The staging of lung cancer refers to the extent of the disease.
If you have the most common form of lung cancer, or non-small cell lung cancer, it will be staged
according to the size of the tumor and whether it has spread to the lymph nodes or other organs of the body.
In the Occult, or hidden, stage, cancer cells are found in coughed-up mucus, or in other lung fluids, but no tumor can be seen in the lungs.
Stage Zero is not considered invasive because the cancer cells are found in the innermost lining of the air passages but have not grown through it.
Stage One-A is considered invasive cancer because the tumor has grown through the inner lining of the airways into the deep lung tissue.
When measured, the tumor is no more than three centimeters in diameter and has not spread to the bronchi, lymph nodes or distant sites.
In Stage One-B, the diameter of the tumor is larger than three centimeters, or has spread to a main bronchus, or has grown through the lung into the inner layer of the pleura.
In Stage Two-A, the tumor is no more than three centimeters across, but it has spread to nearby lymph nodes on the same side of the chest as the tumor.
There are two scenarios that can occur with Stage Two-B lung cancer.
One, where cancer cells have not spread to nearby lymph nodes, but have invaded the chest wall, diaphragm, pleura, the membranes surrounding the heart, or a main bronchus.
In the second scenario for Stage Two-B, the cancer has spread to the lymph nodes on the same side of the chest as the tumor.
Also, the tumor is larger than three centimeters across, or has grown into a main bronchus, or has grown through the lung into the pleura.
In Stage Three-A, the tumor may be any size, and the cancer cells have spread to the lymph nodes on the same side as the lung tumor.
Also, the cancer may have spread to the chest wall, diaphragm, pleura, the membranes around the heart, or a main bronchus, but not the trachea.
In Stage Three-B, the tumor may be any size and has spread to lymph nodes above the collarbone or on the other side of the chest.
The cancer may have spread to nearby structures such as the heart, major heart vessels,
diaphragm, chest wall, trachea, esophagus, breast bone, or to more than one place in the same lung.
In Stage Four, cancer has spread to other lobes of the same lung or into the opposite lung, and has spread to other parts of the body,
such as the brain, liver, kidneys, adrenal glands, or bone.