Radiation-induced sarcomas of the head and neck

Table 4 TNM staging for bone tumors other than lymphoma and myeloma

Primary tumor (T)
TX	Primary tumor cannot be assessed
T0	No evidence of primary tumor
T1	Tumor 8 cm or less in greatest dimension
T2	Tumor more than 8 cm in greatest dimension
T3	Discontinuous tumors in the primary bone site
Regional lymph nodes (N)
NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Regional lymph node metastasis
Distant metastasis (M)
M0	No distant metastasis
M1	Distant metastasis
M1a	Lung
M1b	Other distant sites
Histologic grade (G)
Grade is reported in registry systems by the grade value. A two-grade, three-grade, or four-grade system may be used. If a grading system is not specified, generally the following system is used:
GX	Grade cannot be assessed
G1	Well differentiated-low grade
G2	Moderately differentiated-low grade
G3	Poorly differentiated-high grade
G4	Undifferentiated-high grade
Anatomic stage/prognostic groups
Stage IA	T1	N0	M0	G1, 2 Low grade, GX
Stage IB	T2	N0	M0	G1, 2 Low grade, GX
	T3	N0	M0	G1, 2 Low grade, GX
Stage IIA	T1	N0	M0	G3, 4 High grade
Stage IIB	T2	N0	M0	G3, 4 High grade
Stage III	T3	N0	M0	G3, 4 High grade
Stage IVA	Any T	N0	M1a	Any G
Stage IVB	Any T	N1	Any M	Any G
	Any T	Any N	M1b	Any G