Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. Jun 9, 2020; 11(2): 25-39
Published online Jun 9, 2020. doi: 10.4292/wjgpt.v11.i2.25
Validation of American Joint Committee on Cancer 8th edition of TNM staging in resected distal pancreatic cancer
Feng Yin, Mohammed Saad, Hao Xie, Jingmei Lin, Christopher R Jackson, Bing Ren, Cynthia Lawson, Dipti M Karamchandani, Belen Quereda Bernabeu, Wei Jiang, Teena Dhir, Richard Zheng, Christopher W Schultz, Dongwei Zhang, Courtney L Thomas, Xuchen Zhang, Jinping Lai, Michael Schild, Xuefeng Zhang, Xiuli Liu
Feng Yin, Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO 65212, United States
Mohammed Saad, Jingmei Lin, Department of Pathology, Indiana University, Indianapolis, IN 46202, United States
Hao Xie, Division of Medical Oncology, Mayo Clinic, Rochester, MN 55905, United States
Christopher R Jackson, Bing Ren, Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, PA 03766, United States
Cynthia Lawson, Dipti M Karamchandani, Department of Pathology, Pennsylvania State Health Milton S. Hershey Medical Center, Hershey, PA 17033, United States
Belen Quereda Bernabeu, Wei Jiang, Teena Dhir, Richard Zheng, Christopher W Schultz, Department of Pathology, Thomas Jefferson University Hospital, Philadelphia, PA 19107, United States
Dongwei Zhang, Department of Pathology and Lab Medicine, University of Rochester Medical Center, Rochester, NY 14642, United States
Courtney L Thomas, Xuchen Zhang, Department of Pathology, Yale University, New Haven, CT 06510, United States
Jinping Lai, Department of Pathology and Laboratory Medicine, Kaiser Permanente Sacramento Medical Center, Sacramento, CA 95825, United States
Michael Schild, Department of Pathology, Duke University, Durham, NC 27710, United States
Xuefeng Zhang, Department of Pathology, Cleveland Clinic, Cleveland, OH 44195, United States
Xiuli Liu, Department of Pathology, Immunology and Lab Medicine, University of Florida, Gainesville, FL 32610, United States
Author contributions: Liu X, Yin F, Lin J, Ren B, Karamchandani DM, Jiang W, Zhang D, Zhang X, Lai J, Schild M, Zhang X, and Xie H designed the research; Yin F, Saad M, Jackson CR, Lawson C, Bernabeu BQ, Dhir T, Zheng R, Schultz CW, and Thomas CL collected data; Yin F, Xie H, and Liu X analyzed the data; Yin F wrote the manuscript and Liu X, Xie H critically revised the manuscript.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of University of Florida.
Informed consent statement: Patients were not required to give informed consent to the study because our study was done retrospectively and data for study obtained after each patient agreed to treatment. Informed consent waiver was approved by Institutional review board of University of Florida.
Conflict-of-interest statement: The authors declare no competing interests in this study.
Data sharing statement: No additional data are available.
STROBE statement: The manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Xiuli Liu, MD, PhD, Director, Professor, Department of Pathology, Immunology and Lab Medicine, University of Florida, 1345 Center Dr., Gainesville, FL 32610, United States. xiuliliu@ufl.edu
Received: December 30, 2019
Peer-review started: December 30, 2019
First decision: February 24, 2020
Revised: March 26, 2020
Accepted: May 12, 2020
Article in press: May 12, 2020
Published online: June 9, 2020
ARTICLE HIGHLIGHTS
Research background

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer related death worldwide. For the purpose of better risk stratification and clinical management, the American Joint Committee on Cancer (AJCC) published the eighth edition staging manual for pancreatic cancer that has introduced significant changes for both tumor (T) staging and nodal (N) staging. Notably majority of the validation studies were focused on PDAC in the head of pancreas, and the resected distal pancreatic adenocarcinoma was likely underrepresented due to its clinical rarity. Whether the AJCC 8th edition staging manual provides equal risk stratification for both invasive intraductal papillary mucinous neoplasm (IPMN) and non-IPMN associated PDAC is also unclear.

Research motivation

It’s important to investigate whether the new AJCC staging system provides risk stratification in patients with distal pancreatic cancers. It’s also important to investigate the clinical behavior and risk stratification for invasive IPMN and non-IPMN associated PDAC.

Research objectives

This study aims to validate the AJCC 8th edition staging manual in distal PDAC.

Research methods

Clinicopathological data of resected distal PDAC cases were retrieved. All cases were re-staged based on the AJCC 7th and 8th edition, respectively. Categorical variables were compared with Fisher’s exact test. Progression-free survival (PFS) and overall survival (OS) were evaluated through Kaplan-Meier curves and univariate/multivariate analyses.

Research results

T and N staging of both 7th and 8th edition sufficiently stratify PFS and OS in the entire cohort, although dividing into N1 and N2 according to the 8th edition does not show additional stratification. For PDAC arising in IPMN, T staging of the 7th edition and N1/N2 staging of the 8th edition appear to further stratify PFS and OS. For PDAC without an IPMN component, T staging from both versions fails to stratify PFS and OS.

Research conclusions

The AJCC 8th edition TNM staging system provides even distribution for the T staging, however, it does not provide better risk stratification than previous staging system for distal pancreatic cancer. There is significant difference of clinical outcome and risk stratification between invasive IPMN and non-IPMN associated PDAC.

Research perspectives

Tumor location and subtype are important factors to be considered in future revisions of the AJCC staging system for pancreatic cancer.