Urine-Based Nematode Chemotaxis Assay (N-NOSE) as a Predictor of Recurrence After Curative Surgery for Resectable Pancreatic Cancer: A Single-Center Prospective Study

Background Pancreatic cancer (PC) remains one of the most lethal malignancies, with high recurrence rates even after curative-intent surgery. Current surveillance tools, including imaging and serum carbohydrate antigen 19 − 9, have limitations in specificity and sensitivity. N-NOSE is a urine-based assay using the chemotactic behavior of Caenorhabditis elegans to detect cancer-associated volatile organic compounds. This study prospectively evaluated the prognostic value of N-NOSE in patients undergoing curative surgery for resectable PC. Methods Twenty-four patients with resectable PC, all treated with preoperative gemcitabine plus S-1 chemotherapy followed by curative-intent pancreatectomy, were enrolled. The chemotaxis index was measured at three time points: before treatment, after preoperative chemotherapy, and postoperatively. Recurrence within two years was assessed. Univariate and multivariate logistic regression analyses were performed to identify predictors of recurrence, and recurrence-free survival was analyzed using Kaplan–Meier methods. Results During the two-year follow-up, 13 patients (54.2%) experienced recurrence. Univariate analysis identified pre-treatment platelet-to-lymphocyte ratio > 1.53 ( p  = 0.04), pathological lymph node metastasis ( p  = 0.04), and pre-treatment N-NOSE positivity ( p  = 0.007) as significant predictors. Multivariate analysis confirmed pre-treatment N-NOSE positivity as the only independent predictor (odds ratio: 3.10 × 10⁷; 95% CI: 11.38–; p  = 0.03). In patients who recurred, the chemotaxis index increased significantly after surgery ( p  = 0.02), while remaining stable in non-recurrent cases. Conclusions Pre-treatment N-NOSE positivity and postoperative increases in chemotaxis index were associated with recurrence after curative-intent surgery for resectable PC. This non-invasive urine-based assay could provide valuable prognostic information to guide postoperative surveillance and individualized management.