Survival and prognostic factor analyses in malignant giant cell tumour of bone

Background: The characteristics and survival of patients with malignant giant cell tumour of bone (GCTB) have not been investigated thoroughly due to the rarity of the disease. We evaluated these factors in a large cohort in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database.Methods: Data from 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 intergroup differences were tested by the log-rank test. Univariate and multivariate Cox proportional hazard regression analyses 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. A potential non-linear J-shaped dose–response relationship between the age or diagnosis year and survival were found. Multivariate Cox regression showed poor survival in patients with age from 35 to 60 years (hazard ratio (HR) =9.99, 95% CI: 1.34-74.80, P=0.025), age older than 60 years (HR=62.03, 95% CI: 7.94-484.38, P<0.001), with stage T2 disease (HR=4.85, 95% CI: 1.52-15.47, P=0.008), with stage T3 disease (HR=6.09, 95% CI: 1.03-36.23, P=0.047), and with distant tumours (HR=2.76, 95% CI: 1.14-6.65, P=0.024), and extraskeletal sites (HR=3.33, 95% CI: 1.02-10.85, P=0.046).Conclusions: This large population-based series described the clinical characteristics of malignant GCTB. Patients with stage T2/3disease, distant disease and extra-skeletal sites had more odds to be with worse survival. The elder age than 34 years had a gradually increased risk for survival.