Q&A: Lung Cancer in Nonsmokers
CancerWise - November 2007
Dana Reeve, wife of the late actor Christopher Reeve, never smoked and seemed to be the picture of health. Her death from lung cancer last year at age 44 brought national attention to the dangerous enigma of lung cancer in nonsmokers.
Physicians know smoking causes lung cancer, but many puzzles remain about why nonsmokers make up about 15% of those who contract this deadly cancer.
Answering questions about lung cancer in nonsmokers is Ara Vaporciyan, M.D., an associate professor in M. D. Anderson’s Department of Thoracic and Cardiovascular Surgery and director of the institution’s Oncology Cardiac and Vascular Surgery Program.
What are risk factors for nonsmokers?
Secondhand smoke overwhelms all other risk factors; living with a smoker is the number one danger. The next is a family history of cancer, and this overlaps with genetic predisposition to lung cancer. Many cancers share genetic deviations, and a lot of nonsmokers who get lung cancer have cancer in their family histories.
Radon gas, air pollution and other factors probably play roles, but it is difficult to determine exactly how big the roles are. It's a problem, for instance, to quantify radon gas exposure because people move, levels change and measurement is difficult.
We know more about the role of asbestos. By itself, asbestos does not increase risk. But exposure to asbestos coupled with smoking increases risk dramatically. It synergizes the effect of smoking, and the combination of the two is more dangerous than smoking alone.
What are lung cancer symptoms in nonsmokers?
In its early stages, lung cancer often has no symptoms. But when it does, the symptoms are the same in smokers and nonsmokers.
Symptoms may include:
- Persistent cough, especially coughing up blood
- Hoarseness, wheezing or shortness of breath
- Repeated episodes of pneumonia or bronchitis
- Fatigue, loss of appetite and weight loss
The difference tends to be that because the symptoms are similar to other conditions, the diagnosis of lung cancer is often placed lower on the list of possibilities for nonsmokers. If a 40-year-old nonsmoker has a cough and gets pneumonia, for instance, a physician might not think of lung cancer first.
What is the outlook for nonsmokers with lung cancer?
When you look at some studies, you might think you can make a blanket statement and say nonsmokers with lung cancer do worse. But it may be because they often are diagnosed when the cancer is more advanced. Nonsmokers under 45, who are considered young for lung cancer, may be diagnosed later because the disease is rare in this group.
Is lung cancer in nonsmokers a different disease?
I explain it to my patients this way. There is ice cream and frozen yogurt, and within each of these, there are many flavors. In a similar way, there are two main types of lung cancer: non-small cell and small cell.
Non-small cell lung cancer – NSCLC makes up about 90% of lung cancers, and there are two main types. Squamous cell, which is responsible for about one-fourth of cancers in smokers, is rare in nonsmokers. Adenocarcinoma, which is responsible for about 40% of lung cancers, includes a subset, bronchioloalveolar carcinoma, that is more common in nonsmokers. It often has a better prognosis than other types of lung cancer.
Small cell lung cancer – This type of lung cancer almost never occurs in nonsmokers. The cancer cells are small and spread through the body very quickly.
How can nonsmokers at high risk lessen their risk?
Make sure everything else you do is healthy and avoid other risk factors.
Screening with CT (computed tomography) scans is sometimes effective, but it has not been proven to save lives in smokers, let alone nonsmokers. And it is very expensive.
Should people at risk seek medical care?
It's important for people at heightened risk of lung cancer to have checkups regularly, preferably every year, by a general practitioner they trust. Then, if symptoms arise they know whom to call, and their history is recorded in one place.
Go to a doctor who understands the importance of screening. At your first visit, voice your concerns about your family history and risk factors.
What else should nonsmokers know about lung cancer?
Nonsmoking survivors of lung cancer are at higher risk of getting second cancers. They should be followed especially closely and receive annual CT scans.
M. D. Anderson resources:
- Overview: Lung cancer - non-small cell (American Cancer Society)