Breast Cancer Gene Mutation can Up Lung Cancer Risk in Some People

One in four smokers, who carry BRCA2 gene mutation, will develop lung cancer in the future, a new study suggests.

BRCA2 mutation is well-known for its role in breast cancer. A new study from The Institute of Cancer Research suggests that a mutation in the gene can up lung cancer risk by 1.8 times in smokers.

Together, specific mutation in BRCA1 and BRCA2 accounts for about 20 to 25 percent of hereditary breast cancers, according to the National Cancer Institute. The mutations also increase ovarian cancer risk in women.

The study was based on data from 11,348 Europeans with lung cancer and 15,861 without the disease. Researchers looked for key differences in the DNA of cancer patients and non-cancer participants.

The team found that a mutation in BRCA2 gene was strongly linked to lung cancer diagnosis, especially squamous cell lung cancer. BRCA2 mutation wasn't the only gene that was increasing lung cancer risk. Researchers found another mutation in gene called CHEK2 also ups chances of squamous cell lung cancer. In its normal state, CHEK2 prevents cells with damaged DNA from dividing.

Squamous cell lung cancers are the most common forms of lung cancers. According to researchers, a subset of lung cancer patients could benefit from drugs designed to target the BRCA 2 mutation.

"Our study showed that mutations to two genes, BRCA2 and CHEK2, have a very large effect on lung cancer risk in the context of smoking. Mutated BRCA2 in particular seems to increase risk by around 1.8 times," said Professor Richard Houlston, Professor of Molecular and Population Genetics at The Institute of Cancer Research.

"Smokers in general have nearly a 15 per cent chance of developing lung cancer, far higher than in non-smokers. Our results show that some smokers with BRCA2 mutations are at an enormous risk of lung cancer - somewhere in the region of 25 per cent over their lifetime," Houlston said in a news release.

The study was mainly funded by the US National Institute of Health, with additional support from Cancer Research UK and is published in the journal Nature Genetics.