Correlation Between Gut Microbiota and Radiosensitivity of Rectal Cancer

The Mechanistic Study on the Influence of Gut Microbiota on Radiotherapy Sensitivity in Patients With Locally Advanced Rectal Cancer

The purpose of this process is to clarify the characteristics of gut microbiota changes in patients with locally advanced rectal cancer undergoing preoperative neoadjuvant treatment, and to identify key bacterial species closely related to sensitivity to radiotherapy. This aims to elucidate the mechanism linking gut microbiome dysbiosis with radiotherapy sensitivity, thereby providing new combined treatment strategies to enhance the efficacy of radiotherapy.

The study is expected to enroll 100 patients with locally advanced rectal cancer, including 50 patients in the radiotherapy-sensitive group and 50 in the radiotherapy-resistant group. Each participant will provide stool and blood samples before treatment for subsequent metagenomic and metabolomic sequencing analysis.

Inclusion Criteria:

1. Patients with late-stage rectal cancer (stages IIIB to IV), including those with postoperative recurrence re-staging or those intending to receive neoadjuvant treatment,
2. Pathological type is adenocarcinoma,
3. Have measurable lesions before radiotherapy or chemotherapy,
4. Age between 18 and 75 years,
5. A WHO Performance Status (PS) score of 0 to 2, capable of tolerating radiotherapy or chemotherapy,
6. An expected survival period of 6 months or more;
7. Able to understand the study and sign the informed consent form.

Exclusion Criteria:

1. Patients with severe complications or other malignant diseases.
2. Known severe allergic reactions to components of radiotherapy or chemotherapy.
3. Significant cardiac, hepatic, renal, or other vital organ dysfunction.
4. Pregnant or breastfeeding women.
5. Patients unable to comply with study requirements or affected by psychiatric or psychological diseases.
6. Participation in other clinical trials recently that could affect the assessment of this study's results.