Is it possible to be genetically predisposed to lung cancer? The answer
seems to be “yes”. Why do some smokers develop lung cancer, while others don’t? A team led by the WHO’s International Cancer Research Centre (the CIRC) in Lyons has provided some clues. A genetic predisposition may increase the risk of being affected by the disease.
This hypothesis, which has been around for many years, has now been confirmed.
Researchers at the CIRC monitored over 10,000 people, 90% of them smokers, in 18 different countries. Almost half were suffering from lung cancer; the others made up a control group. The aim was to identify the genetic variations likely to be implicated in the appearance of this type of cancer. It was painstaking work.
After comparing several hundreds of thousands of DNA fragments, an important genetic region was identified. This area contains a number of genetic variants that interact with nicotine and other toxins in tobacco.
Smokers who carry a single example of these variants – which is true of one European in two – have a 30% increased risk of developing lung cancer.
This increased risk rises to 80% in individuals who carry two copies of the variants. And this is the case with one in ten Europeans!
More worrying still, the researchers point out that the DNA variants
identified increase the risk of lung cancer in smokers and former smokers
and that they can also increase the risk in non-smokers.
However, their findings should in no way be interpreted as scientific evidence that cancer is written into our genes. It is the risk that increases, and only the risk.
So the best thing is not to start smoking at all…