According to Johns Hopkins Medicine, the leading cause of cancer and death from cancer is smoking. And 85 percent of lung cancer cases are smoking-related.
But what if you quit smoking long ago? Do you still have a risk of lung cancer?
Yes, even 10 to 15 years after quitting, studies show that former smokers are several times more likely to die of lung cancer than someone who has never smoked, according to Harvard Health Publications.
In the Nurses' Health Study, researcher Stacey A. Kenfield, ScD, of the Harvard School of Public Health, followed about 105,000 American women who were between the ages of 30 and 55 at enrollment in 1976.
Some had never smoked. Others were current and former smokers. Those who quit had smoked for an average of 15 years. The women have completed detailed health questionnaires every two years for the past three decades.
Between 1980 and 2004, it was seen that 12,483 of the women had died. Thirty-six percent of the deaths were women who never smoked, 29 percent were current smokers and 35 percent were past smokers.
The study results indicated that the risk of dying from lung cancer dropped by 21 percent within five years of quitting, but there was still continued risk for 30 years, according to WebMD.
What other factors affect the lung cancer risk? One factor may be the age when someone started smoking and when they quit.
The Nurses' Health Study discovered that early smokers had the highest risk of dying from smoking-related causes. Current smokers who started at 17 or younger had a significantly higher risk of death than smokers who took up the habit after age 25.
A 2005 study in the Annals of Epidemiology found that women who quit before 30 are no more likely to die from lung cancer than their counterparts who never smoked, reported Harvard Health Publications.
The Mirror reported on another study which found that lung cancer was widespread among smokers who quit long ago. The catch? They quit so long ago, they didn’t qualify for lung cancer screening.
Study leader Doctor Ping Yang of the Mayo Clinic Cancer Research Center and her colleagues studied two groups of people who were newly diagnosed with lung cancer. One group comprised people in hospitals and the other was a smaller group of Minnesota residents.
"They found that patients who quit smoking for 15 to 30 years were at the highest risk of lung cancer among patients who didn’t qualify for screening - reaching 12 per cent in the hospital group and 17 per cent in the resident group," reported The Mirror.
That’s because current guidelines recommend cancer screening for those 55 to 80 who smoked at least a pack each day for 30 years and currently smoke, or those who quit within 15 years.
Yang told the Mirror, “This suggests we need to pay attention to people who quit smoking more than 15 years ago, because they are still at high risk from developing lung cancer.”
If you are a former smoker, talk to your doctor about your smoking background and lung cancer screenings.
Reviewed December 13, 2016
by Michele Blacksberg RN
Edited by Jody Smith
Barnes, Luke. "Research Reveals the Risk of Lung Cancer for Ex-smokers." Mirror. N.p., 2016. Web. 23 Nov. 2016.
Boyles, Salynn. "Quit Smoking: Death Risk Drops Fast." WebMD. WebMD, n.d. Web. 23 Nov. 2016.
"Cigarettes: The Lung Cancer Risks - Harvard Health." Harvard Health. N.p., n.d. Web. 23 Nov. 2016.
"Former Smokers: What's Your Risk for Lung Cancer?" John Hopkins Medicine. N.p., n.d. Web. 23 Nov. 2016.