Preoperative and early postoperative albumin thresholds, rather than ΔAlb, predict severe complications after colorectal cancer surgery: a multifactorial model and nomogram

Abstract

Background Postoperative complications of colorectal cancer significantly impact prognosis and healthcare burdens. While the dynamic change from preoperative to the lowest albumin level on postoperative day 2 (ΔAlb) has been linked to complications, their predictive value remains controversial. This study aims to explore the relationship between ΔAlb and postoperative complications, and evaluates a multifactorial predictive model for severe complications. Methods This retrospective study analyzed 932 patients undergoing colorectal cancer resection (August 2020–April 2022). Data included preoperative/postoperative albumin levels, demographics, surgical/anesthetic details, and 30-day complications. ΔAlb’s association with severe complications was assessed via logistic regression, and a nomogram was developed. Results Severe complications (Clavien–Dindo III–V) occurred in 14.2% of patients. ΔAlb showed no significant association with severe complications in univariate (P = 0.185) or multivariate analysis and discriminated poorly on ROC analysis (AUC 0.536, 95% CI 0.479–0.593). In the final multivariable model using clinically dichotomised predictors, preoperative albumin <35 g/L (OR 2.05, 95% CI 1.29–3.25, P = 0.003) and POD2 nadir albumin <28.5 g/L (OR 1.55, 95% CI 1.01–2.38, P = 0.044) were independent risk factors. Other independent predictors were age >65 years (OR 2.14, P = 0.003), ASA ≥3 (OR 2.14, P = 0.001), preoperative NRS2002 ≥2 (OR 1.97, P = 0.028) and rocuronium dose ≥117.5 mg (OR 4.44, P<0.001). A nomogram integrating these factors showed good discrimination (apparent C-index 0.794; optimism-corrected 0.784 by 1000-sample bootstrapping), good calibration (Hosmer–Lemeshow P = 0.72) and net clinical benefit on decision-curve analysis. Conclusion ΔAlb alone has limited predictive value, whereas absolute preoperative albumin <35 g/L and POD2 nadir albumin <28.5 g/L are independent predictors of severe complications. A multifactorial model integrating these absolute albumin thresholds with age, ASA score, preoperative NRS2002 and rocuronium dose improves prediction (optimism-corrected C-index 0.78) compared with individual factors (AUC <0.7). Because rocuronium dose may also reflect surgical complexity and perioperative management, these associations require prospective, multicentre validation.