1Division of Hematology/Oncology, The Hospital
for Sick Children, Toronto, Ontario, Canada; 2Faculty
of Medicine, University of Toronto, Toronto, Ontario, Canada;3Cancer Research Program, Institute for Clinical
Evaluative Sciences, Toronto, Ontario, Canada;4Institute for Health Policy, Evaluation and
Management, University of Toronto, Toronto, Ontario, Canada;5Department of Medical Oncology, Princess Margaret
Cancer Centre, Toronto, Ontario, Canada; 6Dalla Lana
School of Public Health, University of Toronto, Toronto, Ontario,
Canada; 7Li Ka Shing Knowledge Institute, St.
Michael’s Hospital, Toronto, Ontario, Canada,8Melbourne School of Population and Global Health,
University of Melbourne, Melbourne, Victoria, Australia
Abstract Background : Location of cancer care (LOC: pediatric
versus adult center) impacts outcomes in adolescents and young adults
(AYA) with some cancer types. Data on impact of LOC on survival in AYA
with osteogenic sarcoma (OGS) and Ewing sarcoma (EWS) are limited.Objectives : To compare differences in demographics,
disease/treatment characteristics, and survival in a population-based
cohort of AYA with OGS or EWS
treated at pediatric versus adult centers Methods : The IMPACT
Cohort captured demographic, disease, and treatment data for all AYA
(15-21 years old) diagnosed with OGS and EWS in Ontario, Canada between
1992-2012. Patients were linked to provincial administrative healthcare
databases. Outcomes were compared between patients treated in pediatric
versus adult centers using appropriate statistical methods.Results : 137 AYA were diagnosed with OGS (LOC: 47 pediatric, 90
adult) and 84 with EWS (LOC: 38 pediatric, 46 adult). AYA treated at
pediatric centers were more likely to be enrolled in a clinical trial
(OGS 55% vs 1%, [p<0.001]; EWS 53% vs 2%,
[p<0.001]) and received higher cumulative chemotherapy
doses. Five-year event-free survival (EFS ± Standard Error) in OGS and
EWS were 47% ± 4 and 43% ± 5, respectively. In multivariable analysis,
the impact of LOC (pediatric vs adult center) on EFS in OGS (adjusted
hazard ratio [HR] 1.15, 95% CI 0.58-2.27, P=0.69) and EWS (adjusted
HR 1.82, 95% CI 0.97-3.43, P=0.06) were not statistically significant.Conclusion : Outcomes did not differ by LOC suggesting that AYA
with bone tumors can be treated at either pediatric or adult centers.KEYWORDS : adolescent and young adult, Ewing sarcoma, event-free
survival, locus of care, osteosarcoma, population-based