Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Nov 15, 2022; 14(11): 2224-2237
Published online Nov 15, 2022. doi: 10.4251/wjgo.v14.i11.2224
Predictive value of indirect bilirubin before neoadjuvant chemoradiotherapy in evaluating prognosis of local advanced rectal cancer patients
Shuo-Feng Li, Ran Wei, Guan-Hua Yu, Zheng Jiang
Shuo-Feng Li, Ran Wei, Guan-Hua Yu, Zheng Jiang, Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
Author contributions: Li SF and Zheng J designed the study; Li SF, Wei R and Yu GH performed the research; Li SF, Wei R and Yu GH analyzed the data; Li SF and Wei R wrote the paper; Zheng J revised the manuscript for final submission.
Institutional review board statement: The study was reviewed and approved by the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College.
Informed consent statement: This study was a retrospective non-interventional study, which did not affect any medical rights of patient and did not additionally increase patient risk. Some of the patients to be included in this study died or were lost to follow-up, and it is objectively impossible to obtain their informed consent. For these reasons, we have applied to the hospital ethics committee for a waiver of informed consent for all patients in this study at the time of project application, which has been approved.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
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: Zheng Jiang, MD, Chief Physician, Professor, Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No.17 Panjiayuan Nanli, Chaoyang District, Beijing 100021, China. jiangzheng@cicams.ac.cn
Received: July 23, 2022
Peer-review started: July 23, 2022
First decision: August 18, 2022
Revised: August 25, 2022
Accepted: October 2, 2022
Article in press: October 2, 2022
Published online: November 15, 2022
Abstract
BACKGROUND

Many biomarkers have predictive value for overall survival (OS) and disease-free survival (DFS) in tumor patients. However, the role of indirect bilirubin (IBIL) in local advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) has not been studied.

AIM

To explore the predictive value of IBIL before nCRT (pre-IBIL) for the OS and DFS of LARC patients treated with nCRT.

METHODS

A total of 324 LARC patients undergoing nCRT with total mesorectal excision (TME) were enrolled. Preoperative clinical features and postoperative pathological characteristics were collected. Cox regression analysis was performed, and a Cox-based nomogram was developed to predict OS and DFS. We also assessed the predictive performance of the nomogram with calibration plots and receiver operating characteristic (ROC) curves.

RESULTS

Among 324 patients, the median pre-IBIL was 6.2 μmol/L (interquartile range: 4.6 μmol/L-8.4 μmol/L). In the Cox multivariate regression analysis, we found that pre-IBIL, smoking history, tumor regression grade (TRG), vascular invasion, and carbohydrate antigen 19-9 before nCRT (pre-CA19-9) were predictors of OS. Additionally, pre-IBIL, body mass index (BMI), nCRT with surgery interval, TRG, and vascular invasion were predictors of DFS. Predictive nomograms were developed to predict 5-year OS and 5-year DFS with area under the ROC curve values of 0.7518 and 0.7355, respectively. Good statistical performance on internal validation was shown by calibration plots and ROC curves.

CONCLUSION

This study demonstrated that pre-IBIL was an independent prognostic factor for OS and DFS in LARC patients treated with nCRT followed by TME. Nomograms incorporating pre-IBIL, BMI, smoking history, nCRT with surgery interval, TRG, vascular invasion, and pre-CA19-9 could be helpful to predict OS and DFS.

Keywords: Indirect bilirubin, Local advanced rectal cancer, Neoadjuvant chemoradiotherapy, Prognostic factor, Overall survival, Disease-free survival

Core Tip: Our study demonstrated that indirect bilirubin measurement before neoadjuvant chemoradiotherapy (nCRT) (pre-IBIL) is an independent and significant risk factor for survival in local advanced rectal cancer patients treated with nCRT followed by total mesorectal excision. In addition, nomograms based on pre-IBIL can predict 5-year overall survival and 5-year disease-free survival with good agreement.