Comparison of survival between radiation therapy and trans-oral laser microsurgery for early glottic cancer patients; a retrospective cohort study

Abstract

BackgroundThe literature reports various treatment methodologies, such as trans-oral laser microsurgery, radiation therapy, total/partial laryngectomies, and concurrent radiation chemotherapy for patients with early larynx cancer. However, at the forefront of early glottis treatment is trans-oral laser microsurgery and radiation therapy, likely due to better functional and survival outcomes. Here we conduct the largest Canadian head-to-head comparison of consecutive patients treated with either radiation therapy or trans-oral laser microsurgery. Additionally, we compare these two treatments and their 5-year survival rates post treatment to add to the existing literature.MethodsCharts of patients who were diagnosed with early glottic cancer between 2006 and 2013 were reviewed. Seventy-five patients were identified, and split into 2 groups based on their primary treatment, trans-oral laser microsurgery and radiation therapy. Kaplan–Meier survival curves, life-tables, and the log-rank statistic were reported to determine if there was a difference between the two treatment groups and their disease-specific survival, disease-free survival, and total laryngectomy-free survival. Additionally, each different survival analysis was stratified by potential confounding variables, to help conclude which treatment is more efficacious in this population.ResultsThe 5-year disease-specific survival rate is 93.3 % σ = 0.063 and 90.8 % σ = 0.056 for patients treated with trans-oral laser microsurgery and radiation therapy, respectively (χ2 < 0.001, p = 0.983). The disease free survival rate is 60.0 % (σ =0.121) for patients treated with trans-oral laser microsurgery, and 67.2 % (σ = 0.074) for those who received RT (χ2 = 0.19, p = 0.663). Additionally, the total laryngectomy-free survival rate is 84.1 % (σ = 0.1) and 79.1 % (σ = 0.072) for patients’ early glottic cancer treated by trans-oral laser microsurgery and radiation therapy, respectively (χ2 = 0.235, p = 0.628). Chi-square analysis of age-group versus treatment group (χ2 = 6.455, p = 0.04) and T-stage versus treatment group (χ2 = 11.3, p = 0.001) revealed a statistically significant relationship, suggesting survival analysis should be stratified by these variables. However, after stratification, there was no statistically significant difference between the trans-oral laser microsurgery and radiation therapy groups in any of the survival analyses.ConclusionNo difference was demonstrated in the 5-year disease-specific survival, disease-free survival, and total laryngectomy-free survival, between the RT and TLM treatment groups. Additionally, both groups showed similar 5-year survival after stratifying by confounding variables.

Oncologic outcomes of KTP laser surgery versus radiation for T1 glottic carcinoma

“…A study of 75 patients by De Santis et al found no difference in 5-year diseasefree survival, overall survival, or laryngeal preservation for patients with T1 and T2 carcinoma treated with TLM versus radiation. 19 A meta-analysis of voice outcomes by Greulich et al showed similar subjective and objective outcomes between TLM and EBRT. 20 One of the ongoing goals in management of laryngeal cancer is stratification of patients into high-and low-risk groups.…”

“…However, this analysis did not take into account clinical and demographic factors of each patient group, and the local control rate was not significantly different between the two groups. A study of 75 patients by De Santis et al found no difference in 5‐year disease‐free survival, overall survival, or laryngeal preservation for patients with T1 and T2 carcinoma treated with TLM versus radiation . A meta‐analysis of voice outcomes by Greulich et al showed similar subjective and objective outcomes between TLM and EBRT …”

Radiotherapy vs surgery for T1‐2N0M0 laryngeal squamous cell carcinoma: A population‐based and propensity score matching study

“…Among LSCCs, glottic cancer is the most common subtype, accounting for 80% of LSCC patients in the current study. Several studies have concluded that surgery is associated with a higher survival in patients with LSCCs, while there are a number of studies that have reported the opposite results; however, most of these studies were based on <100 patients . In a large meta‐analysis that included 562 participants treated with laser surgery and 706 participants treated with radiotherapy, the pooled analysis showed that laser surgery significantly improved the overall survival of patients with T1 glottic carcinoma group .…”

Clinical analysis of EBRT vs TLM in the treatment of early (T1-T2N0) glottic laryngeal cancer

“…The patients were divided into two groups: the radiotherapy group and the laser-ablation group. The 5-year DSF rates of the two groups were 90.8% and 93.3%, respectively, and there were no significant differences in the 5-year LC or PFS rate [2]. A review in Martine 2017 described a comparison of treatments for T2 disease, and 48 studies showed no significant differences between radiotherapy (n=3191) and TLM (n=1156) at 5 years (75.81% vs 77.26%) [7].…”