Predictors and Treatment Outcomes of Pediatric Osteosarcoma in Diverse Socioeconomic Backgrounds in Southeast Asia: A...

Pediatric osteosarcoma outcomes among developed and developing countries have not been previously compared. Countries in Southeast Asia (SEA) have a wide variety of socioeconomic statuses. A multi-institutional retrospective study was conducted to determine the prognostic factors and outcomes for pediatric osteosarcoma in SEA.

Pediatric patients with osteosarcoma treated between 1998 and 2017 in 4 SEA pediatric oncology centers were studied. Countries were classified using the World Bank Atlas method. Kaplan-Meier method and Cox's Proportion Hazard Model were applied to estimate survival outcomes and identify prognostic factors.

In all, 149 patients with osteosarcoma with a mean age of 12.48±3.66 years were enrolled. The localized to metastatic disease ratio was 1.5:1. The 5-year overall survival (OS) and event-free survival (EFS) were 53.8% and 42%, respectively. Prognostic factors associated with outcomes were country, stage of disease, MTX-containing regimens, and surgery type (p-value <0.05). In patients with localized disease, EFS was superior with limb-salvage surgery (62%) than amputation or rotationplasty (40%) (p-value 0.009). MTX-containing chemotherapies provided higher OS (45.3%) and EFS (37.9%) than non-MTX regimens (12.3% and 10.7%, respectively) among metastatic patients (p-value 0.004 and 0.005, respectively). Metastatic disease was an independent prognostic factor for death but not relapse outcome.  Conclusion: The disease outcomes in SEA were acceptable compared to developed countries. The stage of disease was the only independent prognostic factor. MTX-containing regimens and limb-salvage surgery should be considered where possible.