Genetic Variation increases Lung cancer risk

Scientists all over the world have been working to find the role played by genetics in lung cancer. Three teams of researchers have finally tasted success as they have identified three genetic variants that if inherited, increase a person's risk of developing lung cancer from 30 to 80 percent compared to those who do not have the genes.

Carcinoma of the lung is the most common cause of cancer death worldwide. Although smoking has been long established as the main cause of the cancer, scientists were not able to explain that why some smokers don’t get cancers and also that, why even some non-smokers are infected by this fatal disease.

The teams in the United States, France and Iceland have identified a widely distributed genetic variation that appears to increase the odds of developing lung cancer.

Investigators say that smokers who inherit a full complement of the genetic variants have a twenty-three percent increased risk of developing lung cancer.

Mark Lathrop, co-author of one of the three studies, says it appears many more genes play a role in lung cancer but have yet to be identified. "Undoubtedly with larger studies of the same sort, we'll be able to identify a number of further genetic factors that are involved in the predisposition," he said.

The researchers found that genetic variations located near a cluster of genes on chromosome 15 are involved in the body's response to nicotine.

People who inherit the variation from one parent have a 30% greater chance of developing lung cancer, researchers said. Those who inherit the variation from both parents face an increased risk of 70% to 80%.

Investigators say identifying genetic variants gives scientists a target that can lead to new drugs to treat and possibly prevent lung cancer but the basic option of quitting smoking is still the best.

Two of the studies have been published in the journal Nature and one in the journal, Nature Genetics.

For now, researchers say it's unlikely their work will lead to some kind of a genetic test to determine who is and is not at high risk for lung cancer.

"There's not a public health message here that you know you can find what version of the gene you have and decide whether to keep on smoking or not. Because then also you have to bear in mind that there are so many other diseases that are caused by smoking," said Paul Brennan of the International for Research on Cancer in Lyon, France, who is a senior author of one of the studies.

Iceland study author Kári Stefánsson and Chief executive of Iceland-based deCODE genetics said that inheriting genetic variants is equivalent to smoking more cigarettes, which increases the chances of infection.

Christopher Amos of the University of Texas, M.D. Anderson Cancer Center in Houston, was the lead author of the third study.