[Different Prophylaxis Strategies for Central Nervous System Recurrence of Diffuse Large B-Cell Lymphoma].

Objective: To analyze the effects of highdose methotrexate (HD-MTX) and lenalidomide as central nervous system (CNS) prophylaxis strategies in patients with diffuse large B-cell lymphoma (DLBCL).

Methods: The data of DLBCL patients with high risk of CNS recurrence who were initially treated in Fujian Provincial Hospital and Fujian Cancer Hospital from January 2012 to June 2022 were analyzed retrospectively. The patients were divided into HD-MTX group and lenalidomide group according to different prophylaxis strategies. Each group was further divided into high-risk group and medium-risk group based on CNS-IPI score and/or testicular involvement. The CNS relapse-free survival (CRFS) rate, adverse effects, and the effects of different prophylaxis strategies on overall survival (OS) rate and progression-free survival (PFS) rate were evaluated in different groups and subgroups.

Results: There were 200 patients enrolled in this study, 80 cases in lenalidomide group and 120 cases in HD-MTX group. According to the delivery timing of prophylactic HD-MTX, the patients in HD-MTX group were further divided into two groups: 80 cases at the end of induction chemotherapy and 40 cases during chemotherapy interval. At a median follow-up of 48(14-133) months, the 4-year CRFS rate, 4-year PFS rate, and 4-year OS rate of the HD-MTX group was 93.6%, 57.2%, and 68.8%, respectively, while that of the lenalidomide group was 90.4%, 69.4% and 75.6%. There were no significant differences in 4-year CRFS rate, 4-year PFS rate, and 4-year OS rate between HD-MTX group and lenalidomide group (all >0.05), but lenalidomide group showed a trend of improvement in PFS. Further subgroup analysis showed that there was no significant difference in 4-year CRFS rate between high-risk patients of the two groups (91.7% 83.4%, >0.05), while 4-year PFS rate showed difference (49.5% 64.2%, <0.05). A total of 248 cycles were collected for adverse reaction analysis in the HD-MTX group, and 25 cycles occurred neutropenia accompanied with infection (10.1%), while in lenalidomide group 240 cycles were collected in which 20 cycles occurred neutropenia accompanied with infection (8.3%). Both the two groups had no treatment-related deaths.

Conclusion: Compared with HD-MTX, lenalidomide combined with immunochemotherapy can prevent CNS relapse, at the same time, improve prognosis, which is a safe and well tolerated central prophylaxis strategy.