Primary Tumorb	Regional Lymph Nodes	Distant Metastasis	Histologic Gradec
Stage I	Any tumor size, superfical or deep	N0	M0	G1
				G2
Stage II	T1a (tumor ≤5 cm in maximal diameter, superficial)	N0	M0	G3
	T1b (tumor ≤5 cm in maximal diameter, deep)	N0	M0	G3
	T2a (tumor >5 cm in maximal diameter, superficial)	N0	M0	G3
Stage III	T2b (tumor >5 cm in maximal diameter, deep)	N0	M0	G3
Stage IV	Any tumor size, superfical or deep	N1	M0 or M1	G1, G2, or G3
	Any tumor size, superfical or deep	N0 or N1	M1	G1, G2, or G3

G1 = well differentiated; G2 = moderately differentiated; G3 = poorly differentiated; M0 = no distant metastasis; M1 = distant metastasis; N0 = no regional lymph node metastasis; N1 = regional lymph node metastasis

aAdapted from AJCC Cancer Staging Manual.[10]

bSuperficial tumor is located above the superficial fascia without invasion of the fascia; deep tumor is located either exclusively beneath the superficial fascia or superficial to the fascia with invasion of or through the fascia. All intraperitoneal visceral lesions, retroperitoneal, pelvic, and intrathoracic tumors, and the majority of head and neck tumors are classified as deep tumors.

cThe histologic grade established by central pathology review is to be used for staging purposes.

References

10. American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002.