1. Sarcomas are a heterogeneous group of tumors that
can occur throughout the body and encompass more than 50 subtypes
with distinct histologic lines of differentiation.
2. These rare tumors account for less than 1% of cancers in
adults (estimated 10,000 cases per year in the United States) and
represent 7% of cancers in children.
3. Approximately two thirds of soft tissue sarcomas arise in the
extremities; the remaining one third are distributed between the
retroperitoneum, trunk, abdomen, and head and neck.
4. The treatment algorithm for soft tissue sarcomas depends on tumor
stage, site, and histology.
5. Multimodality treatment including surgical resection, radiation
therapy and, in selected cases, systemic chemotherapy, has been
applied to patients with locally advanced, high-grade, extremity
6. Overall 5-year survival rate for patients with all stages of
soft tissue sarcoma is 50 to 60%.
7. Of the patients who die of sarcoma, most will succumb to metastatic
disease in the lungs, which 80% of the time occurs within
2 to 3 years of the initial diagnosis.
8. Progress in the understanding of soft tissue sarcoma biology
is crucial for the development of new therapeutic targets.
Sarcomas are a heterogeneous group of tumors that arise predominantly
from the embryonic mesoderm, but also can originate, as does the
peripheral nervous system, from the ectoderm. In 2007, approximately
9220 new cases of soft tissue sarcoma were diagnosed in the United
States with 3560 deaths attributable to disease.1 These
rare tumors account for less than 1% of cancers in adults
and represent 7% of cancers in children. Several distinct
groups of sarcomas are recognized; soft tissue sarcomas, the largest
of these groups, are the focus of this chapter. Other groups include
bone sarcomas (osteosarcomas and chondrosarcomas), Ewing’s
sarcomas, and peripheral primitive neuroectodermal tumors.
Soft tissue sarcomas can occur throughout the body and encompass more
than 50 histiotypes (Table 36-1) with distinct
histologic lines of differentiation. The most common histologic
types of soft tissue sarcoma in adults (excluding Kaposi’s
sarcoma) are malignant fibrous histiocytoma (MFH, 28%),
leiomyosarcoma (12%), liposarcoma (15%), synovial
sarcoma (10%), and malignant peripheral nerve sheath tumors
(6%).2 Rhabdomyosarcoma is the most common
soft tissue sarcoma of childhood. Most primary soft tissue sarcomas
originate in an extremity (50 to 60%); the next most common
sites are the trunk, retroperitoneum, and head and neck.
Table 36-1 Relative Frequency of Histologic Subtypes of Soft Tissue Sarcoma2 |Favorite Table|Download (.pdf)
Table 36-1 Relative Frequency of Histologic Subtypes of Soft Tissue Sarcoma2
|Malignant fibrous histiocytoma||349||28|
|Malignant peripheral nerve sheath tumor|| 72|| 6|
|Rhabdomyosarcoma|| 60|| 5|
|Fibrosarcoma|| 38|| 3|