From the Guidelines
E. coli bacteria themselves do not directly cause colon cancer in young people, but certain strains, such as those producing colibactin, have been associated with colorectal cancer development. The rising incidence of early-onset colorectal cancer (diagnosed before age 50) is concerning, with environmental factors and microbiome changes likely playing important roles 1. Recent research has shown an increased prevalence of harmful E. coli strains in younger colorectal cancer patients, highlighting the complex process involving genetics, diet, inflammation, and gut microbiome disruption.
To reduce the risk of colon cancer, it is essential to:
- Maintain a high-fiber diet
- Limit processed meats and alcohol
- Exercise regularly
- Maintain a healthy weight
- Avoid smoking
- Follow age-appropriate screening guidelines, which now recommend initiating CRC screening in individuals at average risk for CRC at the age of 45 years, as suggested by the US Multi-Society Task Force on Colorectal Cancer, the US Preventive Services Task Force, and the American Cancer Society 1.
Key factors to consider in the context of colon cancer risk include:
- Family history of CRC and/or adenomas, which increases the risk of CRC compared to individuals without such a history 1
- Genetic predisposing hereditary CRC syndrome, such as hereditary nonpolyposis colorectal cancer (HNPCC), which requires colonoscopy every 1–2 years beginning at age 20–25 years, or 10 years earlier than the youngest age of colon cancer diagnosis in the family—whichever comes first 1
- Age of initiation of endoscopy screening, with earlier initiation associated with a reduced risk of CRC diagnosed before 55 years of age 1
Anyone experiencing persistent digestive symptoms, rectal bleeding, or changes in bowel habits should consult a healthcare provider promptly, regardless of age. Initiating CRC screening at age 45 years instead of 50 years has been shown to be cost-effective, with a cost of $33,900 per quality-adjusted life-year gained for screening colonoscopy and $7700 per quality-adjusted life-year gained for FIT 1.
From the Research
Ecoli Gene Causing Colon Cancer in Young People
- The relationship between Escherichia coli (E. coli) and colorectal cancer (CRC) is complex and has been the subject of several studies 2, 3, 4.
- Specific strains of intestinal E. coli may influence the initiation and development of CRC by exploiting virulence factors and inflammatory pathways 2.
- Mucosa-associated E. coli strains are more prevalent in CRC biopsies in comparison to healthy controls, and these strains can survive and replicate within macrophages and induce a pro-inflammatory response 2.
- The production of colobactin toxin by mucosa-associated E. coli isolated from CRC patients is a notable finding, and colibactin-producing E. coli strains can induce double-strand DNA breaks, stop the cell cycle, and involve in chromosomal rearrangements of mammalian cells 2, 3, 4.
- Some enteropathogenic E. coli (EPEC) strains can survive and replicate in colon cells as chronic intracellular pathogens and may promote susceptibility to CRC by downregulation of DNA Mismatch Repair (MMR) proteins 2.
Mechanisms of Ecoli in CRC Development
- Chronic exposure to inflammatory mediators induced by E. coli can lead to increased cell proliferation and cancer 2.
- Colibactin-producing E. coli strains can impair the antitumor T-cell response, leading to tumoral resistance to immunotherapy 4.
- The colonization of CRC patients by colibactin-producing E. coli is associated with a decrease of tumor-infiltrating T lymphocytes (CD3+ T-cells) 4.