Screening for bowel cancer at a younger age based on family history could improve early detection and in some cases help prevent the disease, scientists have said.
An analysis by researchers in the US suggests almost all patients between 40 and 49 years of age included in the study could have been diagnosed earlier if they had been screened based on family history of the disease.
At present, the NHS bowel cancer screening is only offered to people aged 55 or over while those too young for screening but worried about a family history of bowel cancer are advised to speak to their GP for guidance.
In the US, guidelines for individuals with a family history of the disease recommend early screening at age 40, or 10 years before the age the immediate family member was diagnosed with bowel cancer.
The researchers said cases of bowel cancer, also known as colorectal cancer, are rising in the under 50s in many countries.
In the UK, more than 2,500 new cases are diagnosed each year in people below the age of 50, according to Bowel Cancer UK.
Scientists led by Dr Samir Gupta, of the the VA San Diego Healthcare System and the University of California San Diego, looked at medical records and specimens of 2,473 patients with bowel cancer and 772 without.
The team found around one in four individuals with bowel cancer and one in 10 without cancer met the criteria for family history-based early screening.
Among the 614 people with bowel cancer who met these criteria, 604 (98.4%) patients should have been screened at a younger age than when their cancer was diagnosed, the researchers said.
They added early screening would have resulted in earlier diagnosis, or possibly even prevented the disease.
Dr Gupta said: “Our findings suggest that using family history-based criteria to identify individuals for earlier screening is justified and has promise for helping to identify individuals at risk for young-onset colorectal cancer.
“We have an opportunity to improve early detection and prevention of colorectal cancer under age 50 if patients more consistently collect and share their family history of colorectal cancer, and healthcare providers more consistently elicit and act on family history.”
The findings are published online in the journal Cancer.
