(P 166) SARCOMA BRAIN METASTASES: EXPERIENCE AT A SINGLE INSTITUTION

Objective: The brain is a rare site of metastases in patients (pts) with sarcoma, and the available data is pretty limited. There is a higher tendency for some subtypes to metastasize in the brain, such as alveolar soft part sarcoma (ASPS). Various local or systemic treatments have been described that have not been sufficiently evaluated, and optimal management has yet to be defined. We examined all consecutive patients with sarcoma brain metastases diagnosed at our institution over three years

Methods: In this retrospective study, we included 45 patients (23 female, 22 male) treated in our institution between the years 1999-2021. Kaplan-Meier estimator with log-rank test was used for survival analysis. Overall survival (OS) was calculated from the time of diagnosis of brain metastases to the date of death. The Median follow-up was 60 months (95%CI 42-NR)

Results: The most common subtypes were pleomorphic sarcoma in 12 pts (26.7%), liposarcoma in 6 pts (13.3%), MPNST in 6 pts (13.3%), ASPS in 5 pts (11.1%), and leiomyosarcoma in 4 pts (8.9%). 96% of the pts had high-grade tumors. 64.4% had a relapse after radical treatment of the primary lesion. 42% of the pts had >1 organ involvement, apart from the brain. 70% had >1 line of systemic therapy before brain metastases. The mean time from the sarcoma diagnosis to brain metastases diagnosis is 38 months (SD:45), mean time from metastatic disease diagnosis to brain involvement was 19 months (SD:29). At the time of diagnosis of brain metastases, 67% of pts had neurological symptoms. 60% had multiple brain lesions. 42% of the pts underwent surgery for the brain lesions, 73% had radiotherapy, 46.7% had chemotherapy, 6.7% received targeted therapy, and two patients with ASPS (4.4%) had immunotherapy. At the time of the analyses, 41 patients are dead. Median OS is 7.4 months. 12-month OS rate was 37%, the longest in the ASPS group – 80%, compared to 32% in the remaining subtypes. Twelve months OS in pts with a single brain lesion is 55% and 24% with multiple lesions. The best treatment result is observed in patients with a single brain lesion who underwent surgery – 12-month OS: 62%, compared to those with multiple lesions with no surgery: 23%

Conclusion: Patients with sarcoma brain metastases have an abysmal prognosis, and an appropriate therapeutic approach is yet to be defined. Surgical resection is associated with prolonged survival, but the prognosis remains dismal.