Bone tumor staging systems

Prepared by:Dr. Abdullah K. Ghafour2nd year IBFMS trainee

Supervised by: Dr. Ali Abdulnabi Alwan

• Bone tumors are classified into: Primary bone tumors Secondary bone tumors ( Metastasis)

• Primary bone tumors are much less than secondary tumors

• All age groups affected, but some tumors occur in certain age

• Almost every bone can be affected, but some tumors prefer certain location

General considerations

Bone tumor

frequency

according to age

Classification of primary bone tumors ; according to the normal cell of origin and apparent pattern of differentiation

Histologic type Benign MalignantHematopoietic (40%) Myeloma, lymphoma

Chondrogenic (22%)

Osteochondroma, chondroma, chondroblastoma, chondromyxoid fibroma

Chondroscarcoma, dedifferentiated and mesenchymal chondrosarcoma

Osteogenic (19%) Osteoid osteoma, osteoblastoma Osteosarcoma

Unknown (10%) Giant cell tumor Ewing sarcoma, giant cell tumor, adamantinoma

Histiocytic Fibrous histiocytoma Malignant fibrous histiocytoma

Fibrogenic Fibroma Desomplastic fibroma, fibrosarcoma

Notochordal Chordoma

Vascular HemangiomaHemangioendothelioma, hemangiopericytoma, angiosarcoma

General considerations

Table 1: frequency of malignant tumors:

Metastatic tumor 28.4%Osteogenic sarcoma 27.2%Ewing’s sarcoma 12.4%NHL 10.6%Chondrosarcoma 8.3%Plasma cell myeloma 8.3%Miscellaneous 4.8%

General considerations

Table 4: incidence of bone metastasis:

Cancer type incidence

Median survival

(mo.)Myeloma 70 –

95%6

Prostate 65 - 75 %

36

Breast cancer

65 – 75 %

24

Thyroid cancer

60 % 48

Lung cancer 30 – 40 %

7

Bladder cancer

40 % 6-9

Renal cancer 20 – 25 %

12

location of Tumors:General considerations

Bone tumor management principles:

• In treating tumors we strive to reconcile two conflicting principles: the lesion must be removed widely enough to ensure that it does not recur, but damage must be kept to a minimum.

• The balance between these objectives depends on knowing (a) how the tumor usually behaves (i.e. how aggressive it is), and (b) how far it has spread. The answers to these two questions are embodied in the staging system

Bone tumor staging:•In bone tumors, staging incorporates the

degree of differentiation as well as local and distant spread, in order to estimate the prognosis of the patient.

•The stage of cancer at the time of diagnosis is a key factor that defines prognosis and is a critical element in determining appropriate treatment

Purposes of staging:

•Determine tumor type•Determine prognosis•planning treatment•Compare results between study groups•Delineate extent of local and distant

disease

Staging Studies:Conventional radiographyMRICT scan

o Tumor siteo Chest CT

Nuclear imagingAngiographyBone Tumor Specimens:

o Fine-needle Aspiration Biopsyo Biopsyo Curettageo Resections and Amputations

Adjunctive Diagnostic Techniqueso Histochemistry, Immunohistochemistry, and Electron

Microscopyo Cytogenetic/Molecular Genetic Techniques

Conventional radiography

•Cortical destruction?•Periosteal reaction? •Involvement of joint space?•Tumor multifocal?•Internal composition of tumor•Is involved bone normal?•What part of the bone?•Tumor interaction with surrounding non-

neoplastic tissue

MRI•Evaluates entire bone and adjacent joint•Best test for intraosseous extent and soft•tissue extent•Skip metastatic lesions•Proximity to vascular structures•Occasionally helpful in diagnosis of bone

or soft tissue tumors (experienced radiologist)

CT scan▫Good for evaluating cortical details and destruction▫Subtle cortical erosions (endosteal ; periosteal)▫Calcifications / ossification▫Chest CT: Presence of metastatic disease

Bone Scintigraphy▫Whole body bone scan▫Sites of bony metastasis▫Active lesion??

Prognosis of bone cancer depends on:1. overall stage of disease2. presence of metastasis3. skip lesions within the same bone4. histologic grade5. tumor size

Bone tumor staging systems:•The are two staging systems that are

commonly used:

▫Musculoskeletal Tumor Society MSTS or Enneking System 

▫American Joint Committee on Cancer AJCC Staging System

MSTS (Enneking) Staging System: most popular and useful for orthopaedic

surgeons

two systems: malignant lesions: are defined using Roman

numerals (e.g. I, II, III) benign lesions: are defined using Arabic

numbers (1,2,3)1= latent lesion 2=active lesion3=aggressive lesion

• Stage 1; Latent ▫ Well defined margin▫ Grows slowly and then stops▫ Heals spontaneously e.g. osteoid osteoma▫ Negligible recurrence after intracapsular resection

• Stage 2; Active▫ Progressive growth limited by natural barriers▫ Well defined margin but may expand thinning cortex e.g.

ABC▫ Negligible recurrence after marginal excision▫ Rx. marginal resection

• Stage 3; aggressive▫ Growth not limited by natural barriers e.g. GCT▫ Metastasis present in 5% of these ptatients▫ Have high recurrence after intracapsular or marginal

resection▫ Extended resection preferred

Enneking staging of benign tumors

Enneking staging of benign tumors

Incorporates :

• Tumor Grade ▫ histologically, tumors are graded based on the percentage of cellular atypia;

low grade tumors (I) low metastatic potential e.g. paraosteal osteosarcoma

high grade tumors (II) greater metastatic potential e.g. intramedullary osteosarcoma, Ewing's sarcoma, dedifferentiated

chondrosarcoma

• Tumor Compartments (Site)▫ Intracompartmental (A)

bone tumors are confined within the cortex of the bone▫ Extracompartmental (B)

bone tumors extend beyond the bone cortex

• distant spread▫ metastasis

Enneking staging of malignant tumors

Enneking staging of malignant tumors

AJCC staging for bone sarcomasit has been used a new, more complex classification of the primary malignant osseous tumors

Tumor grade Low grade tumor (I) High grade tumor (II)

Tumor size <8cm -A >8cm –B

Lymph node metastasis• N0 - no regional lymph node metastases• N1 - regional lymph node metastases

Presence and location of metastasis Skip metastasis -III Pulmonary metastasis -IVA Non-pulmonary metastasis -IVB

AJCC staging for bone sarcomas

Bone tumor staging systems:

References:• Solomon L., Warwick D. , Nayagam S.,[2010] Apley’s System of

Orthopaedics and Fractures, 9th ed. Hodderarnold comp.,London, UK.• Miller M. , Thompson S. , Hart J. ,[2012] REVIEW OF ORTHOPAEDICS

[PDF], 6th ed. by Saunders, an imprint of Elsevier Inc. , Philadelphia, USA.• Canale S. , Beaty J. , [2007] Campbell’s Operative Orthopaedics [PDF], 11th

ed. By Mosby, An Imprint of Elsevier , Tennessee, USA.• Richard J. O’Donnell, MD, Annual Meeting of the Musculoskeletal Tumor

Society [2013] San Francisco, California• American Joint Committee on Cancer • [PDF] Purposes and Principles of

Cancer Staging , published in this manual is effective for cancer cases diagnosed on or after January 1, 2010.

• Alina Maria Sisu, Loredana Gabriela Stana[2012] On the Bone Tumours, incidence classification and staging [PDF] , New York, USA.

• L.-G. Kindblom, MD, PhD, [2008] Bone Tumors: Epidemiology,Classification, Pathology, [PDF] Birmingham B15 , 2TT, UK

• Martin M. Malawer, Paul Sugarbaker, [2012] Musculoskeletal Cancer Surgery , Washington Cancer Institue , Washington , USA.

THANKS