Program finds genetic link to colorectal cancer
By Debbie Bolles
UT Southwestern has developed a lifesaving genetic screening program for families at high risk of contracting colorectal cancer, a deadly yet highly preventable form of cancer.
The joint effort between UT Southwestern and Parkland Memorial Hospital allows doctors to screen the tumors of colorectal cancer patients younger than 70, and uterine cancer patients younger than 55, to determine if there is a high risk for a genetic cancer predisposition syndrome. If a predisposition syndrome is found, patients are encouraged to bring in as many family members as possible for testing.
“If we can bring in family members of those who have been diagnosed, we have a chance to catch their colon cancer early and even prevent it,” said Dr. Samir Gupta, assistant professor of internal medicine at UT Southwestern and head of the high-risk colorectal cancer clinic started at Parkland this year.
Through this unusual tumor-testing protocol, 11 patients have already been identified with Lynch syndrome, one of the more common inherited conditions accounting for 3 percent to
5 percent of all colon cancers. The colorectal cancer clinic’s aim is to test up to 50 family members among the 11 patients for the same condition. Those with Lynch syndrome have an 80 percent risk of contracting colorectal cancer, up to 60 percent risk for uterine cancer and higher than average risks for other cancer types.
Colorectal cancer is the second-leading cancer killer after lung cancer, according to the American Cancer Society. In light of this, the Cancer Prevention and Research Institute of Texas recently awarded UT Southwestern a $1.5 million grant to further its genetic testing efforts. The grant, whose principal investigator is Dr. David Euhus, professor of surgical oncology, funds family history assessments and genetic counseling among low-income and minority communities in Dallas and five surrounding counties, focusing on those at risk for Lynch and hereditary breast-ovarian cancer syndromes.
“If a parent has Lynch syndrome, there’s a 50 percent chance one of their kids will also get it,” said Linda Robinson, genetic counselor supervisor at UT Southwestern. “We’re sometimes the first people telling them they’re not going to die of cancer. We know what it’s caused by, and we can prevent it.”
Although hereditary colorectal cancer is rare, its family impact can be widespread. Cancer tends to develop rapidly in those with Lynch syndrome and is often undiagnosed until the disease is advanced. But with early screenings and monitoring, the syndrome does not have to be a death sentence.
“I think I’ll live a long time,” said Regina Ontiveroz, a 34-year-old Flower Mound woman who was diagnosed with Lynch syndrome through a blood test at UT Southwestern last year.
Ms. Ontiveroz lost her father, grandmother, two uncles and an aunt to cancer. She always suspected a hereditary factor, which was confirmed two years ago when a cousin with cancer was diagnosed with Lynch syndrome. “It’s like this dark cloud that follows me wherever I go,” she said.
But Ms. Ontiveroz, a nurse, has never been diagnosed with cancer. She credits UT Southwestern’s genetic counseling program, a healthy lifestyle and annual screenings. Recently, she had a hysterectomy and removal of her ovaries as another preventive measure.
“That’s the benefit of genetic testing. Not only was she aware she was at risk of getting cancer, she could act and get ahead of the game,” said Heather Fecteau, a genetic counselor at the medical center.
A blood test will reveal if a person has any of the four mutated genes associated with Lynch syndrome. For the diagnosed family member, the recommendations are for annual or every-other-year colonoscopies starting at age 25 and, for women, removal of ovaries and the uterus after child-bearing age. Other cancer screenings may be suggested, depending on the specific genetic mutation.
If cancer runs in the family, or a family member was diagnosed at an unusually young age for that cancer type, genetic testing for hereditary cancer syndromes may be recommended.