To fine-tune their diagnosis of esophageal cancer, doctors will try to determine how deep into the esophagus tissue the cancer has grown and if it has spread and how far.

This process of diagnosing how much cancer is in the body and where it’s located is known as staging.

By staging, a doctor will zero in on how serious the cancer is and the best way to treat it. Staging is also used in describing statistics on survival.

There are four key steps in determining the stage of esophagus cancer:

  • TNM
  • treatment
  • grade
  • location

The first step of the staging system is commonly the TNM system from the American Joint Committee of Cancer:

  • Tumor. The “T” indicates the size of the tumor, including how far it has grown into the wall of the esophagus and if it’s reached other tissues or organs nearby.
  • Nodes. The “N” indicates whether or not the cancer has spread to nearby lymph nodes.
  • Metastasis. The “M” indicates if the cancer has spread to distant lymph nodes or organs such as the liver or the lungs.

Letters and numbers after each of the 3 letters offer greater detail. Higher numbers indicate that the cancer is more advanced.

There are a number of ways to treat esophageal cancer, so a stage has been designated for each treatment group.

  • Pathological stage. Also known as the surgical stage, this is where most cancers are staged. This stage is determined by tissue that was removed during surgery when surgery was done prior to other treatments.
  • Clinical stage. Determined by physical exam, imaging tests, and biopsy, this stage is for cancer that’s unable to be treated surgically or that must be treated prior to surgery being an option.
  • Post-neoadjuvant stage. Also known as the post-therapy stage, this is the determination of how much cancer remains after initial treatment, such as chemotherapy or radiation therapy.
  • Restaging. For cancer that’s come back after treatment, this is to determine the extent of the disease and identify the best treatment options.

Esophageal cancer is graded on a scale based on how closely the cancer resembles normal tissue when viewed through a microscope.

  • GX. It’s unknown or can’t be assessed.
  • Grade 1. Well differentiated, which is an indication that the cancer cells look more like normal esophagus tissue. Sometimes referred to as low grade. This tends to grow and spread more slowly than grade 3 cancer of the same stage.
  • Grade 2. Moderately differentiated, which is an indication that the cancer falls somewhere in between G1 and G3.
  • Grade 3. Poorly differentiated or undifferentiated, which is an indication that the cancer cells look less like normal esophagus tissue. This is sometimes referred to as high grade.

The location is indicated by the area of the esophagus where the middle of the tumor is located:

  • upper esophagus
  • middle esophagus
  • lower esophagus

Stage 0: High-grade dysplasia

  • The cancer is only in the top lining of the esophagus and hasn’t spread to lymph nodes or other parts of the body.
  • The cancer grade doesn’t apply.
  • The cancer can be located in either the upper, middle, or lower part of the esophagus.

Stage 1A

  • The cancer is in the top layers of the esophagus and hasn’t spread to lymph nodes or other parts of the body.
  • The cancer is grade 1 or an unknown grade.
  • The cancer can be located in either the upper, middle, or lower part of the esophagus.

Stage 1B

The cancer is in either of the following:

  • the top layers of the esophagus, but the cancer cells are less differentiated
  • the third layer of the esophagus, but it hasn’t spread to the lymph nodes or other parts of the body

The cancer can be:

  • any grade or an unknown grade
  • located in either the upper, middle, or lower part of the esophagus

Stage 2A

The cancer is:

  • growing into the thick muscle layer, but it hasn’t spread to the lymph nodes or other parts of the body

This cancer can be:

  • grade 2 or 3 or an unknown grade
  • located in either the upper, middle, or lower part of the esophagus

Another type of cancer in this stage is:

  • growing into the outer layer of the esophagus, but it hasn’t spread to the lymph nodes or other parts of the body

This cancer can be:

  • any grade
  • located in the lower esophagus

Another type of cancer in this stage is:

  • growing into the outer layer, but it hasn’t spread to the lymph nodes or other parts of the body

This cancer can be:

  • grade 1
  • located in the upper or middle esophagus

Stage 2B

The cancer is:

  • growing into the outer layer, but it hasn’t spread to the lymph nodes or other parts of the body

This cancer can be either:

  • grade 2 or 3 and located in the upper or middle esophagus
  • an unknown grade and located anywhere in the esophagus
  • any grade and have an unknown location in the esophagus

Another type of cancer in this stage is:

  • growing into the lamina propria, muscularis mucosa, or into the submucosa and has spread to one or two nearby lymph nodes

This cancer can be:

  • any grade and located anywhere in the esophagus

Stage 3A

  • The cancer is growing into the lamina propria, muscularis mucosa, submucosa, or the muscularis propria and it has spread to no more than six nearby lymph nodes. It hasn’t spread to other parts of the body.
  • The cancer can be any grade and can be located in either the upper, middle, or lower part of the esophagus.

Stage 3B

The cancer has any of the following properties:

  • It’s growing into the muscularis propria and has spread to no more than six nearby lymph nodes.
  • It’s growing into the adventitia and has spread to no more than six nearby lymph nodes.
  • It’s growing into the diaphragm, the pleura covering the surface of each lung, or the pericardium surrounding the heart. It has spread to no more than two nearby lymph nodes, but it hasn’t spread to distant organs.
  • It’s any grade and can be located in either the upper, middle, or lower part of the esophagus.

Stage 4A

The cancer is growing into any of the following:

  • the diaphragm, pleura, or pericardium and has spread to no more than six nearby lymph nodes
  • the trachea, aorta, spine, or other critical structures and no more than six nearby lymph nodes
  • any layers of the esophagus and has spread to seven or more nearby lymph nodes, but it hasn’t spread to other parts of the body

The cancer can be any grade and can be located in either the upper, middle, or lower part of the esophagus.

Stage 4B

  • The cancer has spread to distant lymph nodes or other parts of the body, such as the lungs or liver.
  • The cancer can be any grade and located in either the upper, middle, or lower part of the esophagus.

This description of the stages of squamous cell carcinoma is a simplified version of the TNM system. There are different stage descriptions for other cancers such as adenocarcinoma.

This description is meant to give you a basic understanding of the stages. Your doctor will provide you with more detailed information along with a treatment plan that specifically addresses those details.

The process a doctor goes through to determine the extent of cancer in the body is called staging. When staging esophageal cancer, doctors will try to describe the size and location of the cancer and whether it has spread and how far.

By determining a stage, a doctor can identify and communicate the severity of the condition to choose and direct the best treatment options.

Staging esophageal cancer can be complex. If you have any questions about the stage of your cancer or exactly what that stage means, have your doctor review the details. Be sure to ask for further clarification on points you don’t fully understand.