Asian variant of intravascular large B-cell lymphoma: a comparison of clinical features based on involvement of the central nervous system

BACKGROUND/AIMS: There are limited data about the influence of the central nervous system (CNS) involvement on the prognosis for patients with the Asian variant of intravascular large B-cell lymphoma (IVLBCL). METHODS: We analyzed 46 patients who were diagnosed with IVLBCL between 2001 and 2018. All patients were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). RESULTS: CNS involvement was diagnosed by cerebrospinal fluid analysis (n = 6) and brain imaging (n = 5) in 11 patients at diagnosis, and four cases with CNS relapse were found. Thus, 15 patients had CNS involvement (15/46, 33%). The clinical characteristics were not different between patients with and without CNS involvement, but all patients with CNS involvement belonged to the high-risk group of CNS-International Prognostic Index (IPI). Thirty-one patients achieved a complete response (67%, 31/46) whereas eight patients showed disease progression and six patients died after the first or second cycle of R-CHOP. CNS-directed therapy such as high-dose methotrexate was combined with R-CHOP for patients with CNS involvement, and five patients were alive without relapse. The median overall survival of all patients was 45.0 months, and overall survival was not different according to the involvement of CNS. CONCLUSIONS: The treatment outcome of patients with the Asian variant of IVLBCL is still not satisfactory. The prediction of CNS involvement based on the clinical features including CNS-IPI score might not serve to identify patients at high risk of CNS involvement, either. Thus, more effective strategies for diagnosis and treatment should be developed.