Staging gives clarity of the location of cancer. If it has spread, and whether it has applied to other body sections. Distinct forms of Appendix cancer have different stages descriptions. The TNM staging system is considered for determining the stages and grades of tumors in appendix cancer. The appendix cancer consists of five stages involving stage 0 (zero) and stages I through IV (1 through 4).
TNM staging system
The TNM system is one technique that clinicians use to describe the stage. These questions are answered by doctors using the findings of diagnostic tests and scans:
- Tumor (T): Size and location
- Node (N): Has the tumor spread to the lymph nodes?
- Metastasis (M): cancer spread
The results are aggregated to establish each person’s cancer stage. Five stages depend on the type of Appendix cancer: stage 0 (zero) and stages I through IV (1 through 4). The stage is a standardized classification method that allows specialists to collaborate on the best treatment options 1.
Appendix cancer Stages are staged in two different ways by doctors. The first is for neuroendocrine tumors, and the second is for carcinomas, such as adenocarcinomas. For more information on each component of the TNM system for appendix cancer 2, see the following:
Staging for Appendix carcinomas
“T” describes the tumor’s size and location. The stage can also be subdivided into smaller groups to aid in describing the tumor. The information for each tumor stage is shown below.
- TX: no way to assess the primary tumor.
- T0 (T plus zero): There is no evidence of cancer in the appendix. The term “carcinoma in situ” refers to cancer that has developed (also called cancer in situ). Only the first layers lining the inside of the appendix contain cancer cells. The muscularis propria, the muscle layer of the appendix wall, confines a low-grade appendiceal mucinous neoplasm (LAMN). Mucin without cells has the potential to infiltrate the muscularis propria.
- T1: The tumor has spread to the submucosa, the appendix’s next lowest layer.
- T2: The tumor has spread to the muscularis propria of the patient.
- T3: The tumor has developed through the muscularis propria and into the appendix’s subserosa (a thin layer of connective tissue) or the mesoappendix. This fatty tissue area supplies the appendix with blood.
- T4: The tumor has grown through the visceral peritoneum, the lining of the abdominal cavity, or it has spread to other organs nearby.
- T4a: The tumor has spread to the peritoneum viscera.
- T4b: Other organs or structures, such as the colon or rectum, have been invaded by the tumor.
In the TNM system, lymph nodes are represented by the letter “N.” Lymph nodes are little bean-shaped organs that assist the body fight infections, which are located throughout the body and are part of the immune system. Lymph nodes found near the appendix are known as regional lymph nodes.
- NX: the regional lymph nodes cannot be examined.
- N0 (N plus zero): There is no regional lymph node metastasis.
- N1: Cancer has spread to one to three lymph nodes in the region.
- N2: Cancer has progressed to four or more lymph nodes in the region.
Cancer that has progressed to other body regions, such as the liver or lungs, is classified as “M” in the TNM system.
- M0: Cancer has not spread.
- M1: Distant metastases is present.
- M1a: This is an abbreviation for intraperitoneal acellular mucin spread.
- M1b: This refers to peritoneal metastasis that has progressed beyond M1a.
- M1c: A metastasis that has spread beyond the peritoneum.
Appendix cancer is also classified by its grade by doctors (G). The grade describes how much cancer cells resemble healthy cells when viewed under a microscope.
In healthy tissue, numerous different types of cells are clustered together. Cancer is classified as “differentiated” or a “low-grade tumor” since it resembles healthy tissue and has various cell groupings. A “poorly differentiated” or “high-grade tumor” is defined as malignant tissue that looks considerably different from healthy tissue. The cancer grade may aid the doctor in predicting how rapidly cancer may spread. In general, the better the prognosis, the lower the tumor’s grade.
- GX: There is no way to tell what grade the tumor is.
- G1: The tumor cells have a high level of differentiation.
- G2: The tumor cells have a medium level of differentiation.
- G3: The tumor cells have a low level of differentiation.
- G4: Tumor cells have not been differentiated.
Appendix cancer are classified into stages.
Doctors combine the T, N, M, and G classifications to determine the stage of appendix cancer. Appendix cancer in situ is referred to as
- Stage 0 cancer: (Tis, Tis(LAMN), N0, M0) The malignancy has only been identified in one location and has not spread.
- Stage I: Cancer has spread to the inner layers of the appendix tissue but not to the regional lymph nodes or other body parts (T1 or T2, N0, M0).
- Stage IIA: Cancer has spread to the connective or fatty tissue surrounding the appendix but not to the regional lymph nodes or other body regions (T3, N0, M0).
- Stage IIB: Cancer has spread through the appendix’s lining but not to the regional lymph nodes or other body regions (T4a, N0, M0).
- Stage IIC: The tumor has migrated to other organs, such as the colon or rectum, but not to regional lymph nodes or other body regions (T4b, N0, M0).
- Stage IIIA: Cancer has spread to the inner layers of the appendix tissue and one to three regional lymph nodes, but not to other parts of the body (T1 or T2, N1, M0).
- Stage IIIB: Cancer has spread to 1 to 3 regional lymph nodes and surrounding appendix tissue or via the appendix’s lining but has not migrated to other parts of the body (T3 or T4, N1, M0).
Cancer that has spread to four or more regional lymph nodes but not to other body parts is classified as stage IIIC (any T, N2, M0).
- Stage IVA: This stage refers to any of the following scenarios:
Cancer that has spread to other abdomen sections but not to the localized lymph nodes is classified as this stage (any T, N0, M1a).
This stage depicts cancer that has progressed to other parts of the abdomen and may have expanded to the regional lymph nodes; the cancer cells have become well-differentiated (any T, any N, M1b, G1).
- Stage IVB: Cancer has migrated to various parts of the abdomen, including the regional lymph nodes, and the cells are moderately or poorly differentiated (any T, any N, M1b; G2, G3, or GX).
- Stage IVC: Cancer has progressed to other body areas, such as the lungs, from the abdominal area (any T, any N, M1c, and G).
- 1.Shaib W, Assi R, Shamseddine A, et al. Appendiceal Mucinous Neoplasms: Diagnosis and Management. Oncologist. 2017;22(9):1107-1116. doi:10.1634/theoncologist.2017-0081
- 2.Asare E, Compton C, Hanna N, et al. The impact of stage, grade, and mucinous histology on the efficacy of systemic chemotherapy in adenocarcinomas of the appendix: Analysis of the National Cancer Data Base. Cancer. 2016;122(2):213-221. doi:10.1002/cncr.29744