Scientists discover new genetic variants linked to bowel cancer

Cancer Research UK-funded scientists have discovered four new genetic variants linked to bowel cancer by combining data from three major genome studies, reveals a study published in Nature Genetics.

Pooling the data in this way created the largest study of its kind, involving over 45,000 volunteers with and without bowel cancer, allowing previously undetected genetic sites to be pinpointed.

The Cancer Research UK funded research group* is behind all fourteen of the gene variants that have so far been linked to bowel cancer - identified as the result of ten years of investigations.

Professor Richard Houlston, one of three senior authors on the study and head of The Institute of Cancer Research's (ICR) Molecular and Population Genetics Team, said: "Our study identifies four completely new genetic variants that can influence a person's risk of developing bowel cancer, suggesting that even more variants linked to bowel cancer are yet to be discovered.

"Although each of these variants has only a small impact on a person's risk of developing the disease, there is now genuine hope that as we discover more pieces of the jigsaw we can start to identify those who are at highest risk, helping to better target measures to prevent the cancer, or detect it earlier to maximise the chance of treatment being successful."

In the hunt for bowel cancer genes, the researchers led by Professor Richard Houlston from the ICR, Professor Malcolm Dunlop from the MRC Human Genetic Unit and the University of Edinburgh and Professor Ian Tomlinson from the Wellcome Trust Centre for Human Genetics and the University of Oxford, scoured the genomes of 3,334 bowel cancer patients and 4,628 people without the disease from across the UK.

Comparing the genomes of people with and without the disease allowed them to pinpoint a total of seven different one-letter alterations in the genetic code - known as single nucleotide polymorphisms (SNPs) - where genes involved in the development of bowel cancer were most likely to be found.

To confirm their finding they then looked at an additional 18,095 bowel cancer patients and 20,197 people without bowel cancer.

Four of the seven genetic sites were clearly associated with small but significantly raised risk of bowel cancer among the general population, bringing the total number identified to fourteen.

Bowel cancer is the third most common cancer in the UK. Each year more than 38,000 people are diagnosed in the UK, that's more than 100 people a day. Around 16,000 people a year die from bowel cancer in the UK.

Cancer Research UK's director of cancer information, Dr Lesley Walker, said: "The scientists we fund are leading the world in identifying genes that contribute to bowel cancer risk, paving the way for more targeted approaches to treating and diagnosing the disease.

"The vision for the future is that such discoveries will feed into the development of high-tech gene profiling technologies, ensuring those at greatest risk can benefit from closer monitoring. Early detection, improved treatments and effective prevention - like the Flexiscope test we're calling on the government to introduce which detects large pre-cancerous polyps in the bowel - will help cut death rates from this type of cancer."