The lungs are the two organs located beneath the rib cage that provide life-sustaining oxygen throughout the body. They are neither symmetrical nor functionally identical, with the left lung consisting of two lobes and the right three. Lung cancer begins when cells of a lung become abnormal and begin growing out of control. When the abnormal cancer cells grow, they can form into a tumor and even spread to other areas of the body (metastasize).
Lung cancer is designated by two types:
- Small Cell Lung Cancer (SCLC)
- Non-Small Cell Lung Cancer (NSCLC)
Both small cell lung cancer and non-small cell lung cancer are named for the kinds of cells found in the cancer and how the cells appear when viewed under a microscope. The cancer cells of each type grow and spread in different ways.
Small Cell Lung Cancer
The two general types of small cell lung cancer include:
- Small cell carcinoma (oat cell cancer)
- Combined small cell carcinoma
Smoking tobacco is the major risk factor for developing small cell lung cancer.
Non-Small Cell Lung Cancer
Each year in the United States, more than 226,000 people are diagnosed with non-small cell lung cancer. There are several different types of this cancer.
The three main types of non-small cell lung cancer include:
- Squamous cell carcinoma (epidermoid carcinoma)
- Large cell carcinoma
Other less common types of non-small cell lung cancer are: pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.
Smoking can increase the risk of developing non-small cell lung cancer.