Positive Lymph Nodes Independently Affect Long-Term Survival After Pancreaticoduodenectomy for Non-Ampullary Duodenal Adenocarcinoma: A Single-Center, Retrospective Analysis

<b>Background/Objectives</b>: The main treatment for non-ampullary duodenal adenocarcinoma (NDA) is pancreatoduodenectomy (PD) with lymphadenectomy (LN). Several studies have proposed a minimum number of examined lymph nodes (MNELN) to ensure proper staging. This study investigated the impact of nodal parameters-including the pattern of nodal spread-on oncologic outcomes following PD for NDA. Furthermore, we sought to determine the MNELN to ensure reliable detection of nodal involvement. <b>Methods</b>: This was a single-center, retrospective study. Consecutive patients who underwent PD from 2000 to 2019 with a final diagnosis of NDA were retrieved from a prospectively maintained database. The probability of detecting at least one metastatic LN in a node-positive patient was assessed using a model based on the binomial probability law. <b>Results</b>: A total of 70 patients met the inclusion criteria. The median number of ELNs was 35 (22-43, IQR). Thirty-six patients (51%) had at least one PLN. A node-positive disease was associated with adverse pathologic features, including high tumor grade and perineural and peripancreatic fat invasion. This translated into a greater recurrence rate (<i>p</i> < 0.001). The MNELN yielding a 95% probability of detecting at least one metastatic node in a node-positive patient was 25. After a median follow-up of 73 months, the median recurrence-free survival (RFS) was 33 months (95% CI 13-97), and the overall survival (OS) was 41 months (95% CI 17-96). The LN ratio, tumor grade, and metastases at stations 8 and 12 were independently associated with OS (<i>p</i> < 0.05). <b>Conclusions</b>: Nodal metastases are common among patients with NDA and have a considerable impact on long-term survival. Stations 8 and 12 were associated with OS. Therefore, an adequate lymphadenectomy, possibly including stations 8 and 12, is recommended in patients with NDA.