Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Dec 15, 2020; 12(12): 1394-1406
Published online Dec 15, 2020. doi: 10.4251/wjgo.v12.i12.1394
Comparison of survival between adolescent and young adult vs older patients with hepatocellular carcinoma
Jie Ren, Ying-Mu Tong, Rui-Xia Cui, Zi Wang, Qing-Lin Li, Wei Liu, Kai Qu, Jing-Yao Zhang, Chang Liu, Yong Wan
Jie Ren, Ying-Mu Tong, Rui-Xia Cui, Zi Wang, Qing-Lin Li, Wei Liu, Kai Qu, Jing-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Jing-Yao Zhang, Chang Liu, Department of SICU, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Yong Wan, Department of Geriatric Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Author contributions: Ren J, Tong YM, and Cui RX contributed equally to this work; Ren J participated in the research design, data analysis, and writing of the paper; Tong YM and Cui RX participated in the data analysis; Wang Z, Liu W, and Li QL participated in revising of the paper; Qu K participated in research design and revising of the paper; Zhang JY, Liu C, and Wan Y provided substantial advice in designing the study, assisting in the division of labor, and writing and revising the paper; all authors have read and approved the final manuscript.
Institutional review board statement: The IRB has reviewed this information and found that this protocol does not fall under the purview of the IRB as it does not meet the definition of human subject research.
Informed consent statement: As the data used was accessed via a public national database with deidentified patients, there was no need for informed consent.
Conflict-of-interest statement: The authors have no conflict of interest to report.
Data sharing statement: Data from this manuscript will be available upon request.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and 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: Yong Wan, MD, Chief Physician, Department of Geriatric Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 Yanta West Road, Xi’an 710061, Shaanxi Province, China. rareyong@qq.com
Received: August 31, 2020
Peer-review started: August 31, 2020
First decision: September 12, 2020
Revised: September 20, 2020
Accepted: October 26, 2020
Article in press: October 26, 2020
Published online: December 15, 2020
Processing time: 100 Days and 20.9 Hours
ARTICLE HIGHLIGHTS
Research background

Adolescent and young adult (AYA) population refer to people aged 15-39 years old. AYA cancers are different from those in children and elderly individuals due to their special clinical features and biologic characteristics. Liver cancer is the sixth most common malignant cancer in the world and the fourth cancer-related cause of death. Hepatocellular carcinoma (HCC) is the most common pathological type of liver cancer. Age-related studies of HCC are needed to guide the diagnosis and treatment of this malignancy.

Research motivation

There have been studies on liver cancer among children and elderly individuals. However, there are few studies on AYA HCC.

Research objectives

First, this study aimed to describe the clinical characteristics of AYA HCC. Second, this study intended to compare overall survival (OS) between AYA (15-39 years) and older (40-74 years) HCC patients.

Research methods

A total of 12721 patients were included in the study, including 366 (2.9%) AYA HCC patients and 12355 (97.1%) patients in the older group. Kaplan-Meier curves and the log-rank tests were used to compare OS of the AYA and older patients. The Cox proportional hazards regression model was used for multivariate analysis to identify the risk factors for OS of HCC patients. After a 1:1 PSM of the baseline data, the OS difference between the two groups was analyzed again. Subsequently, a subgroup multivariate analysis was carried out, and patients were stratified according to American Joint Committee on Cancer (AJCC) stage.

Research results

Compared to older patients, AYA HCC patients had a worse SEER stage, including distant stage (22.1% vs 15.4%, P < 0.001); a more advanced AJCC stage, including AJCC stages III and IV (49.2% vs 38.3%, P < 0.001); and were more likely to receive surgery (64.5% vs 47.5%, P < 0.001). Before PSM, the AYA group had a longer survival in months (median: 20.00, IQR: 5.00-62.50) than the older group (median: 15.00, IQR: 4.00-40.00) (P < 0.001). After PSM, the AYA group still had a longer survival in months (median: 21.00, IQR: 5.00-64.50) than the older group (median: 18.00, IQR: 6.00-53.00) (P < 0.001). The Cox proportional hazards regression model showed that advanced age (HR = 1.405, 95%CI: 1.218-1.621, P < 0.001) was a risk factor for OS of HCC. In the subgroup analysis, the Cox proportional hazards regression model showed that in AJCC stage I/II patients, advanced age (HR = 1.749, 95%CI: 1.352-2.263, P < 0.001) was a risk factor for OS, while advanced age (HR = 1.186, 95%CI: 0.997-1.410, P = 0.054) was not a risk factor in AJCC stage III/IV patients before PSM. Advanced age (HR = 1.891, 95%CI: 1.356-2.637, P < 0.001) was a risk factor for OS in AJCC stage I/II patients, while it (HR = 1.192, 95%CI: 0.934-1.521, P = 0.157) was not a risk factor for OS in AJCC stage III/IV patients after PSM.

Research conclusions

AYA HCC patients have different clinical characteristics from older adults. In different AJCC stages, the two groups of patients have different OS: In the AJCC stage I/II group, advanced age was a risk factor for OS, while it was not a risk factor for OS in the AJCC stage III/IV group.

Research perspectives

The data in this study came from a database; thus, variable inclusion was limited to the database, and information such as laboratory examinations, combined diseases, and economic status could not be obtained. More samples are needed to verify our research results, and more basic studies are needed to explore the molecular mechanism of this research result.