Association Between Harvesting at Least 15 Lymph Nodes and Survival in Resected Pancreatic Cancer Using a Nationwide Database

Introduction Surgical resection plays a pivotal role in the management of pancreatic cancer by achieving complete tumor removal and regional lymphadenectomy. Although most clinical guidelines recommend examining at least 15 lymph nodes (LNY ≥ 15) for accurate staging and better prognostic assessment, the optimal threshold remains uncertain and requires validation across population-based datasets. Methods Using the Taiwan Cancer Registry and National Health Insurance Research Database, 926 patients with pancreatic adenocarcinoma who underwent curative resection between 2013 and 2019 were identified. Cox proportional hazards regression models were used to evaluate the association between lymph node yield (LNY ≥ 15 vs. <15) and overall survival (OS), adjusting for potential confounders. Several sensitivity analyses were performed to assess the robustness of the findings, including a subgroup analysis restricted to patients with pT1–3 pancreatic head tumors who underwent pancreatoduodenectomy. Stratified analyses were additionally performed according to pathological T and N classifications and treatment modalities. Results The median lymph node yield (LNY) was 15, with 496 (53.6%) patients having ≥ 15 nodes retrieved. Patients with adequate LNY were more likely to have tumors in the pancreatic head, undergo pancreatoduodenectomy, and present with advanced pT/N stages and more positive nodes. Although no significant difference in 3-year overall survival (OS) was observed between the ≥ 15 and < 15 groups, a survival benefit appeared in patients with pT1–3 head tumors treated with pancreatoduodenectomy. After adjustment for confounders, multivariable analysis showed that LNY ≥ 15 was not significantly associated with improved 1-year or 3-year OS in the overall cohort or subgroups. Stratified analyses by AJCC stage and treatment revealed no consistent survival advantage, except for patients with pT1–2 disease who demonstrated better 1-year OS. Conclusions: A lymph node yield of ≥ 15 was not independently associated with improved long-term survival in this cohort. Further large-scale studies are warranted to determine the optimal lymph node threshold for accurate prognostic stratification in pancreatic cancer.