Central nervous system relapse in patients over 80 years with diffuse large B-cell lymphoma: an analysis of two LYSA studies.

CNS relapse is reported in 2-5% of diffuse large B-cell lymphoma (DLBCL) patients, dramatically decreasing overall survival (OS). Very few studies address incidence and risk factors of CNS relapse in very elderly patients, a challenging population to treat given their commonly associated comorbidities. A retrospective analysis was performed of 270 DLBCL patients >80 years treated between 2004 and 2013 in two multicentre phase II LYSA trials (LNH03-7B, LNH09-7B) evaluating the addition of rituximab or ofatumumab to mini-CHOP as front-line therapy. No patients received CNS prophylaxis. CNS relapse was evaluated according to cumulative incidence, patient characteristics, risk factors, and survival. Median age was 83 years (range: 79-95). After a median follow-up of 28.7 months, eight patients had CNS relapse (3.0%). Median time between inclusion and CNS relapse was 19.2 months (range: 3.2-32.6). Patients survived a median of 1.5 months after CNS relapse (range: 0.4-4.1). Median OS from relapse was significantly lower in CNS relapse patients (1.5 months, 95% CI: 0.4-3.5) compared to patients with non-CNS relapse (6.6 months; 95% CI: 4.6-11.9). No baseline characteristics were associated with CNS relapse. The proportion of patients with CNS disease did not differ significantly between patients with low-intermediate risk according to CNS-IPI and patients with high risk (3% vs. 2.8%, P = 1.00). CNS relapse cumulative incidence in very elderly treatment-naive patients is 1.8% at 2 years and is associated with poor survival. This population had a long median time to CNS relapse. Absence of prophylaxis did not strongly impact CNS relapse incidence.