Preoperative Iron Infusions Can Reduce Need for Transfusions in Colorectal Surgery

Toby Richards, MD
Credit: Toby Richards Research Group

An analysis of data from nearly half a dozen randomized controlled trials examining use of intravenous iron infusions before colorectal surgery could significantly reduce the need for blood transfusions in these patients.

A meta-analysis of 5 randomized trials of patients undergoing colorectal cancer surgery, results of the study indicate use of intravenous iron infusions was associated with a 33% relative reduction in risk of requiring a blood transfusion.¹

“With over 20,000 major colorectal cancer resections per year in the UK, the findings of this study have the potential to improve outcomes for the second most common cause of cancer mortality,” said Toby Richards, MD, professor in the Division of Surgery and Interventional Sciences at the University College London.² “In the past, surgeons were uncertain whether the benefits of iron infusion could be realized in the short time frames of cancer care and consequently the uptake of this treatment was limited. Our findings show that improved outcomes can be achieved if iron infusion is given in the period between cancer diagnosis and surgery."

Associations between anemia and poor outcomes is evident and well-documented, including among patients undergoing surgery. However, as Richards and investigators note, some guidelines recommending this practice are based on retrospective and unblinded studies. Citing a lack of large multicenter trials assessing this guideline-based practice, investigators launched the current research endeavor to expand the current evidence base related to use of preoperative iron therapy in patients with colorectal cancer. With this in mind, investigators designed their research endeavor as a meta-analysis of randomized controlled trials on the topic from the MEDLINE, Emboss, and CENTRAL databases.¹

From these studies, investigators obtained data from 485 individual, including 465 who underwent surgery. Among this cohort 202 were women and 263 were men. In the 5 trials included in the meta-analysis, 3 forms of intravenous iron infusions were used—iron sucrose, ferric carboxymaltose, and iron isomaltoside. In total, Investigators pointed out the median interval from intervention to surgery was 14 days for the intervention groups and 19 days for the control group.¹

Upon analysis, a total of 78 patients from the 485-patient cohort required an allogeneic blood transfusion, with blood transfusions required in 12.7% among the intervention groups and 19.5% in the control group (risk ratio [RR] 0.67, 95% Confidence Interval [CI] 0.46 to 0.97, P=.04; risk difference [RD] −0.07, 95% CI, −0.12 to −0.02; P=.02). All 5 trials included in the study reported change in hemoglobin level. Among 465 patients in these trials, receipt of intravenous iron was associated an increased absolute hemoglobin (Hedges’ g, 0.52, 95% CI, 0.08 to 0.96; P=.03).¹

Of the 5 trials included, 4 trials, including 423 patients, reported 30- or 90-day or hospital or all-cause mortality. In these trials, there was no difference between groups for mortality. Investigators noted 4 trials examined duration of hospital stay in 405 patients. In these trials, there was no difference observed between the groups. Additionally, no difference was observed between the study groups for major postoperative complications.¹

“This analysis shows a reduction of over one-third in blood transfusions when anaemic patients are treated with intravenous iron before their colorectal surgery,” said Sue Pavord, MBChB, vice president of British Society for Haematology.² “If we could combine this insight with others from the previous PREVENTT study, then hospital readmissions could potentially be cut even more, which would be important for both patients and the NHS.”

References:

1. Lederhuber H, Massey LH, Abeysiri S, et al. Preoperative intravenous iron and the risk of blood transfusion in colorectal cancer surgery: meta-analysis of randomized clinical trials. Br J Surg. Published online November 23, 2023. doi:10.1093/bjs/znad320
2. University College London News. Iron infusion before bowel surgery reduces need for blood transfusion. EurekAlert! November 22, 2023. Accessed December 1, 2023. https://www.eurekalert.org/news-releases/1008811.