TNMsystemets

The TNM system is a standardized way of describing the extent of cancer in a patient. It is used worldwide to help doctors stage cancer, which is crucial for determining the best treatment plan and predicting the prognosis. The system was developed by the American Joint Committee on Cancer (AJCC).

TNM stands for Tumor, Node, and Metastasis. The 'T' describes the size and local extent of the primary tumor. It can range from TX (tumor cannot be assessed) to T4 (tumor is large or has grown into nearby tissues). The 'N' refers to the involvement of nearby lymph nodes. Again, it ranges from NX (regional lymph nodes cannot be assessed) to N3 (more extensive lymph node involvement). The 'M' indicates whether the cancer has spread to distant parts of the body, known as metastasis. M0 means no distant metastasis, while M1 signifies the presence of distant metastasis.

Each component of the TNM system (T, N, and M) is assigned a number or letter, and these together form the stage of the cancer. For example, a T2N1M0 classification indicates a moderately sized primary tumor that has spread to some nearby lymph nodes but not to distant sites. The specific combinations and their corresponding stages are detailed in staging manuals, such as those published by the AJCC. These manuals are regularly updated to reflect the latest scientific understanding of cancer.

Staging using the TNM system allows for consistent communication among healthcare professionals and facilitates research by enabling comparisons between patient groups. It is a cornerstone of modern cancer diagnosis and treatment planning.