Overview

Lung cancer is the most common cancer and the leading cause of cancer death worldwide, claiming more than one million lives annually (Stewart and Kleihues, 2003). Because patients with lung cancer usually do not experience symptoms until the disease has advanced, most patients are diagnosed in later stages of the disease with poor prognoses.

The leading cause of lung cancer is exposure to tobacco smoke. Smoking causes approximately 90% of lung cancer deaths in men and 80% in women (USDHHS, 2004). Non-smokers who are exposed to secondhand tobacco smoke at home, work, or in social settings are also at an increased risk.

Other risk factors for lung cancer have been identified, some of which are synergistic with smoking. Exposure to environmental carcinogens such as asbestos, radon, workplace chemicals and air pollution as well as diets low in fruits and vegetables increase risk (Boffetta, 2004; Miller et al., 2004). A personal history of lung diseases such as chronic obstructive pulmonary disease and tuberculosis, a previous diagnosis of lung cancer, or a family history of lung cancer may also increase susceptibility (Ardies, 2003; Economou et al., 1994).

Research evidence

The majority of patients are diagnosed with lung cancer after they start experiencing symptoms and have advanced disease. Physical symptoms include fatigue, difficulty in breathing, cough, pain, spitting blood and loss of appetite (Hollen et al., 1999).