540P - Impact of adjuvant radiotherapy (ART) on survival time in patients with hemangiopericytoma (HPC): A population study

Background

HPC is a rare solitary fibrous tumor of the central nervous system (CNS), accounting for only 1% of all vascular tumors. Surgery is the standard treatment. However, the role of ART remains controversial. Therefore, we conducted this study to evaluate the impact of ART on the overall survival (OS) and cancer-specific survival (CSS) of patients with HPC.

Methods

Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2019. Patients with a history of cancer or concurrent malignancies, lacking pathologic diagnosis, tumor not arising from the CNS, and those with unknown data were excluded. T-tests and chi-square tests were used to compare variables, while the Kaplan-Meier estimator, log-rank tests, and Cox proportional hazard regression were used to identify prognostic factors of OS and CSS.

Results

The study population comprised 395 patients. Among them 121 patients with “Surgery,” 246 patients with “Surgery + ART”, 10 patients with “Surgery + Chemotherapy” and 18 patients received “Surgery + ART + Chemotherapy”. Of the patients, 55.2% were females, and 60.5% were over 50 years old. The average tumor size was 5 cm. The white group was the largest racial group (N=315). Most cases (51.9%) had a tumor size greater than 5 cm, with a median tumor size of 5 cm. Most cases were localized (65.8%), and a few had distant metastasis (8.6%, n=34). "Surgery + ART" had the best survival outcome 5-year OS of 81.5%, followed by "Surgery + ART + Chemotherapy" and "Surgery + Chemotherapy" both 80%, and "Surgery" at 61.1%. The therapeutic groups showed significant differences in the OS and CSS (p<0.022 and p<0.017, respectively). Localized stage positively impacted OS and CSS, while age and metastasis had a negative impact. Multivariable analysis confirmed that "Surgery + ART" improved both 5-year OS and CSS (HR=0.6, 95%CI:0.42-0.87 and HR=0.33, 95%CI:0.14-0.77, respectively).

Conclusions

Our results showed that ART may improve the OS and CSS in patients with HPC. These findings provide valuable insights into HPC treatment and may inform future clinical decisions. However, further research is needed to validate these results and investigate any potential confounding factors that may have affected the outcomes.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.