March 20, 2023 -- One in 17 women will be diagnosed with lung cancer in their lifetime. Cigarettes are a known risk factor for lung cancer, and many women may abstain from making smoking a habit for this reason. Yet a recent Spanish study reported that female never-smokers are two-thirds more likely to develop the disease than men who have never smoked.
Lung cancer kills more women than uterine, breast, and ovarian cancers combined, according to Andrea Wolf, MD, associate professor of thoracic surgery at Icahn School of Medicine at Mount Sinai in New York City and director of the New York Mesothelioma Program at the Mount Sinai Health System.
“At least 20% of newly diagnosed women are nonsmokers, and from my research, I’d say that number is even as high as 25%," she says.
Which factors might predict lung cancer in nonsmoking women? A new study from Chinese researchers found that possible reasons for increased diagnosis in women include genetics (having a parent or sibling who had lung cancer), hormonal changes like menopause or benign breast disease, and a history of chronic respiratory disease.
While it's important to not panic about lung cancer risk factors that you can’t control, it's key to understand ways to reduce certain exposures that could cause lung cancer and know the signs of the disease to look out for.
What Are the Causes of Lung Cancer in Nonsmoking Women?
“The mechanisms as to why women who have never smoked get lung cancer are not completely understood,” says Charu Aggarwal, MD, MPH, a lung cancer specialist at Penn Medicine’s Abramson Cancer Center in Philadelphia and associate director of the Penn Center for Precision Medicine. “There do appear to be hormonal risk factors, but there has not been enough research to completely understand why that is.”
Researchers from Brazil recently outlined a range of potential sources of the disease in never-smokers; some of these are well-established, but others are more surprising. These causes include:
- Outdoor pollution
- Radon, an odorless, colorless gas that can build up in indoor spaces
- Exposure to certain chemicals in your workplace, such as silica, arsenic, nickel, cadmium, and chromium
- Drinking alcohol (previous research has linked a higher risk of the disease to frequently consuming beer. It’s thought that beer drinkers may have a less healthy lifestyle in general, and that may explain the connection.)
- Smoke from a wood-burning stove
Certain elements of your family history can be more significant.
“More than one first-degree relative raises your risk further,” says Wolf. “If you grew up in a home with parents who were smokers, that can also add to your risk. Make sure that now you minimize your exposure to secondhand smoke.”
What Are the Symptoms of Lung Cancer in Nonsmoking Women?
According to Mayo Clinic data, lung cancer most often will not cause any symptoms when it’s in an early stage. As the cancer progresses, signs to look for include:
- A new and lingering cough
- Coughing up any amount of blood
- Feeling short of breath
- Pain in the chest
- A hoarse voice
- Unintentional weight loss
- Bone pain
How Is Lung Cancer in Women Diagnosed?
Nonsmoking women are not advised to be screened for lung cancer. And any kind of genetic screening available right now is of limited use diagnostically.
“There does not seem to be a single gene mutation that is very strongly associated with lung cancer risk similar to BRCA1 for breast cancer, the genetic predispositions for other cancers,” says Robert Smith, PhD, senior vice president of cancer screening for the American Cancer Society. “Gene mutations in tumor tissue influence responsiveness to therapy, so even if these are detected in cancer patients, they mostly mean that these patients will respond well to therapy if they develop cancer, not that they are at measurably higher risk of developing lung cancer.”
But if you experience any symptoms that could indicate lung cancer, you should see your doctor immediately and get a low-dose CT scan.
“The earlier you are diagnosed, the more time there is for you to get targeted therapy,” says Aggarwal.
According to the CDC, the main types of lung cancer never-smokers get are called adenocarciomas and squamous cell carcinomas.
Nonsmoking women tend to get cancers that grow slower.
“Nonsmoking women have a better prognosis when diagnosed with lung cancer,” says Wolf. “The good news is, the type of cancer they get is the most favorable in terms of outcome. Their type of cancer tends to progress slowly, for years to decades. Using early detection, this gives you time to come up with a plan with your doctor.”
How Is Lung Cancer in Nonsmoking Women Treated?
New therapies are helping women live full lives with lung cancer as a treatable condition.
“One of the most important things a newly diagnosed lung cancer patient should have is a biomarker test,” says Aggarwal. “The earlier you are diagnosed, the more time there is for you to get targeted therapy.”
Targeted therapy focus on the abnormalities in some tumors; its goal is to stop healthy cells from being damaged by the cancer. The biomarker test “studies” a tumor so treatment can be tailored specifically to treat it, according to the American Lung Association.
In the future, more effective screening will also help nonsmoking women with lung cancer have better outcomes.
“Someday we may be able to identify people who have not smoked but have a constellation of risk factors that do elevate their risk enough to warrant beginning screening at a certain age,” says Smith. “It would require us to be able to measure those risk factors with sufficient accuracy, which is a tall order, and update those measurements regularly.”
For now, it’s good to know that many women who are diagnosed can do well after diagnosis. “Over the past 15 to 20 years, there has been a lot of progress in lung cancer research and treatment,” sums up Wolf. “There’s lots of reason to be optimistic.”