In the field of oncology, the TNM staging system is internationally adopted for tumor classification. T indicates the size of the primary tumor, typically divided into four stages from T1 to T4. A higher number signifies a larger primary tumor with more extensive invasion. N denotes the presence of lymph node metastasis, also categorized into four stages: N0, N1, N2, and N3. N0 indicates no lymph node metastasis, while higher numbers from N1 to N3 represent increasing degrees of lymph node involvement. In cases where lymph node metastasis cannot be determined, NX may be used. M stands for distant metastasis, classified only as M0 or M1, with M0 indicating no distant metastasis and M1 indicating its presence. Based on these criteria, tumors are assigned different stages. Therefore, T4N2M1 represents a relatively severe stage, characterized by a large primary tumor along with lymph node and distant metastases. However, the specific prognosis depends on factors such as the type of tumor, the patient's overall health condition, and the treatment approach employed. For slower-progressing tumors, such as colorectal cancer or thyroid cancer, even patients at stage IV may achieve long-term survival with the tumor under appropriate treatment plans.