The TNM system classifies cancer based on three key components:
T (Tumor): Indicates the size and extent of the primary tumor. It is usually scored from T0 to T4, where T0 indicates no evidence of a primary tumor, and T4 indicates a large or invasive tumor. N (Node): Describes whether the cancer has spread to nearby lymph nodes. It ranges from N0 to N3, where N0 means no lymph node involvement, and N3 indicates extensive lymph node involvement. M (Metastasis): Indicates whether the cancer has spread to other parts of the body. M0 means no distant metastasis, while M1 indicates that metastasis is present.
