Survival Outcomes and Prognostic Factors in Patients With Primary Central Nervous System Low‐Grade B‐Cell Lymphoma: A Population‐Based Cohort Study

The incidence of primary central nervous system low-grade B-cell lymphoma (PCNSL-LG) is rare. We aimed to provide the first large-scale analysis of treatment modalities, survival trends, and prognostic factors for PCNSL-LG. Patient data diagnosed between 2000 and 2021 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. A total of 267 adult PCNSL-LG patients were included. The year of diagnosis was divided into the time period-1 (2000-2009) and the time period-2 (2010-2021). Radiotherapy alone usage remained stable over time (27.34% vs. 30.22%, p = 0.605). Chemotherapy alone showed a modest, non-significant increase (25.00% vs. 31.66%, p = 0.229), while combined chemoradiotherapy declined significantly from 29.69% to 15.11% (p = 0.004). The 1-, 5-, and 10-year overall survival (OS) rates for all PCNSL-LG patients were 84.3%, 73.4%, and 61.8%, respectively. Overall survival improved significantly, with median OS extending from 11.25 years in period-1 to not reached in period-2 (HR 0.46, 95% CI: 0.28-0.74; p = 0.001). Surgery was associated with improved outcomes compared with non-surgical management (HR 0.47, 95% CI: 0.31-0.72, p < 0.001). In patients with MALT lymphoma histology, no significant prognostic difference was observed across treatment modalities (p = 0.838). This study underscores a marked improvement in survival among PCNSL-LG patients over the past two decades and offers valuable insights for optimizing clinical management and improving patient outcomes.