People who have never smoked often assume that they’ll never get lung cancer. But they can—and the prevalence of these cases is increasing at a troubling rate.
Update: Two important recent studies show that rates of lung cancer among so-called “never-smokers” (less than 100 cigarettes smoked in a lifetime) are mysteriously skyrocketing—in one study, from 9% to 20% of all such malignancies.
But it’s not all bad news.
The recent discovery of genetic mutations called “oncogenes” that drive lung cancer in never-smokers has fueled the development of powerful medications that are often more effective and have fewer side effects than conventional chemotherapy. Bonus: These new drugs are taken orally rather than intravenously, as is more common with conventional chemotherapy.
If you’re one of the roughly 24,000 never-smokers diagnosed with lung cancer each year in the US, it’s crucial for you (as well as current and former smokers) to be tested for a genetic mutation that might be driving your disease.
Shockingly, many of these patients are not tested despite the recommendations of national cancer organizations. This is due, in part, to the lack of awareness of many community oncologists in the US.
The most accurate test uses a tissue biopsy to screen for a handful of critical mutations that predict a more than 70% chance of responding to FDA-approved drugs. If the size and location of the tumor make a biopsy impossible, the oncologist should order a blood or urine test to check for mutations.
Important: If possible, get your genetic testing at one of the 45 medical institutions designated by the National Cancer Institute (NCI) as a “Comprehensive Cancer Center” (check Cancer.gov/research/nci-role/cancer-centers/find). You will get the most accurate testing at one of these centers and the most reliably up-to-date information on the latest cutting-edge medicine and clinical trials. A medical oncologist near you can administer the treatment. If you’re not able to travel to an NCI-designated center, a tissue sample from a biopsy performed at your local medical facility can be sent to certain institutions (such as the Mayo Clinic and Johns Hopkins) that offer molecular testing.
If you have a genetic mutation, a targeted medication can be used to treat the lung cancer. (Patients who do not test positive for a mutation receive standard cancer care, including conventional chemotherapy and/or radiation.)
Genetic mutations may include…
• Epidermal growth factor receptor (EGFR). This is the most common mutation in never-smokers with lung cancer, occurring in about 40% of these patients. Several FDA-approved drugs called EGFR-inhibitors can counter this mutation, including gefitinib (Iressa)…erlotinib (Tarceva)…and afatinib (Gilotrif). Additionally, icotinib (Conmana) is in clinical trials.
• Anaplastic lymphoma kinase (ALK). About 5% to 8% of lung cancer patients (most of these never-smokers) have this genetic mutation. The FDA-approved drug is crizotinib (Xalkori) for ALK-positive patients who have never received lung cancer treatment.
Even when a genetic mutation is identified, eventually a new mutation is generated and the tumor starts growing again—a phenomenon called acquired resistance. This typically occurs after about a year of treatment. Therefore, patients on these therapies undergo regular CT scans at two-to-three-month intervals to make sure their disease is not growing.
Best approach: When your tumor develops acquired resistance, it’s important to have another biopsy so that your doctor can determine which drug is right for you. Two months after starting a second-line drug, the patient will undergo a new CT scan to make sure it is shrinking the tumor. Important: The patient should alert the physician if he/she is taking any over-the-counter supplements—some can have life-threatening interactions with the targeted therapies.
The cause of lung cancer in never-smokers is unknown, but it is believed that up to 50% of cases are due to exposure to radon, a naturally occurring radioactive gas, and/or secondhand smoke. A distant third is indoor air pollution, such as particles from wood-burning stoves and cooking fumes from stir-, deep- or pan-frying. Main risks…
• Radon. Get your home tested. If levels are high (4 pCi/L or above), hire a state-licensed “radon mitigation contractor” to reduce levels to 2 pCi/L or below by installing a pipe that vents the gas outdoors.
• Secondhand smoke. Avoid it whenever possible.
• Indoor air pollution. If you have a wood stove, get a high-efficiency particle arresting (HEPA) air filter…if you fry food, vent the fumes—they may contain harmful carcinogens.
Important: If you are a never-smoker who has one or more of the symptoms of lung cancer—a persistent cough, chest pain, shortness of breath and/or sudden weight loss…or if you’ve had pneumonia that’s persisted for months in spite of several rounds of antibiotics—ask your doctor to test for lung cancer.
Unfortunately, never-smoker lung cancer often has no (or only vague) symptoms that doctors may not immediately suspect as a malignancy. For this reason, it is usually diagnosed when the cancer has spread to the bone, brain, liver and/or other organs. At that point, the most that can be done is to control the disease, giving the patient as much as three to five or more extra years of life if the disease is treated. As new therapies continue to emerge, the goal is to make never-smoker lung cancer a chronic disease and to someday provide a cure.
