(P 205) PRIMARY CARDIAC SARCOMA: A RETROSPECTIVE ANALYSIS OF PRESENTATION, MANAGEMENT AND OUTCOMES

Objective: Primary cardiac sarcoma is exceedingly rare and has a poor prognosis. This highly aggressive malignancy leads to progressive heart failure and death without treatment. Here, we review the presentation, management and outcomes of these patients at a regional sarcoma treatment centre and its associated cardiothoracic hospital.

Methods: Medical records of patients diagnosed with and treated for cardiac sarcoma at Addenbrooke’s Hospital and the Royal Papworth Hospital in Cambridge, UK, between 2011 and 2022, were reviewed. All patients were included in the data analysis.

Results: 11 patients were diagnosed with cardiac sarcoma (6 males, 5 females); median age of presentation was 31 years (range 19-73). Presenting features included breathlessness (6), cough (4), chest pain (2), peripheral oedema (1), constitutional symptoms (1), haemoptysis (1) and transient ischaemic attack (1). Cardiac function at diagnosis was often preserved: 5 had normal left ventricular ejection fraction (≥55%), 3 had moderate impairment (30-55%), and 1 with < 30% in the context of previous intensive treatment for childhood leukaemia. Sites of disease were: atrium (8), ventricle (2), and mass encasing the heart (1). Over half (55%) had evidence of metastasis at presentation.

Histological findings were angiosarcoma (6), intimal sarcoma (2), high-grade sarcoma NOS (1) and synovial sarcoma (1). The median tumour dimension was 62 mm (range 27-135). Five patients underwent excision of the primary tumour: 2 with curative intent, 2 debulking surgeries, and 1 had surgery for what was thought to be atrial myxoma. One did not have biopsy/surgery due to significant co-morbidities.

Adjuvant ifosfamide chemotherapy was administered after excision of intimal sarcoma (2) and synovial sarcoma (1). In the palliative setting, partial responses were observed in angiosarcoma with paclitaxel, anthracyclines, gemcitabine and docetaxel, and in synovial sarcoma with ifosfamide. Two patients received the checkpoint inhibitors ipilimumab and nivolumab but neither obtained clinical benefit. The median overall survival (OS) of all patients was 19.5 months (2-year OS rate of 30%). OS was significantly worse in patients with advanced/metastatic disease (vs localised resectable tumour; HR=7.86 (95% CI 1.604-38.5), P=0.011) and primary tumour size of ≥90 mm (HR=36.43 (95% CI 2.99-443.8), P=0.0048). There were only 2 long term surviving patients (76 and 99 months, respectively) – both had R1 resection of atrial intimal sarcoma followed by adjuvant ifosfamide chemotherapy and radiotherapy.

Conclusion: Cardiac sarcomas can present with non-specific symptoms and may be initially misdiagnosed as other benign entities. Unsurprisingly, outcome is significant better for patients with smaller or localised and resectable tumour than those with advanced or metastatic disease. The use of adjuvant ifosfamide chemotherapy (with close monitoring of fluid balance) and radiotherapy following R1 resection of intimal sarcoma appeared to be associated with long-term survival. Further study is required to elucidate how to manage this rare tumour in the adjuvant and palliative settings.