Prediction of pathologic complete response to neoadjuvant chemoradiation in locally advanced rectal cancer

Xiaoling Zhong; Guohua Zeng; Lixiang Zhang; Shuyuan You; Yuxiang Fu; Wan He; Guixiang Liao

doi:10.3389/fonc.2024.1361300

Prediction of pathologic complete response to neoadjuvant chemoradiation in locally advanced rectal cancer

Front Oncol. 2024 Mar 11:14:1361300. doi: 10.3389/fonc.2024.1361300. eCollection 2024.

Authors

Xiaoling Zhong¹, Guohua Zeng¹, Lixiang Zhang¹, Shuyuan You², Yuxiang Fu³, Wan He⁴, Guixiang Liao⁵

Affiliations

¹ Department of Radiology, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology), Shenzhen, Guangdong, China.
² Department of Pathology, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology), Shenzhen, China.
³ Department of Gastrointestinal surgery, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology), Shenzhen, China.
⁴ Department of Oncology, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology), Shenzhen, China.
⁵ Department of Radiation Oncology, Shenzhen People's Hospital (The Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology), Shenzhen, China.

Abstract

Purpose: To investigate the predictive factors of pathologic complete response (pCR) in locally advanced rectal cancer (LARC) patients who had been treated with neoadjuvant chemoradiation (nCRT).

Methods and materials: For this retrospective study, 53 LARC patients (37 males and 16 females; age range 25 to 79 years) were selected. Clinical characteristics, baseline mrTNM staging, MR gross tumor volumes (GTV), and pCR were evaluated. The diagnostic accuracy of GTV for predicting pCR was calculated.

Results: Among 53 LARC patients, 15 patients achieved pCR (28.3%), while 38 patients achieved non-pCR. Only three (5.7%) out of 53 patients did not downstage after nCRT. GTV and tumor differentiation were the significant prognostic parameters for predicting pCR. A tumor volume threshold of 21.1 cm³ was determined as a predictor for pCR, with a sensitivity of 84% and specificity of 47%. In addition, GTV was associated with mrN stage, circumferential resection margin (CRM) status, extramural vascular invasion (EMVI) status, and pretreatment serum CEA level.

Conclusion: Tumor volume and tumor differentiation have significant predictive values in preoperative assessment of pCR among LARC patients. These findings aid clinicians to discriminate those patients who may likely benefit from preoperative regimens and to make optimal treatment plans.

Keywords: LARC; MRI; NCRT; PCR; tumor differentiation; tumor volume.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. National Science of Shenzhen (No. JCYJ20220530152001002) funded this study.