Can we analyse stool content to improve the prediction of the risk of developing bowel cancer?

Background and study aims
Colorectal cancer (CRC) is the third most common cancer in men and the second in women. However, CRC is a highly preventable disease and effective screening methods are available. To date, scientific research is studying new methods to use information relating to the amount of faecal haemoglobin (f-Hb) in stool tests (Faecal Immunochemical Test [FIT]).
The capacity of these tests to identify polyps or tumours is low on a single round of screening, but it increases over repeated rounds. Available evidence suggests that the sum of the f-Hb in the last two screening rounds could better identify the lesions.
This study has two aims: the first one is to compare the effectiveness of risk-tailored screening protocols based on the individual risk, assessed through the cumulative f-HB level of the last two screening rounds, with standard screening strategies.
The second aim is to determine the contribution of other potential biomarkers (such as microbiome profiles and miRNA signatures), to identify the presence of polyps or tumours, alone or in combination with the f-HB level accounting for the exposure to modifiable lifestyle risk factors.
Who can participate?
All people from 59 to 69 years of age invited to the FIT-based screening program in Turin and Biella will be included in the study unless they expressly deny consent. The subjects who report a recent colonoscopy or a positive FIT test result are not eligible for the study.
What does the study involve?
The group of subjects with cumulative f-Hb level in the last two tests above the positive threshold will be considered as a high-risk group and will undergo to a personalized screening protocol. The low-risk group of subjects with undetectable f-Hb level in the last two tests will undergo a less intensive screening protocol.
Moreover, a small group of participants will provide one blood sample and one additional stool sample in order to identify novel CRC biomarkers. The same people will answer a questionnaire about health conditions and lifestyles, such as nutrition, physical activity, and smoking. The relationship between lifestyle information and CRC biomarkers could allow a future more accurate stratification of the risk groups.