A new report in the BMJ has found increasing incidence of colorectal cancer (CRC) in young adults in Europe over the last 25 years.

The researchers retrieved data on 143.7 million people aged 20 to 49 years from 20 European countries and found that 187 918 (0.13%) were diagnosed with CRC, marking an increase of 7.9% per year among subjects from 2004 to 2016.

Although in most European countries the CRC incidence had risen, some heterogeneity was found between countries.

Researchers are still unclear as to why this is happening, but say obesity and poor diet could be factors and urged doctors not to ignore symptoms in young people.

Among people in their 30s, rates of bowel cancer also rose, albeit less steeply, and among those between 40 to 50 rates fluctuated.

The findings were backed up by a study in the Lancet Gastroenterology & Hepatology, which also found a 1.8% increase in colon cancer cases and 1.4% rise in rectal cancer cases in people under 50 in the UK between 1995 and 2014.

Dr Marzieh Araghi, lead study author from International Agency for Research on Cancer in Lyon told the BBC that "While population-based screening in people under 50 years old is not considered to be cost-effective due to relatively low incidence numbers, family history could help to identify younger people at high risk of genetic susceptibility to colorectal cancer, for further assessment."

Colorectal cancer, also known as bowel cancer, colon cancer, or rectal cancer, is any cancer that affects the colon and the rectum.