Abstract
Background: Children treated for cancer are at risk of
developing iron toxicity due to receiving red cell transfusions and
myelosuppressive chemotherapy. Transfusions administered during
prolonged episodes of marrow suppression may increase exposure to toxic,
reactive forms of iron and thereby increase risk of extrahepatic iron
accumulation and long-term organ damage. Objective: This study
aimed to evaluate the severity and organ distribution of clinically
significant iron overload through measurement of hepatic, cardiac,
pancreatic, and pituitary iron deposition in an at-risk cohort of
children and young adults treated for cancer. Methods: This
retrospective study evaluated patients treated for any type of cancer
who underwent an MRI due to clinical concern for evaluation of iron
overload (n=103, 73 post-treatment). Data regarding cancer type and
treatment, MRI and laboratory results, and treatment for iron overload
were analyzed. Results: Over half (53%) of this sample had
moderate or greater hepatic siderosis, 80% had pancreatic siderosis,
and nearly half (45%) had pituitary siderosis and/or volume loss.
Pancreatic iron was associated with both cardiac (p=0.0043) and
pituitary iron (p=0.0101). Patients treated for acute myeloid leukemia
or high-risk acute lymphoblastic leukemia had higher liver iron
concentration (LIC) compared to other cancer types (median LIC 8.5 vs.
2.9 mg/g DLW, p=0.0011). Conclusion: Pediatric cancer patients
are at risk for transfusional iron overload, with significant exposure
to toxic forms of iron indicated by extrahepatic iron deposition
(pancreas, heart and pituitary). Further studies should examine the
effect of exposure to reactive iron on long-term outcomes and develop
management recommendations.