NEW YORK (GenomeWeb News) – A significant proportion of parents who get genetic testing for mutations in the breast and ovarian cancer-related genes BRCA1 and BRCA2 are sharing those test results with their children, according to a survey-based study of hundreds of parents appearing online today in the journal Cancer.
Researchers from the Fox Chase Cancer Center, University of Chicago, and Massachusetts General Hospital found that around two-thirds of children under the age of 25 had learned their parents' BRCA1/2 status, according to more than 250 participating parents, including children at relatively young ages. Their findings suggest that this information sharing — and children's reported reaction to it — varied somewhat with the age and gender of children and on whether the parent tested was positive for a disease-related mutation or had a variant of unknown significance.
Although the study focused on BRCA1/2 testing in families with a strong history of breast or related cancers, the team believes the findings may translate into a better understanding of children's reactions to and understanding of genetic testing in general.
"We see this as not a study of BRCA1/2, but of any type of genetic test that predicts a risk of disease in the future," first author Angela Bradbury, a medical oncologist at the Fox Chase Cancer Center, told GenomeWeb Daily News. "I think the findings from here may be very applicable to other disease settings."
"This work needs to be done in other settings as well — and there may be differences," she added. "But I think BRCA1/2 is a nice place to do this research because the testing has become increasingly available and there's more testing being done."
Bradbury and her colleagues did a smaller, interview-based study a few years ago focusing on children of BRCA1/2 mutation carriers who learned of their parents' risk mutations during adolescence.
So far, there have been few larger studies exploring the prevalence of genetic test result sharing by both mutation-positive parents and those who tested negative for risk mutations, she explained, despite the fact that many parents are motivated, in part, by wanting to learn about potential genetic risks for their children and other family members.
"We have had parents throughout the years who felt really conflicted about talking with their children about this information," Bradbury said. "So we thought it made sense to formally study and better understand the communication patterns, particularly among parents who had embarked on communicating with their children."
"Their experiences might be able to provide guidance for others who are struggling with the decision about whether to communicate," she noted.
To look at this in more detail, she and her colleagues did semi-structured telephone interviews with parents from 232 families in which a parent had been tested for BRCA1/2 mutations at the University of Chicago's Cancer Risk Clinic or through the Fox Chase Cancer Center Risk Assessment Program.
Between them, the 253 participating parents had 505 children under the age of 25 when they received their BRCA1/2 test results.
Some 66 percent of these children learned their parent's BRCA1/2 mutation status, according to survey responses.
When parents did not carry risk mutations, children were more likely to learn of the test results, especially if the children were female, researchers reported.
"Although prior studies have not shown a significant difference in disclosure among parents with a positive or negative test result, we found that offspring are more likely to learn of a parent's negative than positive test result," they wrote, "and daughters are more likely to learn of a negative result, independent of child age."
This finding "is not surprising," the authors note, "given the different medical indications and testing opportunities(when reaching adulthood) for offspring of parents with negative and positive test results."
Parents were also more apt to share test results with older children, particularly those over 14 years old, though roughly half of children between 10 and 13 years old were aware of parents' test results as well.
Many of the children seemed to respond well to the test results, with 28 percent of children expressing relief when learning their test results and more than 40 percent having neutral reactions, at least from their parent's point of view.
But a smaller percentage of children — around 13 percent — reportedly had more negative reactions, such as concern or distress.
"The findings are considered exploratory in the study because it is parents reporting," Bradbury cautioned. "Children's reports may be very different. But the findings are certainly interesting and thought provoking and point to places for study in the future."
Age and gender may be factors in whether children are distressed or perplexed by parents' genetic test results, the study suggests. Survey results hinted that daughters were more likely to appear distressed by the test results. Even so, the team noted that parents "more frequently reported that daughters found the information useful compared with sons."
By unraveling such patterns in more detail, researchers say, it may be possible to come up with strategies for advising parents about if, when, and how to share genetic test results with their children.
They also hope to learn more about how such information influences children's future health behavior and to get other clues about how younger individuals might react to having their own genetic testing should situations arise where such testing is beneficial.
"Seeing how children do with just the communication of genetic testing information gives us a peek into what some of the risks and benefits are of actually testing children or directly counseling children," Bradbury explained.