(P 217) CONTEMPORARY TREATMENT PATTERNS AND OUTCOMES IN THE MANAGEMENT OF ANGIOSARCOMA IN IRELAND

Objective: Angiosarcomas are known to be highly aggressive tumours often with poor outcomes. Surgery is the only potential curative therapy, but radiotherapy (RT), chemotherapy and targeted therapies may also of benefit in the adjuvant and metastatic setting. Overall, there is often a nihilistic view to disease modifying therapy. With an all-island national MDT view of the disease, we present a contemporary series of angiosarcoma.

Methods: All patients with a diagnosis of angiosarcoma who were discussed at the adult / AYA sarcoma MDM between 2017 and 2023 were included in the study. Data were collected on patient demographics, disease characteristics, treatment administered and outcome. Overall survival was calculated using the Kaplan-Meier method.

Results: A total of 39 patients were identified: 25 female and 16 male with a median age of 56 (range 17-89). 53% (n=21) presented with localised disease and 18% (n=7) of patients had metastatic disease on presentation. 28% (n=11) of patients had a history of a previous cancer to the region and were identified as having a radiation induced angiosarcoma (RIA). Primary tumour site was breast in 28% (n=11), scalp in 13% (n=5), bone in 10% (n=4), head/neck in 10% (n=4) chest/abdominal wall in 15% (n=6), pericardial in 5% (n=2) 7 had other primary sites. Median tumour size was 50 mm (range 2-180mm). Tumour grade was available in 27 patients; 62% (n=24) had high grade tumours, 5% (n=2) low grade and 1 patient had intermediate grade. One patient had a de novo germline p53 mutation and another had Stewart Treves Syndrome; no other patients had familial genetic syndromes. Among 11 patients with RIA, 10 had prior breast cancer, and 1 had prior cervical cancer; this patient developed an abdominal wall tumour.
Within the RIA group 81% (n=9) had completion mastectomy, 1 had wide excision and 1 patient died less than 4 weeks from diagnosis with no further treatment. 36% (n=4) proceeded to adjuvant systemic therapy followed by adjuvant RT and 1 patient had adjuvant chemotherapy alone. Systemic treatment included Dox/Ifos in 3 patients, paclitaxel in 2 and propranolol in 1. 45% (n=5) relapsed more than 10 years from original diagnosis. 72% (n=8) are alive and free from disease at time of reporting. Among the other patients, 82% (n=23) had upfront surgery. 21% (n=6) received adjuvant RT, 14% (n=4) adjuvant chemotherapy and 7% (n=2) declined adjuvant therapy. 35% (n=10) are known to be alive at time of reporting. 32% (n=9) RIP. 21% (n=6) in the recurrent/metastatic setting received at least 1 or more lines of systemic therapy with standard regimens.

Conclusion: The management of patients with angiosarcoma is complex and should be managed through an expert centre. Irish patients treated with surgery and adjuvant therapy had outcomes comparable to international standards in this aggressive cancer. These data would suggest radical surgery and adjuvant therapy should be offered to all patients with localised radiation-induced angiosarcoma. Collaboration with regional centres is vital to the best management of patients with this rare disease.