Pathologic Examination of Pancreatic Specimens Resected for Treated Pancreatic Ductal Adenocarcinoma Recommendations From the Pancreatobiliary Pathology Society

• Authors: Huamin Wang, The University of Texas M.D. Anderson Cancer Center; Runjan Chetty, Brighton & Sussex University Hospitals; Mojgan Hosseini, University of California San Diego; Daniela S Allende, Cleveland Clinic; Irene Esposito, University Hospital of Duesseldorf; Yoko Matsuda, Kagawa University; Vikram Deshpande, Harvard Medical School; Jiaqi Shi, University of Michigan; Deepti Dhall, University of Alabama Birmingham; Kee-Taek Jang, Sungkyunkwan University; Grace E Kim, University of California San Francisco; Claudio Luchini, University and Hospital Trust of Verona; Rondell P Graham, Mayo Clinic, Rochester; Michelle Reid, Emory University; Olca Basturk, Memorial Sloan Kettering Cancer Center; Ralph H Hruban, Johns Hopkins University; Alyssa Krasinskas, Emory University; David S Klimstra, Memorial Sloan Kettering Cancer Center; Volkan Adsay, Koc University Hospital and KUTTAM Research Center
• Journal Title: AMERICAN JOURNAL OF SURGICAL PATHOLOGY
• Volume: Volume 46, Number 6
• Publisher: LIPPINCOTT WILLIAMS & WILKINS | 2022-06-01, Pages 754-764
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1097/PAS.0000000000001853
• Subjects: Health Sciences, Pathology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Pathology; Surgery; pancreatic ductal adenocarcinoma; neoadjuvant therapy; gross examination; mapping sections; tumor size; tumor response grade; survival; lymph node metastasis; PREDICTS POOR-PROGNOSIS; NEOADJUVANT THERAPY; POSTTHERAPY PANCREATICODUODENECTOMY; STAGING SYSTEM; CANCER; CHEMOTHERAPY; SURVIVAL; INVASION; NUMBER; BREAST

Abstract

Currently, there are no internationally accepted consensus guidelines for pathologic evaluation of posttherapy pancreatectomy specimens. The Neoadjuvant Therapy Working Group of Pancreatobiliary Pathology Society was formed in 2018 to review grossing protocols, literature, and major issues and to develop recommendations for pathologic evaluation of posttherapy pancreatectomy specimens. The working group generated the following recommendations: (1) Systematic and standardized grossing and sampling protocols should be adopted for pancreatectomy specimens for treated pancreatic ductal adenocarcinoma (PDAC). (2) Consecutive mapping sections along the largest gross tumor dimension are recommended to validate tumor size by histology as required by the College of American Pathologists (CAP) cancer protocol. (3) Tumor size of treated PDACs should be measured microscopically as the largest dimension of tumor outer limits that is bound by viable tumor cells, including intervening stroma. (4) The MD Anderson grading system for tumor response has a better correlation with prognosis and better interobserver concordance among pathologists than does the CAP system. (5) A case should not be classified as a complete response unless the entire pancreas, peripancreatic tissues, ampulla of Vater, common bile duct, and duodenum adjacent to the pancreas are submitted for microscopic examination. (6) Future studies on tumor response of lymph node metastases, molecular and/or immunohistochemical markers, as well as application of artificial intelligence in grading tumor response of treated PDAC are needed. In summary, systematic, standardized pathologic evaluation, accurate tumor size measurement, and reproducible tumor response grading to neoadjuvant therapy are needed for optimal patient care. The criteria and discussions provided here may provide guidance towards these goals.