Which statement describes T4 in TNM staging?

Which statement describes T4 in TNM staging?

• A. Tumour invades adjacent organs or structures, locally advanced.
• B. Small primary tumour, limited local invasion.
• C. Larger primary tumour, may invade nearby tissue.
• D. Metastasis in 4-9 regional lymph nodes.

Answer: (A)

In TNM staging, the T descriptor reflects the size and direct extent of the primary tumor. T4 means the tumor has grown beyond its organ of origin and invades adjacent organs or structures, indicating locally advanced disease. This captures the idea that the cancer has extended into neighboring tissues, not just grown within its own organ. That's why the statement describing invasion into adjacent organs or structures fits T4 best. The other descriptions fit lower T stages or refer to N (lymph nodes) rather than T: a small tumor with limited invasion aligns with earlier T stages, a larger tumor that may invade nearby tissue sounds more like T3, and metastasis to regional lymph nodes describes the N category, not the T category.

In TNM staging, the T descriptor reflects the size and direct extent of the primary tumor. T4 means the tumor has grown beyond its organ of origin and invades adjacent organs or structures, indicating locally advanced disease. This captures the idea that the cancer has extended into neighboring tissues, not just grown within its own organ.

That's why the statement describing invasion into adjacent organs or structures fits T4 best. The other descriptions fit lower T stages or refer to N (lymph nodes) rather than T: a small tumor with limited invasion aligns with earlier T stages, a larger tumor that may invade nearby tissue sounds more like T3, and metastasis to regional lymph nodes describes the N category, not the T category.