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KEY CONCEPTS
Sarcomas represent a heterogenous group of more than 70 tumor types, many with unique disease biology, natural history, and chemotherapeutic sensitivity, driving a growing awareness and interest in subtype-specific therapy.
Tumor histology, size, location, and the presence or absence of metastasis at diagnosis are the most important and well-established prognostic factors for patients with soft tissue sarcoma (STS).
Although the role of adjuvant chemotherapy remains controversial, adjuvant chemotherapy containing anthracyclines in combination with ifosfamide is associated with improved disease-free and overall survival among patients with high-risk STS.
The majority of gastrointestinal stromal tumors harbor activating mutations in either KIT or PDGFRA, conferring sensitivity to imatinib as well as other tyrosine kinase inhibitors. Mutational testing is recommended for both prognosis and to guide treatment selection.
Patients with osteosarcoma and other high-grade bone sarcomas often present with micrometastatic disease at the time of diagnosis. Contemporary treatment consists of neoadjuvant chemotherapy followed by limb-sparing surgery and additional adjuvant chemotherapy.
The lung is the most common site of relapse and metastasis for patients with sarcomas after completion of primary treatment. Surgery with or without additional chemotherapy should be pursued in patients with resectable lung metastases and can result in cure in a subset of patients who can be rendered disease free.
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Sarcomas are a rare and heterogeneous group of tumors that arise from mesenchymal tissues. According to the estimates of the American Cancer Society, approximately 1.8 million people were projected to be diagnosed with cancer in the United States in the year 2020; an estimated 16,730 new sarcoma cases accounts for just less than 1% of new cancer cases and approximately 1% of cancer-related deaths in the United States annually.1 Approximately 80% (13,130) of new sarcoma cases arise in soft tissue, and the remaining 20% (3600) are of bone origin.
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EPIDEMIOLOGY AND PATHOGENESIS
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The etiology and pathogenesis of most sarcomas are not well understood. Multiple environmental factors, including radiation and chemical exposures, trauma, and infection, have been associated with the development of soft tissue and bone sarcomas. Both sporadic and inherited molecular and genetic aberrations have been identified in specific subsets of sarcoma and have been implicated in sarcomagenesis.
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Several inherited familial cancer syndromes have been associated with a predisposition to development of soft tissue and bone sarcomas. The Li-Fraumeni syndrome resulting from a germline mutation of the TP53 tumor suppressor gene is associated with increased risk of soft tissue sarcomas (STS) and osteosarcoma among several other cancers in children and young adults.2 Hereditary retinoblastoma is also associated with the development of sarcomas, both osteosarcoma and STS.3 Neurofibromatosis type 1 (NF1) is associated with an increased risk of development of sarcoma in a preexisting neurofibroma, resulting in a malignant peripheral nerve sheath tumor.4 Sarcomas have been associated with other rare cancer predisposition syndromes, including Werner syndrome, familial adenomatous polyposis, and Gardner syndrome, among others. ...