Event-free survival and overall survival in 2,253 patients with osteosarcoma registered to EURAMOS-1.

10512 Background: EURAMOS-1 (NCT00134030) is an international study in osteosarcoma including two Phase III randomized controlled trials that investigated postoperative treatment optimization on the basis of histological response to preoperative chemotherapy (CT). One study aim was to report outcomes from diagnosis for all registered patients in this large, intergroup study. Methods: Patients (pts) were eligible for registration if: u003c 30 days from diagnostic biopsy; age ≤ 40yrs; with localized or primary metastatic, high-grade extremity or axial osteosarcoma; resectable disease; fit for treatment and follow-up. Treatment was preop CT with methotrexate, doxorubicin, cisplatin (MAP), surgery and then post-op MAP-based CT according to response and optional randomization. The primary outcome measure was event-free survival (EFS), defined as time from diagnostic biopsy until the earliest of: death, local recurrence, new metastatic disease, progression of metastatic disease or secondary malignancy, or date of l...