Nationwide Incidence, Treatment Pattern, and Prognosis of Primary CNS Lymphoma in Taiwan, 2012-2020: A Retrospective Cohort Study.

[BACKGROUND] Primary central nervous system lymphoma (PCNSL) is a rare but devastating form of non-Hodgkin lymphoma with persistently poor outcomes despite treatment advances. This nationwide population-based study evaluated real-world epidemiology, treatment patterns, and survival outcomes in Asian PCNSL patients.

[METHODS] Patients with newly diagnosed PCNSL (2012-2020) were identified from the Taiwan Cancer Registry Database and linked with the National Health Insurance Research Database. Incidence, treatment patterns, survival outcomes, healthcare costs, and adverse events were analyzed for identified PCNSL patients. Specifically, median survival times (MSTs), with 95% confidence intervals (CIs), were estimated using the Kaplan-Meier method.

[RESULTS] Among 820 PCNSL patients (median age 65 [IQR 56-74] years; 53.5% male; 94.4% DLBCL subtype), age-standardized incidence was 0.39 per 100,000 person-years (2012-2020) with male predominance (0.44 vs. 0.34) and elderly burden (1.62 in ≥ 75 years vs. 0.28 in < 65 years). Despite 89.5% receiving induction therapy within median 24 days, outcomes remained poor: median survival 1.85 (95% CI 1.53-2.27) years, with 1-, 2-, and 3-year survival rates of 61.5%, 48.3%, and 40.2%, respectively. All-cause survival deteriorated markedly with age-median survival of 5.71, 3.29, 2.32, 0.97, and 0.69 years for ages < 50, 50-59, 60-69, 70-79, and ≥ 80 years, respectively. MTX-based chemotherapy with rituximab adoption increased (22.2% to 55.3%), achieving superior survival (3.44 years) versus WBRT alone (1.24 years). However, 46.2% developed relapsed/refractory disease at median 156 (89-339) days. Consolidation therapy was administered in 52.5% at median 53 days post-induction. Infection (87.9%), nausea/vomiting (81.1%), and neutropenia (54.4%) dominated adverse events, with first-year costs averaging $35,472 (SD $20,816) USD.

[CONCLUSION] PCNSL demonstrates persistently poor prognosis, with elderly patients experiencing disproportionately worse outcomes. High relapse rates, substantial treatment-related adverse events, and considerable healthcare burden underscore the urgent need for novel therapeutic approaches.