A nationwide survey on central nervous system multiple myeloma in Japan: analysis of prognostic and treatment factors that impact survival

This nationwide multicentre retrospective study was performed to analyze clinical features that predict the prognosis of central nervous system invasion in multiple myeloma (CNS-MM, approximately 1% of MM). Overall, of the 77 adult patients with CNS-MM identified between 2005 and 2016, those diagnosed at MM diagnosis (n = 3) had longer overall survival (OS) than those diagnosed at relapse (n = 74; median: 48·5 vs 2·7 months). Therefore, we compared the relapsed MM with CNS-MM in patients with any treatment (n = 60). Multivariate analyses revealed that lenalidomide treatment [hazard ratio (HR) 0·27, P = 0·003], intrathecal chemotherapy (IT; HR 0·54, P = 0·05), and radiation therapy (RTx; HR 0·33, P