Cancer occurs when cells in the body divide without control or order. If cells keep dividing uncontrollably, a mass of tissue forms. This is called a growth or tumor. The term cancer refers to malignant tumors. They can invade nearby tissue and spread to other parts of the body.

Lung cancer is a disease in which cancer cells grow in the lungs. There are two types of lung cancers:

  • Non-small cell lung cancer—generally grows and spreads more slowly (more common form)
  • Small cell lung cancer—generally grows more quickly and is more likely to spread to other parts of the body

Lung Cancer
Copyright © Nucleus Medical Media, Inc.

The following can cause damage to the cells in the lungs, leading to lung cancer:

  • First- or second-hand smoke from cigarettes, cigars, or pipes
  • Exposure to asbestos (a type of mineral) or radon (radioactive gas)