Osteosarcoma staging

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohammadmain Rezazadehsaatlou[2].

Overview

According to the American Joint Committee on Cancer (AJCC), there are four stages of osteosarcoma based on the size of primary tumor, metastasis, involvement of lymph nodes, and grade of the tumor. For the purpose of treatment, there are only two stages of high-grade osteosarcoma: localized osteosarcoma and metastatic osteosarcoma.

Staging

Historically, the Enneking staging system for skeletal malignancies was widely used.^[1]^[2]^[3]^[4]^[5]
This system inferred the aggressiveness of the primary tumor by the descriptors intracompartmental or extracompartmental.
The American Joint Committee on Cancer (AJCC) staging system for malignant bone tumors has updated this staging system, substituting compartmentalization with size.
The International Union Against Cancer (UICC) uses the TNM system to describe the extent of many solid tumor cancers.
For the purpose of treatment, there are only two stages of high-grade osteosarcoma:

Localized osteosarcoma:

Localized tumors are limited to the bone of origin.
Patients with skip lesions confined to the bone that includes the primary tumor are considered to have localized disease if the skip lesions can be included in the planned surgical resection.

Metastatic osteosarcoma:

Patients in whom it is possible to detect any site of metastasis at the time of initial presentation by routine clinical studies are considered to have metastatic osteosarcoma.

TNM stands for tumor, nodes, metastasis. TNM staging describes:

The size and extent of the primary tumor.
The number and location of any regional lymph nodes that have cancer cells in them.
Whether cancer has spread or metastasized to another part of the body.

**TNM staging of osteosarcoma**
Stage	Tumor Grade	Tumor Size
IA	Low	The tumor is 8 cm or less in size. It has not spread to lymph nodes or distant sites of the body.
IB	Low	The tumor is more than 8 cm in size. It has not spread to lymph nodes or distant sites of the body.
IIA	High	The tumor is 8 cm or less in size. It has not spread to lymph nodes or distant sites of the body.
IIB	High	The tumor is more than 8 cm in size. It has not spread to lymph nodes or distant sites of the body.
III	Any tumor grade, skip metastases.
IV	Any tumor grade, any tumor size, distant metastases.

Enneking system for staging malignant musculoskeletal tumors
Stage	Tumor Grade	Tumor site	Tumor Metastasis
IA	Low	Intracompartmental	No
IB	Low	Extra Compartimental	No
IIA	High	Intracompartmental	No
IIB	High	Extra Compartimental	No
III	Any	Any	Any (Regional or distant)

References

↑ Moore DD, Luu HH (2014). “Osteosarcoma”. Cancer Treat. Res. 162: 65–92. doi:10.1007/978-3-319-07323-1_4. PMID 25070231.
↑ Cates JM (March 2017). “Comparison of the AJCC, MSTS, and Modified Spanier Systems for Clinical and Pathologic Staging of Osteosarcoma”. Am. J. Surg. Pathol. 41 (3): 405–413. doi:10.1097/PAS.0000000000000774. PMID 28195881.
↑ Biazzo A, De Paolis M (December 2016). “Multidisciplinary approach to osteosarcoma”. Acta Orthop Belg. 82 (4): 690–698. PMID 29182106.
↑ Cates J (April 2018). “Modeling Continuous Prognostic Factors in Survival Analysis: Implications for Tumor Staging and Assessing Chemotherapy Effect in Osteosarcoma”. Am. J. Surg. Pathol. 42 (4): 485–491. doi:10.1097/PAS.0000000000000995. PMID 29200101. Vancouver style error: initials (help)
↑ Jeys LM, Thorne CJ, Parry M, Gaston CL, Sumathi VP, Grimer JR (March 2017). “A Novel System for the Surgical Staging of Primary High-grade Osteosarcoma: The Birmingham Classification”. Clin. Orthop. Relat. Res. 475 (3): 842–850. doi:10.1007/s11999-016-4851-y. PMC 5289182. PMID 27138473.

Overview