Staging is a process that tells the doctor how widespread your cancer may be when you are first diagnosed. It will show if the cancer has spread and how far. The treatment and outlook for small intestine cancer depends, to a large extent, on its stage. For early stage cancer, surgery may be all that is needed. For more advanced cancer, other treatments, such as chemotherapy or radiation therapy, may be required. Please be sure to ask your doctor to explain the stage of your cancer so that you can make the best choice about your treatment.

The staging system used is that of the American Joint Committee on Cancer (AJCC). It is also called the TNM system. Stages are described using Roman numerals I through IV.

This staging system describes the spread of the cancer in relation to the layers of the wall of the small intestine. Because for most patients, this stage is unknown until after surgery, most doctors wait till then to decide on the cancer's stage. The stages described below are called pathologic stages. The pathologic stage is determined by the findings of the pathologist from looking at the cancer and other actual tissue that has been removed.

The AJCC/TNM System describes the extent of the primary Tumor (T), the absence or presence of metastasis to nearby lymph Nodes (N), and the absence or presence of distant Metastasis (M).

T categories for small intestine adenocarcinoma

T categories of small intestine cancer describe the extent of spread through the layers that form its wall.

These layers, from the inner to the outer, include the lining (mucosa), the fibrous tissue beneath this muscle layer (submucosa), a thick layer of muscle that contracts to force the contents of the intestines along (muscularis propria), and the thin outermost layers of connective tissue (subserosa and serosa) that cover the small intestine.

• Tx: No description of the tumor's spread is possible because of incomplete information.

• Tis: The cancer is only in the mucosa (inner layer) -- it has not grown into the deeper tissue layers. This is the earliest stage and is also known as carcinoma in situ (CIS) or intramucosal carcinoma.

• T1: The cancer has grown through the mucosa and into the submucosa.

• T2: The cancer has grown through the mucosa and submucosa into the muscularis propria.

• T3: The cancer has grown completely through the inner layers of the intestine wall (mucosa, submucosa, and muscularis propria) into the subserosa. It has not started to grow into any nearby organs or tissues.

• T4: The cancer has spread completely through the wall of the small intestine into nearby tissues or organs.

N categories for small intestine adenocarcinoma

N categories indicate whether or not the cancer has spread to nearby lymph nodes.

• Nx: No information about lymph node involvement is available (often because no lymph nodes have been removed).

• N0: Lymph nodes near the tumor were checked and do not contain cancer.

• N1: Cancer cells found in nearby lymph nodes.

M categories for small intestine adenocarcinoma

M categories indicate whether or not the cancer has spread to distant organs, such as the liver, lungs, or distant lymph nodes.

• Mx: No description of distant spread is possible because of incomplete information.

• M0: No cancer has been found in other organs or tissues.

• M1: Cancer has been found in other organs or tissues.

Stage grouping

The T, N, and M categories are combined (in a process called stage grouping) to determine the stage. The stage is expressed in Roman numerals from stage I (the least advanced stage) to stage IV (the most advanced stage). The following guide illustrates how TNM categories are grouped together into stages:

Stage 0: Tis, N0, M0:

The cancer is in the earliest stage. It has not grown beyond the inner layer (mucosa) of the small intestine. This stage is also known as carcinoma in situ or intramucosal carcinoma.

Stage I: T1 or T2, N0, M0:

The cancer has grown through the mucosa into the submucosa (T1) or the muscularis propria (T2), but it has not spread into nearby lymph nodes or distant sites.

Stage II: T3 or T4, N0, M0:

The cancer has grown through the wall of the small intestine into the outermost layers (T3) or into other nearby tissues or organs (T4). It has not yet spread to the nearby lymph nodes or to distant sites.

Stage III: Any T, N1, M0:

The cancer has spread to nearby lymph nodes but not to distant sites

Stage IV: Any T, Any N, M1:

The cancer has spread to distant sites such as the liver, lung, peritoneum (the membrane lining the abdominal cavity), or ovary.

Five-year survival rates

Five-year survival rates are calculated based on how many patients live at least 5 years after diagnosis of this disease. Many people may live much longer than 5 years, but it is the 5-year mark that is used as a standard measurement for statistics and research. When the term "disease-specific" is used, it means that only patients that died of the cancer are counted -- not deaths from other causes such as heart attacks, accidents, etc.

Five-year disease-specific survival for small intestine adenocarcinoma by AJCC stage:

These numbers reflect the percentage of people who were alive 5 years or more after being diagnosed with small intestine adenocarcinoma, depending on what stage they were in when they were diagnosed.

When you look at these numbers, it is important keep in mind that people are not statistics. Everyone is different -- no 2 people will have the same experience with cancer and its treatment. Also, these statistics are based upon data from patients diagnosed many years ago. As treatments and diagnostic methods improve, outcomes for patients may also improve.

Last Medical Review: 08/13/2009
Last Revised: 08/13/2009