Lymph node examination and survival in resected pancreatic ductal adenocarcinoma: retrospective study.

BACKGROUND: The minimum number of examined lymph nodes (ELN) required for adequate staging and best prediction of survival has not been established in pancreatic ductal adenocarcinoma (PDAC). The aim of the study was to investigate the influence of ELN on staging and survival in PDAC. METHODS: Patients undergoing partial or total pancreatectomy for PDAC at two European university hospitals between 2007 and 2018 were retrospectively reviewed. Multivariate Cox regression model and survival analyses were performed to verify adequate staging. RESULTS: Overall 341 (73 per cent) patients showed lymph node metastasis (N1/N2), whereas 125 (27 per cent) patients had no lymph node involvement (N0). With increasing number of ELN, the proportion of positive lymph nodes increased. The minimum number of ELN needed to detect lymph node involvement was 21. In multivariate analysis, examination of <21 lymph nodes was a significant negative predictor for survival. Examination of ≥21 ELN reversed this effect and ruled out possible misclassification. CONCLUSION: The number of ELN affects survival in PDAC. Possible misclassification was identified when <21 lymph nodes were examined. Therefore, at least 21 lymph nodes must be examined to avoid false lymph node classification in all types of resection.

Margin clearance greater than 1 mm in nodal-positive pancreatic adenocarcinoma patients: multicentre retrospective analysis.

BACKGROUND: The introduction of the 1 mm cut-off for resection margin according to the Leeds Pathology Protocol has transformed the concept of surgical radicality. Its impact on nodal-positive resected pancreatic ductal adenocarcinoma patients is unclear. The aim of this study was to analyse the effect of margin clearance on survival among resected, nodal-positive pancreatic ductal adenocarcinoma patients whose specimens were analysed according to the Leeds Pathology Protocol. METHODS: Data were collected retrospectively from multicentre clinical databases. Resected patients with nodal involvement were included. Overall survival and disease-free survival were analysed according to minimum reported margin clearances of 0, 0.5, 1, and 2 mm. The results are reported separately for patients who had not undergone venous resection and for patients for whom data were available regarding the superior mesenteric vein-facing margin or the vein specimen. The eighth edition of TNM classification by the AJCC was used. RESULTS: The study comprised 290 stage IIB patients and 215 stage III patients without venous resection. The superior mesenteric vein margin analysis comprised 127 stage IIB patients and 198 stage III patients. The different resection margin distances were not associated with overall survival and disease-free survival among patients without venous resection (P > 0.050). Receiving adjuvant therapy was associated with longer overall survival among stage IIB patients (P = 0.034) and stage III patients (P = 0.003) and with longer disease-free survival among stage III patients (P < 0.001). CONCLUSIONS: In this study, a margin clearance greater than 1 mm showed no clear effect on overall survival in pancreatic ductal adenocarcinoma patients with nodal involvement, whereas adjuvant therapy was confirmed to be essential to ensure longer overall survival.