Emanuela Palmerini, Paul C Jutte, José Casanova, Frank Traub, Alberto Righi, Kjetil Boye, Davide Maria Donati, Madeleine Willegger, Elisabetta Setola, Piero Picci, Jendrik Hardes, Georg Gosheger, Andreas Leithner, Stefano Ferrari, Minna Laitinen, Reinhard Windhager, Palmerini, E, Leithner, A, Windhager, R, Gosheger, G, Boye, K, Laitinen, M, Hardes, J, Traub, F, Jutte, P, Willegger, M, Casanova, J, Setola, E, Righi, A, Picci, P, Donati, DM, and Ferrari, S
11046 Background: Angiosarcoma of bone (B-AS) is an exceedingly rare malignant tumor of vascular origin. The aim of this EMSOS retrospective study is to report on natural history, type of treatment and prognosis of B-AS. Methods: Patient data were collected according to the national rules for observational studies through electronic dataset available on EMSOS WEBsite. Results: 80 patients (51 male and 29 female, median age 54 years, range 17 to 92 years, 56% with localized disease, 44% metastatic) from 8 EMSOS Centers were collected. Surgery of the primary tumor was performed in 76% of patients (amputation in 30%), with intralesional margins in 26%. A surgical complete remission status (SCR) was achieved in 47% of the patients. Radiotherapy (RT) was delivered in 41% of the patients (in 15 patients as definitive local treatment), chemotherapy (CT) in 47% (56% in metastatic and 41% in localized cases). With a median follow-up of 31 months (range 40 to 309 months), 68% of patients died, 16% were disease-free, 12% were alive with disease and 4% dead for other causes. The 5-year overall survival (OS) was 27% (95%CI 16-30): 41% (95%CI 25-56) for localized patients (45% SCR, 17% no SCR, p = 0.03) and 8% (95%CI 0-20) for metastatic patients (p = 0.002). Among metastatic patients, 29/35 have died, with a median time to death of 6 months (1-45), while 6 patients were alive with a median follow-up of 22 months (8-106). Improved survival was observed for male patients (30% vs 8%, p = 0.04), while type of treatment (surgery, chemotherapy, radiation), pattern of metastases and age did not affect outcome. In 18 metastatic patients who underwent chemotherapy partial respo nse (PR) was documented in 1/3 patients after paclitaxel (RR 33%), and stable disease (SD) in 5 patients (2/2 with gemcitabine, 2/8 with doxorubicin/ifosfamide, and 1/4 with osteosarcoma-like chemotherapy). In localized patients, the 5-year OS was significantly better for age ≤ 50 years (68% vs 34%, p = 0.02) and extremity and central tumor as compared with pelvis/sacral location (50% vs 58% vs 0%, p = 0.008), with improved disease-free survival (DFS) after chemotherapy (49% vs 33%, p = 0.04). Conclusions: Metastatic B-AS is a fatal disease and inclusion in experimental trials is warranted. In localized patients, a better probability of survival is expected in younger and surgically treated patients. The use of chemotherapy was associated with improved DFS.