Natural Course Of Serum Ferritin In Childhood Cancer Survivors: Need For Iron Removal Therapy?

Iron overload has been reported in adult survivors of leukemia after chemotherapy with or without allogeneic hematopoietic stem cell transplantation (allo-HSCT). Approximately 10-15% of adult survivors suffer from liver dysfunction, endocrine disorders, and/or cardiac dysfunction due to iron overload, in which free radicals produced by iron could damage tissues. Therefore phlebotomy and iron chelation therapy in adult survivors have been used prophylactically, however iron overload has not been studied extensively in childhood survivors, so that it would be a problem how to manage the childhood patients in whom serum ferritin level was high at the completion of chemotherapy. In this study, we retrospectively analyzed the serum ferritin level over time after the completion of therapy and also referred to whether iron chelation therapy and/or phlebotomy would be needed or not in childhood survivors.

We retrospectively analyzed the level of serum ferritin overtime in 48 childhood cancer survivors (ALL 19, AML 13, Lymphoma 5, Pediatric solid tumor 11) except allo-HSCT, who were transfused concentrated red cells in our hospital. All the patients did not receive any phlebotomy and iron chelation therapy throughout the course.

The total mean concentrated blood transfusion volume was 114 ml/kg (114±16, ranges 7-672). At the completion of chemotherapy, the median serum ferritin level was 867 ng/ml (867±216, ranges 7-6558). Three years after chemotherapy, the median serum ferritin levels decreased to 281 ng/ml (281±77, ranges 7-1285). All patients did not show any symptoms related to iron overload such as liver dysfunction and glucose intolerance. Twelve out of 48 patients (25%) exceeded 1000 ng/ml of the serum ferritin at the time of completion of chemotherapy, which has been considered as the initiation of iron chelation therapy in adult patients. However all patients except one decreased the serum ferritin level below 1000 ng/ml in 3 years after chemotherapy without any iron removal therapy. Although serum ferritin level in the exceptional case was extraordinary high (6558 ng/ml) compared to other cases at the completion of chemotherapy, it declined to 1285 ng/ml spontaneously in 3 years, which was much better than expected.

Although 25 percent of our childhood cancer survivors showed high level of serum ferritin more than 1000 ng/ml at the time of completion of chemotherapy, almost all the cases eventually declined thereafter without any iron removal therapy probably due to the iron consumption with growth. Further study would be needed to make specialized criteria for initiating iron removal therapy for childhood cancer survivors.

No relevant conflicts of interest to declare.