Assessment of in vivo response to preoperative chemotherapy and radiation therapy as a predictor of survival in patients with soft-tissue sarcoma

Current histologic methods for staging soft-tissue sarcomas are based on histologic criteria such as number of mitoses or nuclear and cytoplasmic morphology, without taking into account the inherent biologic variablity of tumors within a given histologic classification. This study demonstrated that patients whose tumors were effectively destroyed by preoperarive chemotherapy and radiation therapy had an improved prognosis compared to patients whose tumors did not respond to the therapy. Four-year survival for the group that responded was 82%, compared to only 55% for the group that had a poor response. The response to preoperative chemotherapy and radiation therapy did not predict an improved sensitivity to postoperative adjuvant therapy, since the addition of postoperative chemotherapy in the high-responding group did not improve survival. Our results indicate that grade III soft-tissue sarcomas are a heterogeneous population of tumors with varying degrees of innate biologic aggressiveness and sensitivity to radiation therapy and chemotherapy, despite their apparently similar histologic appearance.