In patients with chemotherapy-induced anemia (CIA), treatment with intravenous (IV) iron resulted in a decreased need for red blood cell (RBC) transfusions with no difference in adverse events (AEs) compared to oral iron or no iron, according to a study published in the Journal of Clinical Medicine.
“IV iron for the treatment of CIA should be considered in clinical practice,” according to the researchers, led by Shira Buchrits, MD, of Beilinson Hospital in Israel.
Dr. Buchrits and colleagues noted the clinical guidelines on the use of IV iron in patients with cancer undergoing chemotherapy are inconsistent. They completed a meta-analysis of randomized, controlled trials that compared IV iron with either no iron or oral iron for the treatment of CIA to assess the effect of IV iron as a monotherapy. Trials were excluded if erythropoiesis-stimulating agents were used.
Eight randomized, controlled trials published between January 1990 and July 2021 were included. Of 1,015 patients, 553 had received IV iron, 271 had taken oral iron, and 191 had not received iron. The primary outcome was the percentage of patients requiring an RBC transfusion. Secondary outcomes included hematopoietic response (i.e., an increase in hemoglobin [Hb] level by more than 1 g/dL or an increase above 11 g/dL); an absolute Hb concentration or a change from the baseline in the Hb concentration at the end of the trial; the absolute ferritin level and transferrin saturation (TSAT) level at the end of the trial; and AEs. Most trials included patients with solid tumors.
Results showed that IV administration of iron for CIA reduced the risk of an RBC transfusion by 28% (95% CI 0.55-0.95; I2=23%).
For the secondary endpoints, IV iron increased the chance of a hematopoietic response (risk ratio [RR] = 1.23, 95% CI 1.01-1.5; I2=0%) and the absolute Hb level or the change from the baseline in Hb at the end of the study (mean difference [MD] = 0.23, 95% CI 0.01-0.44). IV iron was associated with an increase in the ferritin level (MD=260.65, 95% CI 105.79-415.51) but not the TSAT level (MD = -0.4, 95% CI -5.96-5.17). There was no difference in the risk of AEs (RR=0.97, 95% CI 0.88-1.07) or severe AEs (RR=1.09, 95% CI 0.76-1.57).
The authors noted that the main finding of a decrease in the need for RBC transfusions is in accordance with current guidelines that recommend a restrictive transfusion strategy, which can minimize various risks and may potentially reduce hospital visits. Further, they suggested the increase in hematopoietic response is relevant, as anemia may be a negative prognostic factor in cancer.
Limitations of the research included that the eight trials were varied with respect to the types of malignant tumors, chemotherapy regimens, and iron supplement preparations and schedules. There was also a lack of data needed to conduct subgroup analyses according to different baseline hematologic parameters, malignancies, or the total administered iron dose. Further, no long-term follow-up data, beyond 24 weeks, were available regarding efficacy, mortality, and safety, and no data were collected on the effect of IV iron on cancer-related outcomes or the cost-effectiveness of IV iron.
“Our meta-analysis supports the use of iron intravenously administered for the treatment of CIA,” the authors concluded, adding that the results mainly apply to patients with functional iron deficiency, defined as a defect in supplying iron to the erythroid marrow despite sufficient iron stores. They noted further research will help define the optimal IV iron formulation, dose, and schedule and identify the malignancy types that may benefit from IV iron.
Any conflicts of interest declared by the authors can be found in the original article.
Buchrits S, Itzhaki O, Avni T, Raanani P, Gafter-Gvili A. Intravenous iron supplementation for the treatment of chemotherapy-induced anemia: a systematic review and meta-analysis of randomized controlled trials. J Clin Med. 2022;11(14):4156.