image: Jamie Ostroff, Ph.D., is chief of behavioral science services at Memorial Sloan-Kettering Cancer Center and an editorial board member of Cancer Epidemiology, Biomarkers & Prevention. view more
Credit: Jamie Ostroff
PHILADELPHIA - As scientists continue to decode the human genome and the information becomes publicly available, private companies that offer online genetic testing are multiplying. Scientists at the National Institutes of Health were concerned that perhaps these tests posed a risk.
They evaluated responses to an online test among smokers who did or did not have a common genetic variant associated with risk for lung cancer. The results, published in a recent issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, raise a new set of questions, but also allay some of the early concerns.
"Up until now we have had a clear model for genetic testing. You see a professional genetics counselor, undergo a battery of tests and that professional helps you interpret your results," said Saskia Sanderson, Ph.D., a postdoctoral fellow in the Department of Genetics and Genomic Sciences at Mount Sinai School of Medicine, who completed the study while working at the Social and Behavioral Research Branch of the National Human Genome Research Institute of the NIH.
"That model is coming under increasing pressure as more and more genetic information is generated, and as a greater number of genetic tests become available on the internet," said Sanderson. "What we found was encouraging in that people who got these online genetic results recalled them correctly, and no one regretted having taken the test; though it is important to remember that this was a small group of select smokers and that others may respond differently."
Patients at higher risk genetically displayed short-term signs of decreased confidence that quitting smoking could reduce their risk of lung cancer, but scientists did note that all of those who took the test chose to receive at least one of several offered known smoking cessation aids.
"Genetic information is complex, and there is a risk that providing unfiltered information will result in heightened worry and misinterpretation of results," said Jamie Ostroff, Ph.D., chief of behavioral science services at Memorial Sloan-Kettering Cancer Center and an editorial board member of Cancer Epidemiology, Biomarkers & Prevention. "This pilot study found no harm in undergoing these tests and underscores the importance of conducting future research as to how to best educate smokers about gene-environment risks."
Scientists are reluctant to endorse the tests based on this one study, because the sample was limited to 44 individuals who were biologically related to people with lung cancer and who smoked. The online test assessed the presence or absence of the GSTM1 gene, the absence of which has been associated with a slightly increased lung cancer risk.
Exactly half of the smokers were missing GSTM1, thus presenting as higher risk and the other half had GSTM1 present. All the GSTM1 missing individuals correctly identified themselves as "higher risk." Of the GSTM1 present group, 55 percent accurately labeled themselves as "lower risk" while 41 percent interpreted their result as "average risk."
These patterns of accurate interpretation remained at six months, suggesting that these individuals retained the information.
Overall, the individuals taking this test found the results to be believable, trustworthy, easy to understand, relevant and important. At follow-up, no one regretted taking the test.
After taking the test, all of the smokers selected some sort of smoking cessation help with no difference between the higher risk or lower risk groups. Scientists agreed that regardless of the genetic test result, quitting smoking is the single most important step a smoker can take in preventing lung cancer and that a larger comparison study would be needed to determine if knowledge of genetic risk encourages an individual to quit smoking.
Additional Resources:
Download a photo editorial of Cancer Epidemiology, Biomarkers & Prevention board member Jamie Ostroff, Ph.D..
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Learn More about genetic testing and lung cancer through an article from CR Magazine, the AACR's publication for patients, survivors and scientists.
http://www.crmagazine.org/archive/Summer2008/Pages/GeneticLinktoLungCancer.aspx
The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes more than 28,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and nearly 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes six major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists. CR provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship and advocacy.