The Combined Effect of Endoscopic Laser Surgery (ELS) and Mitomycin C on Tumor Control and Voice Outcome in Early Stage Glottic Cancer

Introduction: Both external beam radiotherapy and endoscopic carbon dioxide laser excision offer high and comparable cure rates for the treatment of T1 glottic cancer. However, controversy remains about the best method to achieve oncological cure while minimizing adverse effects on patient voice. Laser surgery depth or the area of vocal cord resection has a greater effect on vocal cord function than radiotherapy. Mit- omycin C is an antineoplastic agent that is known to inhibit proliferation of fibroblasts and tumor growth. The Aim of this Study: Is to demonstrate if the combination of the efficacy of ELS to control Tis and Tla glottic cancer and the anti-fibroblastic action of mitomycin-C could achieve both tumor control and less vocal cord scarring and hence better voice quality post-operatively. Patients and Methods: This prospective randomized study was conducted from 2002 to 2004, in New Kasr Al-Aini Teaching Hospital, over 16 patients with early stage glottic cancer (Tis and Tla) operated using CO2 ELS (endoscopic laser surgery). Tla cases were randomly subdivided into 2a and 2b groups based on the mitomycin C (MMC) application postoperatively, where the 2a group was the one with MMC application and the group 2b was the one without MMC application post-excision. Following surgery, clinical and endoscopic follow-up using 90° zoom endoscope was done with special stress on disease recurrence, vocal cord healing, voice quality and swallowing difficulty. Objective Voice analysis was performed for all patients preoperatively, at 4 weeks and 8 weeks postoperatively. Results: Complete tumor excision could be accomplished in all cases. Mitomycin-C application in group 2a patients was found to have a beneficial effect in reducing the final scaring despite the delayed healing as compared to group 2b cases without MMC application. This was evidenced through the post-operative examination using the 90° endoscope and the final vocal outcome. Conclusion: ELS is an efficient and safe modality of treatment for Tis and Tla glottic cancer. MMC topical application reduces the postoperative scarring and had a favorable outcome on the voice quality. Further prospective studies are required where more patients are included to obtain more statistically significant results.