Modern Soft Tissue Pathology: MEDICAL ONCOLOGY OF SOFT TISSUE SARCOMAS

Chemotherapy, that is, systemic agents whether classic cytotoxic agents or more specifically targeted agents, is used widely in the metastatic setting for patients with soft tissue sarcomas. Conversely, the use of chemotherapy in the adjuvant setting remains controversial, because the benefit for most sarcomas is small. Exceptions to this rule include rhabdomyosarcoma and Ewing sarcoma of soft tissue, in which adjuvant or neoadjuvant chemotherapy is a critical component of treatment in most patients. It is increasingly appreciated that systemic therapy must be tailored to the specific type of sarcoma being treated. In this respect, a working relationship with an expert sarcoma pathologist is paramount to the optimal treatment of the patients with primary or metastatic sarcoma. If chemotherapy is to have the same impact as radiation therapy and surgery in the management of sarcomas, effective drugs must be identified that help to improve the cure rate for patients with primary tumors and unseen microscopic metastatic disease for each specific sarcoma subtype. This section reviews the treatment of gastrointestinal stromal tumor (GIST), which has set a new paradigm for the treatment of solid tumors. Also discussed are the use of systemic chemotherapy in the adjuvant and metastatic settings for non-GIST sarcomas. Finally, a brief discussion of simultaneous chemotherapy and radiotherapy is included in this chapter. GASTROINTESTINAL STROMAL TUMORS: A NEW MODEL FOR SOLID TUMOR CANCER THERAPY GIST, if it can be considered a sarcoma at all, is the most common sarcoma subtype, and it can vary in size and clinical outcome from an incidental finding at operation to life-threatening metastatic disease.