Effect of histopathological grade on treatment and survival in base of tongue adenocarcinoma.

OBJECTIVES: The purpose of this study was to investigate survival differences between low-grade and high-grade base of tongue (BOT) adenocarcinoma by examining demographics, tumor characteristics, and treatment modalities. METHODS: The National Cancer Database was queried for patients with BOT adenocarcinoma between 2004 and 2017. Univariate and multivariate analyses were performed for all cases of BOT adenocarcinoma. Subsequent analysis focused on low-grade (grade 1 and grade 2) and high-grade (grade 3 and grade 4) BOT adenocarcinoma. RESULTS: A total of 286 patients with BOT adenocarcinoma were included in the main cohort and divided into low grade (n = 137) and high grade (n = 66). The 5-year overall survival for all patients, low-grade, and high-grade was 67%, 85%, and 58%, respectively. Prognostic factors associated with decreased survival for the main cohort include advanced age (hazard ratio [HR]: 1.04; 95% confidence interval [CI]: 1.02-1.06), non-white race (HR: 1.79; 95% CI: 1.04-3.25), public insurance (HR: 1.79; 95% CI: 1.02-3.14) and high-grade 3,4 (HR: 2.63; 95% CI: 1.51-4.56). The prognostic factor associated with increased survival for the main cohort was surgery (HR: 0.59; 95% CI: 0.36-0.96). Radiotherapy was associated with improved overall survival for high-grade BOT adenocarcinoma (HR: 0.09; 95% CI: 0.02-0.49) but not for low-grade BOT adenocarcinoma (HR: 0.93; 95% CI: 0.38-2.32). CONCLUSIONS: This investigation is the largest to date analyzing the association of treatment modalities with overall survival in BOT adenocarcinoma. Surgery remains standard of treatment, particularly in low-grade cases, with radiotherapy offering additional survival benefit for high-grade BOT adenocarcinoma.