Although respiratory conditions and lung cancer often simultaneously occur in a patient, few studies have investigated the link between these conditions. However, a new study, recently published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine, entitled, “Is Previous Respiratory Disease a Risk Factor for Lung Cancer?” has shown that patients who have had respiratory diseases in the past are in fact at a higher risk of developing lung cancer.
The team, led by researchers at the International Agency for Research on Cancer, measured the risk of lung cancer associated with chronic bronchitis, emphysema, tuberculosis, pneumonia and asthma, by analyzing seven case-control studies involving 12,739 patients who have previously had respiratory diseases. Researchers divided patients by sex, age, and study center, also indicating whether these patients have ever been employed in a high-risk occupation. Education level, smoking status, the number of packs of cigarettes smoked each year, and when the patient quit smoking were also considered.
Results showed that chronic bronchitis and emphysema were associated with an increased risk of lung cancer. Patients who had pneumonia were also found to be at higher risk to develop lung cancer, two or few years after (but not longer) having the respiratory disease. In addition, patients who suffered from all three of these conditions had a higher risk of lung cancer than those who only had chronic bronchitis.
Asthma, on the other hand, had an inverse association with lung cancer risk. Likewise, researchers found no association between tuberculosis and lung cancer. Contrary to the co-occurring chronic bronchitis, emphysema and pneumonia, there was no link found between chronic bronchitis and lung cancer among patients who also had asthma and tuberculosis.
These findings led researchers to conclude that chronic bronchitis and emphysema continue to be highly associated with lung cancer. Researcher Ann Olsson of the International Agency for Research in Cancer in Lyon, France, said in a press release that these findings may ultimately help determine the type and frequency of clinical surveillance these patients need.