Intravenous iron supplement improves anemia in patients with colorectal cancer and iron deficiency anemia before and after surgery: a propensity score matching analysis

Abstract Purpose Iron deficiency anemia (IDA) affects approximately 50% of patients with colorectal cancer during diagnosis. Correcting IDA reduces postoperative complications, blood transfusions, and hospital stay duration. Intravenous ferric carboxymaltose (FCM) is reported to be more effective than oral iron supplements, but the evidence is limited. This study assesses the effectiveness of a single dose of FCM in improving anemia in patients with colorectal cancer before surgery. Methods Patients with IDA for colorectal cancer surgery received FCM approximately 14 days before surgery. Patients in the period when FCM was not used were used as the comparison group. The two groups were analyzed using propensity score matching. Clinical background and blood collection data 14 days before, 14 days after, 35 days after, and 104 days after surgery were compared using propensity score matching. Results Hemoglobin levels were significantly higher in the FCM group on days 14 (immediately before surgery) and 35 post-administration. Mean corpuscular volume levels were significantly higher in the FCM group on days 14, 35, and 104 post-administration. No differences were observed in postoperative complications, perioperative transfusion rates, or hospital stay duration. Conclusions A single administration of FCM effectively improved anemia within 14 days, with sustained effects over the long term, although no impact on postoperative outcomes was observed. Trial registration: This study was conducted based on the "Retrospective observational study on diagnosis and treatment of gastrointestinal diseases (Approval number: 3043, March 25, 2021)" at Chiba University School of Medicine.