Your doctor may strongly suspect you have lung cancer, or found you have it. The next step is to describe the cancer, such as the size of a tumor and if it has spread. This description is called the cancer stage. MSK’s thoracic (lung) surgeons, lung specialists, and radiologists will define your stage as quickly as possible. They will plan diagnostic procedures that will let them learn the stage of the cancer.

Staging is based on:

• The size and location of the original tumor (also called the primary tumor)
• Whether the cancer has metastasized (spread) to nearby lymph nodes
• Whether the cancer has metastasized (spread) to other organs

Staging is an important step in choosing the best treatment for you. The stage of your cancer also helps doctors predict the outcome (result) of your treatment. To do this, we may recommend you have more tests, including imaging or biopsies.  

Imaging tests to help learn the cancer stage include:

• Computed tomography (CT) scans
• Positron emission tomography (PET)/CT scans
• Magnetic resonance imaging (MRI) of the brain

Doctors use the same staging system for both non-small cell and small cell lung cancer. Small cell lung cancer usually is diagnosed at a later stage than non-small cell lung cancer. It often is diagnosed at stage 3 or 4.
 

Stages of Lung Cancer 

Stage I (1) Lung Cancer

In stage 1, the tumor is only in the lung. It is bit small (4 centimeters or less). It has not spread to nearby lymph nodes or outside the chest. Most stage 1 tumors are treated with surgery. 
We offer patients who cannot have surgery radiation therapy instead. Most stage 1 patients do not need chemotherapy, targeted therapy, or immunotherapy.

Stage II (2) Lung Cancer

In stage 2 lung cancer, there are larger tumors (more than 4 centimeters). Or, there are signs the cancer has spread to nearby lymph nodes, but not outside the lung.  We usually treat stage 2 lung cancer with surgery, followed by chemotherapy and targeted therapies or immune therapies. We often offer patients who cannot have surgery chemotherapy and radiation instead.

Stage III (3) Lung Cancer

In stage 3 lung cancer, there is cancer in lymph nodes of the chest further away from the lung. Or, there may be large tumors that spread to nearby lymph nodes.  Most people with stage 3 cancer have several kinds of treatment. This includes some combination of chemotherapy, surgery, radiation, targeted therapies, and immune therapies. 

Stage IV (4) Lung Cancer

In stage 4 lung cancer, there is cancer outside the chest cavity where it started.  The most common areas are the other lung, bones, brain, and the adrenal gland (a gland on top of the kidneys). Treatment depends on the tumor. It can include chemotherapy, targeted or immune therapies, or a combination.

Treatment Expertise for All Stages of Lung Cancer

MSK led the way in setting the standard of care for treating every stage of cell lung cancer. Doctors everywhere follow best practices developed at MSK. 

For example, MSK led a large research study that showed the standard treatment for stage 1 non-small cell lung cancer should be a lobectomy. In this procedure, a complete lobe of the lung is removed. There are 3 lobes in the right lung and 2 in the left. 

MSK also helped determine the best time to give chemotherapy to people who have stage 2 and 3 cancer. 

Advances made at MSK in 2021 offer new hope to people facing some of the most difficult and complex cancers. MSK researchers and doctors played a lead role in clinical trials that led to a new drug in 2021. The U.S. Food and Drug Administration (FDA) approved a drug that targets a protein, called KRAS, that fuels cancer growth. This protein may cause 1 out of 4 cases of lung cancers, but for decades it was considered “undruggable.” This treatment, called sotorasib (Lumakras™), is a new option for some people who have stage 3 or 4 non-small cell lung cancer.