Autologous Stem Cell Transplantation for Multiple Myeloma: Underutilized but Highly Effective
Menée aux Etats-Unis à partir de données portant sur 13 494 patients âgés de moins de 80 ans et atteints d'un myélome multiple diagnostiqué entre 1998 et 2012, cette étude de cohorte rétrospective évalue l'efficacité, du point de vue de la survie globale, d'une greffe autologue de cellules souches hématopoïétiques
In the current issue of the Journal, Rosenberg et al. describe the results of a population-based study regarding the role of autologous stem cell transplantation (ASCT) for patients with newly diagnosed multiple myeloma (MM) between 1998 and 2012 (1). This time period represents an important era, noteworthy for the development and implementation of several new classes of efficacious myeloma therapies, including immunomodulatory agents (eg, lenalidomide) and proteasome inhibitors (eg, bortezomib), which called into question the role of autologous stem cell transplantation as consolidation for myeloma patients following induction therapy (1–4).
In this retrospective observational cohort study using the California Cancer Registry, the California Patient Discharge Database, and the Ambulatory Surgery Database, the authors identified 13 494 new cases of multiple myeloma and discovered that 20.8% of those patients underwent autologous hematopoietic stem cell transplantation (HSCT) (1). Interestingly, although the utilization of autologous HSCT modestly increased in California between 1998 and 2012, the utilization was substantially lower among patients diagnosed at age 60 years or older compared with patients younger than age 60 years (12% vs 37.6%). As the median age of diagnosis of MM is 69 years (5), this study suggests that the utilization rate of ASCT for most patients in California is remarkably low. This low rate of utilization of ASCT over the past two decades is surprising given that a randomized European trial and a comparative US trial demonstrated superior overall survival in MM patients treated with ASCT compared with standard therapy in 1996 and 1997, respectively (6,7). Subsequently, two additional prospective, randomized studies have shown that ASCT increases overall survival in MM patients, whereas the recently completed Intergroupe Francophone du Myelome (IFM) 2009 study demonstrated a statistically significant increase in progression-free survival in MM patients who underwent ASCT as compared with more modern standard therapy (8–10). Interestingly, the percentages of MM patients undergoing transplantation in this study mirror results from other studies, including a review by the Center for International Blood and Marrow Transplant Research (CIBMTR; 13% utilization of ASCT) and a National Cancer Database Analysis (9% ASCT) (11,12). These studies raise an important question: why do such a small percentage of newly diagnosed patients with MM undergo ASCT? One possibility is poor or failed response to induction therapy, but given that combination therapies such as revlimid/bortezomib/dexamethasone (RVD) produce high response rates in 77% to 88% of patients (10), this would appear to account for a relatively small fraction of patients. The CIBMTR analysis suggested that stem cell transplant utilization rates for MM patients were not uniform across groups, with the lowest utilization among Hispanic and African American patients (11). In the current study, stem cell transplant utilization was statistically significantly decreased among African American patients compared with other populations (1). Other variables that may impact patient referral for ASCT include poor performance status, patient noncompliance, socioeconomic barriers, and physician/patient concern regarding toxicities of the transplantation procedure (10,13,14). In a recent study of referral patterns of patients with lymphoma and myeloma at a large urban community hospital, the primary reasons for nonreferral for transplant were established clinical criteria (13). The current study suggests that it will be important to address potential nonmedical barriers to ASCT for patients with MM in California.
Journal of the National Cancer Institute , éditorial en libre accès, 2017