Long-term observations and salvage operations on patients with T2N0M0 squamous cell carcinoma of the glottic larynx treated with radiation therapy alone

Conclusion: A long-term study was carried out on 57 patients treated with radiation alone who had T2N0M0 squamous cell carcinoma of the glottic larynx. The response and survival rates were satisfactory, but the complete response (CR) and the larynx preservation rates showed a need for improvement. Thirty-four patients underwent salvage operations and a safe margin for the partial laryngectomy was evaluated by histopathological examination of serial sections of the surgical specimen. Objective: Although the effectiveness of combined chemoradiation therapy in the treatment of head and neck cancer has been reported, the facts remain unclear. The purpose of this study was to analyze the long-term outcomes of radiation therapy alone for T2N0M0 squamous cell carcinoma of the glottic larynx, i.e. the survival rate, the larynx preservation rate, and the reality of salvage operations. This is expected to contribute to an understanding of the synergistic effects of anticancer drugs used in combined chemoradiation therapy, the use of which will be expanded in the future. The reason for this is that the radiation source, radiation field, and radiation dose are nearly identical for patients with T2N0M0 squamous cell carcinoma of the glottic larynx. Methods: The subjects were 57 patients with untreated T2N0M0 squamous cell carcinoma of the glottic larynx. There were 55 males and 2 females. Their ages ranged from 31 to 86 years. The 4MV Liniac X-ray external beam radiation therapy was carried out via two-dimensional horizontal opposing ports, 2Gy per dose, five times a week with a total of 66 Gy. Results: In 57 patients, we observed CR in 33 patients, partial response (PR) in 20 patients, no change (NC) in 4 patients, and progression disease (PD) in none of the patients. The response rate was 93.0% and the CR rate was 57.9%. The survival rates (Kaplan-Meier method) were: 5-year survival rate of 88.5% and 10-year survival rate of 73.5%. The larynx preservation rates (Kaplan-Meier method) were: 5-year larynx preservation rate of 60.4% and 10-year larynx preservation rate of 50.1%. The main side effect of grade 3 or more was only stomatitis in four patients, all of which were reversible changes (CTCAT v3.0 JCOG/JSCO). Salvage operation was required in 34 (59.6%) of 57 patients, 10 patients underwent partial laryngectomy, total laryngectomy was performed in 3 of the 10 patients following the partial laryngectomy, and 27 patients (47.4%) underwent total laryngectomy. The surgical specimens were serially sectioned at a thickness of 4 mm and examined histopathologically and compared to the macroscopic findings at surgery. The safe margin for partial laryngectomy was considered grossly to be 5 mm from the edge of the tumor.