Retrospective Cohort Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 14, 2019; 25(46): 6752-6766
Published online Dec 14, 2019. doi: 10.3748/wjg.v25.i46.6752
Mesenterico-portal vein invasion should be an important factor in TNM staging for pancreatic ductal adenocarcinoma: Proposed modification of the 8th edition of the American Joint Committee on Cancer staging system
Hong-Yu Chen, Xing Wang, Hao Zhang, Xu-Bao Liu, Chun-Lu Tan
Hong-Yu Chen, Xing Wang, Hao Zhang, Xu-Bao Liu, Chun-Lu Tan, Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Tan CL, Liu XB, and Chen HY designed the study; Chen HY, Wang X, and Zhang H acquired the data; Wang X and Chen HY analyzed and interpreted the data; Chen HY wrote the paper; Tan CL and Liu XB critically revised the manuscript for important intellectual content.
Supported by the 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University, No. ZY2017302 1-3-5; and the Key Research and Development Projects of Sichuan Province, No. 2017SZ0132 and No. 2019YFS0042.
Institutional review board statement: This study was reviewed and approved by the West China Hospital Review Board.
Informed consent statement: Study participants of the West China Hospital database provided written informed consent prior to study enrollment.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: No additional data are available.
STROBE statement: The guidelines of the STROBE statement have been adopted.
Open-Access: This 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 Non Commercial (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: Chun-Lu Tan, MD, PhD, Associate Professor, Doctor, Surgeon, Department of Pancreatic Surgery, West China Hospital, Sichuan University, No. 37, Guoxue Lane, Wuhou District, Chengdu 610041, Sichuan Province, China. chunlutan@163.com
Telephone: +86-28-85422474 Fax: +86-28-85422474
Received: October 15, 2019
Peer-review started: October 15, 2019
First decision: November 4, 2019
Revised: November 12, 2019
Accepted: November 29, 2019
Article in press: November 29, 2019
Published online: December 14, 2019
Abstract
BACKGROUND

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC) excludes extrapancreatic extension from the assessment of T stage and restages tumors with mesenterico-portal vein (MPV) invasion into T1-3 diseases according to tumor size. However, MPV invasion is believed to be correlated with a poor prognosis.

AIM

To analyze whether the inclusion of MPV invasion can further improve the 8th edition of the AJCC staging system for PDAC.

METHODS

This study retrospectively included 8th edition AJCC T1-3N0-2M0 patients undergoing pancreaticoduodenectomy/total pancreatectomy from two cohorts and analyzed survival outcomes. In the first cohort, a total of 7539 patients in the surveillance, epidemiology, and end results database was included, and in the second cohort, 689 patients from the West China Hospital database were enrolled.

RESULTS

Cox regression analysis showed that MPV invasion is an independent prognostic factor in both databases. In the MPV- group, all pairwise comparisons between the survival functions of patients with different stages were significant except for the comparison between patients with stage IIA and those with stage IIB. However, in the MPV+ group, pairwise comparisons between the survival functions of patients with stage IA, stage IB, stage IIA, stage IIB, and stage III were not significant. T1-3N0 patients in the MPV+ group were compared with the T1N0, T2N0, and T3N0 subgroups of the MPV- group; only the survival of MPV-T3N0 and MPV+T1-3N0 patients had no significant difference. Further comparisons of patients with stage IIA and subgroups of stage IIB showed (1) no significant difference between the survival of T2N1 and T3N0 patients; (2) a longer survival of T1N1 patients that was shorter than the survival of T2N0 patients; and (3) and a shorter survival of T3N1 patients that was similar to that of T1-3N2 patients.

CONCLUSION

The modified 8th edition of the AJCC staging system for PDAC proposed in this study, which includes the factor of MPV invasion, provides improvements in predicting prognosis, especially in MPV+ patients.

Keywords: Pancreatic ductal adenocarcinoma, Portal vein, Mesenteric veins, Neoplasm staging, Pancreaticoduodenectomy

Core Tip: The 8th edition of the American Joint Committee on Cancer staging system for pancreatic ductal adenocarcinoma restages tumors with mesenterico-portal vein (MPV) invasion into T1-3 diseases according to tumor size. However, the survival analysis indicated that these patients have similar prognoses. The modified staging system, which includes the factor of MPV invasion, provides improvements in predicting prognosis.