Lung cancer is the most common cancer in the world and the leading cause of cancer death in the United States in both men and women. There were over 200,000 cases diagnosed in 2007 and the number of cases diagnosed each year continues to increase. Less than 15% of patients diagnosed live 5 years.
Increases in lung cancer risk are associated with exposure to cancer causing agents. The primary risk factor is smoking, but exposure to asbestos, radon, certain chemicals, chromium, nickel, and arsenic also increase risk.
Involvement of large airways can result in cough, wheezing, shortness of breath, coughing up blood, pneumonia or other infection. Tumors growing into bones or chest wall, or spread to other areas can cause pain. Unexplained weight loss may also be a symptom.
A detailed history taking and physical examination by a physician are two very important steps in evaluation. The chest x-ray is often the first study ordered and is often very valuable in the diagnosis. Computed tomography (CT or CAT scan) adds additional information about the tumor and if there is any possible spread to lymph nodes in the chest.
Needle aspiration/biopsy of lung tumors can obtain cells for positive identification of cancer. Using flexible fiber optic scopes, the trachea and airways can be examined and biopsies obtained for diagnosis. A small surgical incision and placement of a scope into the chest (mediastinoscopy) can evaluate lymph node spread and biopsies can be obtained.
Further scans and laboratory blood tests are generally ordered to evaluate for any spread of tumor outside of the chest area.