Compliance:
Of 1566 registered AYA with bone sarcomas, 182 (11.6%) defaulted after diagnosis. among the treatment naive cohorts enrolled respectively on the “OGS-12” and “EFT-2001” protocols, 42 (6.1%) osteosarcoma and 18 (14.2%) Ewing’s sarcoma abandoned treatment subsequently. Overall, 379/481 (78.8%) non-metastatic OGS and 51/70 (72.8%) non-metastatic ES treated per-protocol were compliant to treatment.