Adjuvant and neoadjuvant chemotherapy for osteosarcoma: JCOG Bone and Soft Tissue Tumor Study Group.

The usefulness of adjuvant chemotherapy for high-grade osteosarcoma was established by two randomized, controlled trials conducted in the 1980s, which used six drugs, doxorubicin, cisplatin, high-dose methotrexate, bleomycin, cyclophosphamide and actinomycin D. Since then, development has been promoted in the direction of introducing preoperative chemotherapy, changing post-operative adjuvant chemotherapy according to histological effects, adding ifosfamide as a key drug and strengthening adjuvant chemotherapy. No clinical trials, however, have shown the effectiveness of study treatment, and the improvement of treatment results during that time has been slight, although the JCOG0905 study is now going to verify the effectiveness of introducing ifosfamide for patients who experienced limited preoperative therapeutic effects. We are desperately looking for a breakthrough.