Improving Colorectal Cancer Early Screening in Portugal: Identification of Gut Microbiome Biomarkers in Stool (GUTBIOME-PT)

Colorectal cancer (CRC) is a major public health problem, responsible for 2 million new cases and almost 1 million deaths annually worldwide. In Portugal, as of 2022, CRC is the most common cancer, with 10,575 new cases reported, and the second leading cause of cancer-related mortality, accounting for 4,809 deaths (approximately 14% of all cancer-related deaths). In recent years, there has been an alarming increase in the incidence and mortality of CRC in people \<50 years of age. Early detection is crucial, as survival rates decline sharply from 90% when detected early to just 10% in advanced stages. Non-invasive diagnostic tests, such as the Faecal Immunochemical Test (FIT), have a low sensitivity for early-stage lesions and a high rate of false positives. Therefore, there is an urgent need to improve non-invasive diagnostic methods for the early detection of CRC, as effective screening can prevent it by detecting and removing premalignant lesions. Recent studies suggest that an altered gut microbiota may confer susceptibility to certain types of cancer. Interestingly, the gut microbiota of patients with adenomas or CRC differs from that of healthy individuals. This study aims to identify gut microbiome biomarkers in faecal samples associated with CRC and/or high-risk adenomas to improve early detection.

Sex

All

Minimum age

40 Years

Maximum age

74 Years

Inclusion Criteria:

* Ability to provide written informed consent and comply with study procedures
* Reside in the Lisbon Metropolitan Area,, Portugal
* Age from 40 to 74 years

Exclusion Criteria:

* Age \< 40 years or ≥ 75 years
* Unable to provide informed consent
* Refusal to provide stool samples
* Active oncological disease
* Personal history of CRC
* Personal history of colon adenomas removed in the last 24 months
* First-degree family history of CRC
* Previous diagnosis of inflammatory bowel disease (ulcerative colitis, Crohn's disease or indeterminate colitis), inflammatory bowel syndrome, persistent and infectious gastroenteritis, colitis or gastritis, persistent or chronic diarrhoea of unknown aetiology or recurrent infection by Clostridioides difficile
* Severe cardiovascular or heart diseases with medical diagnosis
* Severe renal failure requiring hemodialysis
* Severe lung disease
* Pregnancy