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.