Survival benefit of resection of early TN-stage osteosarcoma in patients with lung metastasis: A retrospective study

Osteosarcoma (OS) is a highly malignant bone tumor with poor prognosis, especially for patients with lung metastasis (LM). The guidelines do not recommend resection surgery for OS patients with LM. However, some studies showed that surgery may be able to prolong the survival. Here, we aimed to investigate the risk factors for LM and assess survival benefit of cancer-direct surgery (CDS) by analyzing a national cohort. OS patients diagnosed in 2010–2019 with tumors located in the bone and joint was downloaded. The incidence of metastasis and distribution of metastatic foci were counted. All eligible OS patients were used to form a study cohort to explore risk factors for LM and then diagnostic nomogram was generated. Next, 294 patients were categorized into CDS and non-CDS groups. The benefits of CDS were evaluated by Kaplan-Meier method and Cox proportional hazard model. A total of 1925 OS patients were involved in current study, of which 294 cases developed LM. The independent risk factors for LM in OS patients include pathological grade, T stage, N stage and tumor size. In prognostic analyses, CDS appeared to significantly prolong median overall survival, especially for patients at early TN stage. Forest plot by hazard ratio showed that chemotherapy also improved survival, while advancing age had a negative effect. Our study reveals the risk factors for LM and the prominent value of CDS for patients at early TN stage, which could provide important references for clinicians to make treatment decisions.