Trial of Cetuximab in Patients With Metastatic and/or Locally Advanced Soft Tissue and Bony Sarcomas

Sarcomas are mesenchymal malignancies that arise in the connective tissue throughout the body and afflict approximately 11,000 people in the United States yearly. Sarcomas are heterogeneous with well over 50 subtypes described. The peak incidence is subtype-specific with certain sarcomas seen in children and young adults while other subtypes peak in late middle-age, causing significant morbidity and mortality in young patients and productive adults. The precise etiology for most sarcomas remains unknown. External radiation therapy is an established risk factor. Other risk factors include occupational exposures to certain chemicals, lymphedema, and hereditary conditions such as neurofibromatosis and Li-Fraumeni syndrome. Many sarcomas are associated with specific somatic genetic alterations. For example, some specific subtypes are associated with gene translocations causing aberrant fusion proteins including Ewing sarcoma (EWS-FLI-1), synovial sarcoma (SSX-SYT), alveolar rhabdomyosarcoma (PAX3-FHKR), and myxoid liposarcomas (TLS-CHOP). These singular molecular alterations imply that some sarcomas are cytogenetically simple and may be more appropriate substrates for therapy targeted to a single molecular pathway. Sarcomas are commonly present as an asymptomatic mass or with local symptoms in an extremity or the retroperitoneum. Although tumor size, location, and histologic subtype have been implicated as prognostic factors in sarcomas, histologic grade remains the most important factor. Tumor grade is based on the degree of cellularity, differentiation, pleomorphism, necrosis, and the number of mitoses. Approximately 50-60% of patients with high grade soft tissue sarcoma will eventually have metastatic disease, as compared to 5-10% of patients with low grade disease. Sarcomas spread hematogenously with the most common site of spread being the lung, followed by liver, bone, and brain. About 50% of patients with sarcoma eventually expire due to locally advanced or metastatic disease with a median survival of 8-12 months.