Impact of preoperative anemia and perioperative transfusion on short-term outcomes in colorectal cancer surgery: The role of iron supplementation.

Background And Aim: Colorectal cancer is a common malignancy, and many patients with colorectal cancer experience preoperative anemia. Anemia and transfusions negatively impact short-term surgical outcomes. Management of anemia, including iron supplementation, has not been extensively studied in Japanese patients. Thus, the impact of anemia and blood transfusions on short-term surgical outcomes in colorectal cancer patients and the effectiveness of oral iron supplementation with ferrous citrate were investigated.

Methods: A retrospective study of patients with colorectal cancer (≥18 y) who underwent elective surgery from April 2015 to March 2023 was conducted. Patients with benign tumors, malignant lymphoma, emergency surgeries, or nonresectable lesions were excluded from the study. Hemoglobin levels were assessed at consultation, admission, the day after surgery, and discharge. Patients were categorized by anemia severity and divided into iron supplementation and no supplementation groups. Outcomes, including transfusions and postoperative complications, were compared with univariate and multivariate analyses.

Results: The prevalence of postoperative anemia in the 545 enrolled patients increased significantly from 52.8% at admission to 78.7% the day after surgery ( < 0.001). Severe anemia immediately before surgery was an independent risk factor for postoperative complications (odds ratio [OR] = 9.24,  < 0.001). Iron supplementation significantly improved hemoglobin levels and reduced transfusions and complications. The median duration of iron supplementation was 30 d, suggesting a positive influence on outcomes.

Conclusion: Severe anemia immediately before surgery is an independent risk factor for postoperative complications. Iron supplementation with ferrous citrate improves short-term outcomes.