New criteria of resectability for pancreatic cancer: A position paper by the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS).

The symposium "New criteria of resectability for pancreatic cancer" was held during the 33nd meeting of the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS) in 2021 to discuss the potential modifications that could be made in the current resectability classification. The meeting focused on setting the foundation for developing a new prognosis-based resectability classification that is based on the tumor biology and the response to neoadjuvant treatment (NAT). The symposium included selected experts from Western and Eastern high-volume centers who have discussed their concept of resectability status through published literature. During the symposium, presenters reported new resectability classifications from their respective institutions based on tumor biology, conditional status, pathology, and genetics, in addition to anatomical tumor involvement. Interestingly, experts from all the centers reached the agreement that anatomy alone is insufficient to define resectability in the current era of effective NAT. On behalf of the JSHBPS, we would like to summarize the content of the conference in this position paper. We also invite global experts as internal reviewers of this paper for intercontinental cooperation in creating an up-to-date, prognosis-based resectability classification that reflects the trends of contemporary clinical practice.

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.