Non-small cell lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The lungs are a pair of sponge-like breathing organs that are found within the chest. The lungs bring oxygen into the body and take out carbon dioxide, which is a waste product of the body’s cells. Each lung has sections called lobes. The left lung has 2 lobes. The right lung, which is slightly larger, has 3 lobes. A thin membrane called the pleura surrounds the lungs. Two tubes called bronchi lead from the trachea (windpipe) to the right and left lungs. The bronchi are sometimes also involved in lung cancer. Tiny air sacs called alveoli and small tubes bronchioles make up the inside of the lungs.

There are 3 common types of non-small cell lung cancer. Each of these types affect different kinds of cells which grow and spread in different ways. The types of non-small cell lung cancers are named for the kinds of cells seen under the microscope.

1. Squamous cell carcinoma: Cancer that begins in squamous cells, which are thin, flat cells that look like fish scales. This is also called epidermoid carcinoma.
2. Adenocarcinoma: Cancer that begins in cells that have glandular (secretory) properties.
3. Large cell carcinoma: Cancer in which the cells are large and look abnormal when viewed under a microscope.

What you need to know about lung cancer