Comparison of Primary B/NKT Non‐Hodgkin Lymphomas in Nasopharynx, Nasal Cavity, and Paranasal Sinuses.

Objective: We aimed to compare clinical and survival differences between B‐cell (B‐NHL) and NKT‐cell non‐Hodgkin lymphomas (NKT‐NHL) located in the nasal cavity (NC), nasopharynx, and paranasal sinuses, which are always categorized as one sinonasal type. Study Design: Patients diagnosed with primary B‐NHL and NKT‐NHL in the nasal cavity, nasopharynx, and paranasal sinuses from Surveillance, Epidemiology, and End Results (SEER) database were included (1975‐2017). Setting: Population‐based cohort study. Methods: We conducted univariate and multivariate Cox regressions and Kaplan‐Meier analysis to examine survival outcomes of B/NKT‐NHL in the nasal cavity, nasopharynx, and paranasal sinuses, respectively. Results: Overall, most B‐NHL cases originated from the nasopharynx, while the majority of NKT‐NHL cases occurred in the nasal cavity. Notably, the cancer‐special survival (CSS) outcomes improved significantly in all sinonasal B‐NHL cases over time, whereas no such improvement trend was observed in each sinonasal NKT‐NHL type. Additionally, increasing age was linked with an elevated risk of death in B‐NHL, particularly in the nasal cavity (Hazard ratio [HR]: 3.37), rather than in NKT‐NHL. Compared with B‐NHL, the adverse effect of a higher stage on CSS was more evident in NKT‐NHL, particularly in its nasopharynx site (HR: 5.12). Furthermore, radiotherapy was beneficial for survival in patients with sinonasal B‐NHL and NKT‐NHL, except in the nasopharynx NKT‐NHL. However, chemotherapy has only been beneficial for CSS in patients with paranasal sinuses B‐NHL (HR: 0.42) since 2010, rather than in other types of B/NKT‐NHL. Conclusion: Although B‐NHL and NKT‐NHL in the nasal cavity, nasopharynx and paranasal sinuses have similar anatomical locations, their clinicodemographics and prognoses are largely different and should be treated and studied as distinct diseases. [ABSTRACT FROM AUTHOR]