Female Nonsmokers Get More Lung Cancer
Women Who've Never Smoked at Greater Risk Than Nonsmoking Men
Feb. 9, 2007 -- Lung cancer is not solely a smoker's disease -- and women who have never smoked are more at risk than men, new research confirms.
About 20% of lung cancer cases in women occur in nonsmokers, the research suggests. In men, the percentage is about 8%.
To put the risk in perspective, a woman with no history of smoking has the same risk of developing lung cancer as she has of developing cervical cancer, says lead researcher Heather Wakelee, MD, of Stanford University School of Medicine.
“People who have never smoked really do represent a substantial minority of lung cancer patients,” Wakelee tells WebMD. “We need to be working now to better understand why these cancers occur.”
In the Spotlight
The death of actress and activist Dana Reeve last March put the issue into the spotlight. Reeve was never a smoker, and her battle with lung cancer made millions of people aware for the first time that nonsmokers get the disease.
It has been believed that between 10% and 15% of lung cancer cases occur in people with no smoking history, but Wakelee says there has been little hard data to back up the figure.
“That is one of the main reasons we did this study,” she says.
Wakelee and colleagues from Stanford and the Northern California Cancer Center tracked lung cancer incidence and deaths in more than 1 million people between ages 40 and 79 and living in the United States or Sweden.
They then calculated lung cancer cases in terms of new cases per person-year.
The researchers noted that age-adjusted lung cancer rates among current smokers are roughly 12 to 30 times higher than rates in people who never smoked.
But if the numbers are representative of the overall U.S. population, the inference is that about 8% of lung cancer cases in men and 20% of cases in women are among never-smokers, study co-author Ellen T. Chang, ScD, tells WebMD.
The study is published in the Feb. 10 issue of the Journal of Clinical Oncology.
Why Do Nonsmokers Get Lung Cancer?
It is still not clear if the lung cancer rate among never-smokers is growing or if the disease is as deadly in never-smokers.
And though there are many theories about why nonsmokers get lung cancer, little research has been done on the subject.
Air pollution, exposure to radon, and occupational exposure to asbestos have all been implicated in lung cancer risk. But most experts suspect that secondhand cigarette smoke exposure is the biggest risk factor for lung cancer among people who have never smoked.
“In this country, more women who don’t smoke probably live with men who smoke than the other way around,” the American Lung Association's chief medical officer, Norman Edelman, MD, tells WebMD.
“If you have a spouse who smokes, it is not only good for their health if they quit smoking, it is good for yours,” Edelman says.