Eric Kimchi, M.D., Herbert Zeh, M.D., F.A.C.S., Yixing Jiang, M.D., Ph.D., Kevin Staveley-O’Carroll, M.D., Ph.D., F.A.C.S.
SOFT TISSUE SARCOMA
Soft tissue sarcoma (STS) is a collective term for an unusual and
diverse group of malignancies that arise from cells of the embry-
onic mesoderm.Although tissues derived from the mesoderm con-
tain approximately 75% of the cells in the human body, sarcomas
represent only 1% of adult tumors and 15% of pediatric tumors.
Sarcomas may occur anywhere in the body and comprise more
than 50 distinct histologic subtypes. Approximately 43% of STSs
occur in the extremities, 15% in the retroperitoneum, 10% in the
trunk, 19% in the viscera, and 13% in other locations.
some sarcomas occur in the GI tract. It has been estimated that in
2007, there will be approximately 9,220 cases of sarcoma in the
United States, with 3,560 deaths.
STS-related mortality has been
quite constant over the years, indicating that relatively little
progress has been made in the treatment of most sarcomas.
The etiology of STS is unclear and somewhat controversial.
Genetic factors, irradiation, chemical exposure, and lymphedema
have all been shown to have a strong correlation with the evolution
of these lesions.
Chromosomal abnormalities associated with STS may be due
to translocations, point mutations, or deletions resulting in bal-
anced or unbalanced karyotypes. Mutations in regulatory genes,
are a common ±nding.
persons with Li-Fraumeni syndrome, familial retinoblastoma,
Werner syndrome, Gardner syndrome, tuberous sclerosis, basal
cell nevus syndrome, or neuro±bromatosis have an increased inci-
dence of STS (and of other tumors as well).
Ionizing radiation has long been recognized as a factor predis-
posing to the development of osteosarcoma and STS. It may exert
this effect at doses as low as 8 Gy. Sarcomas arising from radiation
exposure often do not become clinically apparent until long after
the inciting exposure; consequently, they are frequently associated
with de±nitive radiation treatments that lead to a long expected
survival, such as may be provided in the setting of breast cancer,
cervical cancer, lymphoma, or childhood malignancies. The most
common of the sarcomas linked with radiation exposure are
osteosarcoma (accounting for 35% of radiation-related STS) and
malignant ±brous histiocytomas (accounting for 22%).
Chemical carcinogenesis has been linked to a variety of sarco-
mas. The thorium dioxide–containing contrast agent Thorotrast,
vinyl chloride, and arsenic all have been conclusively shown to play
a role in the development of hepatic angiosarcomas.
Phenoxyacetic acids, chlorophenols, and dioxins, which have been
used in industry and agriculture, may contribute to the genesis
of STS, but the precise causal relations are unclear and remain