Characteristics and prognosis of telangiectatic osteosarcoma: a population-based study using the Surveillance, Epidemiology and End Results (SEER) database.

Background Telangiectatic osteosarcoma (TOS) is a rare type of osteosarcoma for which limited clinical data is available. Furthermore, the clinical characteristics and prognosis of TOS remain unclear. Methods A large population-based cohort analysis was conducted using the Surveillance, Epidemiology and End Results (SEER) registry. The data of TOS and conventional osteosarcoma (COS) patients from 2000 to 2017 were collected. The categorical variables were assessed by Chi-squared tests. Kaplan-Meier curves and log-rank (Mantel-Cox) tests were used to examine the survival outcomes between the groups. Cox proportional hazard models were used for univariate and multivariate analyses of TOS patient survival-related variables. Results A total of 141 TOS patients and 2961 COS patients were included in this analysis, and the mean age at diagnosis was 23.5 and 29.4 years, respectively. Compared to COS patients, TOS patients were more likely to be under 20 years old (61.7% vs. 51.7%, P=0.022), and without a second peak of incidence after 60 years of age. The median overall survival (mOS) of TOS patients was not reached compared to a median survival of 84 months for COS patients (hazard ratio 0.75, 95% confidence interval 0.59 to 0.95, P=0.0175). After adjusting these data for age at diagnosis, stage, and surgery at the primary site, no significant differences in mOS were observed between the two groups. In univariate analyses, being under 20 years of age, having localized or regional stage disease, and having undergone surgery were associated with a decreased risk of death. Subsequent multivariate analysis indicated that age at diagnosis, stage, and surgery at the primary site were all independent predictors of prognosis in TOS patients. Conclusions Patients with TOS were younger than patients with COS and did not show a second peak after 60 years of age. Age, summary stage at diagnosis, and surgery at the primary site were independent predictors of survival for TOS patients.