Assessing the relationship between lung cancer risk and emphysema detected on low-dose CT of the chest.

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

Emphysema scores predict death from COPD and lung cancer

OBJECTIVE: Our objective was to assess the usefulness of emphysema scores in predicting death from COPD and lung cancer. METHODS: Emphysema was assessed with low-dose CT scans performed on 9,047 men and women for whom age and smoking history were documented. Each scan was scored according to the presence of emphysema as follows: none, mild, moderate, or marked. Follow-up time was calculated from time of CT scan to time of death or December 31, 2007, whichever came first. Cox regression analysis was used to calculate the hazard ratio (HR) of emphysema as a predictor of death. RESULTS: Median age was 65 years, 4,433 (49%) were men, and 4,133 (46%) were currently smoking or had quit within 5 years. Emphysema was identified in 2,637 (29%) and was a significant predictor of death from COPD (HR, 9.3; 95% CI, 4.3-20.2; P < .0001) and from lung cancer (HR, 1.7; 95% CI, 1.1-2.5; P = .013), even when adjusted for age and smoking history. CONCLUSIONS: Visual assessment of emphysema on CT scan is a significant predictor of death from COPD and lung cancer

The global burden of pulmonary diseases: most prevalent problems and opportunities for improvement

Diseases of the respiratory system are a leading cause of morbidity, mortality and disability worldwide. The lungs are constantly exposed to a myriad of noxious agents present in ambient air, such as particles, chemicals and infectious organisms. At least 2 billion people are exposed globally to the toxic smoke produced by combustion of biomass fuel, inefficiently burned in poorly ventilated indoor stoves or fireplaces used for cooking or warming. One billion people inhale polluted outdoor air, and another billion are exposed primarily or secondarily to tobacco smoke. As a consequence, respiratory disease is a major cause of morbidity, disability and death worldwide primarily affecting individuals of low socioeconomic status, who are exposed to crowding, environmental exposures and poor living conditions

The global burden of pulmonary diseases: most prevalent problems and opportunities for improvement

Diseases of the respiratory system are a leading cause of morbidity, mortality and disability worldwide. The lungs are constantly exposed to a myriad of noxious agents present in ambient air, such as particles, chemicals and infectious organisms. At least 2 billion people are exposed globally to the toxic smoke produced by combustion of biomass fuel, inefficiently burned in poorly ventilated indoor stoves or fireplaces used for cooking or warming. One billion people inhale polluted outdoor air, and another billion are exposed primarily or secondarily to tobacco smoke. As a consequence, respiratory disease is a major cause of morbidity, disability and death worldwide primarily affecting individuals of low socioeconomic status, who are exposed to crowding, environmental exposures and poor living conditions

Emphysema scores predict death from COPD and lung cancer

OBJECTIVE: Our objective was to assess the usefulness of emphysema scores in predicting death from COPD and lung cancer. METHODS: Emphysema was assessed with low-dose CT scans performed on 9,047 men and women for whom age and smoking history were documented. Each scan was scored according to the presence of emphysema as follows: none, mild, moderate, or marked. Follow-up time was calculated from time of CT scan to time of death or December 31, 2007, whichever came first. Cox regression analysis was used to calculate the hazard ratio (HR) of emphysema as a predictor of death. RESULTS: Median age was 65 years, 4,433 (49%) were men, and 4,133 (46%) were currently smoking or had quit within 5 years. Emphysema was identified in 2,637 (29%) and was a significant predictor of death from COPD (HR, 9.3; 95% CI, 4.3-20.2; P < .0001) and from lung cancer (HR, 1.7; 95% CI, 1.1-2.5; P = .013), even when adjusted for age and smoking history. CONCLUSIONS: Visual assessment of emphysema on CT scan is a significant predictor of death from COPD and lung cancer