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.