Jan. 21, 2010 -- Smokers with lung cancer who have asked "Why quit now, I'm already sick?" may find new motivation in this answer: Doing so could double their odds of survival over five years.
A report published online today in BMJ suggests that people who give up smoking after being diagnosed with early-stage lung cancerlive longer than patients who continue the habit.
The findings underscore the importance of the notion that it is never too late to quit smoking.
Lung cancer is the most common cause of cancer death, according to the American Lung Association. And smoking causes most cases of lung cancer.
Medical evidence has repeatedly shown that as soon as a person quits smoking the body begins to repair the damage done by tobacco-smoke-related chemicals, and it's been theorized that continued smoking can influence the behavior of lung tumors. But until now it was not clear if ending the smoking habit after being diagnosed with lung cancer had any impact on a patient's survival.
Researchers at the University of Birmingham in England reviewed the results of 10 studies that evaluated how smoking cessation after lung cancer diagnosis affected a patient's prognosis. The review included patients with both non-small-cell and small-cell forms of lung cancer.
Among their findings:
Patients with early-stage lung cancer who continued to smoke had a "substantially higher risk of death" than those who quit after their diagnosis. The increased death risk appeared to be due to the cancer spreading.
The five-year survival rate for the quitters was 64%-70% compared with 29%-33% for those who continued to smoke.
The continued smokers were also more likely to have their cancer return than those who quit.
The researchers say their findings suggest that smoking-cessation programs may benefit patients with early-stage lung cancer, but they add that more research is needed.