Biological and conditional factors should be included when defining criteria for resectability for patients with pancreatic cancer

Background: This study aimed to evaluate novel resectability criteria for pancreatic ductal adenocarcinoma (PDAC) proposed by the International Association of Pancreatology (IAP) by comparing them with the National Comprehensive Cancer Network (NCCN) guidelines. Methods: 369 patients who underwent upfront surgery for PDAC were retrospectively analyzed. Overall survival (OS) of each group as defined by either of the guidelines were compared and preoperative prognostic factors for OS were identified. Results: Based on the IAP-criteria, 157 patients were classified as resectable (R), 192 as borderline resectable (BR) and 20 as unresectable (UR), with the median survival time (MST) of 40 months, 17 and 11, respectively. In contrast to the NCCN-criteria, BR demonstrated significantly better OS than UR (P = 0.023) under the IAP-criteria. Performance status >= 2 (hazard ratio [HR]: 2.47, P = 0.014) and lymph node metastasis suspected by imaging (HR: 1.55, P = 0.003) were identified as independent prognostic factors by the multivariate analysis along with portal or arterial invasion, while carbohydrate antigen 19-9 >= 500 U/ml was not (HR: 1.23, P = 0.190). Conclusion: The IAP-criteria, which includes biological and conditional factors, resulted in superior separation of survival curves stratified by the resectablity when compared with the NCCN-criteria.