Preoperative Prognostic Nutritional Index Predicts Postoperative Outcomes in Colorectal Cancer: A Propensity...

The Prognostic Nutritional Index (PNI) is a numerical score used to assess the nutritional and immunological status, derived from serum albumin concentration and lymphocyte count. While malnutrition and systemic inflammation are known to influence surgical outcomes and cancer prognosis, the predictive value of PNI in colorectal cancer (CRC) is underexplored. This study aimed to evaluate whether preoperative PNI predicts postoperative complications and long-term survival in patients with CRC undergoing curative-intent surgery.

The records of 2,026 patients who underwent curative-intent surgery for CRC between 2011 and 2023 at a tertiary center in Taiwan were retrospectively reviewed. Propensity score matching (PSM) was used and patients were stratified into high and low PNI groups based on the median value. Outcomes included in-hospital complications, 5-year overall survival (OS), and disease-free survival (DFS) in the subgroup of patients with stage I-III disease. Multivariable logistic regression and Cox proportional hazards models were used as well as restricted cubic spline (RCS) analysis.

High PNI was independently associated with lower rates of overall complications (adjusted odds ratio [aOR] = 0.22, 95% confidence interval [CI]: 0.17-0.28), ileus (aOR = 0.23), anastomotic leakage (aOR = 0.16), and lung-related complications (aOR = 0.38). High PNI was also significantly associated with improved 5-year OS (aHR = 0.45, 95% CI: 0.38-0.55), but not DFS. In additional competing-risk and comorbidity-stratified analyses, high PNI remained protective for both cancer-related (p = 0.0005) and non-cancer-related mortality (p < 0.0001), with consistent effects across CCI strata and attenuation for cancer-related death in CCI ≥ 3 (p = 0.1024). Additionally, PNI demonstrated superior predictive performance over the neutrophil-to-lymphocyte ratio (NLR) for all complication types based on receiver operating characteristic (ROC) analysis.

Preoperative PNI was independently associated with postoperative complications and OS in patients with CRC undergoing curative surgery. Routine assessment of PNI may help refine risk stratification and guide perioperative management to improve surgical outcomes.