A recent study discovered that individuals who experience rectal bleeding and then undergo a colonoscopy are significantly more likely to be diagnosed with colorectal cancer. The research underscores the importance of not dismissing such symptoms, even if there is no family history of the disease or if individuals do not meet the criteria for regular screenings.
The connection was particularly strong in patients under 50 years old, with 70% lacking a family history of the illness. Surprisingly, 88% of those who had a colonoscopy did so due to symptoms rather than routine screening.
According to Sandra Kavalukas, a senior author and colorectal surgeon at the University of Louisville School of Medicine in Kentucky, individuals under screening age with rectal bleeding should be seriously considered for a colonoscopy.
In the United States, guidelines suggest routine colonoscopy screenings starting at age 45 for those without a family history of the disease. In contrast, the NHS offers bowel cancer screening tests to individuals aged 50 to 74.
The study, to be presented at the American College of Surgeons Clinical Congress 2025 in Chicago, aims to address the healthcare gap for symptomatic young adults who do not qualify for routine screening but face increasing colorectal cancer risks.
The research included 443 patients under 50 who underwent colonoscopies at the University of Louisville Health System between 2021 and 2023. Of these, 195 were diagnosed with early-onset colorectal cancer, while 248 had normal results.
Surprisingly, only 10% of the cancer cases had genetic markers or a family history of the disease. Those diagnosed with early-onset colorectal cancer were also more likely to be former smokers.
The research team is now commencing a larger study and hopes to create a ‘risk score calculator’ to help healthcare providers and patients identify their risk beyond current criteria like family history.
Colorectal cancer, also known as bowel cancer, ranks as the fourth most common cancer in the UK with a 53.9% survival rate of 10 years or more. However, 54% of cases are preventable.
Contributing factors to the disease include an imbalanced diet high in processed meat, alcohol, and smoking, coupled with low fiber intake and physical inactivity. Approximately 11% of cases in the UK are attributed to being overweight or obese.
Symptoms of colorectal cancer may include rectal bleeding, changes in bowel habits, abdominal pain, and unexplained weight loss.