Lung Cancer In Never-Smokers Is a Different Disease

It seems somehow unfair when a person who has never smoked gets lung cancer — and unfortunately, it happens more often than you might guess. Here in the US, 10% to 15% of lung cancer cases (translating to about 20,000 cases per year) fall into this category. The notoriety of this disease was raised when the actress Dana Reeve (widow of Christopher Reeve) died from it in 2006, and I remember how lots of people were surprised to hear that this could happen.

So where does that put us in terms of risk? And what can be done to avoid this horrible disease? I was very interested to see a special report on this cancer in a recent issue of the journal Clinical Cancer Research. Authored by scientists at Johns Hopkins University, it said that the biology, diagnosis and treatment (everything, in other words) of lung cancer can be very different in never-smokers, defined as people who smoked fewer than 100 cigarettes in their lifetimes. When I called the study author, Charles M. Rudin, MD, PhD, associate director for clinical research at Johns Hopkins Kimmel Cancer Center, he told me that this type of cancer is often completely unrelated to smoking.

Who’s In Danger?

The most important avoidable risk factor is exposure to secondhand smoke, but there are several other known causes of “nonsmoker lung cancer” as well. These include radon gas leaking into homes from naturally occurring uranium in soil… exposure to asbestos… emissions from indoor wood-burning stoves … and as I reported last year in Daily Health News (February 16, 2009), cooking oil that gets aerosolized and breathed in when we cook. Dr. Rudin told me that there is also new evidence that genetics makes some people more vulnerable, noting that mutations increasing risk are now being identified. But he also said that in many cases of nonsmoker lung cancer, it’s not really evident precisely what caused the disease.

Never-Smokers Have a Better Prognosis

A problem with lung cancer overall is that there are no early markers, so it’s often quite advanced before it is diagnosed. “There’s nothing for lung cancer like the PSA for prostate cancer or the Pap smear for cervical cancer,” Dr. Rudin explained, “so there is no method of early detection that has an impact on mortality.” This is particularly problematic for nonsmokers, he noted — when they seek help for the cough and chest discomfort that are typical symptoms of lung cancer, doctors are more apt to think that there is a benign cause, such as a respiratory infection, than to look for a malignancy. Whereas a heavy smoker might be sent for diagnostic tests immediately, this would rarely be the case with a patient with no smoking history.

Nonetheless, the never-smoker with lung cancer usually has a better prognosis than the smoker. A key reason is that, aside from the lung cancer, these patients are typically healthier than smokers, who often have other issues, such as cardiac problems, that impede treatment.

Some patients who are found to have particular genetic alterations can benefit from targeted drug therapies that offer significantly higher response rates, Dr. Rudin said. “Some of the newer anticancer drugs are designed to specifically inhibit some of the alterations that we think are important in causing lung cancer,” he explained. Otherwise, traditional chemotherapy, radiation and/or surgery are the usual treatments for lung cancer in people who never smoked.

If You’re Worried…

Everyone should be aware of risk factors for nonsmoking lung cancer, says Dr. Rudin. He suggests avoiding known causes, particularly exposure to cigarette smoke, asbestos (still found in many building products in older homes) and radon (test your home’s levels). While some experts think that it would be good to broadly screen people with respiratory problems via CT scan, there are obvious concerns about radiation exposure from such scans themselves.

Meanwhile, if you are a never-smoker with a persistent cough, especially one accompanied by blood, shortness of breath, weight loss or chest pain, be aware that these symptoms might suggest lung cancer — voice your concerns to your doctor and be sure that you get the testing you need to either confirm or rule out such a diagnosis. And, if you have been diagnosed with lung cancer and have never smoked, Dr. Rudin says, it is important to be sure that your oncologist has your tumor examined for genetic alterations. If any are found, you might be a candidate for one of the newer targeted therapies that offer more hope for a good outcome.