Genetic link to lung cancer found

The results of three scientific studies have finally come up with a plausible reason why some smokers develop lung cancer while others are spared. The research, some of which was performed by Iceland’s deCode Genetics, points to genetic factors predisposing some smokers to cancer and keeping others healthy, according to a recent report in Scientific America.

In two studies, a specific chromosome (15 in the sequence of 23) has been identified as being responsible for an increased risk of developing lung cancer. The third study links the same mutation in that gene to a tendency for smokers to become addicted to nicotine, and therefore become more prone to lung cancer.

Lung cancer is a growing problem in America with some 200,000 people diagnosed with the disease every year and 150,000 deaths attributed to it annually.

Research suggests that people with a specific genetic mutation on chromosome 15 have up to a 30 per cent greater chance of developing lung cancer than those without it.

For Nora Volkow, director of the National Institute on Drug Abuse (NIDA), the studies also provided insight into genetic links to addiction. The studies, she said, provide “new targets for starting to think about how to treat drug addiction, and also of course, for the prevention or treatment of lung cancer”.

Icelandic research team deCode studied 50,000 smokers in Iceland. In addition to asking them questions about their smoking habits, information was gathered from genomic scans. As a result, the research team was able to identify one variation of a gene which was more present in heavy smokers than in the general population.

“Non-smokers have a higher frequency of this variant than smokers that smoke between one to 10 cigarettes per day,” said neurologist Kári Stefánsson, deCode’s CEO. “Because if you smoke and you have this variant, you tend to smoke more than 10 cigarettes per day.”

The study was then linked to lung cancer and found that those smokers who had two copies of the same genetic variation had a 70 per cent greater chance of developing lung cancer than those without it, while those with just one copy were 30 per cent more likely to develop lung cancer.