Lung cancer

• Fact: Lung cancer is the leading cause of cancer deaths in the United States. It claims more lives each year than colon, prostate, lymphatic and breast cancers combined.
• Proportion of risk that’s in your genes: 14 percent.
• What you can do: Particularly if you're a current or former smoker, knowing from a genetic test whether you have an increased risk of lung cancer can encourage you to make lifestyle changes to improve your health and reduce your risk of developing the disease. Quitting smoking is the most important change you can make. Getting regular exercise and eating fruits and vegetables may also help prevent lung cancer.
• Did you know? While smoking cigarettes increases your risk of lung cancer, so may drinking too much alcohol. Women should limit themselves to no more than one drink a day, while men should stop at two drinks.

In 90 percent of cases, lung cancer is caused by smoking or exposure to secondhand smoke. When smokers inhale smoke – which is full of cancer-causing substances – changes in their lung tissue begin almost immediately. With every puff, normal cells that line the lungs are increasingly damaged. Over time, the damage causes cells to act abnormally, and lung cancer may develop and spread.

Lung cancer is the second most common cancer, affecting one in 13 men and one in 16 women. Deservedly, smoking gets most of the blame, but underlying genetic risks can play a part, too.

Some smokers seem to be more likely than others to develop the disease, probably because their genes make them more susceptible. The available data indicate that the results of the Navigenics test apply primarily to current and former smokers. The genetic variant for which we test was not found to predispose to any subtype of lung cancer in particular. Studies have linked it with the most common types of lung cancer: small cell and non-small cell, including both the squamous cell and adenocarcinoma subtypes. Researchers are still trying to unravel the mystery of how smoking and genetic factors interact to cause lung cancer, but recent research does show a clear connection between them.

Knowing from a gene test that you are at increased genetic risk can help you and your doctor be alert to the symptoms of lung cancer. Your genetic test results could also spur you to come up with a plan for lowering the risk that is due to your behavior and the environment.

Protecting yourself from exposure to asbestos, radon gas and secondhand smoke reduces your risk. Regular exercise and a healthy diet full of fruits and vegetables can also help. If you’re a smoker, quitting now will also reduce your risk of lung cancer, even if you’ve smoked for years.