The number and ratio of positive lymph nodes affect pancreatic cancer patient survival after neoadjuvant therapy and pancreaticoduodenectomy.

AIMS

This study is to examine the significance of the number and ratio of positive nodes in post-neoadjuvant therapy pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS AND RESULTS

Our study population consisted of 398 consecutive PDAC patients, who completed neoadjuvant therapy and PD between 1999 and 2012. Lymph node status was classified as ypN0 (node-negative), ypN1 (1-2 positive nodes) and ypN2 (≥3 positive nodes) and correlated with disease-free survival (DFS) and overall survival (OS). The ypN0, ypN1 and ypN2 was present in 183 (46.0%), 117 (29.4%) and 98 (24.6%) patients, respectively. Additionally, 162 (40.7%) had a lymph node ratio (LNR) ≤0.19 and 53 (13.3%) had a LNR >0.19. Patients with ypN1 disease had shorter DFS and OS than those with ypN0 disease, but better DFS and OS than those with ypN2 disease (P < 0.05). Similarly, patients with a LNR ≤ 0.19 had better DFS and OS than those with a LNR > 0.19 (P < 0.001). In multivariate analysis, both the number of positive nodes and LNR were independent prognostic factors for DFS and OS.

CONCLUSIONS

Subclassification of post-therapy node-positive group into ypN1 (1-2 positive nodes) and ypN2 (≥3 positive nodes) should be incorporated into the American Joint Committee on Cancer (AJCC) staging of PDAC patients.