RESUMEN
BACKGROUND: Patients with osteosarcoma (OS) and Ewing sarcoma (ES) are considered to have a high venous thromboembolism (VTE) risk, although the exact incidence and prognostic impact are under-researched in general as well as in relevant age groups. AIMS: To study the impact of VTE and major bleeding (MB) in OS and ES patients, subdivided in children, Adolescents Young Adults (AYAs; aged 18-39) and older adults. METHODS: Retrospective single-center chart review in 519 OS and 165 ES patients treated between 1980 and 2018. Patients were followed from sarcoma diagnosis until an outcome of interest (VTE, MB) or death occurred. Cumulative incidences were estimated with death as competing risk. Cox models were used to determine prognostic impact. RESULTS: Five-year cumulative incidences of VTE were 12 % (95%CI 9.1-15) for OS and 6.7 % (95%CI 3.5-11) for ES patients, mostly happening in patients ≥18 years; the most frequent VTE presentation was catheter-related upper-extremity thrombosis (OS: 18/65, ES: 7/11). Five-year cumulative incidences for MB were 5.8 % (95%CI 4.0-8.1) in OS and 5.4 % (95%CI 2.5-9.8) in ES patients. 192 OS and 77 ES AYAs were included, who faced similar VTE and MB incidences as older adults. In OS, VTE and MB were both associated with mortality (adjusted HRs 2.0 [95%CI 1.4-2.9] and 2.4 [95%CI 1.4-4.0], respectively), whereas in ES this association was only present for MB (aHR 3.4 [95%CI 1.2-9.6]). CONCLUSIONS: VTE is a frequent complication in adult OS and to a lesser extent in ES patients, while the rate of MB was comparably high in both sarcoma types.