Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Nov 15, 2023; 15(11): 1874-1890
Published online Nov 15, 2023. doi: 10.4251/wjgo.v15.i11.1874
Conditional survival probability of distant-metastatic hepatocellular carcinoma: A population-based study
Yong-Ping Yang, Cheng-Jun Guo, Zhao-Xuan Gu, Jun-Jie Hua, Jia-Xuan Zhang, Jian Shi
Yong-Ping Yang, Cheng-Jun Guo, Zhao-Xuan Gu, Jun-Jie Hua, Jia-Xuan Zhang, Jian Shi, Department of General Surgery, The Second Hospital of Jilin University, Changchun 130041, Jilin Province, China
Author contributions: Shi J conceived and designed the study; Yang YP and Guo CJ collected the data, developed the analytic pipeline; Yang YP, Gu ZX, and Hua JJ led the analysis, generated the tables and figures, and wrote the manuscript; Yang YP, Guo CJ, and Zhang JX verified and processed the underlying data; and all authors have read and approve the final manuscript.
Institutional review board statement: The study was reviewed by the Medical Ethics Committee of the Second Hospital of Jilin University; all our data comes from a public database (the SEER database) and needs no ethical approval.
Informed consent statement: As the study only involved retrospective chart reviews, informed written consents were not required in accordance with institutional IRB policy.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: All of the data used in this study were downloaded from a public database (the SEER database).
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Jian Shi, MD, PhD, Attending Doctor, Department of General Surgery, The Second Hospital of Jilin University, No. 218 Ziqiang Street, Nanguan District, Changchun 130041, Jilin Province, China. atishoo@jlu.edu.cn
Received: June 24, 2023
Peer-review started: June 24, 2023
First decision: August 8, 2023
Revised: August 20, 2023
Accepted: September 6, 2023
Article in press: September 6, 2023
Published online: November 15, 2023
Abstract
BACKGROUND

The prognosis of many patients with distant metastatic hepatocellular carcinoma (HCC) improved after they survived for several months. Compared with traditional survival analysis, conditional survival (CS) which takes into account changes in survival risk could be used to describe dynamic survival probabilities.

AIM

To evaluate CS of distant metastatic HCC patients.

METHODS

Patients diagnosed with distant metastatic HCC between 2010 and 2015 were extracted from the Surveillance, Epidemiology and End Results database. Univariate and multivariate Cox regression analysis were used to identify risk factors for overall survival (OS), while competing risk model was used to identify risk factors for cancer-specific survival (CSS). Six-month CS was used to calculate the probability of survival for an additional 6 mo at a specific time after initial diagnosis, and standardized difference (d) was used to evaluate the survival differences between subgroups. Nomograms were constructed to predict CS.

RESULTS

Positive α-fetoprotein expression, higher T stage (T3 and T4), N1 stage, non-primary site surgery, non-chemotherapy, non-radiotherapy, and lung metastasis were independent risk factors for actual OS and CSS through univariate and multivariate analysis. Actual survival rates decreased over time, while CS rates gradually increased. As for the 6-month CS, the survival difference caused by chemotherapy and radiotherapy gradually disappeared over time, and the survival difference caused by lung metastasis reversed. Moreover, the influence of age and gender on survival gradually appeared. Nomograms were fitted for patients who have lived for 2, 4 and 6 mo to predict 6-month conditional OS and CSS, respectively. The area under the curve (AUC) of nomograms for conditional OS decreased as time passed, and the AUC for conditional CSS gradually increased.

CONCLUSION

CS for distant metastatic HCC patients substantially increased over time. With dynamic risk factors, nomograms constructed at a specific time could predict more accurate survival rates.

Keywords: Conditional survival, Hepatocellular carcinoma, Distant metastasis, Prognosis, Nomogram

Core Tip: Distant metastatic hepatocellular carcinoma (HCC) patients demonstrate high hazard ratios for death in the first few months, which makes survival estimates at the time of initial diagnosis inaccurate. Conditional survival (CS) which takes into account changes in survival risk could be used to describe dynamic survival probabilities. We conducted a population-based study to assess CS for distant metastatic HCC patients. Compared with actual survival rate for HCC patients which gradually decreased after initial diagnosis, CS rate substantially increased over time. With dynamic risk factors, nomograms were constructed to predict more accurate CS at different time after initial diagnosis.