Chromosome linked to colorectal cancer identified

Researchers at the Ontario Institute for Cancer Research and Cancer Care Ontario have successfully identified a specific genetic variation on chromosome 8 that is associated with colorectal cancer.

This is the first genetic predictor that has been identified for the most common forms of colorectal cancer to date and may play a significant role in how people are screened for the disease.

The study was published in Nature Genetics reporting the work of the Assessment of Risk for Colorectal Tumours in Canada (ARCTIC) project. The project involved researchers from around the world including the U.S., France, England and Scotland who nalyzed more than 100,000 genetic elements from 10,000 people, including 2,400 Ontarians from the Ontario Familial Colorectal Cancer Registry.

Previous research on this chromosome has linked it to other forms of cancer, including prostate cancer, suggesting that individuals with this newly discovered variation may be at risk for a broad spectrum of cancers. "This discovery will lead to better understanding of colorectal cancer biology and the cause of this disease," said Dr. Tom Hudson, co-principal investigator and president and scientific director of the Ontario Institute for Cancer Research. "This information can be used to identify those at risk of colorectal cancer and direct them to screening at an earlier age." Colorectal cancer is the second deadliest form of cancer in Canada, but one of the most preventable.

Ontario has one of the highest colorectal cancer rates in the world. In 2007, an estimated 7,800 Ontarians will be diagnosed with colorectal cancer and 3,250 will die from the disease. If detected early, colorectal cancer is 90% curable.

According to the 2007 Cancer System Quality Index, in the years 2004 and 2005, only 17% of Ontarians over age 50 were screened for colorectal cancer using a Fecal Occult Blood Test (FOBT). "This breakthrough could lead to new methods of testing for colorectal cancer," said Dr. Brent Zanke, co-principal investigator and scientist at Cancer Care Ontario. "For example, this genetic variation could be detected through a tool as simple as a blood test. Used as part of a screening program, this information could help individualize screening and prevention efforts saving lives and money. "Further studies may lead to the identification of additional common genetic risk predictors for colorectal cancer.

The ARCTIC Genome project was generously funded by Genome Canada through the Ontario Genomics Institute, by Génome Québec, the Ministère du Dévelopment Economique et Régional et de la Recherche du Québec, Cancer Care Ontario and the Ontario Institute for Cancer Research. The authors also wish to acknowledge the contribution of the high throughput genotyping team at McGill University and the Génome Québec Innovation Centre for technical genotyping assistance.

The Ontario Institute for Cancer Research is a centre of excellence, moving Ontario to the forefront of discovery and innovation. It is dedicated to research in revention, early detection, diagnosis, treatment and control of cancer. The Institute is a not-for profit corporation funded by the Government of Ontario through the Ministry of Research and Innovation.

For more information, please visit the website at www.oicr.on.ca. Cancer Care Ontario is the provincial agency that steers and coordinates Ontario's cancer services and prevention efforts so that fewer people get cancer and patients receive the highest quality of care.

http://www.oicr.on.ca