Serious lung ailments may increase the risk of developing lung cancer, according to a new report, but researchers did not find evidence the diseases cause cancer.
In an analysis of data on more than 25,000 people, researchers found that people who had chronic bronchitis, emphysema or pneumonia had an increased risk of developing lung cancer. Suffering from all three conferred a higher risk than having chronic bronchitis alone.
Asthma and tuberculosis were not associated with a higher lung cancer risk.
The findings were published in the journal American Respiratory and Critical Care Medicine.
Investigators with the International Agency for Research on Cancer in Lyon, France, sifted through data from seven studies conducted in Europe and Canada.
Researcher Ann Olsson says the underlying disease mechanisms of the different respiratory conditions could be the reason they affect the development of lung cancer in different ways.
Knowing the risks, she said, could help doctors monitor patients with certain lung ailments.