New insight into lung cancer genetics

Lung cancer is currently the leading cause of cancer death in the UK. Although smoking is responsible for the vast majority of lung cancer cases, there is existing evidence for a genetic component as well. A study published last week in the journal Cancer Research sheds new light on genetic vulnerability to lung cancer.

Professor Richard Houlston and colleagues at the Institute of Cancer Research took DNA samples from over 8000 individuals (approximately 4000 lung cancer patients and 4000 controls) and found that smokers with specific genetic changes on chromosomes 5, 6, or 15 were more likely to get particular types of lung cancer.

The two crucial sites on chromosome 15 are the same as have been reported previously in the literature. These variants are located in a region of genes that are known to influence smoking behaviour and consumption of tobacco as well as influence cell growth and death. The researchers found that smokers who carried two copies of each variant had an 80 per cent increased risk of developing lung cancer. Those with only one copy of each variant had a 28 per cent increased risk. Control participants who did not smoke but had the genetic changes had no increased risk of lung cancer

The researchers also found that those with certain genetic changes on chromosome 5 were more likely to get a type of cancer called adenocarcinoma which is the most common type of lung cancer in non-smokers. The region highlighted on chromosome 6 was linked to the development of a different type of lung cancer called squamous cell carcinoma.

Professor Houlston said: 'The next step is to dig deeper to pinpoint which gene, or genes in these regions, cause the increased risk of developing lung cancer and how they actually trigger this increase.'