Emergence of central nervous system myeloma in the era of novel agents

Abstract

Although multiple myeloma (MM) remains an incurable disease, considerable improvements in survival have been made with the introduction of autologous stem cell transplantation and new drugs. Central nervous system (CNS) MM is a rare complication associated with poor survival. Historically, CNS disease developed early in the course of MM; however recently, patients often present with CNS disease following multiple lines of therapy. It is hypothesized that exposure to novel agents (thalidomide, lenalidomide and bortezomib) changes the natural history of MM, increasing the lifetime risk of CNS disease. We analysed the baseline characteristics, treatment and outcome data of patients who presented with CNS MM at Peter MacCallum Cancer Centre between 2001 and 2010. Seven patients were identified, from 2005 onwards. All patients were Durie-Salmon stage IIIA or IIIB and International Staging System Scores I to III at baseline. All had received at least three lines of therapy, including high-dose chemotherapy with autologous stem cell transplantation and a novel agent, prior to developing CNS MM. Median time from diagnosis to CNS disease was 24 months (range 10-42). All patients died after developing CNS disease with median survival post-CNS disease of 2 months (range 1-23). The incidence of CNS MM is increasing, and time to development of CNS manifestations is prolonging, associated with increased use of high-dose chemotherapy and novel agents. Whether this is due to improved overall survival or specific characteristics of these therapies is not clear. Despite the availability of novel agents, survival after CNS MM remains poor.