Multiinstitutional phase II study of neoadjuvant chemotherapy for osteosarcoma (NECO study) in Japan: NECO-93J and NECO-95J

Background Osteosarcoma is the most frequent primary malignant bone tumor. In Europe and the United States, its prognosis has been greatly improved by the use of multimodal treatment, including preoperative and postoperative chemotherapy as well as surgery. In Japan, however, only a few clinical studies on osteosarcoma have been carried out.