Nodal status in pancreatic ductal adenocarcimoa: a survival analysis

Abstract

OS after surgery for pancreatic ductal adenocarcinoma (PDAC) is poor. While some studies suggest that N1 is an important prognostic factor after R0 resection, other data imply that nodal disease per se is not associated with survival outcome. The aim of this study was to identify prognostic variables in PDAC and to investigate the value of lymph node (LN) involvement, LN ratio (LNR) and log odds of positive LN (LODDS). Clinicopathological data from 284 patients who received resection for PDAC were analysed. LNR (ratio of positive LN to examined LN) and LODDS (log(positive LN+0.5)/(total LN+0.5)) were calculated. Of the 284 patients, 252 underwent surgery for pancreatic head carcinoma. 223 patients showed N1, while 36 presented with M1. 102 patients displayed a LNR >0.2. 120 patients showed -0.5≤LODDS<0. In our cohort, N1 status was not associated with poor prognosis (p=0.158). LNR >0.2 and LODDS subgroup were correlated with poor survival in univariate analysis (p=0.001 and p=0.012). In multivariate analysis, only LNR >0.2 and M1 status correlated with poor survival. Furthermore a subgroup analysis was performed for 163 patients who received R0 resection for N1 PDAC without M1. In both MV and UV analysis, LNR >0.2 and LODDS subgroup were correlated with poor survival. While N1 per se is of no prognostic value in PDAC, interestingly, LNR and LODDS are an independent prognostic factor in PDAC. Therefore, should be included in pathologic reporting after PDAC resection and taken into consideration for prognosis assessment of PDAC patients.