Copyright: ©Author(s) 2026. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial (CC BY-NC 4.0) license. No commercial re-use. See permissions. Published by Baishideng Publishing Group Inc.
World J Gastrointest Endosc. Aug 16, 2026; 18(8): 122124
Published online Aug 16, 2026. doi: 10.4253/wjge.122124
From surface to depth: Combining white-light and ultrasound endoscopy to predict complete response in rectal cancer
Xiao-Jun Wu, Wen-Hua Fan, Lin-Jie Zhang, Rong Yang, Kun-Hao Bai, Wei-Hao Li, Jun Weng, Jun Chi
Jun Chi, Jun Weng, Wei-Hao Li, Kun-Hao Bai, Rong Yang, Lin-Jie Zhang, Wen-Hua Fan, Xiao-Jun Wu, State Key Laboratory of Oncology in South China, Guangzhou 510060, Guangdong Province, China
Jun Chi, Jun Weng, Wei-Hao Li, Kun-Hao Bai, Rong Yang, Lin-Jie Zhang, Wen-Hua Fan, Xiao-Jun Wu, Guangdong Provincial Clinical Research Center for Cancer, Guangzhou 510060, Guangdong Province, China
Jun Chi, Jun Weng, Kun-Hao Bai, Department of Endoscopy, Sun Yat-sen University Cancer Center, Guangzhou 510060, Guangdong Province, China
Wei-Hao Li, Lin-Jie Zhang, Wen-Hua Fan, Xiao-Jun Wu, Department of Colorectal Surgery, Sun Yat-Sen University Cancer Center, Guangzhou 510060, Guangdong Province, China
Rong Yang, Department of Intensive Care Unit, Sun Yat-Sen University Cancer Center, Guangzhou 510060, Guangdong Province, China
Co-first authors: Jun Chi and Jun Weng.
Co-corresponding authors: Wen-Hua Fan and Xiao-Jun Wu.
Author contributions: Wu XJ and Fan WH designed the study, and critically revised the manuscript, they contributed equally to this article as co-corresponding authors; Chi J, Weng J, and Bai KH collected the endoscopic data; Yang R, Li WH and Zhang LJ acquired the clinical characteristics and follow-up information; Chi J and Weng J performed the data analysis and drafted the manuscript. All authors read and approved the final manuscript. Chi J and Weng J contributed equally to this work as co-first authors. We designated Wu XJ and Fan WH as co-corresponding authors, as the present research was collectively coordinated and supervised by these two investigators. Wu XJ was primarily responsible for the clinical execution of the study, including the rigorous endoscopic evaluations (white-light endoscopy and endoscopic ultrasound), and ensuring the accuracy of the clinical data. Meanwhile, Fan WH led the methodological design and final data interpretation. Both authors jointly conceptualized the original research idea, supervised the entire research process from inception to completion, and provided equal administrative and intellectual support. Furthermore, they both participated equally in critically revising the manuscript for important intellectual content and guarantee the integrity of the study. Given their equally indispensable, yet complementary, contributions to the clinical and scientific aspects of this project, designating them as co-corresponding authors accurately reflects their joint accountability for this work.
AI contribution statement: Portions of this manuscript were edited using AI tools solely for language refinement. The authors carefully reviewed and verified all AI-assisted outputs and take full responsibility for the scientific content of the manuscript.
Supported by National Natural Science Foundation of China, No. 82403973.
Institutional review board statement: This study was approved by the Medical Ethics Committee of Sun Yat-sen University Cancer Center, No. SL-B2025-035-01.
Informed consent statement: All participants were already asked to give signed informed consent before the treatment. So, when this retrospective study was checked by the ethics committee, another informed consent was exempt.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest related to this study.
Data sharing statement: All data analyzed in this research are included in this published article, no additional data are available.
Corresponding author: Xiao-Jun Wu, MD, Chief Physician, Department of Colorectal Surgery, Sun Yat-Sen University Cancer Center, No. 651 Dongfeng East Road, Guangzhou 510060, Guangdong Province, China.
wuxj@sysucc.org.cn
Received: April 14, 2026
Revised: July 7, 2026
Accepted: July 28, 2026
Published online: August 16, 2026
Processing time: 118 Days and 19.4 Hours
BACKGROUND
For patients diagnosed with locally advanced rectal cancer (LARC), radical total mesorectal excision subsequent to neoadjuvant chemoradiotherapy (nCRT) is the standard therapeutic approach. Accurate assessment of complete response (CR) is critical to identify appropriate patients for the nonoperative “Watch and Wait” (W&W) strategy.
AIM
To evaluate white light endoscopy (WLE) and endoscopic ultrasound (EUS) diagnostic efficacy and develop an integrated nomogram to predict CR.
METHODS
We retrospectively analyzed 145 LARC patients receiving nCRT. A dual-review and consensus strategy classified WLE and EUS findings into three categories. Endoscopic diagnostic performance for CR prediction was analyzed, and the association between lesion thickness and CR status was evaluated. Based on logistic regression, a clinical nomogram was developed integrating significant predictors together with objective parameters (tumor location, lesion thickness). The combined model’s clinical utility was assessed by calibration curves, decision curve analysis, and receiver operating characteristic curves.
RESULTS
Of 145 patients, 35 (24.1%) achieved CR. CR correlated with distal tumor location, lower cT stage, and lower preCRT carcinoembryonic antigen level. Positive predictive values for WLE endoscopic CR (eCR) and EUS complete rectal wall restoration were 76.9%-78.6% and 66.7%-85.7%, respectively. EUS findings revealed thinner lesions in CR patients. Overall, WLE and EUS yielded area under the curve (AUC) of 0.741-0.785 and 0.727-0.794, respectively. Multivariate analysis identified WLE non-eCR [odds ratio (OR) = 0.140, P = 0.026] and EUS mass echo (OR = 0.093, P = 0.017) as independent negative predictors. We developed an combined nomogram with these above evaluated endoscopic features and lesion location, demonstrating excellent discrimination (AUC = 0.829, 95% confidence interval: 0.748-0.909), good calibration, and substantial clinical net benefit.
CONCLUSION
Combining WLE and EUS features provides a practical “surface-to-depth” model and a minimally invasive tool for predicting CR, helping clinicians to select suitable patients for W&W strategy.
Core Tip: Accurately identifying a complete response (CR) in patients diagnosed with locally advanced rectal cancer undergoing neoadjuvant treatment is the main challenge for adopting the “Watch and Wait” strategy. By combining white light endoscopy and endoscopic ultrasound features, we constructed a “surface-to-depth” nomogram achieving an area under the curve of 0.829 (95% confidence interval: 0.748-0.909) to predict CR. This integrated model provides clinicians with a practical, minimally invasive tool to select eligible candidates who might obtain clinic benefit from organ preservation management.
