Joint effect of pre-operative anemia and perioperative blood transfusion on outcomes of colon-cancer patients undergoing colectomy

Background: Both pre-operative anemia and perioperative (intra- and/or post-operative) blood transfusion have been reported to increase post-operative complications in patients with colon cancer undergoing colectomy. However, their joint effect has not been investigated. The purpose of this study was to evaluate the joint effect of pre-operative anemia and perioperative blood transfusion on the post-operative outcome of colon-cancer patients after colectomy.

Methods: We identified patients from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database 2006-2016 who underwent colectomy for colon cancer. Multivariate logistic regression analysis was employed to assess the independent and joint effects of anemia and blood transfusion on patient outcomes.

Results: A total of 35,863 patients-18,936 (52.8%) with left-side colon cancer (LCC) and 16,927 (47.2%) with right-side colon cancer (RCC)-were identified. RCC patients were more likely to have mild anemia (62.7%) and severe anemia (2.9%) than LCC patients (40.2% mild anemia and 1.4% severe anemia). A total of 2,661 (7.4%) of all patients (1,079 [5.7%] with LCC and 1,582 [9.3%] with RCC) received a perioperative blood transfusion. Overall, the occurrence rates of complications were comparable between LCC and RCC patients (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.95-1.07; P = 0.750). There were significant joint effects of anemia and transfusion on complications and the 30-day death rate (P for interaction: 0.010). Patients without anemia who received a transfusion had a higher risk of any complications (LCC, OR = 3.51; 95% CI = 2.55-4.85; P < 0.001; RCC, OR = 3.74; 95% CI = 2.50-5.59; P < 0.001), minor complications (LCC, OR = 2.54; 95% CI = 1.63-3.97; P < 0.001; RCC, OR = 2.27; 95% CI = 1.24-4.15; P = 0.008), and major complications (LCC, OR = 5.31; 95% CI = 3.68-7.64; P < 0.001; RCC, OR = 5.64; 95% CI = 3.61-8.79; P < 0.001), and had an increased 30-day death rate (LCC, OR = 6.97; 95% CI = 3.07-15.80; P < 0.001; RCC, OR = 4.91; 95% CI = 1.88-12.85; P = 0.001) than patients without anemia who did not receive a transfusion.

Conclusions: Pre-operative anemia and perioperative transfusion are associated with an increased risk of post-operative complications and increased death rate in colon-cancer patients undergoing colectomy.