The Numbers: Lung cancer accounts for 13% of all new cancers. It’s also the deadliest, causing an estimated 87,750 deaths in men this year in the U.S.

Risk Factors: “Genetics don’t play a major role in developing lung cancer,” says the USPSTF’s Mike LeFevre. Lung cancer is primarily caused by exposure to substances that damage lung cells, such as excessive air pollution; drinking water with high levels of arsenic; radiation; asbestos and other chemicals; and, above all, tobacco smoke.

“If you smoke, you are at high risk,” LeFevre says. There is no “safe” level of smoke, and the effects are cumulative— the more cigarettes you smoke a day and the longer you’ve been a smoker, the greater your risk of developing lung cancer becomes.

Symptoms May Include: A persistent cough, breathing problems or chest pain, a hoarse voice, coughing up blood, fatigue, unexplained weight loss, and loss of appetite.

How It Progresses: Lung cancer usually spreads to the other lung and to the lymph nodes in the chest. It can also spread to the liver, brain, and bones.

Screening Tests: There isn’t a reliable method of screening for lung cancer. A doctor can request a chest X-ray, but studies have shown that these basic tests do little to reduce lung cancer deaths. “Lung cancer is aggressive and spreads early, often before it’s detectable on a chest X-ray, LeFevre says.

The good news is that things may be changing soon. Researchers are looking at the possibility of testing high-risk patients with a CT scan.“High doses of radiation can be harmful, so we want to make sure the risk is worth the reward before we recommend regular CT scans,” LeFevre says. “We’re not there yet.”

Researchers at the University of Missouri are also looking at a new technology that tests blood plasma as a means of detecting lung cancer. It’s still in the theoretical stage, but it may someday soon allow doctors to detect a change in a specific small ribonucleic acid (microRNA) molecule that is often elevated in lung cancer patients. Until this technology is proven, you’ll have to stick with the chest X-ray.

Should You Get Screened? Only if you show any of the symptoms.

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