TABLE 2.

Union for International Cancer Control (UICC) TNM 8

Stage	Primary tumour	Regional lymph nodes	Distant metastasis
Stage 0	Tis	N0	M0
Stage I	T1	N0	M0
Stage IIA	T2, T3	N0	M0
Stage IIB	T4	N0	M0
Stage IIIA	T0	N1b	M0
	T1, T2, T3, T4	N1a(sn), N1a	M0
Stage IIIB	T1, T2, T3, T4	N1b, N2, N3	M0
Stage IV	T0, T1, T2, T3, T4	Any N	M1

TX – Primary tumour cannot be assessed.

T0 – No evidence of primary tumour.

Tis – In situ primary tumour.

T1 – $\le 20$ mm maximal clinical dimension of tumour.

T2 – >20 mm to $\le 50$ mm maximal clinical dimension of tumour.

T3 – >50 mm maximal clinical dimension of tumour.

T4 – Primary tumour invades fascia, muscle, bone or cartilage.

NX – Regional nodes cannot be assessed.

N0 – Regional nodes negative by pathological exam.

N1 – Regional nodes positive by pathological exam.

N1a(sn) – Clinically occult but regional node positive by SLNB.

N1a – Clinically occult but regional nodes positive by lymphadenectomy.

N1b – Clinically detected regional nodes.

N2 – In‐transit metastasis without lymph node metastasis.

N3 – In‐transit metastasis with lymph node metastasis.

M0 – No distant metastases.

M1 – Metastasis beyond regional lymph nodes.

M1a – Metastasis to distant skin, subcutaneous tissues or distant lymph nodes confirmed microscopically.

M1b – Metastases to lung confirmed microscopically.

M1c – Metastasis to other visceral sites conformed.