Predictors of the Survival of Primary and Secondary Older Osteosarcoma Patients

Purpose: Older osteosarcoma patients have a very poor prognosis and treatment for them remains a challenge. The outcomes and potential prognostic factors of primary or secondary older osteosarcoma patients are rarely documented. Therefore, we examined the prognosis of the two special cohorts to identify possible prognostic factors, and provide optimal treatment strategy for them. Methods: The Surveillance, Epidemiology, and End Results (SEER) program database was used to identify osteosarcoma patients aged over 40 years from 1973 to 2015. The prognostic analysis was performed using the Kaplan-Meier method and a Cox proportional hazards regression model. Results: In total, 1162 primary older osteosarcoma patients and 444 secondary older osteosarcoma patients were eligible for this study. The OS and CSS rates of the primary older osteosarcoma patients at 5-year were 38.5% and 37.1%, respectively. The 3- and 5-year OS rates of the secondary older osteosarcoma patients were 22.8% and 14.6%, respectively. On multivariate analysis of the primary older osteosarcoma patients, age > 60, male, axial site, high grade, metastasis, tumor size>10 cm, no surgery, and radiation treatment were negatively associated with OS. In terms of CSS, age, gender, decade of diagnosis, tumor site, tumor grade, tumor stage, tumor size, and surgery were independent prognostic factors. A multivariate Cox regression model showed that secondary older osteosarcoma patients of high grade, metastasis, tumor size > 10 cm, no surgery, and no chemotherapy were independent predictors of decreased OS. Conclusions: Surgery in combination with chemotherapy should be recommended for the treatment of the secondary older osteosarcoma patients, while for the primary older osteosarcoma patients, only surgery should be recommended.