Malignant hemangiopericytoma: A National Cancer Database study of demographic and socioeconomic factors.

Abstract

e22628 Background: Malignant hemangiopericytoma (HPC) is a rare and solitary fibrous tumor arising from pericytes surrounding small blood vessels. Annual incidence in the United States is estimated at 0.6 per million for cases originating in the CNS. Prior case series reported prognosis is poor, with high rates of local recurrence (87%) and metastasis (64%). Definitive diagnosis typically requires tissue biopsy due to nonspecific imaging and histologic features. To address the limitation of large-scale data, the National Cancer Database (NCDB) was analyzed to characterize demographic and socioeconomic factors for an epidemiologic evaluation in patients with malignant HPC. Methods: This retrospective cohort study included patients with histologically-confirmed malignant HPC (N = 1,648) (ICD-O-3 code - 9150) within the 2004–2020 NCDB. Demographic factors (age, sex, race, Hispanic status, educational attainment, insurance status, facility type, location of facility, and Charlson-Deyo score) were analyzed by descriptive statistics, and incidence trends were interpreted in regression analysis. Results: The incidence of HPC remained stable over the study period, with no meaningful temporal trend observed (R^2 = 0.04). Patients were diagnosed at a mean age of 52.7 years (SD = 16.2), with a near equal sex distribution (51.5% female). Patients were predominantly non-Hispanic (89.3%), White (83.3%), residing in metropolitan areas (53.2%) with private insurance (56.4%). Additionally, 38.5% of patients resided in the highest income quartile (≥$74,063). Comorbidity burden was low in this cohort (78.6% with a Charlson–Deyo Score 0). Cerebral meninges was the most common primary site (24.8%), with most tumors considered borderline (41.6%) or malignant/invasive (45.0%). Radiation therapy served as the primary treatment (54.1%). Treatment often occurred at academic/research programs (41.3%) or comprehensive community cancer programs (22.5%). Ninety-day survival following primary surgery was high (98.2%). Estimated overall survival was 93.0% at two years, 80.2% at five years, and 58.9% at ten years, with a mean survival of 132.2 months. Conclusions: To the best of our knowledge, this is the first NCDB analysis on malignant HPC, demonstrating near-equal sex distribution. Analysis revealed patients were more likely to be female, non-Hispanic, in the top income quartile, have private insurance, and reside in populated metropolitan areas. Most patients received care at academic/research institutions, with radiation therapy as the primary treatment. These patterns highlight the need for deeper investigation into how demographic and socioeconomic factors shape diagnostic timing, guide treatment selection, and influence long-term outcomes of this rare malignancy.