Baseline Characteristics:
There were 1103 AYA with OGS registered during the study period, of whom
748 (67.8%) were extremity osteosarcomas uniformly treated with the
“OGS-12” protocol as first-line therapy, consisting of NACT, surgery
and ACT. (Figure 1) Of these, 606 (81.0%) had non-metastatic disease.
There were 263 non-metastatic ES, of whom 104 (39.5%) had extremity
tumours treated with the “EFT-2001” protocol. Among 218 AYA with
metastatic ES, 82 (37.6%) received the “EFT-2001” protocol, of whom
(46.3%) had extremity tumours while the rest (chest wall, pelvis or
other non-appendicular primary) were not included in this analysis as
prespecified. Baseline characteristics are detailed in Table 1 and Table
2.