Stage	Sites of Primary Tumor	T Stage	Tumor Size	Regional Lymph Nodes	Distant Metastasis
I	Favorable sites	T1 or T2	Any size	N0 or N1 or NX	M0
II	Unfavorable sites	T1 or T2	a, ≤ 5 cm	N0 or NX	M0
III	Unfavorable sites	T1 or T2	a, ≤ 5 cm	N1	M0
			b, > 5 cm	N0 or N1 or NX
IV	Any site	T1 or T2	Any size	N0 or N1 or NX	M1
M0 = absence of metastatic spread; M1 = presence of metastatic spread beyond the primary site; N0 = absence of nodal spread; N1 = presence of nodal spread beyond the primary site; X = unknown N status.