Types of Lung Cancer
Lung cancer usually starts in the lining of the bronchi — the main airways of the lungs — but also can begin in other areas of the lungs, including the bronchioles or alveoli. It is the leading cause of cancer death in both men and women.
Lung cancers are believed to develop over a period of many years. Nearly all lung cancers are carcinomas, a cancer that begins in an organ's lining or covering tissues. The tumor cells of each type of lung cancer grow and spread differently, and each type requires different treatment.
Lung cancers are generally divided into two types:
Non-small Cell Lung Cancer
This type of lung cancer is much more common than small cell lung cancer, accounting for about 85–90% of lung cancers. The three main kinds of non-small cell lung cancer are named for the type of cells in the tumor:
- Squamous Cell Carcinoma:
- Also called epidermoid carcinoma, this type often begins in the bronchi, near the middle of the lungs.
- Adenocarcinoma:
- This type typically begins along the outer edges of the lungs. It is the most common type of lung cancer in people who have never smoked.
- Large Cell Carcinomas:
- They are a group of cancers with large, abnormal-looking cells. These tumors may begin anywhere in the lungs and tend to grow quickly.
Small Cell Lung Cancer
This type of lung cancer — sometimes called oat cell cancer because the cells may look like oats when viewed under a microscope — grows rapidly and quickly spreads to other organs. There are two stages of small-cell lung cancer:
- Limited:
- In this stage, cancer is generally found in only one lung. There also may be cancer in nearby lymph nodes on the same side of the chest.
- Extensive:
- In this stage, cancer has spread beyond the primary tumor in the lung into other parts of the body.
