Serum ferritin in stage IV neuroblastoma

Serum ferritin is known to be one of the tumor markers for neuroblastoma. Serum ferritin is elevated in most children with neuroblastoma who are in stages III or IV, but it is not elevated in those in stage I or II. It has also been observed that iron load caused by blood transfusion shows a greater effect on serum ferritin levels than tumor activity due to neuroblastoma. Thus, serum ferritin increases in a linear fashion in children given repeated blood transfusions but the levels increase exponentially in children who have bulky neuroblastomas. Thus, serum ferritin values must be interpreted with caution in patients with advanced stages of neuroblastoma who inevitably require blood transfusions. The authors propose that the pretransfusion and posttransfusion serum ferritin values be in comparison with other tumor markers such as urinary VMA, urinary HVA, and neuron specific enolase. The serum ferritin level should not be used as a sole indicator of tumor activity in neuroblastoma.