About Lung Cancer
Primary lung cancer (starts in the lungs) is divided into two types based on which cell type is affected.
Non-small cell lung cancer (NSCLC) - NSCLC refers to a group of lung cancers that are categorized based on their similar treatment options and outcomes. These subtypes account for about 85-90% of the lung cancers diagnosed each year in the United States.
Small cell lung cancer (SCLC) - SCLC is treated differently than NSCLC and has a different prognosis. This type is generally grows more quickly and is more likely to spread to other parts of the body. This subtype accounts for about 10-15% of the lung cancers diagnosed each year in the United States.
Mesothelioma is a rare type of cancer that typically affects the lining of the lungs, heart and abdomen. Mesothelioma is a rare type of cancer that typically affects the lining of the lungs, heart and abdomen. Mesothelioma is caused by asbestos exposure which occurs when fibers are inhaled or ingested into the body and become lodged in body cavities, causing inflammation or infection.
Anatomy of the Lungs
Human lungs are two spongy organs located on each side of the heart. During inhalation, air flows from the nose or mouth through the pharynx (throat) and larynx (which contain the vocal cords) into the trachea (wind pipe). The trachea divides into two bronchi, which direct air into the right and left lungs.
Within the lungs, the bronchi divide into several smaller bronchioles. Air flows from bronchioles into tiny air sacs, called alveoli. A group of alveoli is referred to as a lobule. Lobules are, in turn, grouped into lobes. The left lung contains two lobes, whereas the right contains three.
A network of tiny blood vessels, called capillaries, surrounds the alveoli. The lining of these blood vessels is so thin that oxygen and carbon dioxide can move between the capillaries and the alveoli. Carbon dioxide diffuses from the capillaries into the alveoli and is released from the body during exhalation. Oxygen diffuses in the opposite direction, from the alveoli into the blood, and is carried throughout the body by the circulatory system.