Metastasis in soft tissue sarcomas: prognostic criteria and treatment perspectives.

Soft tissue sarcomas (STSs) are rare tumors, notorious for early hematogenous metastasizing. Metastatic disease is seldom amenable to curative treatment; therefore new treatment modalities are required. Treatment-related and tumor-related prognostic factors can be assessed to estimate the risk for subsequent metastases, as will be discussed. By this means, high-risk patients can be defined; they are the candidates for clinical trials mandatory for treatment development. The metastatic process as well as the reaction to chemotherapy depends on the biological make-up of the tumor. Current chemotherapy regimens do not improve the survival rates of patients with metastatic disease, due to resistance mechanisms of tumor cells. New drugs with direct access to the cell death machinery in tumor cells might contribute to more effective treatment of STS patients.