This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by de Torres, J. P. Articles by Zulueta, J. J. Search for Related Content PubMed PubMed Citation Articles by de Torres, J. P. Articles by Zulueta, J. J.

Assessing the Relationship Between Lung Cancer Risk and Emphysema Detected on Low-Dose CT of the Chest^*

^* From the Departments of Respiratory Diseases (Drs. de Torres, Alcaide, Campo, Seijo, and Zulueta), Radiology (Drs. Bastarrika, Pueyo, and Villanueva), and Pathology (Dr. Lozano), University Clinic of Navarra, University of Navarra, Navarra, Spain; Division of Pulmonary and Critical Care Medicine, Mount Sinai School of Medicine (Dr. Wisnivesky), New York, NY; and Centre for Applied Medical Research-CIMA (Ms. Montes and Dr. Montuenga), University of Navarra, Navarra, Spain.

Correspondence to: Javier J. Zulueta, MD, FCCP, Department of Respiratory Diseases, Clínica Universitaria de Navarra, Avda. Pío XII, 36, 31008 Pamplona, Spain; e-mail: jzulueta{at}unav.es

Abstract

Rationale: Identification of risk factors for lung cancer can help in selecting patients who may benefit the most from smoking cessation interventions, early detection, or chemoprevention.

Objective: To evaluate whether the presence of emphysema on low-radiation-dose CT (LDCT) of the chest is an independent risk factor for lung cancer.

Methods: The study used data from a prospective cohort of 1,166 former and current smokers participating in a lung cancer screening study. All individuals underwent a baseline LDCT and spirometry followed by yearly repeat LDCT studies. The incidence density of lung cancer among patients with and without emphysema on LDCT was estimated. Stratified and multiple regression analyses were used to assess whether emphysema is an independent risk factor for lung cancer after adjusting for age, gender, smoking history, and the presence of airway obstruction on spirometry.

Results: On univariate analysis, the incidence density of lung cancer among individuals with and without emphysema on LDCT was 25.0 per 1,000 person-years and 7.5 per 1,000 person-years, respectively (risk ratio [RR], 3.33; 95% confidence interval [CI], 1.41 to 7.85). Emphysema was also associated with increased risk of lung cancer when the analysis was limited to individuals without airway obstruction on spirometry (RR, 4.33; 95% CI, 1.04 to 18.16). Multivariate analysis showed that the presence of emphysema (RR, 2.51; 95% CI, 1.01 to 6.23) on LDCT but not airway obstruction (RR, 2.10; 95% CI, 0.79 to 5.58) was associated with increased risk of lung cancer after adjusting for potential cofounders.

Conclusions: Results suggest that the presence of emphysema on LDCT is an independent risk factor for lung cancer.

Key Words: airway obstruction • CT • emphysema • lung cancer • risk factors