Most often, doctors use the TNM staging system to stage cancer. It is managed by AJCC (American Joint Cancer Committee) and UICC (Union for International Cancer Control). The letters T, N, and M in this scheme represent a different field of cancer development. Based on the test results, each letter is assigned to a score by the physicians. But not all cancers, such as Hodgkin’s lymphoma, are classified according to TNM scores.

T = Tumor the T score is a mark of primary tumor magnitude. The first mass of cancer cells in the body is the main tumor. The primary tumor will grow big if untreated. It can also expand through the tissue layers it started out in. This is called the expansion of the tumor. If the tumor has developed through a structure’s outer edge, it may develop into other nearby structures. That is known as an invasion. The T scores are based on primary tumor presence, size, and scale. A TX score means that one cannot determine the primary tumor. A T0 score indicates the primary tumor is not present. Cancer may occur but does not have a primary tumor. A Tis score indicates that there is irregular or cancer cells, but the cells have no risk of spreading to distant locations. Scores of T1, T2, and so on are dependent on the size, extent or both of the primary tumor. Higher values mean greater cancer coverage.

N = Nodes Class N represents the degree of cancer within lymph nodes nearby. Lymph nodes are small organs that contain lymph, which battle the disease. Lymph is a clear fluid that provides water and food to the cells inside the tissue. It also collects cell waste and has white blood cells which combat germs. Lymph drains from the tissue into lymph vessels which carry it to the lymph node. Cancer cells may migrate to lymph nodes and invade lymph vessels. The cancer cells will multiply once in the lymph nodes and form new tumors.

N ratings are dependent on whether cancer is present in neighboring lymph nodes, and the number or area of cancer nodes. An NX score means that one cannot determine the lymph nodes. A score of N0 means there was no cancer in the lymph nodes. N1, N2, and N3 ratings are dependent on the number of cancer nodes, or nodal cancer classes. Higher values mean greater cancer coverage.

M = Metastasis Class M asks you if the cancer has spread to remote locations. Such sites have remote lymph nodes that spread beyond local lymph nodes. Cancer cells can break the primary tumor and spread to remote sites. This is called metastasis. Cancer cells may spread through the lymph or blood to distant locations. M0 means the cancer is not present in remote areas. M1 means cancer in distant areas.

What are TNM staging labels?

T (tumor) N (lymph nodes) M (metastasis) TX: Unable to measure tumor. T0: No evidence of tumor. Tis: Tumor hasn’t grown into nearby tissue. T1 toT4: Tumor has grown into nearby tissue (numbers 14 describe how much the tumor has grown). NX: Unable to evaluate lymph nodes. N0: No cancer found in lymph nodes. N1to N3: Cancer has spread into lymph nodes. (Numbers 13 are based on how many nodes are involved and how much cancer is found in them.) M0: Cancer hasn’t spread to other parts of the body. M1: Cancer has spread to other parts of the body.