Perioperative changes in haemoglobin and ferritin concentrations from preoperative intravenous iron isomaltoside for iron deficiency anaemia in patients with colorectal cancer: A pilot randomised controlled trial

Background Patients with colorectal cancer have a high risk of iron deficiency anaemia (IDA) due to chronic tumour induced blood loss, a reduced dietary iron intake from poor nutrition or gastrointestinal malabsorption. This pilot, double blinded, randomised controlled trial (RCT) examined the effect and feasibility of using preoperative iron isomaltoside for treating iron deficiency anaemia. Methods Forty eligible adults with IDA were randomised to receive either intravenous iron isomaltoside (20 mg.kg -1 up to 1000 mg over 30 minutes) or usual preoperative care (control) three weeks before scheduled colorectal surgery. The primary outcomes were perioperative changes in haemoglobin and ferritin concentrations. Results The recruitment rate was 78% of all eligible referred patients (1.9 patients/month). The haemoglobin and ferritin concentrations were higher in the iron isomaltoside group than the control group over the perioperative period (group*time interaction P = 0.042 and P < 0.001 respectively). Mean haemoglobin change from baseline to before surgery was higher in the iron isomaltoside group (7.8, 95% CI: 3.2 to 12.3 g.l -1 ) than the control group (1.7, 95% CI: -1.9 to 5.3 g.l -1 ) [mean difference 6.1, 95% CI: 0.3 to 11.8 g.l -1 ; P = 0.040]. The ferritin change from baseline to before surgery between groups was large in favour of the iron isomaltoside group (mean difference 296.9, 95% CI: 200.6 to 393.2 μg.l -1 ; P < 0.001]. There were no differences between groups in packed red blood cell transfusions needed, surgical complications, quality of recovery and days (alive and) at home within 30 days after surgery. Conclusion Iron isomaltoside therapy was safe and had a minimal effect on perioperative changes in haemoglobin concentration. Given the slow recruitment and new evidence emerging during the conduct of this study, conducting a multi-centre RCT based on the current pilot trial protocol is unlikely to be feasible. Trial registration ClinicalTrials.gov NCT03565354 .