Among a group of mostly older male veterans suffering from chronic obstructive pulmonary disease (COPD), researchers found that regular use of high-dose inhaled corticosteroids (ICS) lowered the risk of developing lung cancer.
The results for this study appear in the first issue for April 2007 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
David H. Au, MD, MS, of the Veterans Administration Puget Sound Health Care System in Seattle, along with five associates found that among 10,474 patients with COPD, 517 were considered regular users of ICS.
Among users of more than 1,200 micrograms of ICS per day, the relative risk for lung cancer was lowered to 0.39. For users of less than 1,200 micrograms per day, the relative risk was 1.13. (A relative risk of 1 means there is no difference in risk between two groups.)
Over the next 4 years, the researchers found that among a total of 9,957 nonusers of ICS, 402 developed lung cancer. For 298 users of ICS at a level below 1,200 micrograms per day, 16 developed lung cancer. Among 219 patients who used more than 1,200 micrograms per day, five developed lung cancer.
“Lung cancer is the most common cause of cancer-related death in the United States and accounts for more deaths each year than breast, prostate and colon-rectal cancer combined,” said Au. “Studies such as the Lung Health Study have demonstrated that the most common cause of death among subjects with COPD is lung cancer.”
The researchers noted that ICS have been shown in prospective studies to suppress systemic markers of inflammation such as C-reactive protein and to reduce airway inflammation.
They hypothesized that higher doses of ICS among the male veterans reduced such factors as local airway inflammation, cell turnover, and the propagation of genetic errors. Consequently, these effects could lead to a subsequent reduction in lung cancer risk.