CNS disease in younger patients with aggressive B-cell lymphoma: an analysis of patients treated on the Mabthera International Trial and trials of the German High-Grade Non-Hodgkin Lymphoma Study Group

To describe incidence, risk factors, and influence of treatment on occurrence of central nervous system (CNS) relapse or progression in younger patients with aggressive B-cell lymphoma. We analyzed 2210 patients with aggressive B-cell lymphoma treated on various studies for CNS relapse/progression. Treatment consisted of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) +/- etoposide. Six hundred and twenty patients also received rituximab. CNS prophylaxis was intrathecal methotrexate on High-CHOEP and MegaCHOEP phase III studies if upper neck, head, bone marrow, or testes were involved. Fifty-six of 2196 patients (2.6%) developed CNS disease. It occurred early (median 7.0 months), median survival was 5.0 months. Patients with age-adjusted International Prognostic Index (aaIPI) 0 or 1 treated with rituximab showed a low risk for CNS disease (2-year rates: 0% or 0.5%), and rituximab decreased the risk (relative risk 0.3, 95% confidence interval 0.1-0.9, P = 0.029). Patients with aaIPI 2 or 3 showed a moderate risk (4.2%-9.7%) and no significant reduction of CNS disease with rituximab. CNS prophylaxis was of no significant benefit. In younger patients with aaIPI 0 or 1, CNS relapse/progression is very rare; in patients with aaIPI 2 or 3, the risk is higher (up to 10%) and requires new diagnostic strategies and treatment.