Disparities in Criteria for Initiating Chelation Therapy for Iron Overload in Patients with Myelodysplastic Syndromes (MDS).

Abstract

In the majority of MDS cases, isolated anemia is the only clinical evidence of impaired hematopoiesis at the time of MDS diagnosis. It is estimated that >40% of MDS patients require regular red blood cell transfusions during some stage of their disease. Findings from The MDS Foundation's 2004–2005 Practices & Treatment Survey indicate that a substantial proportion of MDS patients in all International Prognostic Scoring System (IPSS) risk groups are transfusion-dependent: Low, 30%; Intermediate-1, 50%; Intermediate-2, 70%; High, 90% (median values). Seventy (38 US and 22 international) of the MDS Foundation's102 Centers of Excellence responded to the survey as of July 1, 2005. Survey responses revealed that an average of 30% of transfusion-dependent patients receive parenteral iron chelation therapy (median, 20%; range: 3–100%) and that the criteria for initiating chelation therapy are not uniform. The number of transfusions was reported as a determining criterion by 46% of respondents, with a mean number of 35 transfusions (median, 30; range: 4–100). 15% of respondents indicated at the number of transfusions was the sole criterion used. Serum ferritin levels were reported as a determining criterion by 57% of respondents, with the following cutoff values:Ferritin concentrations for initiating chelation therapy>1000 ng/mL41%*>1500 ng/mL11%>2000 ng/mL37%Other (>3000, unspecified)9%*% respondents using this cutoff as criterion32% of respondents indicated that serum ferritin was the sole criterion used. (Irrespective of chelation therapy, 92% indicated that they monitored ferritin levels in transfusion-dependent patients.) Other criteria used to determine start of chelation therapy included age/life expectancy, MDS subtype, clinical signs of hemochromatosis, quantitative CT liver iron estimation, liver function, transferrin saturation >50%, BMT, anticipated chronic transfusion need, and logistical issues and insurance coverage. A combination of criteria was reported to be used by 38% of respondents. The majority of respondents (90%) reported that they would increase the number of patients on chelation therapy if an oral agent were available. Although the decision for initiating chelation therapy in transfusion-dependent anemic MDS patients is individualized because of the heterogeneous patient population, this data analysis suggests a need for the standardization of select criteria (e.g., number of transfusions, serum ferritin).