BACKGROUND

Diffuse large B cell lymphoma (DLBCL) is the most commonly diagnosed subtype of non-Hodgkin's lymphoma (NHL). R-CHOP has significantly improved clinical outcomes in patients with DLBCL, however, its indication in the prevention of CNS relapse and recurrence is still inconsistent. Moreover, prophylactic methotrexate and/or cytarabine have been used prophylactically for DLBCL patients is at high risk of CNS relapse and to treat CNS DLBCL, however, their efficacy remains unclear.

METHODS

The aim of our retrospective study was to determine the incidence of CNS in-volvement in patients with DLBCL and to describe its risk factors and survival outcomes.

RESULTS

A total of 406 patients with DLBCL were identified, and 17 (4.2%) of DLBCL patients had CNS involvement i.e. 9 (2.2 %) at diagnosis and 8 (~2%) at relapse. The patients were younger, had advanced stage, high CNS-IPI, and had extra nodal involvement. Seven out of the 17 patients who survived received chemotherapy and a prophylactic methotrexate. Considering the CNS-IPI, of the 146 patients with high CNS-IPI at presentation, 18 received the prophylactic HDMTX and 3 (16.7%) of them had CNS relapse. Two (1.6%) out of 128 who did not receive the prophylactic HDMTX had CNS relapse. On the other hand, of the 223 patients with intermediate CNS-IPI, 25 received the prophylactic HDMTX and 2 (8%) of them had CNS relapse and in 198 patients who did not receive the prophylactic HDMTX, 2 (1.01%) had CNS relapse. The 5-year progression-free survival and overall survival rates for the entire cohort were 73% and 84%, respectively. The median OS for those who had CNS involvement was 17 months and the 2-year OS was 40%.

CONCLUSION

CNS involvement in DLBCL has a poor prognosis, thus, aggressive CNS-directed therapy should be considered, especially in young patients.