Efficacy of Preoperative Intravenous Iron in Anaemic Colorectal Cancer Surgical Patients

Inclusion Criteria: * Age \>18 years old with written informed consent * Anaemia defined as: hemoglobin concentration \< 13g/dL (same cut-off for both male and female patients according to the International consensus statement on the perioperative management of anaemia and iron deficiency)2 * Laboratory test confirmed iron deficiency: serum ferritin \<30mcg/L alone or serum ferritin 30-100mcg/L with TSAT \< 20% Exclusion Criteria: * Pregnancy or lactation * Other known causes of anaemia apart from iron deficiency: untreated B12/folate deficiency, hemolytic disease, hemoglobinopathy/thalassemia, chronic renal failure on dialysis * Presence of iron overload (serum ferritin \> 300g/dL or TSAT \> 50%); known hemochromatosis * Previous or ongoing iron replacement/use of erythropoietin within 12 weeks before recruitment * Known hypersensitivity towards iron isomaltoside * Significant liver function derangement (AST/ALP exceeding three times upper limit of normal range) * Participation in another ongoing interventional clinical trial(s) * Patients with less than 3 weeks waiting time to surgery