Everyone's at Risk for Lung Cancer (Even Non-smokers)by Barbara O'Dair Health Writer
If you’re not a current smoker or you never smoked, you might think you’re not at risk for lung cancer, the second most-common cancer among American men and women (after skin cancer), and the leading cause of U.S. cancer deaths among both sexes, according to the American Cancer Society. The truth is, everyone has a lung cancer risk of one kind or other, with some groups facing higher odds of developing the disease than others. We’ll break it down for you here. What you learn just might surprise you.
Smokers and Former Smokers
Let’s start with what won’t shock you: Cigarettes are the number-one risk factor for lung cancer among smokers and ex-smokers alike. Smoking is linked to four out of five lung cancer cases and 80% to 90% of deaths, including those who still light up and those who’ve quit. However, rates are falling: The number of Americans who died from non-small cell lung cancer, the most common form of lung cancer, dropped by 6.3% per year from 2013 through 2016, according to research published in the New England Journal of Medicine, partly due to “a reduction in incidence along with treatment advances.”
Here’s where it gets surprising. For all the obvious connections between smoking and lung cancer, “we see a lot of lung cancer in people who have never smoked,” says Kim L. Sandler, M.D., assistant professor of radiology at Vanderbilt University Medical Center in Nashville, TN. In fact, up to 20% of people with lung cancer have never lit up or ever used any form of tobacco. So, if smoking is not the problem, what is? “It’s an area that needs work,” she admits, although exposure to second-hand smoke, radon, or previous radiation top the list of potential culprits.
The average age of lung cancer diagnosis is 70. Seniors are most susceptible because “there’s more time for their bodies to develop cancer,” explains Dr. Sandler. Also, for smokers, the longer you smoke, the greater your risk. “The number-one high-risk group is people who have smoked ‘30-pack years,’” says David Tom Cooke, M.D., head of thoracic surgery at the University of California, Davis. “That [means] a pack a day for 30 years or two packs a day for 15 years.” As we age, our body’s DNA repair mechanisms become less effective, making environmental toxins and carcinogens harder to fight off.
Symptoms of lung cancer (chronic cough, chest pain, shortness of breath, hoarseness, and weight loss) are generally the same between men and women. However, lung cancer is the deadliest cancer for women, killing more each year in the U.S. than breast, ovarian, and uterine cancers combined.
While overall lung cancer rates among both sexes are decreasing, research shows a jump in diagnoses among women between 30 and 49, exceeding rates of their male peers. Researchers still don’t know why. Smoking behavior alone can’t explain it—half of this group are never-smokers. “There’s a push [among researchers] to look at these women,” says Dr. Sandler. Evidence points to more adenocarcinoma, a type of lung cancer seen in both smokers and nonsmokers, which is more likely to occur in younger women. Young female smokers may also possess different genetic risk factors for lung cancer than men, reports the American Cancer Society.
Lung cancer is the second most common cancer in both Black men and women in the U.S., with higher mortality rates than whites. “There is an immense lung cancer disparity in the African-American community,” says Henry Henderson, Ph.D., oncology post-doctoral fellow at Vanderbilt University Medical Center in Nashville, TN. He points to systemic healthcare inequities, leading to fewer high-risk Black smokers being screened for lung cancer in its early stages when it’s most treatable. Even so, lung cancer rates are falling furthest among Black women, who are historically less likely to smoke, and to smoke fewer cigarettes than white women do.
The Less Educated
The latest research on lung cancer and education level suggests that less schooling may contribute to higher lung cancer risk. Dr. Sandler co-authored a recent study from the American College of Radiology that looked at the behavior of individuals who’d received a lung cancer screening. People with higher levels of education followed up on their tests. Researchers attributed the lack of follow-up to lower education that compromised health literacy or access to health care. "We need to address disparities in health literacy in our screening population to ensure we provide the best possible care for all patients," says Dr. Sandler.
Exposure to Toxic Gases, Minerals, or Chemicals
Now let's return to radon, which can exist naturally in the soil in some areas. However, when this elemental gas enters a home environment it can build to dangerous levels, says Dr. Cooke. In fact, radon exposure is the second-leading cause of lung cancer, and the leading cause of lung cancer in non-smokers, according to the U.S. Environmental Protection Agency. (The EPA attributes 21,000 lung cancer deaths from radon exposure each year.) Other environmental factors that can pose a lung cancer risk include exposure to asbestos, uranium, arsenic, cadmium, chromium, nickel, and some petroleum products.
Family History of Lung Cancer
Recent research has shown that a family history of lung cancer increases the risk for the disease in both smokers and never-smokers. About 8% of lung cancers are inherited or occur as a result of a genetic predisposition, according to a review published by the National Institutes of Health. Having a first-degree relative who’s had early-onset lung cancer or multiple affected family members significantly ups your risk of developing it yourself, the report states. However, “major gaps exist in our knowledge of the genetics of lung cancer,” researchers caution.
While it’s true that lung cancer targets different groups differently, with varying diagnosis and mortality rates, one thing that is quite common, says Dr. Cooke, is how so few people who are at risk for this disease are screened for it—even when early detection provides their best odds for survival. “Seventy percent of patients are diagnosed at a late stage 3 or 4,” he says. “Which is one reason why early screenings are needed.” Check out the CDC’s guidelines for lung cancer screening, and talk to your doctor about whether you should get one—especially if you smoke.