Lung Cancer

STAGING

After lung cancer has been diagnosed, the patient will go through a staging workup. This includes tests such as a CT scan of the chest and sometimes a PET scan (Positron Emission Tomography) to define the extent of spread within the chest. Other testing may include an MRI of the brain, a CT scan of the abdomen and bone scan.

Staging depends on both the size of the primary tumor itself as well as spread. The spread of lung cancer takes place initially into the lymph nodes and eventually into the bloodstream. Once cancer is in the blood stream, it can metastasize to almost any part of the body.

Stage I lung cancer means that the disease has not spread into lymph nodes or distantly into any other part of the body. The cancer must also be confined to the lung and not invade into the mediastinum or chest wall.

Stage II cancer has spread into the chest wall or into the portion of the mediastinum immediately adjacent to the lung. Stage II disease can also include patients with positive lymph nodes in the hilum of the lung.

Stage III cancer means the cancer has spread into the central portion of the mediastinum either directly or via lymphatic channels into mediastinal lymph nodes.

Stage IV cancer implies metastasis to other parts of the body, such as the liver, bone, or brain.

HISTOLOGY

Histology refers to the appearance of the cancer under the microscope. The term “non-small cell lung cancer” at first may seem inexact. Actually this classification is quite reliable in predicting the biologic behavior of lung cancer.

As opposed to small cell lung cancer (also called “oat cell cancer”), non-small cell lung cancer tends to spread a little more slowly and tends to respond less quickly to chemotherapy or radiation therapy. Both of these factors would mitigate toward a surgical approach when possible (this is discussed further below).

Non-small cell lung cancer includes several sub-types, such as squamous cell cancer of the lung, adenocarcinoma of the lung, and so-called large cell undifferentiated cancer of the lung. All three of these sub-types behave in a similar manner, providing the rationale for combining them under the heading of “non-small cell lung cancer.”