Soft Tissue Sarcoma Staging

Updated: May 23, 2023
  • Author: Mrinal M Gounder, MD; Chief Editor: Edwin Choy, MD, PhD  more...
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TNM Classification for Soft Tissue Sarcoma

The revised AJCC Cancer Staging Manual, Eighth edition classifies soft tissue sarcoma based on tumor-node-metastasis (TNM) and tumor grade (G). [1] The AJCC follows the grading system of the French Federation of Cancer Centers Sarcoma Group (FNCLCC). Tumor grade is based on cellular differentiation, mitotic rate, and extent of necrosis, as outlined in Table 1.

Table 1. Histologic Grade (G) for Soft Tissue Sarcoma  (Open Table in a new window)

 
Tumor Differentiation  Mitotic Count Tumor Necrosis
Sarcoma closely resembling normal adult mesenchymal tissue (eg, low-grade leiomyosarcoma (1 point) 0-9 mitoses per 10 high-power fields (HPF) (1 point) No necrosis (0 points)
Sarcomas for which histologic typing is certain (eg, myxoid/round cell liposarcoma) (2 points) 10-19 mitoses per 10 HPF (2 points) < 50% tumor necrosis (1 point)
Embryonal and undifferentiated sarcomas, sarcomas of doubtful type, synovial sarcomas, soft tissue osteosarcoma, Ewing sarcoma/primative neuroectodermal tumor (PNET) of soft tissue (3 points) ≥20 mitoses per 10 HPF (3 points) ≥50% tumor necrosis (2 points)

The scores for these variables are added to calculate the following G values:

  • GX - Grade cannot be assessed
  • G1 - Total score of 2 or 3
  • G2 - Total score of 4 or 5
  • G3 - Total score of 6 or higher

Histology and grade are critical components of staging. Lymph node involvement is not characteristic of most sarcomas except rhabdomyosarcoma  and synovial, clear cell, vascular, and epithelioid sarcomas.

Separate staging systems have been created based on anatomic location and type as follows:

  • Soft tissue sarcoma of the head and neck
  • Soft tissue sarcoma of the trunk and extremities
  • Soft tissue sarcoma of the abdomen and thoracic visceral organs
  • Soft tissue sarcoma of the retroperitoneum

These guidelines do not pertain to the management of gastrointestinal stroma tumors (GISTs), rhabdomyosarcoma, Ewing sarcoma, desmoplastic round cell tumors, and primitive neuroectodermal tumors.

Soft tissue sarcoma of the head and neck

Soft tissue sarcoma of the head and neck is a new classification and anatomic staging and prognostic groups have not yet been defined due to a lack of data. The TNM and G classifications are provided in Tables 2 and 3 below. [2]

Table 2. TNM Classification for Soft Tissue Sarcoma of the Head and Neck (Open Table in a new window)

Primary tumor (T)

TX

Primary tumor cannot be assessed

T1

Tumor ≤ 2 cm

T2

Tumor > 2 cm to ≤ 4 cm

T3

Tumor > 4 cm

T4

Tumor  with invasion to adjoining structures

T4a

Tumor with orbital invation, skull base/dural invasion, invasion of central compartment viscera, involvement of facial skeleton, or invasion of pterygold muscles

T4b

Tumor with brain parenchymal invasion, carotid artery encasement, prevertebal muscle invasion, or central nervous system involvement via perineural spread

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

  Table3. Histologic grade (Open Table in a new window)

Histologic grade (G)

GX

Grade cannot be assessed

G1

Grade 1

G2

Grade 2

G3

Grade 3

Soft tissue sarcoma of the trunk and extremites

The TNM and G classifications and anatomic stage/prognostic groups are provided in Tables 4, 5 and 6 below. [2]

Table 4. TNM Classification for Soft Tissue Sarcoma of the Trunk and Extremities (Open Table in a new window)

Primary tumor (T)

TX

Primary tumor cannot be assessed

T0

No evidence for primary tumor

T1 Tumor ≤ 5 cm in greatest dimension

T2

Tumor > 5 cm to ≤ 10 cm in greatest dimension

T3

Tumor > 10 cm to ≤ 15 cm in greatest dimension

T4

Tumor > 15 cm

Regional lymph nodes (N)

N0

No regional lymph node metastasis or nodes cannot be assessed

N1

Regional lymph node metastasis

Distant metastasis (M)

M0

No distant metastasis

M1

Distant metastasis

  Table 5. Histologic grade (Open Table in a new window)

Histologic grade (G)

GX

Grade cannot be assessed

G1

Grade 1

G2

Grade 2

G3

Grade 3

  Table 6. Anatomic stage/prognostic groups (Open Table in a new window)

Stage

T

N

M

Histologic grade

Stage IA

T1

N0

M0

G1, GX

Stage IB

T2

N0

M0

G1, GX

T3

N0

M0

G1, GX

T4 N0 M0 G1, GX

Stage II

T1

N0

M0

G2, G3

Stage IIIA

T2

N0

M0

G2, G3

Stage IIIB

T3

N0

M0

G2, G3

T4

N0

M0

G2, G3

Stage IV

Any T N1 M0 Any G

Any T

Any N

M1

Any G

Soft tissue sarcoma of the abdomen and thoracic visceral organs

The TNM and G classifications are provided in Tables 7 and 8 below. There is currently no recommended prognostic stage grouping. [2]

Table 7. TNM Classification for Soft Tissue Sarcoma of the Abdomen and Thoracic Visceral Organs (Open Table in a new window)

Primary tumor (T)

TX

Primary tumor cannot be assessed

T1 Organ confined

T2

Tumor extends to tissue beyond organ

T2a Tumor invades serosa or visceral peritoneum
T2b Tumor extends beyond serosa (mesentery)

T3

Tumor invades another organ

T4

Multifocal tumor involvement

T4a Multifocal tumor involvement (2 sites)
T4b Multifocal tumor involvement (3-5 sites)
T4c Multifocal tumor involvement (> 5 sites)

Regional lymph nodes (N)

N0

No regional lymph node metastasis or nodes cannot be assessed

N1

Regional lymph node metastasis

Distant metastasis (M)

M0

No distant metastasis

M1

Distant metastasis

  Table 8. Histologic grade (Open Table in a new window)

Histologic grade (G)

GX

Grade cannot be assessed

G1

Grade 1

G2

Grade 2

G3

Grade 3

Soft tissue sarcoma of the retroperitoneum

The TNM and G classifications and anatomic stage/prognostic groups are provided in Tables 9, 10, and 11, below.  [2]

Table 9. TNM Classification for Soft Tissue Sarcoma of the Retroperitoneum (Open Table in a new window)

Primary tumor (T)

TX

Primary tumor cannot be assessed

T0

No evidence for primary tumor

T1 Tumor ≤ 5 cm in greatest dimension

T2

Tumor > 5 cm to ≤ 10 cm in greatest dimension

T3

Tumor > 10 cm to ≤ 15 cm in greatest dimension

T4

Tumor > 15 cm

Regional lymph nodes (N)

N0

No regional lymph node metastasis or nodes cannot be assessed

N1

Regional lymph node metastasis

Distant metastasis (M)

M0

No distant metastasis

M1

Distant metastasis

Table 10. Histologic grade (Open Table in a new window)

Histologic grade (G)

GX

Grade cannot be assessed

G1

Grade 1

G2

Grade 2

G3

Grade 3

Table 11. Anatomic stage/prognostic groups (Open Table in a new window)

Stage

T

N

M

Histologic grade

Stage IA

T1

N0

M0

G1, GX

Stage IB

T2

N0

M0

G1, GX

T3

N0

M0

G1, GX

T4 N0 M0 G1, GX

Stage II

T1

N0

M0

G2, G3

Stage IIIA

T2

N0

M0

G2, G3

Stage IIIB

T3

N0

M0

G2, G3

T4

N0

M0

G2, G3

Any T N1 M0 Any G

Stage IV

Any T

Any N

M1

Any G

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