Radiological tumor thickness as a risk factor for local recurrence in early glottic cancer treated with laser cordectomy.

ABSTRACT

OBJECTIVES: Despite the excellent prognosis of early glottic cancer (T1-T2), the significance of preoperatively measured tumor thickness has not been elucidated. We evaluated the role of tumor thickness measured using computed tomography (CT) as a predictive factor for recurrence of early glottic cancer after transoral laser microsurgery (TLM). METHODS: The medical records of 134 patients who were diagnosed with early glottic squamous cell carcinoma and underwent TLM were reviewed. Age, sex, clinical stage, preoperative biopsy, anterior commissure involvement, CT findings, recurrence, and overall survival were evaluated. RESULTS: Seventy-three patients (54 T1a, 2 T1b, and 17 T2) were enrolled. Tumor thickness on pathology increased proportionally with increased tumor thickness on CT. The recurrence-free survival (RFS) and overall survival rates were 82.2 and 91.2%, respectively. Upon univariate analysis, RFS was affected by the type of cordectomy, tumor differentiation, margin involvement, anterior commissure involvement, impaired vocal fold mobility, and tumor thickness (> 4 mm) on CT scan (all p < 0.01). Among the relevant covariates, an involved or close resection margin [hazard ratio (HR) 19.2; 95% confidence interval (CI) 3.5-105.6; p < 0.01], impaired vocal cord mobility (HR 8.5; 95% CI 1.45-49.2; p = 0.02), and pathological tumor thickness (> 4 mm) (HR 6.0; p = 0.02) were predictive of RFS. CONCLUSION: Tumor thickness may be another predictive factor for recurrence in early glottic cancer. Before TLM, reviewing the extent of tumor thickness will help to improve local control in cases of early glottic cancer.