Dr. Samir Gupta, assistant professor of internal medicine at the University of Texas Southwestern in Dallas, who is also head of the high-risk colorectal cancer clinic, said colorectal cancer is the second-leading killer after lung cancer -- and while hereditary colorectal cancer is rare, its family impact can be widespread.
Cancer tends to develop rapidly in those with Lynch syndrome, one of the more common inherited conditions. Lynch syndrome accounts for 3 percent to 5 percent of all colon cancers, and often is undiagnosed until the disease is advanced.
Families that have Lynch syndrome usually have more cases of colon cancer than would typically be expected, and at an earlier ages, than in the general population.
Gupta said doctors screen the tumors of colorectal cancer patients younger than age 70 and uterine cancer patients younger than age 55 to determine whether there is a high risk of a genetic cancer predisposition. If so, patients are encouraged to bring in as many family members as possible for testing, Gupta said.
"If we can bring in family members, we have a chance to catch their colon cancer early and even prevent it," Gupta said in a statement.
Patients with Lynch syndrome have an 80 percent risk of contracting colorectal cancer and as much as a 60 percent risk for uterine cancer, and higher than average risks for other cancer types, Gupta added.