What does the stage of a cancer mean?
The stage of a cancer is how much cancer there is and how far it has spread in your body. Your healthcare provider uses exams and tests to find out the size of the tumor and where it is. Scans can also show if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.
Esophageal cancer starts in the inner lining of the esophagus. This is the swallowing tube that connects your mouth to your stomach. As esophageal cancer grows, it can grow through the layers of the wall of the esophagus into nearby tissues. Then, like all cancers, it can spread (metastasize) to other parts of the body.
The TNM system for esophageal cancer
The most commonly used system to stage esophageal cancer is the TNM system from the American Joint Committee on Cancer. Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.
The first step in staging is to find the value for each part of the TNM system. Here's what the letters stand for in the TNM system:
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T tells how much the main (primary) tumor has grown inside the esophagus and into nearby tissues.
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N tells if the lymph nodes near the primary tumor have cancer in them.
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M tells if the cancer has spread ( metastasized) to distant organs in the body, like the liver or lungs.
Numbers or letters after T, N, and M provide more details about each of these factors. There are also two other values that can be assigned:
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X means the provider does not have enough information to tell the extent of the main tumor (TX), or if the lymph nodes have cancer cells in them (NX).
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0 means no sign of cancer, such as no sign of spread to the lymph nodes (N0).
For esophageal cancer, the grade (G) is also important. The grade is based on how much the cancer cells look like normal cells. The cancer cells are graded on a scale from 1 to 3. But X can be used too, if the grade is unknown. Lower grade cancers look more like normal cells. They tend to grow and spread more slowly than higher grade cancers.
What are the stage groupings of esophageal cancer?
The T, N, M values from the TNM system and the grade (G) are used to put these cancers into stage groupings. These groupings give an overall description of your cancer. A stage grouping is listed as a Roman numeral and can have a value of I (1), II (2), III (3), or IV (4). The higher the number, the more advanced the cancer is. Letters and numbers can be used after the Roman numeral to give more details.
The stages for esophageal cancer are slightly different depending on if the cancer is an adenocarcinoma or a squamous cell carcinoma.
Stage groupings of esophageal adenocarcinoma
Stage 0 (high-grade dysplasia). Cancer is found only in the inner layer of cells that line the esophagus. It has not spread to deeper layers of the wall of the esophagus or outside the esophagus. Grade isn't used.
Stage I. The cancer has not spread to lymph nodes or distant parts of the body. This stage is divided into three groups:
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Stage IA. The cancer has grown from the inner layer of cells to the next two layers in the wall of the esophagus. Grade isn't known (GX) or it's G1.
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Stage IB. The cancer has grown from the inner layer of cells to the layers deeper in the wall of the esophagus. Grade is GX, G1, or G2.
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Stage IC. The cancer has grown from the inner layer of cells deeper into the wall, and maybe to the thick muscle layer deep in the wall of the esophagus called the muscularis propria. Grade is G1, G2, or G3.
Stage II. The cancer has not spread to distant parts of the body. This stage is divided into two groups:
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Stage IIA. The cancer has grown into the thick muscle layer of the esophagus (muscularis propria). It has not spread to nearby lymph nodes. Grade is GX or G3.
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Stage IIB. The cancer is any grade, and one of these is true:
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The cancer has grown from the inner layer of cells to the next three layers in the wall of the esophagus and has spread to one or two nearby lymph nodes.
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The cancer has grown into the outer layer of the esophagus, but has not spread to nearby lymph nodes.
Stage III. The cancer has not spread to distant parts of the body. It can be any grade. This stage is divided into two groups:
Stage IV. The cancer can be any grade and is divided into these two groups:
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Stage IVA. The cancer hasn't spread to distant parts of the body, and one of these is true:
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It has grown into any layer(s) of the wall of the esophagus and has spread to seven or more nearby lymph nodes.
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It has grown into the pleura, the pericardium, or the diaphragm, and it has spread to no more than six nearby lymph nodes.
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It's growing into the windpipe (trachea), the large blood vessel that carries blood away from the heart (the aorta), the spine, or other key organs, and it has spread to no more than six nearby lymph nodes.
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Stage IVB. Cancer has spread to other parts of the body, such as distant lymph nodes, the liver, or the lungs.
Stage groupings of esophageal squamous cell carcinoma
Where the cancer is in the esophagus affects some stage groupings of squamous cell carcinoma:
Stage 0 (high-grade dysplasia). Cancer is found only in the inner layer of cells anywhere in the esophagus. It has not spread to deeper layers of the wall of the esophagus. Grade isn't used.
Stage I. The cancer has not spread to lymph nodes or distant parts of the body. This stage is divided into two groups:
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Stage IA. The cancer has grown from the inner layer of cells to the next two layers anywhere in the wall of the esophagus. Grade isn't known (GX) or it's G1.
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Stage IB. The cancer has grown from the inner layer of cells deeper into the wall, and maybe to the thick muscle layer deep in the wall of the esophagus (muscularis propria). It can be anywhere in the esophagus. Grade may be unknown (GX) or it can be any grade.
Stage II. The cancer has not spread to distant parts of the body. This stage is divided into two groups:
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Stage IIA. The cancer has not spread to nearby lymph nodes, and one of these is true:
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It has grown into the muscularis propria anywhere in the esophagus. Grade is GX, G2, or G3.
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It has grown through the wall of the esophagus to the outer layer. It can be any grade and in the lower esophagus, or it can be G1 and in the middle or upper esophagus.
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Stage IIB. The cancer has not spread to distant parts of the body, and one of these is true:
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The cancer has grown through the wall of the esophagus to the outer layer, but not to nearby lymph nodes. It can be:
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Any grade and the part of the esophagus it's in isn't known
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The grade can be unknown (GX) and it can be anywhere in the esophagus
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G2 or G3 and in the middle or upper esophagus
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It has grown through the wall of the esophagus to the outer layer and has spread to one or two nearby lymph nodes. It can be any grade and anywhere in the esophagus.
Stage III. The cancer has not spread to distant parts of the body. This stage is divided into two groups:
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Stage IIIA. The cancer has not grown past the muscle layer (muscularis propria) of the esophagus, and it has spread to no more than six nearby lymph nodes. It can be any grade and anywhere in the esophagus.
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Stage IIIB. The cancer can be any grade, anywhere in the esophagus, and one of these is true:
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It has grown into the outer layer of the esophagus wall and it has spread to no more than six nearby lymph nodes.
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It has grown through the muscularis propria and has spread to no more than six nearby lymph nodes.
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It's growing into the tissue that covers the lungs (the pleura), the sac around the heart (the pericardium), or the breathing muscle (the diaphragm) that separates the chest and the belly (abdomen). It may or may not have spread to one or two nearby lymph nodes.
Stage IV. The cancer can be any grade, anywhere in the esophagus, and is divided into these two groups:
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Stage IVA. The cancer hasn't spread to distant parts of the body, and one of these is true:
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It has grown into any layer(s) of the wall of the esophagus and has spread to seven or more nearby lymph nodes.
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It has grown into the pleura, the pericardium, or the diaphragm, and it has spread to no more than six nearby lymph nodes.
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It's growing into the windpipe (trachea), the large blood vessel that carries blood away from the heart (the aorta), the spine, or other key organs, and it has spread to no more than six nearby lymph nodes.
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Stage IVB. Cancer has spread to other parts of the body, such as distant lymph nodes, the liver, or the lungs.