[Therapeutic response of various histological osteosarcoma subtypes to high-dose methotrexate treatment].

The successful or unsuccessful chemotherapy of osteosarcoma has given rise to the division of these tumors into responders and non responders from the clinical point of view. In order to work out drug sensitive tumor components we studied 9 osteosarcomas by a histological subdivision of the osteosarcoma tissue into 6 subtypes. Seven of the 9 osteosarcoma patients had developed lung metastases under adjuvant high dosage methotrexate (HDMTX) therapy. The aim was to identify the components of the primary tumors which had endured HDMTX-therapy as lung metastases. As HDMTX-sensitive histologic differentiation form of osteosarcoma tissue we regarded the no matrix producing-subtype (III), because it did not occur in the lung metastases. The classical subtype (IV) seems to be only partially sensitive because the corresponding lung metastases showed a higher osteoblastic differentiation with increased osteoid production. No therapeutic effect could be observed in the chondromatous (I) and in the sarcomatous (II) subtypes as well as in the two subtypes with intensive osteoid production being termed trabecularly sclerosing (V) and massively osteoid producing subtypes (VI).