Analysis of prognostic factors for T1N0M0 glottic cancer treated with definitive radiotherapy alone: experience of the cancer hospital of Peking Union Medical College and the Chinese Academy Of Medical Sciences

Abstract

Purpose: To analyze the prognostic factors for early-stage glottic cancer (T1N0M0) treated with radiotherapy alone.Methods and Materials: Between 1958 and 1994, 238 patients (220 male) with T1N0M0 (UICC 1997) squamous cell carcinoma of the glottis were treated with 6- or 8 MV X-ray or 60Co radiation in parallel-opposed fields (median size: 22.5 cm2) over a median of 52 days to a median dose of 68 Gy. Locoregional control (LC) and overall survival (OS) were estimated by the Kaplan-Meier method. Log-rank and Cox regression analyses were used to identify prognostic factors.Results: The median follow-up time was 127 months (range: 4–410 months). Five- and 10-year OS rates were 84.0% and 74.9%. The 5-year LC rate was 82.2%. Forty-four patients had recurrent disease (41 locally, 2 in cervical lymph nodes, 1 lost to follow-up); 23 had second malignancies. On multivariate analysis, unfavorable prognostic factors for OS were age >65 years (p < 0.001) and second malignancy (p < 0.001). Unfavorable prognostic factors for LC were bulky tumor (p = 0.023), anterior commissure involvement (p = 0.024), and decrease in hemoglobin during treatment (p = 0.025).Conclusions: Radiotherapy alone provides good control of early-stage glottic cancer. Bulky tumor, anterior commissure involvement, and decreasing hemoglobin are negative prognostic factors for LC.