Primary radiotherapy of T1 squamous cell carcinoma of the larynx: analysis of 478 patients treated from 1963 to 1985.

Radiotherapy was administered to 478 consecutively treated patients with laryngeal T1 squamous cell carcinoma between 1963-1985. One hundred and seventeen had a supraglottic, 358 a glottic, and 3 a subglottic tumor. Supraglottis: 71% males; 49% T1a; 14 patients with nodes. Glottis: 90% males; 82% T1a; 1 patient with node. The 10-year value for local control in the supraglottic group was 55% and in the glottic group 81%. No difference was observed between T1a and T1b. Regional nodes and distant metastases were seldom seen in the glottic, but frequently observed in the supraglottic group. The treatment results appeared to be most favorable in women. The 10-year corrected survival for supraglottic and glottic tumors demonstrated a highly significant difference, 67% compared to 94%. There was a significantly increasing incidence of events with lower tumor differentiation. Split-course and conventional radiotherapy gave equal treatment results, but late complications were significantly more common with the former. A major problem was new primary cancers, which within 20 years occurred in 34% of patients surviving a supraglottic tumor and in 23% of the glottic patients. The predominant new site was the lung (23% and 13%, respectively). Thus, in the glottic group more patients died from the new cancer than from the glottic carcinoma.