Larger Non-metastatic No. 8 Lymph Node Size Is Associated With Favorable Prognosis After Pancreaticoduodenectomy for Pancreatic Cancer.

Background/Aim: Although lymph node metastasis is a negative prognostic factor in pancreatic cancer, the significance of non-metastatic lymph node enlargement remains unclear. This study evaluated the prognostic impact of the No. 8 lymph node (N8LN), which is routinely assessed during pancreaticoduodenectomy and identifiable on preoperative imaging. Patients and Methods: We retrospectively reviewed 99 patients who underwent pancreaticoduodenectomy for pancreatic cancer between 2009 and 2019. The size of the N8LN was measured on preoperative imaging, and patients were divided into small and large groups based on the median value. Long-term oncologic outcomes were compared between the two groups. To assess the local immune response, CD8 immunohistochemistry was performed on nodal sections, and CD8⁺ T-cell density was quantified using QuPath software. Results: . 17.1 months) than the small group. Enlarged N8LN remained an independent favorable prognostic factor in multivariable analysis. CD8⁺ T-cell density did not differ between groups. Conclusion: Enlarged N8LN size was independently associated with better survival after pancreaticoduodenectomy. Nodal enlargement may reflect host immune activity rather than tumor progression and merits further investigation.