In a new study entitled “The association between combined non-cystic fibrosis bronchiectasis and lung cancer in patients with chronic obstructive lung disease,” authors evaluated whether inflammatory status characteristic of non-cystic fibrosis (non-CF) bronchiectasis, a type of inflammatory lung disease, is associated with increased risk for lung cancer in patients suffering from chronic obstructive pulmonary disease. They found a potential protective role for bronchiectasis against lung cancer. The study was published in the journal International Journal of Chronic Obstructive Pulmonary Disease.
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease affecting the lungs and has been associated with increased risk for lung cancer. However, whether other inflammatory lung diseases, such as non-cystic fibrosis (non-CF) bronchiectasis, characterized by permanent dilatation of the bronchi and high levels of inflammation, are also a risk factor for lung cancer is currently poorly understood.
A team of researchers at the Seoul National University College of Medicine recently researched the association between bronchiectasis and lung cancer in patients with COPD. They enrolled COPD patients with moderate to very severe airflow impairment, and from these selected patients with lung cancer (identified as positive by chest computed tomography). Matched control patients were selected from the screened patients as those negative for lung cancer (negative chest scan). The presence of bronchiectasis was determined by chest scan and further validated by a radiologist and pulmonologist. In the end, the team was able to enroll 99 COPD patients with lung cancer and 198 matched COPD patients without lung cancer.
The authors discovered that COPD patients with bronchiectasis and moderate to very severe airflow limitation were inversely associated with the risk of lung cancer, i.e., COPD patients with bronchiectasis are associated with a lower risk of lung cancer. Significant associations were found in patients with squamous cell carcinoma and history of smoking.
The team hypothesizes that since the inflammatory profile characteristic of bronchiectasis is different from the one of COPD, this difference may render bronchiectasis patients more protected against lung carcinogenesis. One potential factor for this protection is TGF-β1. In a previous report, TGF-β1 levels were found increased in serum of patients with bronchiectasis, and TGF-β1 was reported as potentially protecting against carcinogenesis.
The authors note that their results are still preliminary but suggest that exploring a potential protective role for bronchiectasis in lung cancer should be addressed in future studies with larger samples.