Lung and bone metastases patterns in limb osteosarcoma: Surgical treatment of primary site improves overall survival

Osteosarcoma (OS) is one of the most prevalent malignant bone tumors. The proportion of patients with limb OS was relatively high. Lung metastasis (LM) and bone metastasis are the first and second most common metastatic types of OS, respectively. A total of 270 new cases of LM, 55 new cases of bone metastases (BM), and 36 new cases of lung and BM were diagnosed in the surveillance, epidemiology and end results database from 2010 to 2019. Univariate and multivariate logistic regression analyses were used to identify the risk factors for lung and/or BM, and Cox regression analyses were performed to identify the prognostic factors for lung and/or BM. Kaplan-Meier curves and log-rank tests were used to analyze the overall survival of limb OS patients with lung and/or BM. Female sex, telangiectatic OS type, central OS type, T3 stage, N1 stage, BM, surgical treatments, radiotherapy and chemotherapy were significantly correlated with LM. T3 stage, LM, liver metastases, and radiotherapy significantly correlated with BM. The small cell OS type, T2 stage, T3 stage, N1 stage, liver metastases, and radiotherapy were significantly correlated with lung and BM. Among limb OS patients with LM, the mean survival months of older age, black race, N1 stage, BM, brain metastases, no surgery, and no chemotherapy were lower than those of the control group. In limb OS patients with LM and BM, the mean survival months in the no surgery group was lower than in the surgery group. T stage and radiotherapy significantly influence the occurrence of limb OS with lung and/or BM. Surgery at the primary site has been shown to be effective in improving the survival rate of patients with lung and/or BM.