Lung Cancer's Genetic Link Better Defined

Understanding why some non-smokers get lung cancer usually associated with a life-time of smoking took a huge step forward according a new study published in the journal Nature on October 23.

It took over 100 scientists at 19 research institutions located around the globe to discover that there appear to be 26 key genes that are involved in the potential genesis of one of the most lethal forms of cancer, lung adenocarcinoma. That more than doubles the number of genes been identified that form a link between aging and environmental exposures that can lead to the development of the lethal disease.

Researchers can now turn their eye to how to implement these new findings, according to Alan E. Guttmacher, M.D., Acting Director of the National Human Genome Research Institute which funded the research.

"By harnessing the power of genomic research, this pioneering work has painted the clearest and most complete portrait yet of lung cancer's molecular complexities. This big picture perspective will help to focus our research vision and speed our efforts to develop new strategies for disarming this common and devastating disease," Guttmacher said in a press release from the National Institute of Health.

Lung and other cancers are caused by damage done to a person's DNA, some from aging and faulty transcription when cells divide, and some caused by environmental factors such as smoking, exposure to carcinogenic chemical agents, and viruses. This damage is cumulative over a person's lifetime.

The multidisciplinary, multi-institutional team, called the Tumor Sequencing Project, looked at tissue samples from 188 cancer patients.

One of their most startling discoveries is that non-smoking patients with the disease only had damage-induced changes in five genes, while in smokers with the same type of cancer, 49 different mutations were found.

As a consequence of their research, the team suggested studies be implemented for two therapies, one involving a family of compounds called MEK inhibitors, and another on the drug rapamycin which is currently used for kidney cancer treatment and on organ transplant recipients. The also found that a family of drugs currently being used to treat other forms of cancer, kinase domain inhibitors such as sorafenib and sunitinib, might warrant testing in patients with certain forms of lung cancer.

The 5-year survival rate for someone developing lung adenocarcinoma is only 15%, mainly because, for now, early detection of this form of cancer is very difficult. Early detection and treatment can greatly improve a lung cancer sufferer's survival time. An estimated 1.3 million people die from lung cancer each year, according to the American Cancer Society.