Biology and treatment of metastasis of sarcoma to the brain

Sarcomas are rare tumors with devastating clinical consequences, often affecting children as well as adults. Brain metastasis in sarcoma is frequently preceded by lung metastasis. Common offenders include Ewing sarcoma, osteosarcoma and leiomyosarcoma. Although our understanding of sarcoma metastasis remains limited, several cellular factors and signaling pathways appear to play regulatory roles and/or exhibit prognostic values in sarcoma metastasis. In addition, MicroRNAs have been shown to have either positive or negative impact on sarcoma biology and metastasis. Sarcoma is considered one of the classic radio- and chemo-resistant brain metastasis, hence the use of multiple modalities in order to improve the therapeutic ratio and overcome the inherent resistance. Treatment modalities include surgical resection, chemotherapy, gamma knife radiosurgery and/or fractionated whole-brain radiotherapy. The efficacy of chemotherapy is limited by the ability of the drug(s) to cross the blood-brain barrier (BBB), and the chemosensitivity of the tumor to the chemotherapeutic agent. In this review, we discuss the pathology, biology and therapy for sarcoma brain metastasis.