Association of projected transfusional iron burden with treatment intensity in childhood cancer survivors

Abstract

Packed red blood cell (PRBC) transfusion is a mainstay in childhood cancer treatment, but has potential for inducing iron overload. The purpose of this study was to determine whether treatment intensity is predictive of projected iron burden resulting from PRBC transfusions among survivors of several forms of childhood cancer. This retrospective cohort study involved patients treated at Children's Hospital Los Angeles (CHLA) between June 1, 2004 and December 31, 2009. Clinical/demographic data were abstracted from medical records. Treatment Intensity Level was determined for each patient using a published scale. Adjusted cumulative PRBC transfusion volume for each patient (ml/kg) was used to compute the adjusted total iron burden (mg/kg) based upon the average hematocrit of the product. Median age of the cohort (n = 214) was 7.9 years (range 0.2-20.2). One hundred and fourteen (53.3%) were male and 129 (60.3%) were Hispanic/Latino. Diagnoses included acute leukemia and six solid tumors, management of which represents a range of cancer treatment intensities. The number of transfusions, transfusion volumes, and projected iron burden were significantly increased and exceeded upper limits of normal among patients with higher treatment intensity. Multivariate analysis found younger age and lower hemoglobin at diagnosis to be associated with greater iron burden after adjusting for treatment intensity. Greater treatment intensity is associated with need for more PRBC transfusions, and thus increased risk of iron overload among childhood cancer survivors. Iron overload may represent another clinically significant late effect following childhood cancer treatment.