Comparison of overall survival of adult and pediatric osteosarcoma patients using the National Cancer Database

Background: Differences in overall survival (OS) between children and adult patients diagnosed with osteosarcoma are poorly understood. The objective of this study is to compare the OS of pediatric and adult patients diagnosed with osteosarcoma, identify prognostic factors associated with OS, and explore factors specifically associated with pediatric patients with osteosarcoma using data gathered from the National Cancer Database (NCDB). Methods: Patients >=1 years old and diagnosed with osteosarcoma between 2004 and 2017 were included in the study. Multivariable Cox regression analysis adjusted for gender, race, income, education, place of living, health insurance status, year of diagnosis, stage of cancer, surgery, chemotherapy, radiation therapy (RT), and immunotherapy was used to assess the association of age with the OS of the patients. Results: The analysis included 7,890 patients among whom 2,972 (37.7%) were between 1-17 years old. In the multivariable Cox regression analysis, adult patients had worse OS compared with pediatric patients (HR: 1.90; p<.01). When stratified by treatment type, pediatric patients had better OS in several groups. This includes those who received chemotherapy alone (HR: 0.58, p < .01), surgery alone (HR: 0.48, p < .01), surgery plus chemotherapy (HR: 0.55, p < .01), and those who received no treatment (HR: 0.25, p < .01). There was no significant difference in OS between pediatric and adult patients receiving a combination of chemotherapy, surgery, and RT (HR: 0.66, p = 0.11). In analysis stratified by cancer stage, pediatric patients had better OS compared to adult patients at each stage. Multivariable logistic regression analysis revealed that pediatric patients are more likely to be non-white, have insurance, present with unknown/occult stage disease, have poorly differentiated tumors, and receive immunotherapy, chemotherapy, or surgery. Additionally, multivariable Cox regression analysis identified factors associated with improved OS: age, diagnosis between 2011-2015, private insurance, non-metastatic disease, well-differentiated tumors, and receiving chemotherapy or surgery, but not RT. Conclusion: Pediatric patients diagnosed with osteosarcoma had better OS compared to their adult counterparts. Pediatric patients had better OS compared to adults when the analysis was stratified by treatment modality and stage of cancer. More research is necessary to delineate the underlying reason for this difference.