Primary Central Nervous System Lymphoma − Recent Advance on Clinical Research

A primary central nervous system lymphoma (PCNSL) is an extranodal form of non-Hodg‐ kin’s lymphoma arising in the craniospinal axis. For many years, PCNSLs were reported to represent 3–5% of all primary central nervous system (CNS) tumors [1]. However, PCNSL appears to be increasing in incidence [2-4]. PCNSL age-adjusted incidence (0.15 to 0.48, a 3fold increase) outpaced that of systemic lymphoma (14.1 to 18.5, a 33% increase) for the same registries over the same time periods [2]. The increase is evident in all age groups and in both genders [2]. The tumor manifestation is often diffuse and multifocal, and most fre‐ quently affects the supratentorial brain parenchyma. The absence of systemic lymphadeno‐ pathies and other extracranial localizations of disease should be confirmed. Most PCNSLs belong to the diffuse large B-cell lymphomas (DLBCLs), but differ from systemic DLBCLs by their less favorable prognosis. The systemic use of high-dose methotrexate (HD-MTX)-based chemotherapy with radiation therapy for newly diagnosed PCNSL has improved the me‐ dian overall survival (OS) from 20 to 36 months [5-8]. However, more intense efforts are re‐ quired to improve the outcome of the patients and to identify novel therapeutic strategies. In this article, we will review the recent developments of basic and clinical research on PCNSL.