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Stomach cancer

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Staging stomach cancer

Staging is a way of describing or classifying a cancer based on the extent of cancer in the body. Extent includes where the cancer is in the body. Your healthcare team uses the stage to plan treatment and estimate your prognosis.

The most common staging system for stomach cancer is the TNM system. Each stage is given a number from 0 to 4. Stages 1 to 4 are usually given as the Roman numerals I, II, III and IV. Generally, the higher the number, the more the cancer has spread.

When describing the stage, doctors may use the terms local, regional and distant. Local means that the cancer is only in the stomach and has not spread to other parts of the body. Regional means close to or around the stomach. Distant means in a part of the body farther from the stomach.

TNM descriptions

T describes the size of the primary tumour and if it has grown into tissues around the stomach. T is usually given as a number from 1 to 4. A higher number means that the tumour has grown farther into the layers of the stomach or into nearby tissues.

 

N describes the lymph nodes around the stomach. N0 means the cancer hasn’t spread to the lymph nodes. N1, N2 or N3 means cancer has spread to lymph nodes. N1 to N3 can also describe the number of lymph nodes that contain cancer.

 

M describes whether or not the cancer has spread, or metastasized, to other parts of the body. M0 means that cancer has not spread to other parts of the body. M1 means that it has spread to other parts of the body.

Stage 0

TNMDescription

Tis

N0

M0

Cancer is within the inner lining (mucosa) of the stomach and has not spread to the connective tissue layer of the mucosa (lamina propria) of the stomach. Also called carcinoma in situcarcinoma in situA very early stage of cancer in which tumour cells have not yet invaded surrounding tissues. or high grade dysplasiadysplasiaAbnormal development, appearance and organization of cells so that they are different from normal cells in size, shape and organization within tissue. Dysplasia almost always refers to a precancerous condition..

Stage IA

TNMDescription

T1

N0

M0

The tumour has grown into the lamina propria, the muscle layer of the mucosa (muscularis mucosae) or the submucosa.

T1a – The tumour has grown into the lamina propria or the muscularis mucosae.

T1b – The tumour has grown into the submucosa.

Stage IB

TNMDescription

T2

N0

M0

The tumour has grown into the main muscle layer of the stomach (muscularis propria).

T1

N1

M0

The tumour has grown into the lamina propria, the muscle layer of the mucosa (muscularis mucosae) or the submucosa.

T1a – The tumour has grown into the lamina propria or the muscularis mucosae.

T1b – The tumour has grown into the submucosa.

The cancer has spread to 1 or 2 lymph nodes around the stomach (called regional lymph nodes).

Stage IIA

TNMDescription

T3

N0

M0

The tumour has grown into the area of the stomach wall between the main muscle layer (muscularis propria) and the outer layer of the stomach (serosa) called the subserosa.

T2

N1

M0

The tumour has grown into the main muscle layer of the stomach (muscularis propria).

The cancer has spread to 1 or 2 lymph nodes around the stomach (called regional lymph nodes).

T1

N2

M0

The tumour has grown into the lamina propria, the muscle layer of the mucosa (muscularis mucosae) or the submucosa.

T1a – The tumour has grown into the lamina propria or the muscularis mucosae.

T1b – The tumour has grown into the submucosa.

The cancer has spread to 3 to 6 lymph nodes around the stomach.

Stage IIB

TNMDescription

T4a

N0

M0

The tumour has grown through the outer layer of the stomach (serosa).

T3

N1

M0

The tumour has grown into the area of the stomach wall between the main muscle layer (muscularis propria) and the outer layer of the stomach (serosa) called the subserosa.

The cancer has spread to 1 or 2 lymph nodes around the stomach (called regional lymph nodes).

T2

N2

M0

The tumour has grown into the main muscle layer of the stomach (muscularis propria).

The cancer has spread to 3 to 6 lymph nodes around the stomach.

T1

N3

M0

The tumour has grown into the lamina propria, the muscle layer of the mucosa (muscularis mucosae) or the submucosa.

T1a – The tumour has grown into the lamina propria or the muscularis mucosae.

T1b – The tumour has grown into the submucosa.

The cancer has spread to 7 or more lymph nodes around the stomach.

Stage IIIA

TNMDescription

T4a

N1

M0

The tumour has grown through the outer layer of the stomach (serosa).

The cancer has spread to 1 or 2 lymph nodes around the stomach (called regional lymph nodes).

T3

N2

M0

The tumour has grown into the area of the stomach wall between the main muscle layer (muscularis propria) and the outer layer of the stomach (serosa) called the subserosa.

The cancer has spread to 3 to 6 lymph nodes around the stomach.

T2

N3

M0

The tumour has grown into the main muscle layer of the stomach (muscularis propria).

The cancer has spread to 7 or more lymph nodes around the stomach.

Stage IIIB

TNMDescription

T4b

N0 or N1

M0

The tumour has grown into any organ or structure near the stomach.

The cancer may or may not have spread to 1 or 2 lymph nodes around the stomach (called regional lymph nodes).

T4a

N2

M0

The tumour has grown through the outer layer of the stomach (serosa).

The cancer has spread to 3 to 6 lymph nodes around the stomach.

T3

N3

M0

The tumour has grown into the area of the stomach wall between the main muscle layer (muscularis propria) and the serosa called the subserosa.

The cancer has spread to 7 or more lymph nodes around the stomach.

Stage IIIC

TNMDescription

T4a

N3

M0

The tumour has grown through the outer layer of the stomach (serosa).

The cancer has spread to 7 or more lymph nodes around the stomach (called regional lymph nodes).

T4b

N2 or N3

M0

The tumour has grown into any organ or structure near the stomach.

The cancer has spread to 3 or more lymph nodes around the stomach.

Stage IV

TNMDescription

any T

any N

M1

The tumour is anywhere in the stomach and may or may not have grown into the surrounding tissues.

The cancer may or may not have spread to lymph nodes around the stomach.

The cancer has spread to other parts of the body, such as the lungs, liver or bone (called a distant metastasis).

Recurrent stomach cancer

Recurrent stomach cancer means that the cancer has come back after it has been treated. If it comes back in the same place where the cancer first started, it’s called local recurrence. If it comes back in tissues or lymph nodes close to the primary tumour, it’s called regional recurrence. It can also recur in another part of the body, which is called a distant metastasis.

Gastroesophageal (GE) junction tumours

The GE junction is the area where the esophagus joins the stomach. Sometimes it’s hard for a doctor to know whether the cancer started in the lower end of the esophagus or the upper part of the stomach, especially if the cancer has spread to the GE junction. These cancers are called GE junction cancer and are treated as either esophageal cancer or stomach cancer.

In Canada, the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) staging systems are commonly used to classify GE junction tumours. To be staged as a stomach cancer:

  • The tumour has grown into the GE junction. The centre of the tumour is in the stomach and is more than 5 cm away from the GE junction.
  • The tumour is within 5 cm of the GE junction but hasn’t grown into the GE junction or esophagus.

The Siewert classification system may sometimes be used to stage GE junction tumours, but it is rarely used in Canada.

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