Survival and prognostic factors analyses in malignant giant cell tumor of bone

Background The characteristics and survival in patients with malignant giant tumor cancer of bone (GCTB) were not investigated thoroughly due to the limited population. We evaluated the issues based on a large cohort in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database. Methods Patients who were diagnosed with malignant GCTB from 1975 to 2016 were extracted from the SEER database. The overall survival (OS) was calculated by Kaplan–Meier analysis and the inter-group difference was tested by log-rank test. Univariate and multivariate Cox proportional hazard regression were conducted to identify the independent survival factors. Results A total of 325 patients with malignant GCTB were included. The overall 1-, 5-, and 10-year survival rates were 94.3% (95% CI: 91.7-96.8), 82.3% (95% CI: 77.9-86.6), and 80.1% (95% CI: 75.4-84.7), respectively. In the univariate analysis, age older than 34 years, grade IV, T2/3 stage, M1, distant and surgery of the primary site. Multivariate Cox regression showed the poor survival in patients with age older than 34 years (hazard ratio (HR) =3.68, 95% CI: 2.06-6.57, P<0.001), T2 stage (HR=4.96, 95% CI: 1.57-15.63, P=0.006), distant tumor (HR=3.02, 95% CI: 1.32-6.92, P=0.009), and the extra-skeletal sites (HR=8.84, 95% CI: 2.89-27.07, P<0.001), respectively. Conclusions This large population-based series described the clinical characteristics of the malignant GCTB. Age, T2, distant tumor and extra-skeletal sites were determinant survival factors of the patients with malignant GCTB.