Association of Preoperative Prognostic Nutritional Index on Long-Term Outcomes and Postoperative Complications of...

The prognostic nutritional index (PNI), derived from serum albumin levels and lymphocyte counts, reflects both nutritional and immunologic status. This study aimed to evaluate the association between preoperative PNI and long-term oncologic outcomes and postoperative complications in patients undergoing curative resection for colorectal cancer (CRC).

A multicenter retrospective analysis was conducted on 3045 patients with stage I-III CRC who underwent curative surgery at five Hallym University-affiliated hospitals between 2012 and 2023. Preoperative PNI, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were calculated using laboratory values within 2 weeks prior to surgery. The optimal PNI cutoff for overall survival (OS) was determined by receiver operating characteristic analysis.

The optimal preoperative PNI cutoff was 43.4 (area under the curve = 0.643, sensitivity = 60.4%, specificity = 59.4%). Patients with low PNI (< 43.4) exhibited significantly poorer 5-year OS (59.0% vs. 80.0%, p < 0.001) and recurrence-free survival (RFS) (51.4% vs. 73.2%, p < 0.001) compared to the high PNI group. These associations remained consistent across all cancer stages. In multivariate analysis, low PNI was independently associated with OS (hazard ratio [HR] = 1.535, p < 0.001) and RFS (HR = 1.519, p < 0.001), as well as increased risk of severe complications (odds ratio = 2.503, p < 0.001). PNI showed better predictive performance than LMR, NLR, and PLR for these outcomes.

Preoperative PNI is an independent predictor of oncologic outcomes and perioperative risk in CRC patients and may serve as a practical biomarker for preoperative risk stratification.