Non-Small Cell Lung Cancer – Overview

When your cells are healthy, they grow and create new cells as your body needs them. But when you have lung cancer, the DNA of cells in your lung tissue is damaged, and the cells become cancerous. With lung cancer, DNA is usually damaged from cigarette smoking. But it can also be inherited (passed down) from a family member, or be caused by exposure to radon, secondhand smoke or other chemicals.

DNA is inside all of your cells and makes up your genes. It tells your cells how to act and what to do. Usually, when a cell’s DNA is damaged, it repairs itself or the cell dies. With cancer, the damaged cells don’t die, and they continue making new cancerous cells. These cells can build up and form a tumor. In your lungs, tumors can grow in the cells lining your bronchi, and in your bronchioles and alveoli.

How It Spreads

If they aren’t treated early, lung cancer cells can spread (metastasize) to other parts of your body. This can happen when:

cancer cells grow into nearby tissue
cancer cells break off from your original lung tumor and get into your bloodstream or lymph vessels

Lymph vessels are like blood vessels, but instead of blood, they carry clear lymph fluid. Cancer cells can spread through your lymph vessels and bloodstream to your lymph nodes (organs throughout your body that create and store cells to fight infection). Lung cancer cells can also spread to other organs. This can happen even before you have symptoms or before your cancer can be seen on an X-ray.

TIP: If lung cancer spreads to another part of your body, it is still made of lung cancer cells. For example, if lung cancer spreads to your bones, you have metastatic lung cancer, not bone cancer.