Primary Tumor Surgery Improves Survival Of Cancer Patients With Synchronous Solitary Bone Metastasis: A Large Population-Based Study

Background: There is a heated debate on whether or not a late-stage cancer patient with bone metastasis should receive primary surgery. The aim was to assess whether primary tumor surgery in cancer patients with bone metastasis was associated with improved survival.Methods: Cancer patients with bone metastasis were identified in the Surveillance, Epidemiology, and End Results database between 2010 and 2016. Overall survival and cancer-specific survival were compared between patients with and without primary tumor surgery using risk-adjusted Cox proportional hazard regression models and stratified propensity score methods. Further nomograms were constructed to predict personalized survival.Results: Overall, 22,631 cancer patients with synchronous bone metastasis were identified and the surgery rates were 33.3%, 76.3%, 42.0% and 2.0% for breast, bladder, renal and lung cancer, respectively. In Cox regression analysis after propensity score matching, primary cancer surgery was associated with a significantly improved overall survival for breast [hazard ratio (HR) = 0.56], bladder (HR = 0.69), lung (HR = 0.61) and renal carcinoma (HR = 0.37), while the prolonged median survival time was 20 months, 3 months, 4months and 21 months, respectively. Nomograms were constructed based on predictive factors, showing good consistency between the actual and predicted outcomes (C-index between 0.697 to 0.750) and feasibility in clinical practice.Conclusions: This population-based cohort of cancer patients with bone metastasis supports primary tumor surgery as a significant protective factor for cancer patients with bone metastasis, and nomograms hold promise in assisting individualized risk stratification and accurate therapeutic strategy making.