But data insufficient to change current practice, expert says.
By Steven Reinberg HealthDay Reporter
WEDNESDAY, Nov. 3 (HealthDay News) -- University of Missouri researchers believe they have found a correlation between asthma and lung cancer in a small study.
Previous research has shown a correlation between chronic obstructive pulmonary disease (COPD) and lung cancer, but this is the first time such a link has been shown for asthma and lung cancer, the researchers said.
However, based on the available data, people with asthma should not worry that they are at an increased risk for developing lung cancer, said Dr. Marilyn Glassberg, an associate professor of clinical medicine, pulmonary and critical care medicine at the University of Miami Miller School of Medicine.
"This is a correlation study," she said. "The problem with correlation studies is you never get cause-and-effect." Still, "it's of interest," she added.
The findings were to be presented Tuesday by lead researcher Dr. Vamsi Guntur at the annual meeting of the American College of Chest Physicians in Vancouver.
For the study, Guntur's team examined the medical records of 759 lung cancer patients and similar patients without lung cancer.
The researchers found that 46.2 percent of those with asthma also had lung cancer, compared with 22.5 percent of those without asthma.
The researchers speculate that "chronic repeated inflammatory insults from asthma" could trigger lung cancer, but exactly how that might happen remains unclear, they said in a news release from the college.
The authors say their study "underscores the importance of more aggressive management of inflammatory airway disease, development of diagnostics for early and ideally noninvasive screening and risk stratification, and promotion of additional research on the mechanisms of carcinogenesis induced by inflammation."
Glassberg took issue with the findings, noting that while asthma and COPD scar the lungs, lung cancer is not caused by scarring of lung tissue. Also, she said it doesn't appear that the researchers took into account smoking, which is a major cause of lung cancer.
"This is not going to change how we take care of people, or [cause us] to screen asthmatics for lung cancer," she said.
(SOURCES: Marilyn Glassberg, M.D., associate professor, clinical medicine, pulmonary and critical care medicine, University of Miami Miller School of Medicine; Nov. 2, 2010, presentation, American College of Chest Physicians annual meeting, Vancouver)