Multiple myeloma in Latin America: Are we moving at the same pace as other regions?

Multiple myeloma (MM) is a plasma cell disorder that has recently experienced a dramatic improvement in clinical outcomes mainly due to the advent of novel drugs and the implementation of better supportive care strategies (1). Recently available combinations of proteasome inhibitors (PIs), immunomodulators (IMiDs), and monoclonal antibodies like daratumumab and isatuximab are shifting the MM therapeutic landscape (2-4). Nonetheless, MM still remains incurable, with an estimated 5-year survival of 55% and an estimated death rate of 2% in 2021 (% of all cancer deaths) (5). In Latin America (LATAM), the Hemato-Oncology Latin America (HOLA) study was recently designed to evaluate the epidemiology of hematologic malignancies in the real-world setting (6). In some countries from LATAM, stage III MM was the most frequently observed disease stage, with Mexico (62.5%), Chile (60.0%), Brazil (49.3%), and Colombia (45.8%) being the regions where MM patients presented with a more advanced stage. This is in contrast with the original report of revised staging criteria, where stage III MM represented 22% of the cases (7). In the entire cohort of the HOLA study, 497 patients with MM (32.7%) underwent autologous stem-cell transplantation (ASCT); however, the proportion of patients submitted to ASCT varied among countries, ranging from 3% to 69%. The 497 patients who underwent ASCT had received induction chemotherapy predominantly based on thalidomide (151; 30.4%) and bortezomib (125; 25.2%) regimens. This is quite different when compared to countries like Canada, where in a recent study by Mian et al. (8), a total of 5,154 patients with MM were identified, among which 3,030 patients (58.8%) received an upfront ASCT and 2,124 (41.2%) did not. Bortezomib and lenalidomide were the most frequently used agents (>50%) in first- and second-line treatment, respectively, in both the ASCT and non-ASCT cohorts. In Colombia, Abello et al. (9) reported on the outcomes of 890 patients with MM from a real-world registry. Most patients in this group received bortezomib and thalidomide-based therapies with a 65% response rate for CyBorD (cyclophosphamide, bortezomib, and dexamethasone) and 79% for VTD (bortezomib, thalidomide, and dexamethasone), which is in contrast with 78.1-84.3% and 85-94% reported in other series treated with similar regimens (10-12).