Impact of Preoperative Neutrophil Percentage-to-Albumin Ratio (NPAR) on Short-Term Complications and Long-Term Prognosis in Patients Undergoing Robot-Assisted Laparoscopic Radical Surgery for Colorectal Cancer

Objective: To assess the prognostic utility of the preoperative neutrophil percentage-to-albumin ratio (NPAR) for short-term complications and long-term survival in colorectal cancer patients receiving robot-assisted laparoscopic radical surgery. Methods: This retrospective study included 230 patients with stage I–III colorectal cancer who underwent Da Vinci robot-assisted laparoscopic radical resection at the Department of Gastrointestinal Surgery, Second Xiangya Hospital of Central South University, between June 2016 and December 2024. Laboratory indicators were collected within 7 days prior to surgery, and NPAR was calculated. The optimal cutoff value of NPAR (14.75) was determined using restricted cubic spline (RCS) analysis and receiver operating characteristic (ROC) curve. Based on a cutoff value of 14.75, patients were categorized into high (≥ 14.75) and low (< 14.75) NPAR groups. Multivariate logistic regression was employed to examine the relationship between NPAR levels and postoperative complications. Additionally, Kaplan–Meier survival analysis was conducted to evaluate its influence on overall survival (OS). Results: A significant non-linear positive association was observed between NPAR and the risk of postoperative complications (P for non-linearity = 0.008). The high NPAR group exhibited a markedly higher incidence of complications (OR = 138.53, 95% CI: 12.79– 1500.47, P < 0.001). Kaplan–Meier analysis demonstrated significantly reduced overall survival among patients with elevated NPAR (log-rank P = 6.2 × 10⁻ 7 ). Furthermore, subgroup analyses confirmed the consistent predictive performance of NPAR across diverse clinical subsets. Conclusion: Elevated preoperative NPAR significantly predicts higher risks of complications and poorer survival following robotic surgery for colorectal cancer. As a straightforward and clinically applicable biomarker, it shows great promise for preoperative risk stratification and outcome evaluation, supporting its broader adoption in clinical practice. Keywords: Neutrophil Percentage-to-Albumin Ratio, NPAR, colorectal cancer, robotic surgery, postoperative complications, prognosis