Final answer:
Lung cancers are divided into non–small cell lung cancer and small cell lung cancer. They originate from uncontrolled cell growth in lung tissues and are diagnosed through a biopsy. Lung cancer is one of the most common cancers and is most often associated with tobacco smoke exposure.
Step-by-step explanation:
Cancers that begin in the lungs are divided into two major types, non–small cell lung cancer and small cell lung cancer. These cancers are classified based on the appearance and size of the cancer cells under a microscope. Lung cancer is a malignant tumor characterized by uncontrolled cell growth in tissues of the lung and is one of the most common types of cancer, especially in adults over the age of 50. A definitive diagnosis requires a biopsy, where a tissue sample is examined microscopically by a pathologist.
The major carcinogens implicated in lung cancer, as in other common cancers like breast, colon, and stomach cancers, have been widely studied. For lung cancer, the most well-known carcinogen is tobacco smoke, which causes DNA damage over time. The damage accumulates and increases the risk of developing lung cancer, which can manifest as symptoms like coughing, wheezing, and shortness of breath.