Authors: Caroline Telford, Future Science Group
In a recent study published in the American Journal of Respiratory and Critical Care Medicine, a group of researchers from across the world have reported links between a number of common respiratory diseases and an increased risk of developing lung cancer.
Previous studies have analyzed the association of respiratory diseases with increased lung cancer risk; however, few studies have investigated the effects of multiple co-occurring conditions. This study aimed to investigate the risk of lung cancer associated with chronic bronchitis, emphysema, tuberculosis, pneumonia and asthma.
The team conducted a pooled analysis of information on previous respiratory disease from 12,739 cases and 14,945 controls from 7 case–control studies conducted in Europe and Canada. Analyses were adjusted for age, sex, study center, employment in a high-risk occupation and smoking status.
After accounting for other respiratory diseases and smoking, chronic bronchitis and emphysema were positively associated with lung cancer. The team also observed a positive association between lung cancer and pneumonia diagnosed 2 or fewer years prior to lung cancer diagnosis.
Asthma was observed to have an inverse association with risk of lung cancer and no association with increased risk was observed with tuberculosis. Patients with co-occurrence of chronic bronchitis, emphysema and pneumonia had a stronger positive association with lung cancer risk than those with the individual conditions.
Researcher Ann Olsson from the International Agency for Research in Cancer (Lyon, France) stated that “the variations in the associations between lung cancer and different patterns of previous respiratory diseases that we observed in our study may indicate differences in the underlying etiological mechanisms. Better understanding of these associations may help guide the type and frequency of clinical surveillance needed for patients with each of these diseases.”
Sources: Denholm R, Schüz J, Straif K et al. Is Previous Respiratory Disease a Risk Factor for Lung Cancer? Am J Respir Crit Care Med. doi: 10.1164/rccm.201402-0338OC (2014) [Epub ahead of print].