An observational study in Rectal Neoplasms, Colon Neoplasms and Microbiota, sponsored by Sixth Affiliated Hospital, Sun Yat-sen University. Recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-31.
Sponsored by Sixth Affiliated Hospital, Sun Yat-sen University · Observational
Colorectal cancer (CRC) is one of the most common and deadly cancers worldwide. About 1 in 4 people with CRC already have cancer spread (metastasis) when first diagnosed, and about half develop spread during their illness. Recent research shows that bacteria living in the gut and even within tumors might play an important role in how cancer spreads.
The goal of this study is to better understand how bacteria might influence the spread of colorectal cancer. The main questions the investigators aim to answer are:
Are there differences in bacteria between people whose cancer has spread and those whose cancer has not spread? Could certain bacteria help predict which cancers might spread?
To answer these questions, the investigators will:
Collect different types of samples from participants:
Tumor tissue Normal tissue near the tumor Tissue from where cancer has spread Stool samples before surgery Study the bacteria in these samples using advanced testing methods Compare bacterial patterns between different groups
People can take part in this study if they:
Are between 18 and 75 years old Have colorectal cancer confirmed by doctors Have not taken antibiotics recently Do not have immune system problems
This research may help us:
Understand why some colorectal cancers spread Find new ways to predict which cancers might spread Develop better treatments for colorectal cancer
1,761 studies on the registry are indexed under Rectal Neoplasms; 518 are open to participants now.
This study's planned enrollment of 300 is above the median of 160 across 413 observational studies indexed under Rectal Neoplasms.
Browse Rectal Neoplasms studies →Sixth Affiliated Hospital, Sun Yat-sen University is the lead sponsor of 211 studies on the registry; 110 are open to participants now.
Counted across the registry records on this site, refreshed daily.
This study will enroll patients aged 18-75 years with pathologically confirmed colorectal cancer treated at the Sixth Affiliated Hospital of Sun Yat-sen University. Participants will be divided into two main groups: those with peritoneal metastasis (metastasis group) and those without distant metastasis (non-metastasis group). The study population will include both male and female patients who meet all inclusion criteria and none of the exclusion criteria. All participants must have clearly defined clinical staging and be scheduled for surgical treatment, with an expected survival of at least 3 months. Patients with recent use of antibiotics, probiotics, or immunosuppressants, those with intestinal obstruction or perforation, and those with other severe comorbidities will be excluded.
Exclusion Criteria:
Healthy individuals without colorectal cancer or other cancers Will provide stool samples Matched by age and gender with cancer groups
Procedure: Biospecimen Collection Procedure
Participants with colorectal cancer without distant metastasis (M0 stage) Confirmed by imaging studies and/or pathological examination Will provide primary tumor tissue, adjacent normal tissue, and stool samples
Procedure: Biospecimen Collection Procedure
Participants with colorectal cancer with distant metastasis (M1 stage) Confirmed by imaging studies and/or pathological examination Will provide primary tumor tissue, metastatic tumor tissue, adjacent normal tissue, and stool samples
Procedure: Biospecimen Collection Procedure
Collection of fecal samples from healthy volunteers, non-metastatic (M0) and metastatic (M1) colorectal cancer patients. Additionally, collection of tissue samples during surgery from operable patients (M0 and M1) for subsequent research analysis.
Intestinal Microbiota Diversity Differences Between Colorectal Cancer Patients With and Without Peritoneal Metastasis
Comparison of microbial diversity between metastasis and non-metastasis groups, including alpha diversity (Chao1 index for species richness, Shannon index for species diversity) and beta diversity (Bray-Curtis distance, UniFrac distance). These measurements will evaluate differences in intestinal microbiota composition related to colorectal cancer peritoneal metastasis.
Time frame: Fecal samples collected at patient's first hospital admission; tissue specimens collected during surgery. All specimens analyzed within 6 months after collection.
Plan to share: No
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Sixth Affiliated Hospital, Sun Yat-sen University