Development and validation of a neutrophil percentage to albumin ratio-based nomogram for predicting survival in patients with locally advanced gastric cancer.

Abstract

Objective: This study aimed to clarify the predictive value of the neutrophil percentage to albumin ratio (NPAR) for postoperative survival in patients with locally advanced gastric cancer (LAGC) and to develop a prognostic model on the basis of these findings.

Methods: Patients with LAGC who underwent radical surgery at Peking University Cancer Hospital between June 2010 and January 2021 were retrospectively screened. Three analytical approaches, percentile classification, cutoff value analysis, and restricted cubic splines (RCS), were utilized to evaluate the association between the NPAR and 3-year disease-free survival (DFS) rates. Survival curves were generated using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to identify the risk factors for 3-year DFS. A novel prognostic nomogram was then constructed and validated using both internal validation (via a 7:3 random split) and temporal external validation (stratified by the surgery dates before and after December 2017).

Results: A total of 348 patients were enrolled. All three analytical approaches consistently identified a high NPAR as a robust predictor of an unfavorable prognosis. Specifically, NPAR>1.70 (75th percentile) was associated with significantly lower DFS rates [hazard ratio (HR)=2.506; 95% confidence interval (95% CI): 1.964-3.198]. The optimal cutoff analysis confirmed that NPAR of 1.60 exhibited good discriminative ability (HR=3.639; 95% CI: 2.640-5.016), whereas the RCS analysis revealed a non-linear dose-response relationship between an elevated NPAR and low DFS rates. Multivariate Cox regression revealed the NPAR as an independent risk factor, along with pathological stage, differentiation type, and incomplete postoperative chemotherapy. The resulting prognostic nomogram demonstrated excellent and stable predictive performance across both internal and external temporal validation.

Conclusions: The NPAR was strongly associated with 3-year DFS rates in LAGC patients. Nomogram based on the NPAR exhibits high predictive accuracy and represents a practical tool for assessing DFS in clinical practice.