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
Processing time: 115 Days and 3 Hours
ARTICLE HIGHLIGHTS
Research background

Neoadjuvant chemoradiotherapy (nCRT) has been regarded as the standard treatment for local advanced rectal cancer (LARC). Bilirubin has shown significance in the prognosis of various cancer types, including ovarian cancer and lung cancer. However, the predictive values of indirect bilirubin (IBIL) in the prognoses of LARC patients treated with nCRT remain unknown.

Research motivation

The present study attempted to identify the prognostic value of IBIL before nCRT (pre-IBIL) in LARC patients and to construct a nomogram based on pre-IBIL to predict the survival of the patients.

Research objectives

This study aimed to identify the prognostic value of pre-IBIL in LARC patients and to construct a nomogram to predict their 5-year overall survival (OS) and 5-year disease-free survival (DFS).

Research 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. A 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 receiver operating characteristic (ROC) and curves calibration plots.

Research results

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 were predictors of OS. Furthermore, pre-IBIL, body mass index, 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 areas under the ROC curve of 0.7518 and 0.7355, respectively. Good statistical performance on internal validation was shown via the calibration plots and ROC curves.

Research conclusions

Pre-IBIL was an independent prognostic factor for OS and DFS in LARC patients treated with nCRT followed by TME. Nomograms based on pre-IBIL could be helpful for predicting survival in LARC patients.

Research perspectives

Although our single-center study identified the prognostic value of pre-IBIL in LARC patients, a future prospective study with larger samples should be conducted to further explore the association between pre-IBIL and the prognosis of LARC patients.