Gene test for lung cancer
9 June 2009
Stuff News / The Dominion Post
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A QUICK SWIPE: Robert Young, left, and Alan Conlon show how easy it is to take a DNA swab. Mr Conlon, 67, a former smoker, says he owes his life to a genetic swab, which indicated he was at risk of lung cancer. A suspicious nodule on his lungs has not changed, but he plans to keep up regular testing.
Smokers can now take a test to predict their risk of getting lung cancer, using world-first technology developed by Kiwi researchers.
The gene-based mouth swab, which will cost $275, was developed from research carried out by Associate Professor Robert Young and Auckland University colleagues.
But smokers who find themselves at the lower end of the risk scale have been warned they should not see it as an excuse "to happily go on smoking". Dr Young said yesterday the test, which goes by the trade name Respiragene, combined clinical risk factors, such as age, chronic obstructive pulmonary disease and family history of lung cancer, with DNA obtained through mouth swabs.
Lung cancer kills about 1400 New Zealanders each year. All smokers faced an increased risk of developing lung cancer but the risk was much greater for some than others, Dr Young said. Research suggested many smokers had an "optimistic bias", believing bad outcomes happened to other people rather than themselves. "The majority of smokers do not think they are at risk of lung cancer."
The test, which can also be used by former smokers, would help doctors to overcome that belief, he said. Identifying high-risk patients early could lead to earlier cancer detection. The test groups smokers and past smokers into moderate, high and very high risk groups. "There is no such thing as low risk," Dr Young said. "Everybody should quit and there are some people at the very high-risk end."
It was not recommended for non-smokers. "For someone who does not smoke, their risk of getting lung cancer is very, very low." But the researchers were investigating whether it would be useful for non-smokers exposed to passive smoke.
Smokers wanting to take the test could call an 0800 number to discuss how to obtain it. They were asked to get their GPs to sign a request form and could be sent the swab test by mail. Dr Young and his colleagues will present the test to GPs at a conference in Rotorua this week.
The test was developed by Synergenz Bioscience, a company spin-off from Auckland University. Results will be processed in Auckland by another university spin-off, DNA Diagnostics. Dr Young said the $275 cost per test would cover processing and continued research. Synergenz's test was the first in the world to combine genetic testing with clinical variables to establish relative lung cancer risk. Respiratory physician Peter Martin, medical adviser to the Quit Group, said the technology was "an extremely interesting scientific breakthrough" with significant applications.
But he warned its purpose was not to identify smokers who could "happily go on smoking". Even those found to have a moderate risk were at least 20 times as likely as non-smokers to develop lung cancer, he said.
The test would be most useful for former smokers, because the heightened risk of developing lung cancer remained for many years after quitting. If they fell into the high-risk category, they could choose to have regular scans or other tests. "We know if lung cancer is diagnosed earlier, it has a better chance of being cured."
'THEY SAVED MY LIFE'
After more than 30 years of smoking, Alan Conlon had his "fingers crossed" that he wouldn't get lung cancer. But the gene-based "Respiragene" test developed by Auckland University researchers has identified him as very high risk.
Mr Conlon took the test last year as part of the research. He had previously been involved in studies into chronic obstructive pulmonary disease also known as smoker's lung, or emphysema. People who have the disease are about six times more likely to get lung cancer than smokers without the disease.
His gene test was followed up with a CT scan that revealed a suspicious nodule on his lungs. Fortunately, a follow-up scan three months later found it had not changed but Mr Conlon intends to keep up regular testing. "They effectively saved my life. It's my long-term goal to try and live to 100."
The Auckland man, 67, started smoking when he was a teenager and gave up only a few years ago, when he was in his early sixties. He smoked two packets of pipe tobacco about every 10 days. "I had my fingers crossed. There's no cancer in my family so I hoped it would be OK. But it was flying by the seat of my pants."
He hoped smokers would choose to take the test. "I think many smokers would be concerned about lung cancer if they were prepared to be honest and admit it."