The Metastatic/Examined Lymph Node Ratio is an Important Prognostic Factor after Pancreaticoduodenectomy for Pancreatic Adenocarcinoma

Abstract

Survival after curative resection for pancreatic adenocarcinoma remains poor; an important prognostic factor is lymph node (LN) status. Recent reports have established the number of LN examined as a separate prognostic factor in many malignancies. We retrospectively reviewed the charts of 128 patients undergoing pancreaticoduodenectomy (PD) for pancreatic cancer and obtained information such as overall survival (OS), disease-free survival (DFS), tumor characteristics, preoperative carbohydrate antigen (CA) 19-9, sex, and age. The ratio of metastatic to examined LN (LNR) was determined, and OS and DFS were analyzed in relation to the three groups: LNR = 0, LNR < 0.15, and LNR > 0.15. The median number of LN collected was 17. There were 46 N0 patients (median = 12) and 83 N1 patients (median = 19). The number of LN harvested had no impact on OS or DFS in the N0 or N1 patient populations. When LNR was examined as a continuous variable, it had a borderline impact on OS (P = 0.068). Examination of LNR by three groups showed an impact on OS (P = 0.037) and DFS (P = 0.013). After curative PD for pancreatic cancer, the ratio of metastatic to examined lymph nodes is an important prognostic factor and should be evaluated in stratification schemes for future clinical trials investigating adjuvant treatments.