Longitudinal Patient-Reported Voice Quality in Early-Stage Glottic Cancer

Objective: Patient-reported voice quality is an important outcome during counseling in early-stage glottic cancer. However, there is a paucity of adequate longitudinal studies concerning voice outcomes. This study aimed to investigate longitudinal trajectories for patient-reported voice quality and associated risk factors for treatment modalities such as transoral CO₂ laser microsurgery, single vocal cord irradiation, and local radiotherapy.

Study design: A longitudinal observational cohort study.

Setting: Tertiary cancer center.

Methods: Patients treated for Tcis-T1b, N0M0 glottic cancer were included in this study (N = 294). The Voice Handicap Index was obtained at baseline and during follow-up (N = 1944). Mixed-effects models were used for investigating the different trajectories for patient-reported voice quality.

Results: The mean follow-up duration was 43.4 (SD 21.5) months. Patients received transoral CO₂ laser microsurgery (57.8%), single vocal cord irradiation (24.5%), or local radiotherapy (17.5%). A steeper improvement during the first year after treatment for single vocal cord irradiation (-15.7) and local radiotherapy (-12.4) was seen, compared with a more stable trajectory for laser surgery (-6.1). All treatment modalities showed equivalent outcomes during long-term follow-up. Associated risk factors for different longitudinal trajectories were age, tumor stage, and comorbidity.

Conclusion: Longitudinal patient-reported voice quality after treatment for early-stage glottic cancer is heterogeneous and nonlinear. Most improvement is seen during the first year of follow-up and differs between treatment modalities. No clinically significant differences in long-term trajectories were found. Insight into longitudinal trajectories can enhance individual patient counseling and provide the foundation for an individualized dynamic prediction model.