Efficacy and safety of the R2-MTX regimen in primary central nervous system lymphoma (PCNSL): a single-center retrospective analysis.

PURPOSE: Primary central nervous system lymphoma (PCNSL) has a poor prognosis, mainly because of the significant challenges with the efficacy and tolerability of induction chemotherapy. This retrospective study aimed to evaluate the efficacy and safety of the R2-MTX regimen in PCNSL patients.

METHODS

We conducted a retrospective analysis of 39 PCNSL patients treated with the R2-MTX regimen, focusing on treatment outcomes and adverse events (AEs).

RESULTS

The overall response rate (ORR) was 72.2%, with a complete response (CR) rate of 69.4% and a partial response (PR) rate of 2.8%. With a median follow-up of 37.2 months (interquartile range [IQR] 24.2-47.5), the estimated 2-year progression-free survival (PFS) and overall survival (OS) rates were 54.9% (95% CI, 37.2-69.5%) and 78.5% (95% CI, 59.8-89.2%), respectively. The most common grade 3 or 4 AEs included neutropenia (33.3%), leukopenia (13.9%), anemia (2.8%), and thrombocytopenia (2.8%). Consolidation or maintenance therapy was associated with prolonged survival in PCNSL patients (2-year OS rates 100% vs. 42.9%, P = 0.067). Survival analysis revealed that clinicopathological factors, such as double-expressor lymphoma (DEL), ECOG PS ≥ 2, and high-risk classification based on the Memorial Sloan Kettering Cancer Center model (MSKCC), predicted poor survival.

CONCLUSIONS

Our results underscore the therapeutic potential of the R2-MTX regimen in managing newly diagnosed PCNSL patients. Further prospective studies with larger patient cohorts are imperative to solidify these preliminary findings.