Lung cancer is most closely associated with smoking, and with good cause; Most lung cancers are diagnosed in people who smoked. While it is far rarer, lung cancer can also be found in people who never smoked.
“One thing that has happened in the United States over the past 60 years is that the population has grown a huge amount and at the same time far fewer people are smoking,” said Yale New Haven Hospital pulmonary medicine specialist Lynn Tanoue, MD, MBA, director of the Yale Lung Screening and Nodule Program. “The result of those two changes is that there are many more people who never smoked and so even though lung cancer in never-smokers is rare, it has become more likely that you will hear of or know somebody who never smoked but has lung cancer.”
How common is lung cancer?
Lung cancer is the second most common cancer in the U.S. in both men and women. There are more breast and prostate cancer cases diagnosed every year, yet lung cancer is the leading cause of cancer death in the U.S. It is also the leading cause of cancer death in the world.
How is lung cancer detected?
The United States Preventive Services Task Force recommends yearly lung cancer screening for those who have increased risk of lung cancer due to a history of smoking. Typically, this screening includes a low-dose CT scan, which is the gold standard for lung cancer screening.
Those who qualify for screening include adults between 50 and 80-years-old who smoked the equivalent of one pack of cigarettes a day for the last 20 years. Medicare covers screening for those up to 77-years-old.
However, unlike screenings for other cancers like colon cancer or breast cancer, there is no universal screening recommendation for nonsmokers. Therefore, lung cancer is usually not detected in nonsmokers until they experience symptoms, which tend to appear when the cancer is more advanced.
Lung cancer symptoms
Lung cancer symptoms may include the persistence over more than a few weeks of one or more of the following:
- Cough
- Chest discomfort or pain
- Shortness of breath
- Symptoms related to other organs, including pain, weight loss, fatigue
Dr. Tanoue says anyone who has persistent unexplained symptoms such as a cough that won’t go away for weeks, unexplained or significant weight loss or unexplained pain or shortness of breath should speak to their doctor.
Lung cancer risk factors
In addition to smoking, there are many factors that can contribute to cancer. These include:
- Exposure to carcinogens such as radon or asbestos
- Exposure to secondhand smoke
- Air pollution and diesel fumes
- UV light
“None of these risk factors compares to the high risk of lung cancer from smoking. The risks related to things like air pollution and secondhand smoke are relatively low compared to smoking cigarettes yourself. But risks are cumulative, and so they all can contribute,” said Dr. Tanoue.
Genetic factors can also impact risk.
“We do know that some lung cancers, maybe 15-20% of lung cancers, are related to specific genetic mutations. The best described in lung cancer are mutations in the EGFR gene. These mutations are called 'driver' mutations, because they literally are driving the cancer. Recognizing these mutations by doing testing is important because we can target therapy to those mutations and very precisely and effectively treat those cancers,” said Dr. Tanoue.
How to reduce the risk of lung cancer
The best way to reduce the risk of lung cancer is to reduce exposure to known culprits. For example, smokers should quit, and nonsmokers should limit their exposure to secondhand smoke. Test your home for radon, which can easily be remedied, and avoid occupational carcinogens. There is also value in having a healthy lifestyle. For example, eating a balanced diet rich in fruits and vegetables has been associated with fewer cancers.
In addition, everyone should speak with their clinician about their own risk factors, such as family history so that concerns about cancer risks can be appropriately addressed.
