Reappraisal of the current resectability criteria and optimal treatment strategies for pancreatic cancer.

ABSTRACT

Background: Recent advances in anticancer treatment and prolonged survival are the background of this study. The study aimed to reappraise the Japan Pancreas Society (JPS) resectability criteria in pancreatic cancer and to propose optimal treatment strategies. Methods: Three hundred ninety-six consecutive patients with curative-intent surgery for pancreatic cancer from April 2011 to December 2022 were included. Overall survival based on the resectability criteria was analyzed, and Cox regression analyses were performed to identify factors associated with overall survival. Results: The median survival times (MSTs) based on the current resectability status were 37.4, 20.1, and 26.6 months in resectable (R), in borderline resectable (BR), and unresectable (UR) disease, respectively (P<0.001), revealing an inversion phenomenon between BR and UR. Using the International Association of Pancreatology (IAP) criteria, the MST of biological BR disease was demonstrably worse than that of R disease (27.1 vs. 40.7 months, P=0.04), but no difference was observed between classical BR and UR locally advanced disease (18.8 vs. 18.7 months, P=0.97). Rather, ≤180° superior mesenteric artery (SMA) invasion was a more powerful prognostic factor than >180° SMA/celiac artery invasion in multivariate analysis (hazard ratio 2.101, 95% confidence interval 1.296-3.404, P=0.003). When biological BR was combined with BR, and BR with artery invasion was considered locally advanced disease as a new resectability criterion, the MSTs were 38.8, 23.5, and 18.5 months in the new R, new BR, and locally advanced groups, respectively (P<0.001). Conclusions: The decision-making and treatment strategies based on our new classification in pancreatic cancer are considered reasonable for clinical practice.