Lung cancer is cancer that starts in the lungs, typically in cells that are in the air passages. Your lungs are part of the respiratory system and help you breathe. Tumors in your lungs may be benign or malignant; it is only the malignant tumors that are considered lung cancer.
Significance
The National Cancer Institute estimates that in 2009, approximately 219,440 new cases of lung cancer will be diagnosed in the United States. Lung cancer kills more people every year than colon, ovarian, prostate, lymph and breast cancers combined.
Types
There are two types of lung cancer: small cell lung cancer and non-small cell lung cancer. Small cell lung cancer makes up nearly 13 percent of lung cancer cases and is aggressive. Non-small cell lung cancer makes up the remaining 87 percent of diagnoses and grows more slowly.
Risk Factors
Risk factors for developing lung cancer include smoking cigarettes, second-hand smoke exposure, a family history of lung cancer, high levels of alcohol use and exposure to asbestos or other chemicals.
Signs and Symptoms
Typically, early lung cancer does not have any symptoms. As the cancer advances, some symptoms that appear may include a cough that does not go away, changes in a cough that has become chronic, coughing up blood, wheezing, shortness of breath, chest pain, weight loss, bone pain and headache.
Signs of Late-Stage Lung Cancer
As lung cancer progresses, it can cause additional symptoms. These include pain, especially if it has spread to the bones; pneumonia; and fluid buildup around or in the lungs. If it spreads to the brain, it can cause seizures, headaches and mobility and balance problems.
