Long-term response of gemcitabine plus docetaxel chemotherapy regimen for extraskeletal osteosarcoma: A case report.

Extraskeletal osteosarcomas (EOSs) are rare variants of primary osteosarcoma of the bone, and are defined as sarcomas located in the soft tissues and characterized by osteoid production. EOS exhibits distinctive demographic, imaging and prognostic features compared with osteosarcoma of bone origin. The available data are contradictory with regard to the use of chemotherapy regimens in the management of EOS. The present study describes a case of EOS that progressed following two lines of therapy oriented to soft-tissue and bone sarcoma histology, respectively. As a gemcitabine-docetaxel combination schedule has demonstrated synergistic activity against bone and soft-tissue sarcoma histologies, this chemotherapy regimen was selected as salvage therapy. The treatment was well-tolerated and induced a long lasting partial response for ~14 months. To the best of our knowledge, this is the first report involving the clinical use of this combination regimen for the treatment of EOS. Furthermore, as demonstrated in this report, EOS may maintain relative chemosensitivity, indicating the potential to control advanced disease in the long term and to plan subsequent chemotherapy regimens.