Risk factors for metastatic disease at presentation with osteosarcoma: an analysis of the SEER database.

backgroundOsteosarcoma is the most common primary bone sarcoma and affects all ages. There are substantial differences in management and outcomes for patients who have localized disease compared with distant spread at the time of diagnosis. Our goal was to examine potential risk factors predictive of metastatic disease at presentation.

methodsThe Surveillance, Epidemiology, and End Results (SEER) Program database was used to identify all patients diagnosed with osteosarcoma from 2000 to 2008 and to classify each patient as having metastatic or localized disease at the time of diagnosis. Patient-based characteristics, tumor characteristics, and county-level socioeconomic measures were analyzed to determine which factors were predictive of an increased rate of distant metastatic disease at presentation. These factors were analyzed as univariate characteristics as well as in a multivariate logistic regression model.

resultsWe identified 2017 cases of high-grade osteosarcoma, and 464 (23.0%) of the patients presented with metastatic disease. In the unadjusted logistic regression analysis, patients had increased odds of metastatic disease at presentation if they had an age of sixty years or more (odds ratio [OR] = 2.22; 95% confidence interval [CI], 1.71 to 2.89), had a tumor located in the axial skeleton (OR = 2.47; 95% CI, 1.88 to 3.26), and lived in a county with low socioeconomic status (OR = 1.59; 95% CI, 1.08 to 2.35). These factors remained significant when combined in multivariate models controlling for age, location, and socioeconomic status. For patients with recorded tumor size information (n = 1398), the odds of metastasis at presentation increased by 10% with each additional centimeter of tumor size (OR = 1.10; 95% CI, 1.08 to 1.13). When the patients with missing tumor size information were excluded, socioeconomic status was no longer a significant risk factor for metastasis at presentation in the multivariate model.

conclusionsOsteosarcoma patients with advanced age, a tumor in the axial skeleton, a larger tumor size, and a residence in a less affluent county were more likely to have metastatic disease at presentation.