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Staging small intestine cancer

The following information is about small intestine adenocarcinoma. Other types of small intestine cancers are staged differently. Talk to your healthcare team if you have a different type of small intestine cancer.

Staging is a way of describing or classifying a cancer based on the extent of cancer in the body. Extent includes how deeply the cancer has grown into the wall of the small intestine and 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 small intestine adenocarcinoma 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 small intestine and has not spread to other parts of the body. Regional means close to or around the small intestine. Distant means in a part of the body farther from the small intestine.

TNM descriptions

T describes how far the primary tumour has grown into the wall of the small intestine or into tissues or organs around the small intestine. T is usually given as a number from 1 to 4. A higher number means that the tumour has grown deeper into the wall of the small intestine, into nearby tissues or organs, or both.

 

N describes the lymph nodes around the small intestine. N0 means the cancer hasn’t spread to the lymph nodes. N1 or N2 means cancer has spread to lymph nodes. N1 and N2 can also describe the number and location of the 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 (or carcinoma in situ)

TNMDescription

Tis

N0

M0

Cancer cells are only in the inner lining of the small intestine (called the mucosa). They may be in the epitheliumepitheliumA thin layer of epithelial cells that makes up the outer surfaces of the body (the skin) and lines hollow organs, glands and all passages of the respiratory, digestive, reproductive and urinary systems., or they may have grown into the layer of connective tissue in the mucosa (called the lamina propria). Cancer cells have not grown past the inner muscle layer of the mucosa (called the muscularis mucosa).

Stage I

TNMDescription

T1a

N0

M0

The tumour has grown into the layer of connective tissue in the mucosa (called the lamina propria) and the layer of muscle in the mucosa (called the muscularis mucosa).

T1b

N0

M0

The tumour has grown through the mucosa and into the submucosa.

T2

N0

M0

The tumour has grown into the muscle layer of the small intestine wall (called the muscularis propria).

Stage IIA

TNMDescription

T3

N0

M0

One of the following applies:

The tumour has grown into the outermost layer of the wall of the small intestine (called the serosa).

The tumour has grown into the membrane that supports the small intestine (called the mesentery), but it hasn’t grown more than 2 cm into the mesentery.

The tumour has grown into the retroperitoneum, but it hasn’t grown more than 2 cm into the retroperitoneum.

Stage IIB

TNMDescription

T4

N0

M0

One of the following applies:

The tumour has grown through the lining that surrounds the abdominal organs (called the peritoneum).

The tumour has grown into organs near the tumour, such as other loops of the small intestine or the pancreas.

The tumour has grown more than 2 cm into the retroperitoneum.

Stage IIIA

TNM

Description

any T

N1

M0

The tumour may or may not have grown through the layers of the wall of the small intestine and into surrounding tissues.

Cancer has spread to 1–3 lymph nodes near the small intestine.

Stage IIIB

TNMDescription

any T

N2

M0

The tumour may or may not have grown through the layers of the wall of the small intestine and into surrounding tissues.

Cancer has spread to 4 or more lymph nodes near the small intestine.

Stage IV

TNM

Description

any T

any N

M1

The tumour may or may not have grown through the layers of the wall of the small intestine and into surrounding tissues.

The cancer may or may not have spread to lymph nodes.

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

Recurrent small intestine cancer

Recurrent small intestine cancer means that the cancer has come back after it has been treated. If it comes back in the same place that 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 distant metastasis

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