Different prognostic implications of lymph node dissection in pancreatic body and tail cancer: a retrospective cohort study with propensity score-matched analysis

Background: Although right-sided lymph node dissection (RLND) is commonly performed during left-sided pancreatectomy for pancreatic ductal adenocarcinoma (PDAC), its oncological benefit remains controversial. In this study, we investigated whether the survival benefit of RLND depends on the tumor location in patients with left-sided PDAC. Materials and methods: Data on patients who underwent curative-intent left-sided pancreatectomy for PDAC between 2010 and 2023 were retrospectively analyzed. Patients were stratified into pancreatic body (Pb) and pancreatic tail (Pt) groups. Within each group, propensity score matching (PSM) was applied to compare patients undergoing RLND with those undergoing left-sided lymph node dissection (LLND) only. The primary endpoints were overall survival (OS) and recurrence-free survival (RFS). Results: After PSM, data from 180 patients with Pb tumors and 122 patients with Pt tumors were analyzed. The baseline characteristics of the patients were well-balanced between the groups. In the Pt group, RLND showed no significant benefit in OS (median 43 vs. 55 months; P = 0.947) or RFS (median 23 vs. 22 months; P = 0.544). In the Pb group, RLND significantly improved OS (median 95 vs. 42 months; P < 0.001) and RFS (median 65 vs. 22 months; P = 0.012). Multivariable Cox regression identified RLND as an independent protective factor for both OS [hazard ratio (HR), 0.42; 95% confidence interval (CI), 0.27–0.66; P < 0.001] and RFS (HR, 0.54; 95% CI, 0.37–0.80; P = 0.002) in the Pb group, whereas RLND was not a significant prognostic factor in the Pt group in univariable analysis (OS: HR, 0.89; 95% CI, 0.53–1.50; P = 0.665; RFS: HR, 0.83; 95% CI, 0.54–1.29; P = 0.406). Conclusion: The survival benefit of RLND in left-sided PDAC appears to be location-dependent, being more evident in tumors of the pancreatic body than in those of the pancreatic tail, thereby supporting a tailored, site-specific approach to lymphadenectomy.