Genes may explain why some smokers develop lung cancer and some don’t.
Three independent genetic studies point to a genetic variation that is linked to developing lung cancer.
Smoking is largely responsible for about five million premature lung cancer deaths a year worldwide. It’s been long understood that having a family member with lung cancer increases your odds of developing it, suggesting some genetic component.
Scanning the human genome is yielding new discoveries, among them, there is a cluster of genes on chromosome 15 that predict how the body reacts to nicotine found in tobacco.
In people with the variation from one parent, they have a 30 percent chance of developing lung cancer. But the studies say if the variation is from both parents, your risk increases to 70 to 80 percent.
These results suggest that among smokers, genetic implication may mean that some are as much as 80 percent more at risk than others without the genes.
Even if you never smoked, two parents contributing the gene variant might increase your risk of developing the disease.
As genome detection become more sophisticated researchers are able to detect the variations among more than 35,000 smokers and former smokers. They were primarily from Europe, Canada and the U.S. Half of the Europeans have one copy of the variation. In African or Asian people the gene variation are more common.
The studies don’t agree on whether genetics increase the risk of lung cancer or just tend to increase the craving for nicotine therefore leading to more cancers.
Among smokers, those with the two variants to the genes had an average of two cigarettes a day more than those with one variant.
The genetic variation may help explain why some occasional smokers never become addicted.
While two studies linked the variant directly to lung cancer, the other study from the International Agency for Research on Cancer in Lyon, France said there that the gene variant is not connected to smoking addiction.
Although the studies disagree on whether those who have the double genetic risk factor have an increased risk of developing lung cancer, if you never smoke, you have less than one percent chance of ever having lung cancer. #