Original ArticlesEvaluation of Pathologic Response on Overall Survival After Neoadjuvant Therapy in Pancreatic Ductal AdenocarcinomaSell, Naomi M. MD, MHS∗; Lee, Grace C. MD∗; Fernández-Del Castillo, Carlos MD∗; Ferrone, Cristina R. MD∗; Warshaw, Andrew L. MD∗; Hong, Theodore S. MD†; Blaszkowsky, Lawrence S. MD‡; Lillemoe, Keith D. MD∗; Qadan, Motaz MD, PhD∗Author Information From the ∗Department of Surgery †Division of Radiation Oncology ‡Division of Medical Oncology, Massachusetts General Hospital, Boston, MA. Received for publication November 8, 2019; accepted May 8, 2020. Address correspondence to: Motaz Qadan, MD, PhD, Massachusetts General Hospital, 55 Fruit St, Yawkey 7B, Boston, MA 02114 (e-mail: firstname.lastname@example.org). This study was presented at the 2019 Annual Meeting of the Society for Surgical Oncology, on March 29, 2019, in San Diego, CA, and at the 2019 Annual Meeting of the Pancreas Club, on May 18, 2019, in San Diego, CA. N.M.S. was supported by the NIH T32 Research Training in Aging grant 5T32AG023480-13. The NIH had no involvement in study design; collection, analysis, or interpretation of data; writing of the report; or decision to submit the article for publication. T.S.H. is on the Advisory Board for Merck and consults for Synthetic Biologics. He additionally receives research support for clinical trials from Taiho, Astra-Zeneca, Tesaro, BMS, and IntraOp. The rest of the authors declare no conflict of interest. Pancreas: August 2020 - Volume 49 - Issue 7 - p 897-903 doi: 10.1097/MPA.0000000000001590 Buy Metrics Abstract Objectives Single-institution studies have shown improved outcomes among patients with a pathologic complete response (pCR) following neoadjuvant therapy. We sought to evaluate the impact of pCR and near-complete response (nCR) on overall survival (OS) using a large national database. Methods The National Cancer Database was queried for patients given a diagnosis of pancreatic cancer from 2004 to 2014. A pCR was defined as no tumor identified in the pancreas after surgical resection. An nCR was defined as a primary tumor less than 1 cm without lymph node metastases. The primary outcome was OS. Results A total of 5364 patients underwent neoadjuvant chemotherapy and/or radiation followed by pancreatectomy. Forty-one patients (0.8%) had a pCR, 54 (1%) had an nCR, and the remaining 5266 (98.2%) had an otherwise incomplete response. Patients with pCR had a median OS of 43 months compared with 24 months for nCR and 23 months for incomplete response (P < 0.0001). Only pCR was associated with improved OS on adjusted Cox regression. Conclusions For patients given a diagnosis of pancreatic cancer who underwent neoadjuvant treatment and surgical resection, achieving a pCR was associated with improved OS compared with those with residual tumor. An association between nCR and improved survival was not observed. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.