Prophylaxis strategies containing high dose intravenous methotrexate on preventing CNS relapse for patients with diffuse large B-cell lymphoma at intermediate to high risk: A study based on 12 cohorts in the rituximab era.

During the Rituximab era, high dose intravenous methotrexate (HD) and intrathecal methotrexate (IT) are recommended prophylaxis in preventing central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) patients. However, the optimal CNS prophylaxis strategies remained uncertain. This meta-analysis research explored the findings of previous studies and highlighted the efficacy of HD and/or IT on CNS prophylaxis of DLBCL patients at intermediate to high risk. Specifically, it aims to answer the following research questions: (1) Is there a difference on CNS relapse rate between HD and IT cohorts? (2) Is there a correlation between CNS prophylaxis and survival? This meta-analysis research performed an in-depth examination of pertinent studies available in PubMed, Embase, and Cochrane databases. The primary endpoints included: CNS relapse rate and 2-year or 3-year survival rate. The findings of the qualified studies were reviewed and analyzed using 5.3 version of the Review Manager software. After thorough analysis of 12 studies involving 5950 DLBCL patients, it was revealed that in comparison with IT alone, HD with or without additional IT (HD ± IT) significantly reduced the risk of CNS relapse (Risk Ratio (RR)= 0.41, 95 % CI (0.24-0.68), P = 0.0007). Besides, the efficacy of HD alone was comparable to HD + IT (RR = 1.08, 95 % CI (0.19-6.32), P = 0.93), which was also considered to be more optimal than IT alone on CNS prophylaxis (RR = 0.39, 95 % CI (0.15-1.06), P = 0.06).Based on these results, IT alone or no-prophylaxis were viewed as a group of inadequate prophylaxis. Comparing to HD ± IT, the 3-year survival rate of inadequate prophylaxis group was lower (RR = 1.17, 95 % CI (1.03-1.32), P = 0.01). The results of this study reveals that in the Rituximab Era, prophylaxis strategies containing HD is better than IT alone or no-prophylaxis on preventing CNS relapse of DLBCL patients with intermediate to high risk.