Elevated cancer risk revealed by personal genomic testing doesn’t change behavior, City of Hope study suggests

December 13, 2016

Letisia Marquez
[email protected]

Results are part of larger NIH-funded Impact of Personal Genomics Study to determine consumers’ reactions to genetic risk information for common diseases

DUARTE, Calif. — Swabbing the inside of your mouth and sending a saliva sample through the mail for analysis is one of the easiest and least invasive ways to test for a multitude of health risks. But since the advent of direct-to-consumer (DTC) genetic testing for medical purposes, the industry has been fraught with controversy with the Food and Drug Administration (FDA) effectively halting the release of risk-specific genetic information in 2013.

Which is why a group of interdisciplinary researchers is aiming to gain a deeper understanding of the pros and cons that DTC genetic testing can offer both consumers and the health care industry through the Impact of Personal Genomics (PGen) Study.

The latest results from the PGen study, an analysis led by City of Hope’s Stacy Gray, M.D., clinical professor of clinical cancer genetics in the Department of Population Sciences, was published in the Dec. 12 issue of the Journal of Clinical Oncology. The PGen study was launched in 2012 by joint principal investigators Robert C. Green, M.D., M.P.H., of Brigham and Women's Hospital and Harvard Medical School and J. Scott Roberts, Ph.D., of the University of Michigan School of Public Health and examines the impact of consumer genomics in relation to a wide range of health-related issues.

Gray’s arm of the research project examined consumer behavior after receiving DTC genetic testing that revealed an elevated cancer risk. She and her team followed 762 new customers who received cancer-related health data from either 23andMe or Pathway Genomics. The study was done prior to the FDA ruling that halted such companies from releasing health-related data via DTC genetic testing.

“The FDA is actively trying to grapple with how to regulate this industry,” Gray said. “There are few data that document the benefits and harms of direct-to-consumer access to genomic technologies, so studies like this are needed.”

One of the big worries about DTC testing, she said, is that people who receive data suggesting an elevated risk for cancer may rush out and overutilize screening tests, overwhelming an already strained health care industry. But the study showed that such fears were not likely to be warranted.

“In this population of people who are already engaged in personal genomic testing online, we did not see evidence of overutilization of cancer screening tests, including mammography, colonoscopy or prostate-specific antigen (PSA) testing,” Gray said. “One of the reasons we might not have seen an increase in utilization among those who tested and were at an increased genetic risk as determined by the company is that the people in our study were already largely compliant with cancer screening recommendations. At the same time, these findings are reassuring because we have evidence that people are not having more testing as a result of direct-to-consumer genetic testing.”

At the same time, Gray and her team also did not find a correlation between elevated cancer-risk results and positive behavior changes, such as diet adjustments, increased exercise or advanced care planning.

“The one exception to that is that men who were told that they were at an elevated genetic risk for prostate cancer significantly changed their use of vitamins and supplements” Gray said. “That’s one area where we want to conduct more research because use of some types of supplements has been associated with the development of prostate cancer. So the question now is whether their change in behavior was one that was positive or whether it could have negative health consequences.”

Gray said it’s important to note that the study involved changes in risk level that were fairly low (not like the high levels of risk seen with BRCA mutations), which may account for the lack of significant change in health behaviors. In addition, researchers aren’t sure how consumers are interpreting health information when they receive it online versus through a physician or other health care provider. Since the study examined a population of people who were already engaged in genetic testing, the results cannot be applied to everyone in the general population, she added.

“What people who are less engaged with health will do with DTC personal genomic information is very difficult to predict,” Gray said. “At the same time, finding that there wasn’t overutilization of medical testing is reassuring. Furthermore, finding that direct access to genetics can be a way for people to engage in genomics — without evidence of harm — is something that is very promising.”

This research was supported by the National Institutes of Health (NIH) National Human Genome

Research Institute (Grant No. R01-HG005092); National Human Genome Research Institute (Grant No. U01HG006492); the American Cancer Society Grant No. 120529-MRSG-11-006-01-CPPB; a Canadian Institutes of Health Research Doctoral Foreign Study Award; and these NIH grants K07CA131103, U01-HG006500, U19-HD077671, U01-HG008685 and U41-HG006834.

About City of Hope

City of Hope is an independent research and treatment center for cancer, diabetes and other life-threatening diseases. Designated as one of only 47 comprehensive cancer centers, the highest recognition bestowed by the National Cancer Institute, City of Hope is also a founding member of the National Comprehensive Cancer Network, with research and treatment protocols that advance care throughout the world. City of Hope is located in Duarte, California, just northeast of Los Angeles, with community clinics throughout Southern California. It is ranked as one of "America's Best Hospitals" in cancer by U.S. News & World Report. Founded in 1913, City of Hope is a pioneer in the fields of bone marrow transplantation, diabetes and numerous breakthrough cancer drugs based on technology developed at the institution. For more information about City of Hope, follow us on Facebook, Twitter, YouTube or Instagram.


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