Oncologic Outcome and Predictor of Local Recurrence in Patients with Glottic Cancer Treated with Transoral Laser Microsurgery

Abstract

Background and Objectives Transoral laser microsurgery (TLM) is minimally invasive and has become the standard approach for early and intermediate stage laryngeal cancers. Many studies show that the oncologic results of TLM are equivalent to those obtained by conventional conservative surgery and radiotherapy (RT). The purpose of this study were to analyze the treatment outcome and predictors of local recurrence in glottic cancer patients who underwent TLM.Subjects and Method Sixty-seven patients who received TLM for glottis cancer between 2008 and 2019 were analyzed retrospectively. Patients were predominantly male (98.5%), with a median age of 64.3 years (range 45 to 87 years). There were 35 cases of T1 (52.2%), 15 cases of T2 (22.3%), and 17 cases of T3 (25.3%) in the primary tumor stage. There were no patients with lymph node metastasis (cN0). When classified into types, there were 2 cases of type I (3%), 15 cases of type II (22.3%), 34 cases of type III (50.7%), 4 cases of type IV (5.9%), 12 cases of type V (17.9%). The local control rate and overall survival rate were calculated with KaplanMeier curve analysis. Additionally, multivariate analysis of factors associated with local recurrence used Cox proportional-hazards model.Results TLM alone was performed in 54 patients (80.5%) whereas 13 patients (19.5%) underwent TLM followed by adjuvant RT. The 5-year local control rate and 5-year overall survival rate were 81.9% and 93.3%, respectively. In the Univariate analysis, the significant factors of local recurrence were difficult laryngeal exposure [odds ratio (OR)=22.8, 95% confidence interval (CI)=1.7-297.4, <i>p</i>-value=0.03], anterior commissure invasion (OR=17.2, 95% CI=1.9-154.7, <i>p</i>-value=0.004, positive lymphovascular invasion (OR=18.0, 95% CI=2.9-109.8, <i>p</i>-value=0.003) and positive resection margin (OR=9.5, 95% CI=1.6-55.6, <i>p</i>-value=0.011). In the multivariate analysis, the independent factors of local recurrence were anterior commissure invasion [hazard ratio (HR)=18.4, 95% CI=1.98-170.99, <i>p</i>-value=0.010] and lymphovascular invasion (HR=7.5, 95% CI=1.49-38.15, <i>p</i>-value=0.015). No major or lethal complications were observed.Conclusion TLM is a reliable modality to treat early and select cases of moderately advanced glottic cancer. Our study found that independent factors of local recurrence included anterior commissure invasion, and lymphovascular invasion. These findings may be useful to follow-up glottic cancer patients after TLM.