4 Causes of Lung Cancer That Aren't Smoking

One of them could be right in your basement.

Medically reviewed in April 2021

If you don't smoke, you might think you're off the hook when it comes to lung cancer—the leading cancer killer in the US. Unfortunately, that's a deadly myth, as studies show that the rate of nonsmokers with lung cancer is steadily going up.

A different kind of lung cancer
As fewer people are choosing to smoke, other culprits that lead to lung cancer are starting to become more common. In fact, up to 20 percent of people who die from lung cancer are nonsmokers. And researchers have found that lung cancer in nonsmokers is a different disease altogether. So doctors are now stressing just how harmful other environmental factors can be.  

"There's definitely a molecular profile that's far different in someone who's a smoker versus a nonsmoker," says Robert M. Jotte, MD, PhD, at Presbyterian/St. Luke's Medical Center. This means the cancer cells develop differently, which can affect treatment and the likelihood of other health complications.

For example, nonsmokers with lung cancer seem less likely to have chronic obstructive pulmonary disease (COPD) and heart disease than their smoking counterparts. There's also some suggestion that cancers in nonsmokers may have more treatment options, meaning they may live longer. Another big difference is that women seem more likely to get lung cancer if they've never smoked, compared to men.

"Why more women are developing this particular gene mutation is not entirely understood," Dr. Jotte says. "There are a lot of theories, but the true cause is still being studied."

What causes cancer in nonsmokers?
Smoking is still the hands-down leading cause of lung cancer, but these other risk factors can lead to lung cancer in people who don't smoke:

  • Family history
  • Secondhand smoke
  • Previous cancer diagnosis
  • Air pollution or other environmental dangers 

How can you lower your risk of lung cancer?
Lung cancer is so unexpected in nonsmokers that it's usually found in later stages, which also means it's often harder to treat. As with all health issues, an ounce of prevention is worth a pound of cure, so try these tips to cut your chances of getting lung cancer:

  • Radon test your home. Radon is a naturally occurring carcinogen that can lurk in home basements or crawl spaces. You can buy radon test kits at your local hardware store to confirm your home is safe. But Jotte adds that while radon testing is recommended, don't stress out about it. "Someone would have to spend a pretty high proportion of hours in the day in an enclosed environment to really get exposure levels implicated in lung cancer," he adds.
  • Avoid secondhand smoke. If a loved one is a smoker, encourage them to quit. These five steps to quit smoking can boost their chances of kicking the habit by 60 percent. Not only will it benefit their health, but it'll help you dodge lung cancer, too.
  • Avoid carcinogens. You may be exposed to asbestos and other harsh pollutants as part of your job. Make sure your employer is following OSHA guidelines and always wear appropriate gear, like face masks, to limit inhalation.
  • See if screening is right for you. If you're really worried about your lungs, you may want to look into getting screened for lung cancer. But most insurance companies cover these tests only for people with a history of smoking. Ask your doctor if it makes sense for you.
  • Keep your doctor in the loop. If anyone in your family has had lung cancer, speak up, so your doctor can be extra vigilant in spotting early signs of lung cancer in you. "Even if those family members with lung cancer were smokers, I think that needs to be on your radar," Jotte says.

And be sure to discuss any odd—and not-so-odd—symptoms. "A persistent cough that doesn't go away is not something that should be ignored," Jotte says. "A lot of the symptoms that can indicate an underlying problem like lung cancer are actually very common symptoms that all of us get at some point in our lifetimes," he says. "Having a cough, having a little pain in the chest and feeling a little bit short of breath are common problems, but those are also the symptoms of lung cancer."

While any form of cancer is scary, you don't need to panic. Jotte says it's important to remember that even though the rate of nonsmokers getting lung cancer is going up, most healthy nonsmokers don't get lung cancer.

See More from Dr. Jotte:
Do genetics influence lung cancer?
How can I reduce my risk of lung cancer if I'm a nonsmoker?
How are certain types of lung cancer caused in nonsmokers?

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