Systemic treatments and outcomes in CIC-rearranged Sarcoma: A national multi-centre clinicopathological series and literature review

CIC-rearranged sarcoma is a recently established, ultra-rare, molecularly defined sarcoma subtype. We aimed to further characterise clinical features of CIC-rearranged sarcomas and explore clinical management including systemic treatments and outcomes. Methods A multi-centre retrospective cohort study of patients diagnosed between 2014-2019. Results Eighteen patients were identified. The median age was 27 years (range 13-56), 10 patients were male (56%), 11 patients (61%) had localised disease and 7 patients had advanced (metastatic or unresectable) disease at diagnosis. Of 11 patients with localised disease at diagnosis, median overall survival (OS) was 40.6 months and the 1-, 2- and 5-year OS estimates were 82%, 64% and 34% respectively. Nine patients (82%) underwent surgery (all had R0 resections), 8 (73%) patients received radiotherapy to the primary site (median dose 57Gy in 28 fractions), and 8 (73%) patients received chemotherapy (predominantly Ewing-based regimens). Metastases developed in 55% with a median time to recurrence of 10.5 months. In patients with advanced disease at diagnosis, median OS was 12.6 months (95% CI 5.1-20.1), 1-year OS was 57%. Median progression-free survival was 5.8 months (95% CI 4.5-7.2). Durable systemic therapy responses occurred infrequently with a median duration of systemic treatment response of 2.1 months. One durable complete response of metastatic disease to VDC/IE chemotherapy was seen. Responses to pazopanib (n = 1) and pembrolizumab (n = 1) were not seen. Conclusion In this series, CIC-rearranged sarcomas affected young adults and had a high incidence of presenting with, or developing, metastatic disease. The prognosis overall was poor. In advanced disease, durable systemic therapy responses were infrequent.