TNM system for soft tissue sarcoma
The American Joint Commission on Cancer (AJCC) TNM system is commonly used to stage soft tissue sarcoma. This system is defined by three key components: tumors, lymph nodes and the presence or absence of tumor metastases (spread). Each category (T, N and M) is assessed and rated.
Grade (G) is also a determining factor used when staging soft tissue sarcoma. The G indicates the rate the tumor is likely to grow and spread based upon the appearance of the cancerous cells under the microscope. Soft tissue sarcomas are graded from G1 to G3, with higher grade sarcomas having a greater likelihood of growing and spreading at a faster and more aggressive rate than lower grade sarcomas.
The soft tissue sarcoma staging process involves several values, including:
- Tumor (T) describes the size of the original tumor. T1 means the tumor is 5 cm or less across, T2 means it is greater than 5 cm. The letter “a” (T1a, T2a) indicates that the tumor is near the surface of the body, while “b” (T1b, T2b) indicates it is deeper in the body.
- Lymph Node (N) indicates whether the cancer is present in the regional lymph nodes. N0 indicates that the tumor has not spread to the lymph nodes, and N1 means that it has spread to the lymph nodes.
- Metastasis (M) refers to whether the cancer has spread to other parts of the body. M0 means that the tumor has not spread, while M1 indicates that the tumor has spread to other parts of the body.
The T, N and M ratings are combined with the grade to determine the stage of soft tissue sarcoma, characterized as stage 0 – stage IV. Determining the patient’s exact stage of soft tissue sarcoma is extremely important in order to develop his or her personalized treatment plan. Other factors, such as the type and location of the sarcoma, will also play a role in developing an individualized treatment plan.