The objective of this low-risk interventional study is to evaluate whether the PreveCol® test has sufficient efficiency to be considered as a second-line method for the detection of both colorectal cancer and advanced adenomas when used prospectively in the screening population with a previous positive FOBT result, which could include any of the following: both sexes, age 50-69 years, asympthomatic volunteers. The main aims to be answered are:

• Values of efficacy, efficiency, impact and safety of PreveCol.
• Values of preferences of participants for screening methods.
• Values of PREMs into screening programme.

Participants will provide a blood sample prior to a screening colonoscopy, and complete two questionnaires. They will give their sample, information and clinical data to the investigator or health care personnel.

Inclusion Criteria:

• Participants ages from 50 to 69 years (both included) at the time of informed consent signed.
• Participants should sign an informed consent. They must understand the nature, significance, implications, and risks of the clinical study before signing the informed consent form.
• Participants with a positive result of FIT/FOBT analysis referred to the gastroenterology department who are eligible to undertake colonoscopy as a regular procedure of the colorectal cancer screening programme.
• Participants asymptomatic, average risk for CRC. Average risk is defined as those individuals who are age 50 or over with no history of adenoma, colorectal cancer, or inflammatory bowel disease, and with no family history of CRC (first degree relatives).

Exclusion Criteria:

• Participants who have developed any another type of cancer in the 5 years prior to their participation in the study.
• Participants who have previously received chemotherapy or radiotherapy (5 years).
• Participants previously or currently diagnosed with Familiar Adenomatous Polyposis or Lynch Syndrome or Inflammatory Bowel Disease.
• Inadequate intestinal preparation for colonoscopy with BBPS score ≤1 in any colon section, excluding diagnostic of CRC.
• Participants who have undergone polypectomy in the previous 5 years.
• Hemolysis of blood sample or absence of blood sample.
• Participants who are arrested at judicial or official request
• Participants who are in a dependent personal or non-medical relationship with the Sponsor or the investigator.

Laboratory Technicians