Osteosarcoma

Musculoskeletal Tumor Society (MSTS) staging system[31]Heck RK Jr, Peabody TD, Simon MA. Staging of primary malignancies of bone. CA Cancer J Clin. 2006 Nov-Dec;56(6):366-75. http://onlinelibrary.wiley.com/doi/10.3322/canjclin.56.6.366/full http://www.ncbi.nlm.nih.gov/pubmed/17135693?tool=bestpractice.com

The MSTS surgical staging system is frequently used for bone sarcomas and defines grades of non-metastatic malignant bone tumours.

• I-A: low-grade, intra-compartmental

• I-B: low-grade, extra-compartmental

• II-A: high-grade, intra-compartmental

• II-B: high-grade, extra-compartmental

• III: any grade, metastatic.

American Joint Committee on Cancer TNM staging system (8th Edition)[32]Amin MB, Edge S, Greene F, et al. AJCC cancer staging manual, 8th edition. New York: Springer; 2016.

The American Joint Committee on Cancer (AJCC) staging system describes the extent of disease based on the following anatomical factors: size and extent of the primary tumour (T); regional lymph node involvement (N); and presence or absence of distant metastases (M). Non-anatomical prognostic factors (e.g., tumour grade, biomarkers) may be used to supplement the staging of certain cancers.

National Comprehensive Cancer Network (NCCN)[23]National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: bone cancer [internet publication]. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp

The NCCN practice guidelines describe 5 subtypes.

• High-grade, intra-medullary + surface

• Low-grade, intra-medullary + surface

• Periosteal

• Metastatic disease at presentation

• Extraskeletal (see Soft-tissue sarcoma)