications and similar disease resolution compared to immediate post-surgery treatment in the sampled horses.