Analysis of the Distribution of Lymph Node Metastases and Their Impact on the Prognosis in Ductal Adenocarcinoma of the Distal Part of the Pancreas—A Single-Center Retrospective Study

Background: Lymphadenectomy is an important element of the surgical treatment of pancreatic ductal adenocarcinoma (PDAC). The study aimed to analyze the distribution of lymph node metastases in three nodal stations—group 10 (splenic hilum), group 11 (along the splenic artery), and group 18 (inferior pancreatic margin) depending on the location of PDAC in the distal pancreas: pancreatic neck (PN) vs. pancreatic body (PB) vs. pancreatic tail (PT). Methods: Data from 163 patients who underwent radical (R0) distal pancreatectomy with splenectomy (DP-S) with standard lymphadenectomy (removal of lymph nodes in groups 10, 11, and 18) for PDAC between 2010 and 2023 were analyzed. Patients were assigned to three groups based on the location of the primary tumor: neck (PN, n = 52), body (PB, n = 66), and tail (PT, n = 45). Results: The pattern of nodal metastasis was found to be dependent on the location of PDAC: group 10 (p < 0.001) is characteristic for tumor location in the PT (84.4%; 95% CI: 70–93%) and group 11 (p = 0.004) for tumors located in the PB (72.7%; 95% CI: 60–83%). Lymphatic drainage in group 18 constitutes a common zone, involved regardless of PDAC location (p = 0.185). In multivariate analysis, independent factors influencing overall survival were grading (HR 4.74; 95% CI 2.93–7.68; p < 0.001), lymph node metastasis in group 10 (HR = 3.65; 95% CI: 2.34–5.70; p < 0.001), group 11 (HR = 4.42; CI: 2.56–7.63; p < 0.001), group 18 (HR = 3.26; CI: 1.93–5.51; p < 0.001), and the use of neoadjuvant chemotherapy (HR = 0.57; CI: 0.39–0.84; p = 0.005). Conclusions: PDAC location in the distal pancreas influences metastasis to specific lymph node locations. Metastases to regional lymph node stations are associated with survival after DP-S procedures. In our retrospective cohort, neoadjuvant chemotherapy is associated with a lower risk of death and distant metastases due to PDAC after DP-S procedures.