New Study Suggests Smoking Damage May Be Long-Lasting

PITTSBURGH — People who smoked for many years may face a permanently increased risk of lung cancer, even after giving up the habit, research at the University of Pittsburgh indicates.

Long-term smoking may throw a a biological “switch” that drives the growth of lung cells and could lead to cancer, according to Dr. Jill Siegfried, director of basic science at the University of Pittsburgh Cancer Institute’s Lung Cancer Center.

Research directed by Siegfried, who is also an associate professor of pharmacology at the university’s School of Medicine, was published in this month’s issue of the Journal of Respiratory and Critical Care Medicine.

“We believe this switch is an indicator of lung cancer risk, because we see it activated in most people with a long history of smoking, regardless of whether they already have developed cancer,” Siegfried said.

“Once this switch is turned on, it appears to be permanent,” she said. “[That] may explain in part why long-term ex-smokers who have not had a cigarette in over 25 years are still at high risk for getting lung cancer.”

Dr. Michael Tuhn, director of analytic epidemiology at the American Cancer Society, said the research should not discourage smokers from kicking the habit because they think it means they will develop cancer whether they quit or not.

“The benefits to quitting are huge,” he said. “The benefits are very well established, as in reducing the risk of heart attack, lung cancer and stroke.