Role of rituximab in treatment of patients with primary central nervous system lymphoma: An updated systematic review and meta-analysis.

[BACKGROUND] Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extranodal non-Hodgkin lymphoma, most often a diffuse large B-cell lymphoma. Rituximab, an anti-CD20 monoclonal antibody is widely used in PCNSL treatment but its efficacy remains uncertain. Therefore, we conducted a systematic review and meta-analysis to assess the efficacy of rituximab in newly diagnosed adult PCNSL patients.

[METHODS] Medline/PubMed and Scopus were searched for studies comparing rituximab/rituximab-containing regimens with therapies not including rituximab in adult PCNSL patients. A random-effects meta-analysis was conducted, and risk ratios (RR) and hazard ratios (HR) were reported with 95% confidence interval (CI). Outcomes included 3- and 5-year overall survival (OS), OS independent of time, 3- and 5-year progression-free survival (PFS), and complete response (CR).

[RESULTS] Sixteen studies (three RCTs, thirteen retrospective) with 2,325 patients (rituximab: 1010; control: 1315) were included. Rituximab-containing therapy was significantly associated with higher 3-year OS (RR: 1.37; 95% CI: 1.07-1.76), higher CR rate (RR: 1.37; 95% CI: 1.05-1.79) and reduced hazard of death (HR: 0.65; 95% CI: 0.43-0.98). 3-year PFS showed a non-significant trend favoring rituximab (RR: 1.29; 95% CI: 0.99-1.68) which reached statistical significance in sensitivity analysis after excluding one study (RR: 1.40; 95% CI: 1.12-1.77). No statistically significant differences were observed for 5-year OS (RR: 1.33; 95% CI: 0.99-1.78) or 5-year PFS (RR: 1.24; 95% CI: 0.79-1.94) between the two groups.

[CONCLUSION] Our findings indicate that rituximab-containing therapy was associated with improved short-term outcomes in newly diagnosed adult PCNSL. However, long-term advantages remain uncertain. Therefore, there is a need for larger randomized trials with standardized outcome and toxicity reporting and extended follow-up to confirm long-term survival benefit.