Experience of the EORTC Radiotherapy/Chemotherapy Group in osteosarcoma trials

Abstract

One of the earliest cooperative groups of the GECA, the forerunner of the EORTC, was the Radiotherapy Chemotherapy Group, comprising mainly French, Belgian, and Dutch centers. Next to work on lymphomas, this group initiated randomized trials on bonesarcoma in children and young adults, respectively for Ewing’s sarcoma in 1969 and for osteosarcoma of the limbs in 1970. At that time chemotherapy for osteosarcoma was not yet available, and the radiosensitivity of the tumor is limited. Observations and calculations of Profs. Breur [1] and Abbatucci [2] had shown that the radiosensitivity of osteosarcoma is sufficient to eradicate tumor nodules of 104 to 105 cells with a dose of 20 Gy over 10 days, that is, the maximum dose that is tolerable for both lungs. The chance that subclinical lung metastases at the time of diagnosis are of this size or smaller is about 20%. Therefore prophylactic bilateral pulmonary irradiation directly after amputation or after irradiation of the primary tumor should increase the survival level by this proportion. This first study of the Radiotherapy Chemotherapy Group, 02, collected 86 patients. The late Prof. Breur was study coordinator, together with Dr. Schweisguth [3]. The 3-year disease-free survival rose from 28% to 43% (p = 0.056). The study could not collect sufficient patients because the first reports on the beneficial effects of adjuvant Adriamycin or methotrexate appeared around 1974 and thereafter patient accrual diminished.