Background: Iron supplementation could improve the hematopoietic response of erythropoiesis-stimulating agents (ESAs) used for chemotherapy-induced anemia.
Methods: We performed a meta-analysis of randomized, controlled trials by comparing parenteral or oral iron and no iron, when added to ESAs in anemic cancer patients, in order to calculate the relative risk (RR) of hematopoietic response and transfusions, the time required to reach this response, and toxicity.
Results: A total of 1,606 patients out of eight trials were available for meta-analysis. The RR of obtaining an hematopoietic response was 1.29 (P = 0.0001) with parenteral iron and 1.04 for oral iron (P = 0.59). The risk of transfusion was reduced with parenteral iron versus no iron (RR 0.77; P = 0.02) but not with oral iron (RR 0.68; P = 0.08). The time to reach hematopoietic response was 1 month shorter and no increased toxicity appeared with iron supplementation.
Conclusion: Overall parenteral iron reduces the risk of transfusions by 23% and increases the chance of hematopoietic response by 29% when compared with ESAs alone. On the contrary, oral iron does not increase hematopoietic response nor transfusion rate. The significance of these results is that the proportion of non-responders to ESAs will have strongly improved and quality of life and cost ameliorated.