Claim: Lung cancer occurs in people.

Lung cancer , also known as lung carcinoma , is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung . This growth can spread beyond the lung by the process of metastasis into nearby tissue or other parts of the body . Most cancers that start in the lung , known as primary lung cancers , are carcinomas . The two main types are small-cell lung carcinoma -LRB- SCLC -RRB- and non-small-cell lung carcinoma -LRB- NSCLC -RRB- . The most common symptoms are coughing -LRB- including coughing up blood -RRB- , weight loss , shortness of breath , and chest pains .   The vast majority -LRB- 85 % -RRB- of cases of lung cancer are due to long-term tobacco smoking . About 10 -- 15 % of cases occur in people who have never smoked . These cases are often caused by a combination of genetic factors and exposure to radon gas , asbestos , second-hand smoke , or other forms of air pollution . Lung cancer may be seen on chest radiographs and computed tomography -LRB- CT -RRB- scans . The diagnosis is confirmed by biopsy which is usually performed by bronchoscopy or CT-guidance .   Avoidance of risk factors , including smoking and air pollution , is the primary method of prevention . Treatment and long-term outcomes depend on the type of cancer , the stage -LRB- degree of spread -RRB- , and the person 's overall health . Most cases are not curable . Common treatments include surgery , chemotherapy , and radiotherapy . NSCLC is sometimes treated with surgery , whereas SCLC usually responds better to chemotherapy and radiotherapy .   Worldwide in 2012 , lung cancer occurred in 1.8 million people and resulted in 1.6 million deaths . This makes it the most common cause of cancer-related death in men and second most common in women after breast cancer . The most common age at diagnosis is 70 years . Overall , 17.4 % of people in the United States diagnosed with lung cancer survive five years after the diagnosis , while outcomes on average are worse in the developing world .