Smokers who inherit a particular genetic trait could triple their chances of getting lung cancer according to a report in the British Journal of Cancer1.
While tobacco is the biggest cause of lung cancer, the risk of developing it varies. This has led scientists to believe that genetics may have a crucial role in deciding who is most susceptible to the disease.
German researchers have found that a quarter of patients with the most common form of lung cancer carry a particular version of a gene involved in keeping the airways clear. By contrast only nine per cent of healthy people carried it.
And it is known that a number of respiratory diseases, are related to the condition of the airways, are associated with an increased risk of lung cancer.
The researchers studied 117 lung cancer patients – nearly all of whom were, or had been, smokers.
They compared these patients with a similar number of healthy individuals and a third group of patients who were smokers and suffering from a variety of illnesses other than lung cancer.
The study showed that one version of the surfactant protein B gene, which is essential for normal lung function, was found in a significantly higher number of lung cancer patients than those in the other groups.
It was identified in 25 per cent of patients with the most common type of the disease – the squamous form of non-small cell lung cancer.
Leading researcher Dr Carola Seifart says: “Smoking is by far the biggest risk factor for lung cancer. But not all smokers go on to develop the disease which means there must be other factors involved.”
Dr Lesley Walker, Director of Information for Cancer Research UK, says: “This is important because scientists are increasingly turning their attention to identifying gene variants. These may not carry a high risk in themselves but in combination with other genes and lifestyle factors can tip the balance as to whether a person is more susceptible to cancer.”
Sir Paul Nurse, interim Chief Executive of Cancer Research UK, said: “We know that smokers run a major risk of getting lung cancer. This report suggests that if people who smoke also possess this particular gene variant – their risk of lung cancer is even higher.
“Any information that discourages smoking contributes towards our efforts to help prevent cancer as well as to find ways to cure it.”
- British Journal of Cancer87 (2)