A novel scoring system predicts postsurgical survival and adjuvant chemotherapeutic benefits in patients with pancreatic adenocarcinoma: Implications for AJCC-TNM staging.

Abstract

We evaluated the application of the latest 8^th American Joint Committee on Cancer (AJCC) staging system in Chinese patients and determined whether the addition of biologic markers could improve the prediction of postsurgical survival in pancreatic adenocarcinoma (PC). This multicenter study involved 1,223 consecutive patients who underwent margin-negative pancreatectomy for PC. A scoring system was devised based on AJCC pathologic parameters and biologic markers and defined using a Cox proportional hazards model. Prognostic accuracies were evaluated by concordance index (C-index) and Akaike information criterion (AIC). The 8^th edition AJCC staging system had a better survival distribution of PC with different stages and a similar C-index (0.62 in the training cohort, 0.60 in the validation cohort) than the 7^th edition (0.59 in the training cohort, 0.58 in the validation cohort). Nevertheless, survival of resected patients with stage IIA or IIB disease was indistinguishable. Incorporation of postoperative carbohydrate antigen 19-9 (CA19-9) levels and tumor grade into the 8^th edition AJCC staging system generated a scoring system with better predictive accuracy for overall survival (OS) (C-index of 0.73 and AIC of 4301.05 in the training cohort, C-index of 0.71 and AIC of 3309.23 in the validation cohort). More importantly, patients with median or higher scores experienced OS benefits from adjuvant chemotherapy. Postoperative CA19-9 levels and tumor grade are two well-known PC biologic markers that could be incorporated into a standard AJCC staging system to refine risk stratification and predict OS benefit from adjuvant chemotherapy in resected PC.