An international consortium of researchers, including investigators from the Institute for Cancer Research in London, the International Agency for Research on Cancer in Lyon, the National Cancer Institute in Bethesda, Harvard College and Dartmouth College conducted a comprehensive review of genetic studies of lung cancer to find a genetic vulnerability for smokers in developing lung cancer.

The study, published on June 1 in the journal Nature Genetics incorporated results from the 1000 Genomes Project and scanned over 11 000 genomes from individuals of European descent to search for common genetic variations associated with non small-cell carcinoma, a common type of lung cancer. The study definitively implicated the BRCA2, CHEK2 and TP63 genes in containing mutations responsible for making one in four smokers more genetically vulnerable to developing lung cancer.

Without BRCA2 mutations, smokers generally hold a 15 percent risk of developing lung cancer. Variations in the BRCA2 gene were found to contribute to a doubling of the risk of developing lung cancer in smokers. BRCA2 mutations have already been implicated in causing increased risks for other types of cancers, including breast, ovarian and prostate cancers.

Of the total 50 mutations found, the mutation in BRCA2 was found in approximately two percent of the European population studied. “It’s the strongest genetic association in lung cancer reported so far,” said researchers.

The study has invoked a controversial discussion about screening smokers for risk of cancer. Experts claim that at least high-risk smokers, especially those with a strong family history of cancer, should be subject to screening for their benefit. Companies such as Myriad Genetics, are increasingly making it possible for such tests to be widely available.

The study has also prompted the further exploration of cancer drugs known as PARP inhibitors, which have shown the possibility to aid individuals with this BRCA2 mutation who have lung and other types of cancers.