Prognostic factors in patients with T1 glottic cancer treated with radiotherapy

PURPOSE: Presentation of long-term results of radiation treatment in patients with T1 glottic cancer and evaluation of prognostic factors. METHODS: We performed a retrospective analysis in a group of 569 patients with T1 squamous cell glottic carcinoma treated with radiotherapy at the Center of Oncology in Cracow between 1977 and 2007. In all, 503 (88%) patients presented with T1a stage disease and 66 (12%) with T1b. Anterior commissure infiltration was present in 179 (31%) patients. Average hemoglobin level prior to therapy was 13.9 g/dl. Using the body mass index (BMI), 114 (20%) patients were underweight, and 91 (16%) were overweight. Median time between collecting tumor specimen and beginning of radiotherapy was 56 days (range 14–145 days). Treatment regimen was normofractionated with single fraction ≤2 Gy in 102 (18%) and hypofractionated in 467 (82%) patients. RESULTS: The 5‑ and 10-year overall survival (OS), disease-specific survival (DSS) and local control (LC) rates were 85 and 68%, 88 and 86%, 89 and 87%, respectively. Multivariate analysis showed that tobacco smoking, low hemoglobin level (<13 g/dl), anterior commissure infiltration, fraction dose ≤2 Gy and time from collecting specimen to beginning of therapy longer than 30 days had negative impact on LC and DSS. Patients’ age over 60 years, worse performance status and malnutrition (BMI <18.5) had negative impacts on OS. CONCLUSIONS: Radiotherapy is a highly effective treatment method in patients with T1N0M0 glottic cancer. LC and DSS may be improved following hypofractionation, smoking cessation, and shortening of waiting-time until start of treatment. OS was mainly influenced by nutritional and performance status.