Genetic Test Results Encourage Smokers to Quit

GenomeWeb News is reporting the results of a very preliminary study in which researchers test smokers for a genetic variant that slightly increases their risk of lung cancer:

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 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…

Half of the smokers tested were missing GSTM1. All of these individuals reported that they understood that this was a higher risk condition…

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." 

Of course, some bioethicists think that such direct-to-consumer genetic testing needs to be strictly regulated. 

Go here for whole GenomeWeb News report. 

Comments

[johnl]

Interesting study and of course it's simply rational for people to make more of an effort to cut back or quit if they learn of additional risks. And it's always reassuring to read about people behaving rationally. But, as the authors state, one shouldn't read too much into 6 people who report quitting.

[Bronwyn]

If the link proves to be a robust one, particularly if the mechanism is elucidated, the GSTM1 test could approach the usefulness of BRCA.

The problem I see - and as always, I'll point out that the problem is one of interpretation - is when people get a negative result and assume they're in the clear.

Test results should be accompanied by proper interpretation stating that overall lung cancer risk is X, the risk of lung cancer in smokers is Y, and the risk of patients missing the GSTM1 gene is Z.

Hell, non-smokers who get lung cancer have to face down people who think they brought it on themselves.

DTC genotyping is well and good, but I worry about the potential for harm in the absence of interpretation.

Disease risk genotyping, though, is a different ball of wax than pharmacogenetic testing. It's easier, I think, for a layman to understand the former - the latter presents a challenge to even the most well-trained physicians and scientists.

[D.A. Ridgely]

Let me know when we've determined the carcinogenic risks of genetic testing.