Case 3: Iron Overload Increasingly is a Concern in Patients with Myelodysplastic Syndrome
In 2002, Walter P., a white, 71-year-old retired banker, widowed, with two adult sons, presented at a myelodysplastic syndrome (MDS) treatment center for a repeat bone marrow biopsy. He first saw his primary care physician in 1998 with complaints of fatigue and dyspnea. Blood testing revealed a mean corpuscular volume of 102 fL, indicating a macrocytic anemia. Results of a bone marrow biopsy showed a normocellular marrow with dysplastic changes and no myeloid blasts. A cytogenetic evaluation was not performed because of inadequate genetic material in the specimen. He was diagnosed with MDS, classified as refractory anemia. He was then referred to a community oncologist and treated with folic acid and blood transfusions. His anemia persisted, however. When his transfusion requirement eventually increased to 2 units per month, he was referred to the center.
Diagnosis and Treatment
Walter received a bone marrow biopsy, which found dysplasia and ringed sideroblasts but no myeloid blasts. Ringed sideroblasts indicate the amount of iron in red blood cell (RBC) precursors seen on a bone marrow biopsy and are a morphologic hallmark of MDS.13 Cytogenetic testing showed a 20q deletion chromosomal abnormality.
Walter's diagnosis was then revised to refractory anemia with ringed sideroblasts with an International Prognostic Scoring System score of 0 (low risk).52 Erythropoietin 40,000 units subcutaneously weekly was initiated. After 4 weeks, no response was observed and filgrastim 300 mcg subcutaneously biweekly was added. The addition of filgrastim to erythropoietin has been shown to have a synergistic effect, notably in patients with ringed sideroblasts.53 No response was observed, however, and Walter continued to require 2 units/month to 4 units/month of packed RBCs.
In 2005, Walter developed iron overload from his transfusions. To manage it, he was offered chelation therapy with deferoxamine. (Deferasirox would be approved later that year.) He declined, not wanting to endure the lengthy daily infusions deferoxamine necessitates. However, once deferasirox—an orally administered, once-daily regimen—received an indication from the FDA as a chelator in iron overload, Walter was willing to begin treatment; his serum ferritin at that time was elevated (2600 mcg/L). Treatment with deferasirox 20 mg/kg/day, the recommended initial dosage, was initiated. Serum ferritin was monitored every 3 months; the goal was to decrease Walter's ferritin to 500 mcg/L.
In 2006, Walter's ferritin level had decreased to 1250 mcg/L; in 2007, it was 850 mcg/L; in 2008, it was 400 mcg/L. Deferasirox was then discontinued. Later that year, however, his ferritin increased to 1200 mcg/L; deferasirox was reinitiated at 20 mg/kg/day. In 2009, his ferritin level was back down to 600 mcg/L, indicating chelation therapy was working.
Due to Walter's persistent transfusion requirement and the risk for iron overload, he continues chelation with deferasirox 20 mg/kg/day, as well as erythropoietin 40,000 units/week and filgrastim 300 mcg/week to maintain his current transfusion rate. His serum ferritin is monitored every 4 months. He has no reported side effects to deferasirox and the decrease in his serum ferritin indicates continued response to treatment. Now 79 years of age, he feels well and continues to be active.
Nurses should provide patients who receive chronic transfusions with information regarding the clinical sequelae and consequences of iron overload, as well as the treatment options. In addition, barriers to adherence to therapy need to be identified and addressed. At a time when deferoxamine was his only option for chelation therapy, Walter was educated on iron overload and the available treatment; he made an informed decision not to proceed, due to the significant negative impact on his quality of life. Once deferasirox became available, he began treatment and has achieved a therapeutic benefit.