NEW YORK (GenomeWeb News) – Online genetic tests for lung cancer risk variants are well accepted — and could potentially improve the uptake of smoking cessation aids among smokers, according to a pilot study appearing online last night in the journal Cancer Epidemiology, Biomarkers & Prevention.
Researchers from the National Human Genome Research Institute and elsewhere used online and telephone surveys to gauge smokers' perceptions and understanding of online genetic test results indicating whether individuals carried a copy of the glutathione S-transferase gene GSTM1. Previous research suggests those missing the enzyme have a slightly elevated lung cancer risk.
The team targeted smokers who had relatives recently diagnosed with lung cancer. They found that the test was well accepted, with most individuals accurately interpreting their results. All of the smokers participating reportedly took steps to quit smoking, though the researchers noted that their study was probably somewhat biased toward smokers who were already motivated to quit.
"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," lead author Saskia Sanderson, a genetics and genomics researcher at Mount Sinai School of Medicine, said in a statement. Sanderson did the research while working at the NHGRI's Social and Behavioral Research Branch.
Hundreds of thousands of Americans are diagnosed with lung cancer annually. And more than 85 percent of these are smokers. While as many as 70 percent of current smokers express a desire to give it up, the authors noted, relatively few do. Some have speculated that smoking cessation programs might be more widely used by smokers who have access to genetic information regarding their lung cancer risk.
"Genetic risk assessments of genetic test results might have particular beneficial potential when individuals are identified to be at increased risk," the authors wrote.
In particular, the researchers focused on then effect of online genetic tests for variants in GSTM1. Previous research suggests half of individuals in the general population are missing the gene, slightly increasing their lung cancer risk.
The researchers evaluated 44 smokers between the ages of 23 and 55 years old. Participants received a mouth swab kit by mail and were notified when the results were available online.
The team then gauged participants' perceptions of and reactions to the test using online surveys taken before testing and immediately after receiving the results. They also did a telephone survey six months later and tracked smokers' use of a web site describing the GSTM1 test. Participants had access to telephone counseling and smoking cessation services, if requested.
Half of the smokers tested were missing GSTM1. All of these individuals reported that they understood that this was a higher risk condition. Fewer participants in the lower risk group (those who had the gene) accurately classified themselves as "lower" risk (about 40 percent thought they had an average risk of lung cancer).
Most individuals in both groups rated the test high in terms of trustworthiness, relevance, understandability, and related measures.
Those with the higher risk genetic variant (GSTM1-missing) tended to have decreased confidence that quitting smoking would curb their lung cancer risk, the researchers found. Even so, the uptake of smoking cessation services was very high in both groups. All participants sought some form of help quitting and 91 percent of individuals in both groups requested nicotine replacement therapy.
After six months, five individuals in the higher risk group and one in the lower risk group reported that they had quit smoking. Still, the study authors were cautious about linking smoking cessation to the test itself, noting that "the study was not sufficiently powered for, nor was it a study aim to, assess smoking cessation as an outcome." They also noted that their study attracted smokers who were probably already motivated to quit given their relatives' lung cancer diagnoses.
Overall, the team expressed enthusiasm about the potential of providing individuals with online genetic risk information, though they called for additional research regarding the impact of such tests.
"These preliminary findings tentatively suggest that delivering genetic test results for smoking-related disease risk online might be acceptable to some individuals … although further research on the acceptability of online delivery of genetic test results is clearly needed," the authors wrote.
[Citation: Sanderson et al., Cancer Epidemiol Biomarkers Prev]