Significance of Preoperative Therapy in Bone and Soft-Tissue Sarcomas and Its Present Status

Neoadjuvant or preoperative chemotherapy in musculoskeletal sarcomas began in 1970s for the pur-pose of preventing tumour growth and distant metastasis in patients with osteosarcoma while custom-made endoprosthesis for limb-saving surgery was manufactured. The purposes of neoadjuvant chemotherapy are to prevent distant metastases, to reduce the tumour size and to evaluate the efficacy of the chemotherapy. Reducing the tumour size facilitates easier excision with less risk of local recur-rence. In addition, not only limb-saving but also function-preserving surgery is made possible. Evalu-ating the efficacy of the chemotherapeutic agents in preoperative chemotherapy facilitates rational se-lection of postoperative chemotherapeutic agents. Chemosensitive sarcomas, such as osteosarcoma and Ewing’s sarcoma, are absolute indication of neoadjuvant chemotherapy. On the other hand, because efficacy of chemotherapy is not statistically demonstrated in most of non-round cell high-grade sarcomas, such as malignant fibrous histiocytoma, adjuvant chemotherapy is relatively indicated for these sarcomas. Neoadjuvant chemotherapy in musculoskeletal oncology, where efficacy of chemo therapy is unclear in most sarcomas, is important because efficacy of chemotherapy can be evaluated by reduction of tumour size as a surrogate marker and indication of postoperative chemotherapy can be determined, and because good limb function can be preserve postoperatively.