RADIOTHERAPY IN T1 LARYNGEAL-CANCER - PROGNOSTIC FACTORS FOR LOCOREGIONAL CONTROL AND SURVIVAL, UNIVARIATE AND MULTIVARIATE-ANALYSIS

From 1975 through 1985, 194 patients with T1 glottic, 37 patients with T1 supraglottic, and 3 patients with T1 subglottic cancer were treated with radiotherapy. Local control and ultimate locoregional control (after salvage surgery) was 91% and 97% for T1 glottic, 84% and 81% for T1 supraglottic, and 2/3 and 3/3, respectively for subglottic tumors. In uni- and multivariate analysis local control for glottic tumors was associated with extension of the tumor on the vocal cord (entire length of vocal cord vs others, p = 0.01) and continuation of smoking after therapy (yes/no, p = 0.03). No prognostic factor for local control was found in supraglottic tumors. However, regional control and survival were impaired by N stage (N0 vs N +, p < 0.0005), local recurrence (yes/no, p < 0.0005), and extension of the tumor (one supraglottic subsite vs more than one, p < 0.05). Mild late complications were seen in 13% of patients without salvage therapy. Following univariate analysis, field size, fraction size (> 2 Gy), maximum tumor dose (> 70 Gy), age, post-treatment biopsy, and tumor site were associated with complication rate. Following multivariate analysis, site, fraction size, maximum tumor dose, and continuation of smoking after therapy were independent prognostic factors for mild late complications (mostly arytenoid edema).