About one-third of colorectal cancers are inherited, but the genetic cause of most of these cancers is unknown. The genes linked to colorectal cancer account for less than five percent of all cases.

Scientists at Northwestern University’s Feinberg School of Medicine and colleagues have discovered a genetic trait that is present in 10 to 20 percent of patients with colorectal cancer. The findings strongly suggest that the trait is a major contributor to colorectal cancer risk and likely the most common cause of colorectal cancer to date.

If a person inherits this trait—which is dominant and clusters in families—the study found the lifetime risk of developing colorectal cancer is 50 percent, compared to 6 percent for the general population. The study will be published in an advanced on-line report in the journal Science.

“This probably accounts for more colorectal cancers than all other gene mutations discovered thus far,” said Boris Pasche, MD, a lead author of the paper and director of the Cancer Genetics Program at the Feinberg School and the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. Pasche also is a physician at Northwestern Memorial Hospital.

Release date: August 14, 2008
Source: Northwestern University