Distinct Risk Profiles for Intraoperative Blood Loss and Perioperative Transfusion in Colorectal Cancer: A Comparative Predictive Modelling Study

Background Significant intraoperative blood loss (SIBL) and perioperative transfusion (PTF) are major concerns in colorectal cancer (CRC) surgery, yet they are often considered sequential events despite potentially distinct mechanisms. Methods We retrospectively analysed 706 patients who underwent curative resection for non‐metastatic CRC. Logistic LASSO regression was used to identify predictors for SIBL (> 200 mL) and PTF. Model performance was evaluated using area under the curve (AUC), calibration metrics, and 1000 bootstrap validation. Results SIBL occurred in 18.1% of patients, and PTF was required in 12.3%. Independent predictors of SIBL included rectal cancer, preoperative radio‐ or chemotherapy, and surgeon experience less than 3 years, while minimally invasive surgery was associated with a reduced risk. In contrast, predictors of PTF included haemoglobin < 10.0 g/dL, albumin < 3.5 g/dL, CEA > 5 ng/mL, congestive heart failure, and renal dysfunction. cT4 stage, concurrent resection and platelet < 100 × 10 3 /μL were common predictors in both models. The bootstrap‐validated AUCs were 0.836 for SIBL and 0.934 for PTF, with calibration slopes of 0.886 and 0.893, respectively. In sensitivity analysis, PTF model showed an AUC of 0.897 (95% CI: 0.838–0.957) in patients without preoperative transfusion and SIBL defined as > 500 mL showed an AUC of 0.843 (95% CI: 0.763–0.924). Conclusion Our findings suggest that SIBL and PTF arise from different risk factors. SIBL reflects surgical complexity, whereas PTF reflects impaired physiological reserve. Further research is warranted to validate these models in diverse cohorts to establish preventive strategies for these adverse outcomes.