The Psychological Side of Gene Testing
hile the hum of DNA sequencer machines and their promise to pinpoint the genetic profile of every major cancer fills labs across the country, what to do with the ensuing information at the interface of physician and patient is a mostly unexplored issue. One genetic test, for instance, can pick up any of five mutated genes that confer a lifetime risk of hereditary non-polyposis colorectal cancer (HNPCC) approaching 80 percent. But given that HNPCC accounts for just 5 percent or less of all colorectal cancer, who should get the genetic test?
Family history is obviously important. Underlying psychological factors are equally important but more subtle, says Ann-Marie Codori, Ph.D., a psychologist in the Department of Psychiatry. Using one of 10 ethics-related grants from the National Human Genome Research Institute, Codori and colleagues are exploring people’s reactions to genetic testing.
“We want to know if genetic testing will scare people away from screening,” Codori says. “It’s well-established that there’s a subgroup of patients who, given unfavorable medical information, have extreme psychological distress. Those people tend not to follow up with the next screening step.”
Codori and colleagues offered free HNPCC gene tests to people with significant family histories of colorectal cancer, then tracked what factors relate to accepting or declining the test. They found four significant correlations, all psychological.
“Those who accepted are what I call health-seekers,” she says. “They think about getting colon cancer, they’ve gone for a colonoscopy in the past, they suspect they may get colon cancer, and they can handle bad news.”
People who felt they may not be able to deal with a positive test generally opted out of the screening, as did those who had never had a colonoscopy. But Codori says it’s this group who could benefit most from genetic testing. “These people may not seek screening because they need more incentive. Colonoscopies are uncomfortable, but if they knew they had a mutation, maybe they’d be more willing to have one.” She added that because of their perceived inability to handle a positive test, this group may need more counseling and support before and after testing.
At the completion of the study, which is tracking participants for two years to see who follows through with colonoscopies, Codori will have a more definitive answer. Until then, she needs to keep enrolling subjects who are at least 18 years of age and have a first-degree relative (parent, sibling, or child) with a history of colorectal cancer.
-— Brian Vastag