Sarcomas



Sarcomas


Beth L. Kozak Onners



I. Definition

A. Tumors Arising From Connective Tissues

1. Comes from the Greek word meaning “fleshy growth”

2. Types of sarcomas: Bone and soft tissue

a. Bone sarcomas are malignant tumors arising from the skeletal system of the body. Malignant bone tumors represent 5% of all malignancies in children and 10% of all malignancies in adolescents. For specific types of bone sarcomas and the tissues from which they originate, see Table 20-1.

b. Soft tissue sarcomas are malignant tumors arising from the extraskeletal connective tissue of the body. Soft tissues are those that connect, support, or surround other structures and organs in the body. The incidence of soft tissue sarcomas outnumbers bone sarcomas 3:1. For specific types of soft tissue sarcomas and the tissue from which they originate, see Table 20-1.

B. Incidence (American Cancer Society, 2003)

1. About 8,300 new cases yearly in the United States, and make up less than 1% of all newly diagnosed cancers.








TABLE 20-1 Types of Sarcomas

















































Type of Sarcoma

Tissue Origin


Bone Sarcomas


Osteosarcoma

Bone


Chondrosarcoma

Cartilage


Ewing’s sarcoma

Bone marrow


Fibrosarcoma of the bone

Spindle cell connective tissue


Soft Tissue Sarcomas


Clear cell sarcoma

Bone marrow


Liposarcoma

Fat


Kaposi’s sarcoma

Endothelial cells


Fibrosarcoma

Fibrous soft tissue (eg, tendons, ligaments)


Angiosarcoma

Blood vessels


Lymphangiosarcoma

Lymph vessels


Synoviosarcoma

Synovia


Leiomyosarcoma

Smooth muscle


Rhabdomyosarcoma

Striated/skeletal muscle



2. The morbidity rate of soft tissue cancer in 2003 is predicted to be 8,000, with the mortality estimate of 3,900.

3. Five-year survival rate is 90% in localized disease, but 10% to 15% when diagnosed after it has metastasized.

4. The diagnosis of most sarcomas is distributed equally among male and female with the incidence peaking during childhood and in the fifth decade of life.

5. The incidence is slightly higher in males than females and no racial preference except for Ewing’s sarcoma, which is even more rare in African Americans.

C. Grading of sarcomas: Tables 20-2 and 20-3 review the grading system used for bone and soft tissue sarcomas.

1. Clinical staging includes physical examination, clinical laboratory tests, and biopsy of the sarcoma for microscopic diagnosis and grading.








TABLE 20-2 Grading System for Bone Cancers












































































































Primary Tumors (T)


TX

Primary tumor cannot be assessed


T0

No evidence of primary tumor


T1

Tumor confined within the cortex


T2

Tumor invades beyond the cortex


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)


MX

Presence of distant metastasis cannot be assessed


M0

No distant metastasis


M1

Distant metastasis


Histopathologic Grade (G)


GX

Grade cannot be assessed


G1

Well differentiated


G2

Moderately differentiated


G3

Poorly differentiated


G4

Undifferentiated


Note: Ewing’s sarcoma is classified as G4.


Stage Grouping


Stage

IA

G1,2

T1

N0

M0


Stage

IB

G1,2

T2

N0

M0


Stage

IIA

G3,4

T1

N0

M0


Stage

IIB

G3,4

T2

N0

M0


Stage

III

Not defined


Stage

IVA

Any G

Any T

N1

M0


Stage

IVB

Any G

Any T

Any N

M1


American Joint Committee on Cancer, 1997.










TABLE 20-3 Grading System for Soft Tissue Sarcomas* in People ≥16 years of age












































































































Primary Tumors (T)


TX

Primary tumor cannot be assessed


T0

No evidence of primary tumor


T1

Tumor 5 cm or less in greatest dimension


T2

Tumor more than 5 cm in greatest dimension


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)


MX

Presence of distant metastasis cannot be assessed


M0

No distant metastasis


M1

Distant metastasis


Histopathologic Grade (G)


GX

Grade cannot be assessed


G1

Well differentiated


G2

Moderately differentiated


G3

Poorly differentiated


G4

Undifferentiated


Stage Grouping


Stage

IA

G1,2

T1

N0

M0


Stage

IB

G1,2

T2

N0

M0


Stage

IIA

G3,4

T1

N0

M0


Stage

IIB

G3,4

T2

N0

M0


Stage

III

Not defined


Stage

IVA

Any G

Any T

N1

M0


Stage

IVB

Any G

Any T

Any N

M1


*With exception of Kaposi’s sarcoma, dermatofibrosarcoma, desmoid type fibrosarcoma grade 1, sarcomas arising from the dura mater, brain, or parenchymatous organs or hollow viscera.


American Joint Committee on Cancer. (1997). AJCC cancer staging handbook (pp. 133-146). Philadelphia: Lippincott-Raven Publishers. (Reprinted with permission.)


2. Pathologic staging includes removal of the primary tumor, nodes, and suspected metastases.


II. Etiology:

Little is known regarding the cause of primary bone and soft tissue tumors; however, a few risk factors have been identified. Table 20-4 shows the more common types of sarcomas and their incidence and etiology. The following have been identified as possible risk factors for the development of sarcomas:

A. Prior cancer therapy, including high-dose irradiation

B. Exposure to alkylating agents (ie, melphalan, procarbazine, nitrosureas, and chlorambucil) and chemicals (ie, vinyl chloride gas, arsenic, and dioxin, or Agent Orange).

C. Chronic immunosuppressed patients, such as organ transplant recipients and patients who have acquired immunodeficiency syndrome (AIDS), are at high risk for soft tissue sarcomas.










TABLE 20-4 Incidence and Etiology of Sarcoma











































Type

Epidemiology

Etiology


Bone Sarcomas


Osteosarcoma


  • Most common type of bone cancer



  • Accounts for 34% of bone cancer



  • Incidence is greatest in people 1-25 years of age



  • Twice as common in males after the age of 13. In children younger than 13 years of age, the incidence is similar in males and females



  • Located primarily around the knee joint, either in the distal femur or proximal tibia


  • Etiology of osteosarcoma is unclear



  • Increased incidence of osteosarcoma during adolescence, which has been correlated with skeletal growth patterns



  • People with Paget’s disease have a higher affinity


Chondrosarcoma


  • Second most common bone tumor



  • Accounts for about 13% of malignant bone cancers



  • Incidence is greatest in people 30-60 years of age



  • More common in males



  • Usually located in the pelvis or femur


  • Development of chondrosarcoma has been associated with syndromes of skeletal maldevelopment



  • People with Ollier’s disease (a syndrome of polyosteotic benign cartilage tumors) have a higher affinity


Fibrosarcoma of the bone


  • Rare; accounts for fewer than 4% of primary bone tumors



  • Occurs in any age range, but is rare in children



  • No sex predominance



  • Generally originates in many mesenchymal sites; usually involves the abdominal wall or extremities



  • 50% occurrence in the femur and tibia



  • 10% are poorly differentiated with survival directly related to tumor grade


  • Paget’s disease



  • Chronic osteomyelitis



  • Fibrous dysplasia



  • Previous therapeutic irradiation


Ewing’s sarcoma


  • Accounts for 5% of malignant bone cancers, represents 1% of all childhood cancers



  • 80% of people diagnosed are under the age of 30, younger patient population than any other primary bone cancers. Ewing’s is rarely seen before age 5 or after age 30.



  • 66% are males



  • Caucasians six times more likely to be diagnosed with Ewing’s sarcoma than African Americans



  • Prognosis is poorer in males than females



  • More commonly found in the bones of the trunk than in long bones


  • No specific etiologic factors, but may be genetic in origin given family predisposition


Soft Tissue Sarcomas


Soft tissue sarcoma


  • Occur over 50% of the time in the extremities, with the remainder in the head, neck, and the retroperitoneum regions


  • Exposure to herbicides and other chemicals



  • Prior radiotherapy for cancers



  • Neurofibromatosis can lead to soft tissue sarcomas


Liposarcoma


  • Most commonly diagnosed soft tissue tumor



  • These tumors usually originate in the deep fatty tissues of the thigh, behind the knee, the groin, the gluteal area, or behind the abdominal cavity (retroperitoneum)



  • Liposarcomas are most commonly found in adults between 30 and 60 years of age



  • Slightly more prevalent in males than females



  • Rarely metastasize (less than 10%) and are usually present as firm lumps which will aggressively invade the surrounding tissues


  • Same as above


AIDS-related Kaposi’s sarcoma


  • More common in homosexual/bisexual males



  • 20,000 times more likely to occur in an HIV-infected person than the general population



  • Lesions or nodules can occur anywhere on the body


  • HIV infection



  • Prolonged immunosuppression



  • African, Jewish, or Mediterin ranean descent with possible genetic predisposition


Clear cell sarcoma


  • Now recognized as a form of malignant melanoma; however, incidence is rare



  • Affects adults younger than 40 years of age



  • Presents as painless, firm, spherical growths on tendon sheaths and aponeurotic structures of distal extremities



  • 5-year survival rate is approximately 50%


  • Herbicides or other environmental carcinogen exposures

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Sep 16, 2016 | Posted by in NURSING | Comments Off on Sarcomas

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