ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. In addition, you can read about how doctors evaluate and compare cancer cells to normal cells, called the grade. Use the menu to see other pages.
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What is cancer staging?
Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body.
Doctors use diagnostic tests to find out the cancer's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor recommend the best kind of treatment, and it can help predict a patient's prognosis, which is the chance of recovery and longevity. There are different stage descriptions for different types of cancer.
TNM staging system
One tool that doctors use to describe the stage is the TNM system. Doctors use the results from diagnostic tests and scans to answer these questions:
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Tumor (T): How large is the primary tumor? Where is it located?
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Node (N): Has the tumor spread to the lymph nodes? If so, where and how many?
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Metastasis (M): Has the cancer spread to other parts of the body? If so, where and how much?
The results are combined to determine the stage of cancer for each person. There are 5 stages: stage 0 (zero) and stages I through IV (1 through 4), depending on the type of cancer. The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.
There are 2 different ways that doctors stage appendix cancer. One is for neuroendocrine tumors and the other for carcinomas, which also includes adenocarcinomas. More details on each part of the TNM system for appendix cancer are described below.
Staging for neuroendocrine tumors of the appendix
Read about the staging of neuroendocrine tumors of the appendix in another section of this website.
Staging for carcinomas of the appendix
Appendiceal carcinomas are staged according to the TNM staging system, below:
Tumor (T)
Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Stage may also be divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information is listed below.
TX: The primary tumor cannot be evaluated.
T0 (T zero): There is no evidence of cancer in the appendix.
Tis: This refers to carcinoma in situ (also called cancer in situ). Cancer cells are found only in the first layers lining the inside of the appendix.
Tis (LAMN): A low-grade appendiceal mucinous neoplasm (LAMN) confined by the muscularis propria, which is the muscle layer of the appendix wall. Mucin without cells may invade into the muscularis propria.
T1: The tumor has invaded the submucosa, which is the next deepest layer of the appendix.
T2: The tumor has invaded the muscularis propria.
T3: The tumor has grown through the muscularis propria and into the subserosa (a thin layer of connective tissue) of the appendix or into the mesoappendix, which is an area of fatty tissue next to the appendix that provides the blood supply for the appendix.
T4: The tumor has grown through the visceral peritoneum, or it has invaded other nearby organs. The peritoneum is a tissue that lines the abdomen and most of the organs in the abdomen.
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T4a: The tumor has invaded the visceral peritoneum.
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T4b: The tumor has invaded other organs or structures, such as the colon or rectum.
Node (N)
The "N" in the TNM system stands for lymph nodes. The lymph nodes are small, bean-shaped organs that are located throughout the body that help the body fight infections as part of the body's immune system. There are regional lymph nodes, which are lymph nodes near the appendix. All others are distant lymph nodes, which are lymph nodes found in other parts of the body.
NX: The regional lymph nodes cannot be evaluated because of a lack of information.
N0 (N zero): There is no regional lymph node metastasis.
N1: Cancer has spread to 1 to 3 regional lymph nodes.
N2: Cancer has spread to 4 or more regional lymph nodes.
Metastasis (M)
The "M" in the TNM system describes cancer that has spread to other parts of the body, such as the liver or lungs.
M0 (M zero): The cancer has not metastasized.
M1: There is metastasis or spread of the cancer to distant parts of the body.
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M1a: This refers to an area of spread called intraperitoneal acellular mucin.
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M1b: This refers to a metastasis within the peritoneum beyond M1a.
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M1c: This refers to a metastasis beyond the peritoneum.
Grade (G)
Doctors also describe appendix cancer by its grade (G). The grade describes how much cancer cells look like healthy cells when viewed under a microscope.
The doctor compares the cancerous tissue with healthy tissue. Healthy tissue usually contains many different types of cells grouped together. If the cancer looks similar to healthy tissue and has different cell groupings, it is called “differentiated” or a “low-grade tumor.” If the cancerous tissue looks very different from healthy tissue, it is called “poorly differentiated” or a “high-grade tumor.” The cancer’s grade may help the doctor predict how quickly the cancer will spread or grow. In general, the lower the tumor’s grade, the better the prognosis.
GX: The tumor grade cannot be identified.
G1: The tumor cells are well-differentiated.
G2: The tumor cells are moderately differentiated.
G3: The tumor cells are poorly differentiated.
G4: The tumor cells are undifferentiated.
Stage groups for carcinomas of the appendix
Doctors combine the T, N, M, and G information (see above) to say what stage the cancer is.
Stage 0: This refers to cancer in situ. The cancer is found in only 1 place and has not spread (Tis or Tis(LAMN), N0, M0).
Stage I: The cancer has spread to inner layers of appendix tissue but has not spread to the regional lymph nodes or to other parts of the body (T1 or T2, N0, M0).
Stage IIA: The cancer has grown into the connective or fatty tissue next to the appendix but has not spread to the regional lymph nodes or to other parts of the body (T3, N0, M0).
Stage IIB: The cancer has grown through the lining of the appendix but has not spread to the regional lymph nodes or to other parts of the body (T4a, N0, M0).
Stage IIC: The tumor has grown into other organs, such as the colon or rectum, but has not spread to the regional lymph nodes or to other parts of the body (T4b, N0, M0).
Stage IIIA: The cancer has spread to inner layers of appendix tissue and to 1 to 3 regional lymph nodes but has not spread to other parts of the body (T1 or T2, N1, M0).
Stage IIIB: The cancer has grown into nearby tissue of the appendix or through the lining of the appendix and to 1 to 3 regional lymph nodes but has not spread to other areas of the body (T3 or T4, N1, M0).
Stage IIIC: The cancer has spread to 4 or more regional lymph nodes but not to other areas of the body (any T, N2, M0).
Stage IVA: Stage IVA describes any of the following situations:
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The cancer has spread to other areas in the abdomen but not to the regional lymph nodes (any T, N0, M1a).
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The cancer has spread to other areas in the abdomen and may be in the regional lymph nodes; the cancer cells are well differentiated (any T, any N, M1b, G1).
Stage IVB: The cancer has spread to other areas in the abdomen and may be in the regional lymph nodes; the cells are moderately or poorly differentiated (any T, any N, M1b; G2, G3, or GX).
Stage IVC: The cancer has spread outside the abdominal area to distant parts of the body, such as the lungs (any T, any N, M1c, any G).
Recurrent: For both neuroendocrine tumors and carcinomas, recurrent cancer is cancer that has come back after treatment. If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.
Used with permission of the American College of Surgeons, Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, Eighth Edition (2017), published by Springer International Publishing.
Information about the cancer’s stage will help the doctor recommend a specific treatment plan. The next section in this guide is Types of Treatment. Use the menu to choose a different section to read in this guide.