Exploring the Predictive Effect of Intestinal and Oral Microbiota on the Efficacy of Neoadjuvant Radiotherapy and Chemotherapy for Locally Advanced Rectal Cancer Based on Machine Learning

This study is a one-year, observational, prospective cohort study. For enrolled patients with newly diagnosed locally advanced rectal cancer, the treatment plan will be decided by the physician based on the 2022 NCCN Rectal Cancer Clinical Practice Guidelines in combination with the hospital's protocols. The researchers will review the patient's medical history and laboratory reports, along with imaging examinations, to determine the patient's eligibility based on the inclusion and exclusion criteria. Before data collection, patients must sign the most recent IRB/IEC-approved informed consent form (ICF). After being diagnosed with locally advanced MSS rectal cancer, patients will provide stool and saliva samples upon admission before receiving treatment. Metagenomic sequencing will be performed to determine the abundance of gut and oral microbiota. Using these data, a predictive model will be established using machine learning methods to predict the TRG (Tumor Regression Grade) after neoadjuvant chemoradiotherapy in the enrolled patients, with internal validation conducted.

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Key information

Conditions

Rectal Cancer Colorectal Neoplasms Digestive System Diseases Digestive System Neoplasms Gastrointestinal Diseases Gastrointestinal Neoplasms Intestinal Diseases Intestinal Neoplasms Neoplasms Neoplasms by Site Rectal Diseases Rectal Neoplasms

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Nanfang Hosptial

Guangzhou, Guangdong, 510515, China

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Voluntary signing of informed consent form
Age range: 18-75 years old
Diagnosed by histopathological examination and indicated by comprehensive evaluation for neoadjuvant radiotherapy and chemotherapy in locally advanced rectal cancer patients
Immunohistochemistry or genetic testing for MSS
Imaging shows no distant metastatic lesions
ECOG score 0-1
All patients are required to complete neoadjuvant concurrent chemoradiotherapy and intraoperative chemotherapy at our center, and return to the hospital on schedule for preoperative evaluation and tumor resection surgery
After inspection and evaluation, there is normal bone marrow hematopoiesis, liver and kidney function

Exclusion criteria

Previously received anti-tumor treatment
History of other malignant tumors
Imaging confirms the presence of distant metastases
Patients with MSI-H or dMMR rectal cancer detected by immunohistochemistry or genetic testing
Used probiotics, antibiotics, prebiotics, immunosuppressants, and glucocorticoids within the 4 weeks
Pathological tissue specimens without assessable efficacy of neoadjuvant therapy
Change treatment plan due to disease progression or severe treatment side effects
According to the researcher's judgment, it is not suitable to participate in this study

Treatment and study plan

Primary outcomes

Tumor Pathological Response Grading (TRG Grading)

Time frame: an average of 3 months after neoadjuvant radiotherapy and chemotherapy

Tumor Pathological Response Grading (TRG Grading) of Patients after Neoadjuvant Radiotherapy and Chemotherapy

Secondary outcomes

Pathological Complete Response Rate (pCR)

Time frame: an average of 3 months after neoadjuvant radiotherapy and chemotherapy
Clinical Complete Response Rate (cCR)

Time frame: an average of 3 months after neoadjuvant radiotherapy and chemotherapy

Sponsors and collaborators

Lead sponsor

Nanfang Hospital, Southern Medical University

Other

Registry information

Important dates

Study start: 2023
Primary completion: 2024
Study completion: 2024
First posted: Jan 16, 2026
Registry last updated: Jan 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed