While there’s no single cause of lung cancer in nonsmoking females, research suggests that a combination of toxin exposure, genetics, and hormones may play a role.
Tobacco smoking continues to account for most lung cancer cases and 80%Trusted Source of related deaths. But even if you don’t have a history of smoking, you might develop lung cancer. In fact, lung cancer rates are rising in nonsmokers — particularly females.
Research suggests that while smoking rates are decreasing worldwide, lung cancer rates are increasing. And about two-thirdsTrusted Source of lung cancers in people who do not smoke occur in females.
In the United States, lung cancer is the leading causeTrusted Source of cancer-related deaths in women.
Smoking is still the greatest modifiable risk factor for lung cancer, but it’s also important to be aware of other reasons this type of cancer may be on the rise in nonsmoking females.
Most cases of lung cancer in nonsmokers are non-small cell lung cancer, such as adenocarcinoma.
Rather than a single risk factor, lung cancer development in nonsmoking females may be due to a combination of factors, including toxins, genetics, and hormones.
Secondhand smoke may increase your risk of lung cancer
Whether you’re exposed to secondhand smoke at home or at work, the carcinogens can increase your risk of developing lung cancer, as well as heart disease and stroke. There’s no “safe” level of secondhand smoke exposure — even short-term exposure is considered unsafe.
According to the American Lung Association, more than 41,000 people per year die as a result of complications of secondhand smoke exposure. Secondhand smoke contains a variety of toxins, including:
- arsenic ammonia
- benzene
- formaldehyde
- hydrogen cyanide
- vinyl chloride
The risk of secondhand smoke-related lung cancers appears to be greatestTrusted Source in people who have a spouse or partner who is a smoker.
Environmental and workplace exposures may increase your risk of lung cancer
Aside from cigarette smoke, exposure to other toxins may also increase the risk of lung cancer in nonsmoking females. You might be exposed to these substances at work or where you live. Examples includeTrusted Source:
- air pollution
- asbestos
- diesel exhaust
- radon
Estrogen may increase your risk of lung cancer
Estrogen, one of the sex hormones in your body, may also contribute to lung cancer development.
As a 2021 research review mentions, non-small cell lung cancer may express estrogen receptors, which could contribute. The authors also report that premenopausal women may be at a higher risk of more aggressive lung cancers than both postmenopausal women and men.
Genetic changes may increase your risk of lung cancer
Lung cancer in nonsmokers may also have a genetic component. The genetic mutations (changes) that could contribute to it are mostly the type you can acquire during your lifetime, not the type you might inherit from your parents.
Acquired gene mutations that are involved in nonsmoking lung cancer development are called driver mutations. Examples includeTrusted Source:
- ALK
- BRAF
- EGFR (the most commonTrusted Source)
- MET
- NTRK
- RET
- ROS1
Genetic mutations are usually not detected until after a lung cancer diagnosis. But genetic testing is still important in these cases because it can influence a doctor’s decisions about treatment. If driver mutations are present, certain targeted therapies can be most effective.
Driver mutations can also develop in people who have a history of smoking, but this is less common.
A history of certain lung diseases may increase your risk of lung cancer
Nonsmoking adults may also be at an increased risk of developing lung cancer if they have a history of lung diseases such as chronic obstructive pulmonary disease (COPD).
The three most commonTrusted Source types of lung disease in women overall are COPD, asthma, and lung cancer.
A 2020 reviewTrusted Source suggests that pulmonary fibrosis (scarring of your lungs) may also contribute to future lung cancer development.
Certain types of viruses may increase your risk of lung cancer
While current researchTrusted Source has not yet found a direct cause-and-effect relationship, some experts are looking into the role that certain viruses might play in later lung cancer development in nonsmokers. These include:
- Epstein-Barr virus
- hepatitis B
- hepatitis C
- human papillomavirus (HPV)
If you’re at risk of lung cancer, are there recommended screening guidelines?
Currently, the U.S. Preventive Services Task Force (USPSTF)Trusted Source recommends annual lung cancer screenings via a CT scan for adults who meet all the following criteria:
- They are 50 to 80 years old.
- They currently smoke or have stopped within the last 15 years.
- They have a 20-pack-yearTrusted Source smoking history (which means they’ve smoked 1 pack of cigarettes per day for 20 years or 2 packs per day for 10 years).
The problem is that these guidelines do not account for nonsmokers who might have other risk factors, such as a history of secondhand smoke exposure. Furthermore, nonsmokers who develop lung cancer tend to do so at a younger ageTrusted Source than those who have a history of smoking.
The USPSTF does not recommend annual screenings for nonsmokers because the risk of radiation exposure from regular CT scans could possibly outweighTrusted Source the benefits.
But if you wait to get screened until you have symptoms of lung cancer, the cancer will likely already have become advancedTrusted Source or spread. This can be a challenging situation to navigate.
Instead, a doctor may recommend regular screenings based on other individual risk factors. If you think you may need screenings, talk with a doctor. They can help you figure out your next steps.
Lung cancer symptoms
Contact a doctor right away if you’re experiencing the followingTrusted Source possible symptoms of lung cancer:
- a cough that lasts a long time or gets worse
- recurring pneumonia
- coughing up blood
- chest pain
- wheezing
- shortness of breath
- chronic fatigue
- unintentional weight loss
Takeaway
While smoking rates are decreasing, lung cancer cases are increasing among nonsmoking females. Researchers believe this could be due to toxin exposures in work and home environments, as well as genetics, hormones, and other risk factors.
Because there are currently no screening guidelines for nonsmokers, lung cancer can be difficult to detect in its early stages.
Consider talking with a healthcare professional if you develop respiratory symptoms that concern you or if you have risk factors for lung cancer.
