Spirometry: a predictor of lung cancer among asbestos workers

The significance of lung function as an independent risk factor for lung cancer remains unclear. The objective of the study is to answer the question if spirometry can identify patients at risk for lung cancer among people occupationally exposed to asbestos dust in the past.

In order to identify a group of individuals with the highest risk of lung cancer incidence based on lung function levels of FEV₁% predicted value, we examined 6882 subjects enrolled in the health surveillance program for asbestos related diseases over the years 2000-2014. We found a total of 110 cases confirmed as primary lung cancer.

Using Cox's proportional hazards model after adjustment for age, gender, number of cigarettes, duration of smoking and cumulative asbestos exposure, we estimated that compared with the subjects with FEV₁ ≥90% pred, the HR of lung cancer was 1.40 (95%CI: 0.94-2.08) for the subjects with FEV₁ less than 90% and 1.95 (HR = 1.86; 95%CI: 1.12-3.08) for those with FEV₁ less than 70%. In addition, probability of the occurrence of lung cancer for FEV₁ <90% of the predicted value was HR = 2.19 (95%CI: 1.04-4.61) in the subjects whose time since spirometry and cancer diagnosis was three years or less.

The results strongly support the hypothesis that spirometry can identify patients at a risk of lung cancer development. Regular spirometry should be offered to all patients with a history of asbestos exposure, at least once every three years.