Characteristics and Outcome of Multiple Myeloma Patients Presenting with Anemia Only: a Retrospective Multi-Center Study

Background: Multiple myeloma (MM) is defined as bone marrow monoclonal plasmocytosis combined with either specific laboratory or imaging findings (SLIM criteria) or one or more of the following myeloma defining events (MDE) including anemia, hypercalcemia, renal failure or lytic bone lesions (CRAB criteria). Patients who presents with anemia but without additional CRAB criteria are scarce, and their clinical course has not yet been characterized in the literature. The current study was designed to evaluate the characteristics, responsiveness to treatment, progression free and overall survival in newly diagnosed MM patients presenting with anemia only. Methods: We retrospectively analyzed the clinical features and outcomes of MM patients that presented with anemia as the only CRAB criteria (i.e. having no evidence of skeletal involvement by PETCT, MRI or total body CT, no renal involvement and no hypercalcemia), that were diagnosed and treated in 9 Israeli and Greek centers between 2010 and 2018. Baseline characteristics at diagnosis, ISS score, treatment regimens, depth and duration of response (by IMWG criteria), hemoglobin (HB) levels during treatment and overall survival (OS) were collected and analyzed. Results: 63 (28 females) patients were included in the analysis. The median age was 72.2 (range 34.4-91.9) years. The median HB level at diagnosis was 9.4 g/l (IQR 6.0-12.0) and median platelets level was 172000 (IQR 59000-454000). The median percent of plasma cells (PCs) in bone marrow at diagnosis was 60% (range 20% to 99%). 11 out of 56 (19%) patients had a high-risk FISH (t 4;14, t 14;16 or del 17p). Bortezomib -based induction was administered in 83%, and upfront autologous hematopoietic stem cell transplantation (autoHCT) was employed in 32%. ORR to 1st line was 87%. 37 (62%) achieved ≥ VGPR, 16 (25%) PR and 7 (13%) SD/PD. Significant predictors for achieving at least VGPR vs. SD or PD were higher albumin level at diagnosis (3.9±0.5 g/l vs. 3.5±0.4g/l, p