AB058. P030. The 8th versus the 7th edition of the AJCC Cancer Staging Manual in predicting the prognosis of pancreatic ductal adenocarcinoma

Background: The American Joint Committee on Cancer (AJCC) released the AJCC Cancer Staging Manual 8th edition with modifications mainly on the definitions of T3 and N2 stages pancreatic cancer. This study aims to assess its strengths and weaknesses related to the 7th edition AJCC staging system.

Methods: A clinicopathological data of 225 patients who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) between 2010 and 2016 were statistically analyzed.

Results: AJCC 8th edition (P=0.022) predicts survival more effectively than the 7th edition (P=0.180). On multivariate analysis, tumor grading (P=0.000), positive lymph nodes (P=0.028) and tumor location (P=0.022) are independent predictor s for survival, and among stage N0 patients, tumor grading (P=0.002), tumor locations (P=0.016) and level of preoperative serum cancer antigen 19-9 (CA19-9) (P=0.006) are independent predictors for survival.

Conclusions: This finding suggests that the 8th edition of the AJCC grading system achieves the higher predictive ability on pancreatic cancer than the previous edition. Further predictive ability can be achieved by combining the tumor differentiation grades and their locations.