Evolution of iron overload in patients with low-risk myelodysplastic syndrome: iron chelation therapy and organ complications

Abstract

This study aimed to evaluate the evolution of iron overload, assessed by serum ferritin (SF), in transfusion-dependent lower risk patients with myelodysplastic syndrome (MDS), as well as to describe the occurrence of organ complications, and to analyze its relationship with iron chelation therapy. This observational retrospective study was conducted from March 2010 to March 2011 in 47 Spanish hospitals. A total of 263 patients with lower risk MDS (International Prognostic Scoring System [IPSS] low/intermediate-1 risk or Spanish Prognostic Index [SPI] 0-1 risk), transfusion-dependent, and who had received ≥10 packed red blood cells (PRBC) were included. At MDS diagnosis, patients received a mean of 2.8 ± 3.9 PRBC/month, and 8.7% of patients showed SF ≥1000 μg/L. Over the course of the disease, patients received a mean of 83.4 ± 83.3 PRBC, and 36.1% of patients presented SF ≥2500 μg/L. Cardiac, hepatic, endocrine, or arthropathy complications appeared/worsened in 20.2, 11.4, 9.9, and 3.8% of patients, respectively. According to investigator, iron overload was a main cause of hepatic (70.0%) and endocrine (26.9%) complications. A total of 96 (36.5%) patients received iron chelation therapy for ≥6 months, being deferasirox the most frequent first chelation treatment (71.9%). Chelation-treated patients showed longer overall survival (p < 0.001), leukemia-free survival (p = 0.007), and cardiac event-free survival (p = 0.017) than non-chelated patients. In multivariable analyses, age (p = 0.011), IPSS (p < 0.001), and chelation treatment (p = 0.015) were predictors for overall survival; IPSS (p = 0.014) and transfusion frequency (p = 0.001) for leukemia-free survival; and chelation treatment (p = 0.040) and Sorror comorbidity index (p = 0.039) for cardiac event-free survival. In conclusion, these results confirm the potential survival benefit of iron chelation therapy and provide additional evidence on the deleterious effect of iron overload in lower risk MDS patients.