Inclusion Criteria for Case Arm:
1. Aged over 18 years.
2. Participants confirmed with colorectal adenocarcinoma or advanced adenoma through colonoscopy and pathological examination.
3. Provision of informed consent prior to any study specific procedures, sampling, and analyses.
Inclusion Criteria for Control Arm:
1. Individuals of "General risk arm" should meet all the following criteria:
1. No history of colorectal adenomas or sessile serrated polyps.
2. No history of inflammatory bowel disease (8-10 years ).
3. No family history (first-degree relatives) of colorectal cancer.
2. Individuals of "High-risk arm" should meet at least one of the following criteria:
1. Asia-Pacific Colorectal Screening (APC) score ≥ 3.
2. Family history (first-degree relatives) of colorectal cancer.
3. History of positive fecal occult blood test.
4. Any 2 of the following: chronic diarrhea, chronic constipation, mucous bloody stools, history of psychological stimulation, history of chronic appendicitis or appendectomy, history of chronic biliary disease or cholecystectomy.
5. Individuals with inflammatory bowel disease.
3. All participants must be confirmed not to have colorectal malignancy or advanced adenomas through colonoscopy.
4. Provision of informed consent prior to any study specific procedures, sampling, and analyses.
Exclusion Criteria:
1. History of other malignant tumors (excluding non-melanoma skin cancer).
2. Prior or related treatments previously (including colorectal cancer or advanced adenoma surgery, endoscopic treatment, chemotherapy, targeted therapy, immunotherapy, radiation, neoadjuvant therapy, etc.).
3. Patients with hereditary colorectal diseases (including Lynch syndrome, familial CRC type X (FCCX), familial adenomatous polyposis (FAP), MUTHY-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome (JPS), serrated polyposis syndrome (SPS), etc.).
4. Usage of anti-tumor drugs such as methotrexate, cyclophosphamide, mercaptopurine, and bendamustine for other diseases within 30 days before blood collection.
5. Prior blood transfusion (including blood components) within the past 2 weeks.
6. Prior organ transplantation, bone marrow transplantation, or stem cell transplantation.
7. Pregnancy women.
8. Prior or current anti-infection treatment within 14 days before blood collection.
9. Inability to comply with study procedures such as blood collection and related examinations.
10. Deemed unsuitable for participation in the clinical trial by the investigator.
