You Don't Have to Smoke to Get Lung Cancer

People who smoke have the highest risk, and smokeless tobacco is also a threat. About 90% of lung cancer cases could be prevented by eliminating tobacco use, according to the World Health Organization.

"There are many other risk factors, and risk factors we don't know," said Dr. Aaron Mansfield, an oncologist who specializes in treating lung cancer at the Mayo Clinic in Rochester, Minn. "All you need to be at risk of developing lung cancer is a lung."

Exposure to secondhand smoke can increase the odds of developing lung cancer. Other risk factors include a family history of lung cancer and exposure to radon gas, asbestos and other cancer-causing substances.

Some lung cancer patients don't have any obvious risk factors.

If you do smoke, however, you can reduce your lung cancer risk by quitting.

Dr. J. Taylor Hays is associate director of the Mayo Clinic Nicotine Dependence Center. He said, "Even if you're in your 60s or 70s, we know that by quitting smoking you add years of life, and reduce the chronic health impacts and symptoms that occur from smoking."

Hays added that even people who have had chronic bronchitis and other diseases quickly benefit from smoking cessation.

"They see within months to years significant reduction in symptoms, significant improvement in shortness of breath, and the ability to function without symptoms," he explained in a Mayo news release.

Symptoms of lung cancer include shortness of breath and persistent cough, chest pain, coughing up blood, weight loss, bone pain and headache.

These symptoms often appear only when the cancer has spread into other areas of the body.

"One of the problems with lung cancer is that by the time a patient is diagnosed with lung cancer ― 80% of the time ― the lung cancer has spread," said Dr. Karen Swanson, a pulmonologist and critical care specialist at the Mayo Clinic in Phoenix. "Unfortunately, when tumors grow within our lungs, it's not something our bodies can sense or feel. So we miss it at its earliest stages, unless we screen."

Screening with an annual low-dose CT scan is recommended for those who are at high risk.

"Patients should talk to their primary care provider about lung cancer screening, especially if they have any history of smoking," Swanson said.