There are two main forms of lung cancer – small cell lung cancer and non-small cell lung cancer.
There are several types of non-small cell lung cancer characterized by different kinds of cancer cells. The cancer cells of each type grow and spread in different ways. The most common types of non-small cell lung cancer are squamous cell carcinoma that begins in the thin, flat squamous cells; large cell carcinoma; and adenocarcinoma, which begins in the cells that line the alveoli. Other less common types of non-small cell lung cancer are: pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.
There are two types of small cell lung cancer – small cell carcinoma, also called oat cell cancer, and combined small cell carcinoma.
According to estimates by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program, 222,500 patients will be diagnosed with lung and bronchus cancer and 155,870 patients die of the disease in the United States in 2017. The five year survival rate for these cancer is 18.1 percent.
Smoking cigarettes, pipes, or cigars is the most common cause of lung cancer. Other risk factors for lung cancer include being exposed to secondhand smoke, having a family history of lung cancer, being treated with radiation therapy to the breast or chest, exposure to asbestos, chromium, nickel, arsenic, soot, or tar in the workplace, and exposure to radon. When smoking is combined with other risk factors, the risk of lung cancer is increased.
Source: National Cancer Institute