Impact of treatment refusal and abandonment on survival outcomes in pediatric osteosarcoma in Southeast Asia: A multicenter study

Treatment refusal and abandonment (TxRA) are major barriers to improving outcomes among children with sarcomas of the extremities as curative treatment options bearing on amputation or disfiguring surgery, particularly in countries with limited resources. A multi-institutional retrospective study was conducted to determine the predictive factors for TxRA among patients with osteosarcoma associated with survival outcomes across Southeast Asia (SEA).

Pediatric patients with osteosarcoma treated between January 1998 and December 2017 in four SEA pediatric oncology centers from three countries were studied. Nelson-Aalen estimates, Kaplan-Meier method, and Cox's proportion hazard model were applied to address the cumulative incidence, survival outcomes, and to identify prognostic factors associated with TxRA.

From a total of 208 patients with osteosarcoma enrolled; 18 (8.7%) patients refused and 41 (19.7%) patients abandoned treatment. Income classification of countries, age at diagnosis, tumor size, disease extent, chemotherapy protocols, and types of surgery were associated with TxRA. Tumor size more than 15 cm was an independent risk factor associated with TxRA. The 5-year overall and relapse-free survivals were 49.4% and 50.4%, respectively. However, these rates declined further to 37.9% and 35.8%, respectively, when TxRA were considered as events. Tumor size larger than 15 cm and metastatic disease were independent risk factors associated with TxRA-sensitive outcomes.

The prevalence of TxRA was high in SEA, particularly in lower middle-income countries. Factors associated with TxRA related to tumor burden. Treatment outcomes could be substantially improved by lowering the refusal and abandonment rates.