Published online Nov 15, 2022. doi: 10.4251/wjgo.v14.i11.2224
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
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.
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.
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).
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.
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.
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.
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.