Stomach Cancer Stages

After someone is diagnosed with stomach cancer, doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of a cancer describes the extent of the cancer in the body. It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer's stage when talking about survival statistics.

The earliest stage stomach cancers are called stage 0 (carcinoma in situ), and then range from stages I (1) through IV (4). As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means cancer has spread more. Although each person’s cancer experience is unique, cancers with similar stages tend to have a similar outlook and are often treated in much the same way.

How is the stage determined?

The staging system most often used for stomach cancer is the American Joint Committee on Cancer (AJCC) TNM system, which is based on 3 key pieces of information:

  • The extent (size) of the tumor (T): How far has the cancer grown into the 5 layers of the stomach wall? Has the cancer reached nearby structures or organs?

illustration showing the stomach with a detailed cross-section of its layers: the mucosa, submucosa, muscularis propria, subserosa and serosa

The innermost layer is the mucosa. The mucosa has 3 parts: epithelial cells, which lie on top of a layer of connective tissue (the lamina propria), which is on top of a thin layer of muscle (the muscularis mucosa). Under the mucosa is a supporting layer called the submucosa. Below this is the muscularis propria, a thick layer of muscle that moves and mixes the stomach contents. The next 2 layers, the subserosa and the outermost serosa, act as wrapping layers for the stomach.

  • The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes?
  • The spread (metastasis) to distant sites (M): Has the cancer spread to distant lymph nodes or distant organs such as the liver or lungs?

The system described below is the most recent AJCC system, effective January 2018. This system is for staging all stomach cancers except those starting in either the gastroesophageal junction (where the stomach and the esophagus meet) or in the cardia (the first part of the stomach) and growing into the gastroesophageal junction. Those cancers are staged (and often treated) like cancers of the esophagus (See Esophagus Cancer).

Numbers or letters after T, N, and M provide more details about each of these factors. Higher numbers mean the cancer is more advanced. Once a person’s T, N, and M categories have been determined, this information is combined in a process called stage grouping to assign an overall stage. For more information see Cancer Staging.

The staging system in the table below is the pathologic stage (also called the surgical stage). It is determined by examining tissue removed during an operation.

Sometimes, if surgery is not possible right away or at all, the cancer will be given a clinical stage instead. This is based on the results of a physical exam, biopsy, and imaging tests, not on what is found at surgery. The clinical stage will be used to help plan treatment. Sometimes, though, the cancer has spread further than the clinical stage estimates, and may not predict the patient’s outlook as accurately as a pathologic stage.

Other staging systems have been created if your cancer has been clinically staged or if you have had surgery or neoadjuvant therapy. It is best to talk to your doctor about your specific stage for those situations.

Cancer staging can be complex, so ask your doctor to explain it to you in a way you understand.

AJCC Stage

Stage grouping

Stage description*

0

 

Tis

N0

M0

There is high grade dysplasia (very abnormal looking cells) in the stomach lining OR there are cancer cells only in the top layer of cells of the mucosa (innermost layer of the stomach) and have not grown into deeper layers of tissue such as the lamina propria (Tis). This stage is also known as carcinoma in situ (Tis). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

IA

 

T1

N0

M0

The tumor has grown from the top layer of cells of the mucosa into the next layers below such as the lamina propria, the muscularis mucosa, or submucosa (T1).

It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IB

 

 

T1

N1

M0

The cancer has grown from the top layer of cells of the mucosa into the next layers below such as the lamina propria, the muscularis mucosa, or submucosa (T1) AND it has spread to 1 to 2 nearby lymph nodes (N1).

It has not spread to distant sites (M0).

OR

T2

N0

M0

The cancer is growing into the muscularis propria layer (T2).  

It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

 

IIA

T1

N2

M0

The cancer has grown from the top layer of cells of the mucosa into the next layers below such as the lamina propria, the muscularis mucosa, or submucosa (T1) AND it has spread to 3 to 6 nearby lymph nodes (N2).

It has not spread to distant sites (M0).

OR

T2

N1

M0

The cancer is growing into the muscularis propria layer (T2) AND it has spread to 1 to 2 nearby lymph nodes (N1) but not to distant sites (M0).

OR

T3

N0

M0

The cancer is growing into the subserosa layer (T3).

It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IIB

 

T1

N3a

M0

The cancer has grown from the top layer of cells of the mucosa into the next layers below such as the lamina propria, the muscularis mucosa, or submucosa (T1) AND it has spread to 7 to 15 nearby lymph nodes (N3a).

It has not spread to distant sites (M0).

OR

T2

N2

M0

The cancer is growing into the muscularis propria layer (T2) AND it has spread to 3 to 6 nearby lymph nodes (N2). It has not spread to distant sites (M0).

 

 

T3

N1

M0

The cancer is growing into the subserosa layer (T3) AND AND it has spread to 1 to 2 nearby lymph nodes (N1) but not to distant sites (M0).

OR

T4a

N0

M0

The tumor has grown through the stomach wall into the serosa, but the cancer hasn’t grown into any of the nearby organs or structures (T4a). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IIIA

 

T2

N3a

M0

The cancer is growing into the muscularis propria layer (T2) AND it has spread to 7 to 15 nearby lymph nodes (N3a). It has not spread to distant sites (M0).

OR

T3

N2

M0

The cancer is growing into the subserosa layer (T3) AND it has spread to 3 to 6 nearby lymph nodes (N2).

It has not spread to distant sites (M0).

OR

T4a

N1

M0

The cancer has grown through the stomach wall into the serosa, but it has not grown into any of the nearby organs or structures (T4a). 

It has spread to 1 to 2 nearby lymph nodes (N1) but not to distant sites (M0).

OR

T4a

N2

M0

The cancer has grown through the stomach wall into the serosa, but it has not grown into any of the nearby organs or structures (T4a).

It has spread to 3 to 6 nearby lymph nodes (N1) but not to distant sites (M0).

OR

T4b

N0

M0

The cancer has grown through the stomach wall and into nearby organs or structures (T4b). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IIIB

 

T1

N3b

M0

The cancer has grown from the top layer of cells of the mucosa into the next layers below such as the lamina propria, the muscularis mucosa, or submucosa (T1) AND it has spread to 16 or more nearby lymph nodes (N3b).

It has not spread to distant sites (M0).

OR

T2

N3b

M0

The cancer is growing into the muscularis propria layer (T2) AND it has spread to 16 or more nearby lymph nodes (N3b).

It has not spread to distant sites (M0).

OR

T3

N3a

M0

The cancer is growing into the subserosa layer (T3) AND it has spread to 7 to 15 nearby lymph nodes (N3a).

It has not spread to distant sites (M0).

OR

T4a

N3a

M0

The cancer has grown through the stomach wall into the serosa, but it has not grown into any of the nearby organs or structures (T4a) AND it has spread to 7 to 15 nearby lymph nodes (N3a).

It has not spread to distant sites (M0).

OR

T4b

N1

M0

The cancer has grown through the stomach wall and into nearby organs or structures (T4b).

It has spread to 1 to 2 nearby lymph nodes (N1) but not to distant sites (M0).

OR

T4b

N2

M0

The cancer has grown through the stomach wall and into nearby organs or structures (T4b).

It has spread to 3 to 6 nearby lymph nodes (N1) but not to distant sites (M0).

IIIC

T3

N3b

M0

The cancer is growing into the subserosa layer (T3) AND it has spread to 16 or more nearby lymph nodes (N3b).

It has not spread to distant sites (M0).

OR

T4a

N3b

M0

The cancer has grown through the stomach wall into the serosa, but it has not grown into any of the nearby organs or structures (T4a) AND it has spread to 16 or more nearby lymph nodes (N3b).

It has not spread to distant sites (M0).

OR

T4b

N3a

M0

The cancer has grown through the stomach wall and into nearby organs or structures (T4b) AND it has spread to 7 to 15 nearby lymph nodes (N3a).

It has not spread to distant sites (M0).

OR

T4b

N3b

M0

The cancer has grown through the stomach wall and into nearby organs or structures (T4b) AND it has spread to 16 or more nearby lymph nodes (N3b).

It has not spread to distant sites (M0).

IV

Any T

Any N

M1

The cancer can grow into any layers (Any T) and might or might not have spread to nearby lymph nodes (Any N).

It has spread to distant organs such as the liver, lungs, brain, or the peritoneum (the lining of the space around the digestive organs) (M1).

 

* The T categories are described in the table above, except for: TX: Main tumor cannot be assessed due to lack of information. T0: No evidence of a primary tumor. The N categories are described in the table above, except for: NX: Regional lymph nodes cannot be assessed due to lack of information.

 

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

American Joint Committee on Cancer. Stomach Cancer. In: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer; 2017: 117–121. 

Last Medical Review: December 18, 2017 Last Revised: December 18, 2017

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