This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on June 8, 2022.
After an appendix cancer diagnosis, the care team will determine the stage of the disease before establishing a treatment plan. Most cancer types, including appendix cancer, are grouped into stages ranging from 0 to 4.
Neuroendocrine tumors and carcinomas of the appendix are staged differently. Treatment for neuroendocrine tumors of the appendix is not based on the stage of the cancer, but instead on whether the tumor may be removed with surgery and whether the tumor has spread.
Carcinomas of the appendix are staged using the American Joint Committee on Cancer’s TNM system. This system differentiates stages based on the following information listed below.
T (tumor): This refers to the size of the primary tumor. The measurement also evaluates to what extent, if any, the cancer has spread.
N (node): This describes the involvement of lymph nodes near the primary tumor. Lymph nodes are small, bean-shaped clusters of immune system cells that are crucial to fighting infections. They’re usually one of the first sites in the body where cancer spreads.
M (metastasis): This indicates whether the cancer has spread (metastasized) to other areas of the body.
The stages of appendiceal carcinomas go from 0 to 4.
The cancer is found in only one location and has not spread. This stage is also known as appendix cancer in situ.
The cancer has spread to the inner layers of appendix tissue but not to the regional lymph nodes or other parts of the body.
The three subcategories of stage 2 appendix cancer are 2A, 2B and 2C. The categories differ by the extent to which the cancer has spread, as detailed below.
Stage 2A: The cancer has grown into the connective or fatty tissue next to the appendix but has not spread to the regional lymph nodes or other parts of the body.
Stage 2B: The cancer has grown through the lining of the appendix but has not spread to the regional lymph nodes or other parts of the body.
Stage 2C: The appendix tumor has grown into other organs, such as the colon or rectum, but has not spread to the regional lymph nodes or other parts of the body.
Stage 3 is also divided into three subcategories listed below.
Stage 3A: The cancer has spread to the inner layers of the appendix tissue and to one to three regional lymph nodes but has not spread to other parts of the body.
Stage 3B: The cancer has grown into nearby tissues of the appendix, or through the lining of the appendix, and to one to three regional lymph nodes but has not spread to other areas of the body.
Stage 3C: The cancer has spread to four or more regional lymph nodes but not to other areas of the body.
The most advanced stage of appendix cancer has three sub-categories:
Stage 4A: The cancer has spread to other areas in the abdomen, but not to the regional lymph nodes, and the cancer cells are well-differentiated.
Stage 4B: The cancer has spread to other areas in the abdomen and possibly into the regional lymph nodes; the cells are moderately or poorly differentiated.
Stage 4C: The cancer has spread outside the abdominal area to distant parts of the body, such as the lungs.
Identifying the stage of cancer not only helps the care team determine a treatment plan, it also helps predict a potential prognosis. This is achieved by calculating the percentage of people with appendix cancer who survive five years or more after diagnosis compared to people who don’t have that type of cancer. It’s important to remember that this is only a statistic based on all people with appendix cancer several years in the past, so individual patient experiences may vary.
For patients with neuroendocrine tumors of the appendix and other low-grade tumors, the five-year relative survival rate ranges from 67 percent to 97 percent, according to the National Cancer Institute (NCI). Because appendix cancer is rare, the NCI cautions patients to keep in mind that these rates may not be precise, and that more advanced appendix cancers may have lower survival rates.
The patient’s care team may be able to create a more specific prognosis based on the patient’s overall health, cancer stage and other factors.
Next topic: How is appendix cancer diagnosed?