Interstitial lung abnormalities increase risk for lung cancer, mortality

People with interstitial lung abnormalities have an increased risk for lung cancer and lung cancer mortality, but not other cancers, according to a study published in the European Respiratory Journal.

“People with interstitial lung abnormalities are at increased risk of lung cancer and lung cancer mortality, but not of other cancers,” Gisli Thor Axelsson, BSc, professor and faculty of medicine at the University of Iceland, Reykjavik, and colleagues wrote. “This implies that an association between fibrotic and neoplastic lung diseases of the lung exists from the early stages of lung fibrosis and suggests interstitial lung abnormalities as a risk factor in lung cancer screening efforts.”

Researchers analyzed data from the AGES-Reykjavik longitudinal birth cohort study of 5,764 older adults in Iceland. Based on chest CT, 92% of the cohort had interstitial lung abnormalities, which were defined as nondependent ground-glass or reticular abnormalities, diffuse centrilobular nodularity, nonemphysematous cysts, honeycombing and traction bronchiectasis affecting more than 5% of any lung zone.

Participants were followed from their entry into the study (2002-2006) until a first diagnosis of cancer or the end of the study.

The researchers found greater cumulative incidence of lung cancer diagnoses and lung cancer mortality in participants with interstitial lung abnormalities compared with those who did not have interstitial lung abnormalities (P < .001).

In Cox proportional hazards models, participants with interstitial lung abnormalities had an increased hazard of lung cancer diagnosis (adjusted HR = 2.77; 95% CI, 1.76-4.36) and lung cancer mortality (aHR = 2.89; 95% CI, 1.8-4.66).

In Cox proportional hazards models adjusted for age, sex, smoking pack-years and smoking at the time of the study, risk for a diagnosis of and mortality related to all cancers excluding lung cancer was not significant among participants with interstitial lung abnormalities (HR = 1.24; 95% CI, 0.98-1.57).

“Validation of these results in other more heterogenous populations, preferably in prospective studies, is important if changes such as [interstitial lung abnormalities] are to be established as a risk factor for lung cancer,” Axelsson told Healio. “The results suggest that studies exploring the biological relationship between diseases such as idiopathic pulmonary fibrosis and lung cancers could extend their approach to earlier forms of pulmonary fibrosis.”

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Gisli Thor Axelsson, BSc, can be reached at gtha7@hi.is or on Twitter: @Axelsson_GT.