Biomarkers in Exhaled Breath Condensate and Serum of Chronic Obstructive Pulmonary Disease and Non-Small-Cell Lung Cancer

Figure 2

Smoking is the major cause of COPD and lung cancer. Oxidants in cigarette smoking are not only a direct cause of lung cancer by DNA damage through protein and lipid peroxidation but also an indirect cause by triggering inflammation. While products of recruited inflammatory mediators cause COPD by degrading lung matrix and promoting mucus hypersecretion, COPD is itself a disease of chronic inflammation which promotes tumorigenesis.