Radiotherapy for T1a glottic cancer: the influence of smoking cessation and fractionation schedule of radiotherapy.

The objective of the presented study is to report on retrospectively collected data on long-term outcome and toxicity and prospective assessment of quality of life (QoL) and Voice-Handicap Index (VHI) of patients with T1a glottic cancer treated with radiotherapy. Between 1985 and 2011, 549 patients were treated. Endpoints were local control (LC), toxicity, QoL and VHI. After a median follow-up of 93 months, the actuarial rates of LC were 91, and 90 % at 5- and 10-years, respectively. Continuing smoking (p < 0.001) and anaemia (p = 0.02) were significantly correlated with poor LC on univariate analysis and fractionation schedule did not show significant correlation (p = 0.08). On multivariate analysis, only continuing smoking retained significance (p = 0.001). These patients had also significantly increased incidence of second primary tumour and lower overall survival rates. The incidence of grade ≥2 late xerostomia and dysphagia were 10 and 6 %, respectively. Slight and temporary deterioration of QoL-scores was reported. The scores on the EROTC-QOL-H&N35 dysphagia and xerostomia at 24 months were -2 and -3, compared to baseline, respectively. VHI improved significantly from 34 at baseline to 21 at 24 months. Patients who continued smoking had significantly worse VHI. In conclusion, excellent outcome with good QoL and VHI were reported. Patients who continued smoking after radiotherapy had significantly poor LC and worse VHI. The current study emphasizes the importance of smoking cessation and the non-inferiority of hypofractionated schemes in terms of outcome and VHI. At our institution, phase II study is going to evaluate the role of single vocal cord irradiation with high fraction dose.