Aim: In this study we aimed to determine the prognostic factors affecting local control (LC) in limited glottic carcinoma treated with definitive radiotherapy (RT).
Material and methods: Between June 1991 and December 2001, 114 patients with early squamous-cell carcinoma of the glottis were treated with definitive RT at our institution. Only four (3.5%) patients were women. The median age was 60 (27-79). Fifteen percent, 72% and 13% of the patients had Tis, T1 and T2 tumors, respectively. Forty-three (37.7%) patients had anterior commissure invasion. Prior to RT 35 (31%) patients had undergone vocal cord stripping and two (2%) cordectomy. A median dose of 66 Gy (50-70.2) was given over a median period of 46 days (20-60). Univariate and multivariate analyses were performed for LC. The prognostic parameters analyzed for LC were T classification, anterior commissure involvement, total RT dose, and overall treatment time.
Results: Five-year local and regional control rates were 84.2% and 97.7%. RTOG grade 3-4 late side effects were observed only in one (0.9%) patient. In 15 patients with local failure, salvage treatment consisted of partial laryngectomy in eight patients and total laryngectomy in five. One of the remaining two patients was medically inoperable, and the other refused salvage surgery. In one of the three patients with regional failure, salvage surgery was applied and the other two were given palliative chemotherapy because of unresectable disease. Following salvage treatments, the ultimate five-year LC rate was 96.9% and the five-year larynx preservation rate was 91.1%. Second primary cancer was diagnosed in 17 (14.9%) patients. Only one patient developed distant metastases and two patients died of laryngeal cancer. While T2 disease and anterior commissure involvement were found to be unfavorable prognostic factors significantly influencing LC in univariate analyses, only T2 disease remained independent in multivariate analysis.
Conclusion: In patients with early glottic carcinoma, T classification proved to be the only independent prognostic factor affecting LC after primary radiotherapy according to the results of this study.