Osteogenic Sarcoma Staging 

Updated: Jan 15, 2018
  • Author: Nellowe C Candelario, MD; Chief Editor: Edwin Choy, MD, PhD  more...
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TNM Classification for Osteogenic Sarcoma

The American Joint Committee on Cancer (AJCC) tumor/node/metastasis (TNM) classification and staging system for osteogenic sarcoma are provided below. [1]  The 8th edition of the AJCC system took effect on January 1, 2018.

Table. TNM Classification for Osteogenic Sarcoma (Open Table in a new window)

Primary Tumor (T)
Appendicular Skeleton, Trunk, Skull and Facial Bones
TX Primary Tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor less than or equal to 8 cm
T2 Tumor more than 8 cm
T3 Discontinuous tumors in the primary bone site
Spine
TX Primary Tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor confined to one vertebral segment or two adjacent vertebral segments
T2 Tumor confine to three vertebral segments
T3 Tumor confined to four or more adjacent vertebral segments or any nn adjacent segments
T4 Extension to the spinal canal or great vessels
T4a Extension to the spinal canal
T4b Evidence of gross vascular invasionor tumor thrombus in the great vessels
Pelvis
TX Primary Tumor cannot be assessed
T0 No evidence of primary tumor
T1 Tumor confine to one pelvic segment with no extraosseous extension
T1a Tumor less than or equal to 8 cm in greatest dimension
T1b Tumor more than 8 cm in greatest dimension
T2 Tumor confined to one pelvic segment with extraosseous extension or two segments without extraossous extension
T2a Tumor less than or equal to 8 cm in greatest dimension
T2b Tumor more than 8 cm in greatest dimension
T3 Tumor spanning two pelvic segments with extraosseous extension
T3a Tumor less than or equal to 8 cm in greatest dimension
T3b Tumor more than 8 cm in greatest dimension
T4 Tumor spanning three pelvic segments or crossing the sacroiliac joint
T4a Tumor involves sacroiliac joint and extends medial to sacral neuroforamen
T4b Tumor encasement of external iliac vessels or presence of gross tumor thrombus in major pelvic vessels
Regional lymph nodes (N)
NX Regional lymph nodes cannot be assessed; because of rarity of  lymph node involvement in bone sarcomas, the designation of NX may not be appropriate and cases should be considered N0 unless cliical node involvement is clearly evident
N0 No regional lymph node metastasis
N1 Regional lymph node metastasis
Distant metastasis (M)
M0 No distant metastasis
M1 Distant metastasis
M1a Lung
M1b Bone and other distant sites
Histologic grade (G)
GX Grade cannot be assessed
G1 Well differentiated, low grade
G2 Moderately differentiated, high grade
G3 Poorly differentiated, high grade

Table. Anatomic Stage/Prognostic Groups (Open Table in a new window)

Appendicular Skeleton, Trunk, Skull, and Facial Bones  
When T is … And N is … And M is… And the grade is … Then stage group is …
T1 N0 M0 G1 or GX IA
T2 N0 M0 G1 or GX IB
T3 N0 M0 G1 or GX IB
T1 N0 M0 G2 or G3 IIA
T2 N0 M0 G2 or G3 IIB
T3 N0 M0 G2 or G3 III
Any T N0 M1a Any G IVA
Any T N1 Any M Any G IVB
Any T Any N M1b Any G IVB