Sarcomas are rare malignant
tumors that develop from mesenchymal tissue. Most
sarcomas are idiopathic, however, a significant minority develops as a consequence of prior radiation exposure. Although the absolute risk of developing a radiation-associated
sarcoma is small, these
tumors represent significant clinical challenges. For recurrent, unresectable or metastatic disease, the standard treatment is systemic
chemotherapy. Radiation-associated
sarcomas tend to be undifferentiated
sarcomas,
angiosarcomas, or
leiomyosarcomas, which are variably sensitive to
chemotherapy. The best general approach is to treat each radiation-associated
sarcoma as one would its sporadic histologic counterpart. There are limited data to guide the best treatment for radiation-associated
sarcoma, therefore, the standard
chemotherapy options are reasonable choices. These include
doxorubicin,
ifosfamide,
gemcitabine,
docetaxel, and
pazopanib. Patients with radiation-associated
sarcomas may have received prior
anthracyclines to treat antecedent
malignancies such as
breast cancer or
lymphoma. Thus, if additional
doxorubicin cannot be used,
liposomal doxorubicin is a reasonable substitute. More prospective research is needed on how radiation-associated
sarcomas respond to systemic
therapy. Future clinical trials of new agents in
sarcoma should identify and include patients with radiation-associated
sarcoma.