Lung function predicts lung cancer risk in smokers: a tool for targeting screening programs

¹ Division of Thoracic Surgery and Division of Radiology°, Fondazione IRCCS Istituto Nazionale dei tumouri, Milano, Italy
² Istituto di Statistica Medica e Biometria "Giulio A. Maccacaro", Università degli Studi di Milano, Italy; and Mario Negri Institute, Milano, Italy
³ Unità Operativa Pneumologica Ospedale San Carlo Borromeo, Milano, Italy
⁴ University of Bologna, Radiology, Policlinico S. Orsola Malpighi Bologna, Italy
⁵ Unità di Pneumologia e Terapia Semi-Intensiva Respiratoria, Ospedale San Giuseppe AFAR, Milano, Italy

^* To whom correspondence should be addressed. E-mail: ugo.pastorino{at}istitutotumouri.mi.it.

	Abstract

The relationship between smoking, lung cancer and airflow obstruction is recognized but it is unclear whether the presence of minimal lung function damage constitutes an independent risk factor for the development of lung cancer.

In order to identify those individuals at higher risk of lung cancer on the basis of functional impairment, we evaluated baseline pulmonary function tests of 3,806 heavy smokers undergoing annual chest CT screening, and compared the Forced Expiratory Volume in 1 second % predicted (FEV₁PP) of 57 lung cancer cases and that of 3,749 subjects without cancer.

We obtained odds ratios (OR) of lung cancer and the corresponding 95% confidence intervals (CI) by unconditional logistic regression, adjusting for age, sex, study, and smoking variables. As compared to subjects with FEV₁PP 90%, the OR of lung cancer was 2.45 (95% CI: 1.39–4.33) for subjects with FEV₁PP <90% and 2.90 (95% CI: 1.34–6.27) for subjects with FEV₁PP <70%.

These data show that even a relatively small reduction in FEV₁PP is a significant predictor of increased lung cancer risk. Testing screening for lung cancer using airflow obstruction with FEV₁PP less than 90% is a strategy worth future consideration.