Outpatient chemotherapy plus radiotherapy in sarcomas: improving cancer control with radiosensitizing agents

Cancer control by radiotherapy (RT) can be improved with concurrent chemotherapy. Outpatient strategies for sarcomas that combine chemotherapy and RT are possible since supportive care and RT techniques have improved.

The current status of non-anthracycline chemotherapy in combination with radiation for high-risk sarcoma is reviewed.

Ifosfamide with mesna and newer activated ifosfamide agents (ZIO-201 and glufosfamide) have high potential to improve sarcoma cancer control. In Ewing's sarcoma and osteosarcoma, high-dose ifosfamide with mesna (2.8 g/m2/day of each x 5 days; mesna day 6) can be safely given to outpatients using continuous infusion. Reducing ifosfamide nephrotoxicity and central nervous system side effects are discussed. Other outpatient radiosensitization regimens include gemcitabine (600-1000 mg/m2/dose IV over 1 hour weekly x 2-3 doses), temozolomide (75 mg/m2/daily x 3-6 weeks), or temozolomide (100 mg/m2/dose daily x 5) + irinotecan (10 mg/m2/dose daily x 5 x 2 weeks). In osteosarcoma with osteoblastic metastases on bone scan, samarium (1 mCi/kg; day 3 of RT) and gemcitabine (600 mg/m2 IV over 1 hour day 9 of RT) is a radiosensitization strategy. Future drugs for radiosensitization include beta-D-glucose targeted activated ifosfamide (glufosfamide) and sapacitabine, an oral nucleoside with in vitro activity against solid tumors including sarcomas.

The potential to treat major causes of sarcoma treatment failure (local recurrence and distant metastases) with concurrent chemotherapy during radiation should be considered in high-grade sarcomas.