Incidence and survival trends in patients with primary tonsillar lymphoma: a large population-based study

Purpose This study aims to reveal changes in the incidence and prognosis of patients with tonsillar lymphoma on a population level. Methods The incidence, clinicopathological, and prognostic data of tonsillar lymphoma patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The Join-point software and R packages were utilized to analyze the annual percentage changes (APCs) and survival outcomes. Results The incidence of primary tonsillar lymphoma increased from 0.1204 per 100,000 person-years (95% CI, 0.0680-0.1962) in 1983 to 0.2158 (95% CI, 0.1675-0.2740) in 2015 with an APC of 1.20. When classified by decades, both cancer-specific survival (CSS) and overall survival (OS) improved with time. The 2006-2015 decade showed the highest rate of CSS and OS. Nevertheless, for disease-specific survival (DSS), the difference was not significant between 1996-2005 and 2006-2015 decades. The main cause of mortality among this cohort was heart diseases. Three nomograms were constructed to predict OS, CSS, and DSS for patients with primary tonsillar lymphoma, respectively. Histological subtype made the most contribution to poor prognosis in OS-predicting and CSS-predicting nomograms. While, for DSS, age at diagnosis made the most contribution to poor outcomes. Conclusions The incidence of primary tonsillar lymphoma has increased in the past decades. The OS and CSS rates of tonsillar lymphoma improved continuously, while there was no significant improvement in DSS in the past decades. These changes indicated an improved management of tonsillar lymphoma with newer therapeutic agents and the need of multi-disciplinary treatments to offset the future burden of noncancer diseases.