Preoperative intravenous iron therapy and survival after colorectal cancer surgery: long-term results from the IVICA randomised controlled trial

Aim Preoperative iron is frequently used for the correction of anaemia in colorectal cancer surgery. However, enteral iron intake may promote tumour growth and progression which could influence cancer recurrence and patient survival. We explore the long-term outcomes of patients receiving either oral or intravenous iron replacement therapy as part of a previous randomized controlled trial. Methods The IVICA trial randomized anaemic colorectal cancer patients to receive either oral (OI, control) or intravenous (IVI, treatment) iron prior to their elective operation. Follow-up analysis of all patients recruited to this multicentre trial who underwent surgical resection with curative intent was performed. Kaplan-Meier survival estimates and Cox proportional hazard models were used to compare groups. A pooled group multivariable analysis comparing patients who achieved resolution of anaemia preoperatively to those who did not was also undertaken. Results In all, 110 of the 116 patients previously enrolled were eligible for analysis (OIn = 56, IVIn = 54). Median overall follow-up duration was 61 months (interquartile range 46-67). No significant difference in 5-year overall survival (hazard ratio (HR) 1.22, 95% CI 0.65-2.28,P = 0.522) or disease-free survival (HR 1.08, 95% CI 0.61-1.92,P = 0.79) was observed between OI and IVI. A pooled analysis of treatment groups found that preoperative resolution of anaemia led to improved 5-year overall survival on multivariable analysis (HR 3.38, 95% CI 1.07-11.56,P = 0.044). Conclusion We recommend IVI for the preoperative correction of anaemia. Route of iron therapy did not significantly influence survival. Preoperative anaemia correction may lead to an overall survival advantage following elective colorectal cancer surgery.