P3C181: Racial Differences in Localized Pediatric Diffuse and Anaplastic Astrocytoma Survival

Background: Brain tumors represent the leading cause of cancer deaths in children. Moreover, 60% of these tumors are astrocytomas, a class of neoplasms of the star-shaped glial cells, astrocytes, which provide physical support and aid in neurotransmission. Diffuse astrocytomas are indolent with low metastatic tendency and are commonly known as low grade and have survival ranges greater than 5 years. Anaplastic astrocytomas, however, represent a more aggressive neoplasm with greater metastatic potential and carry a survival range of 2-5 years. Both tumors are more common in adulthood, commonly reside in the frontal and temporal lobes, and are associated with few risk factors aside from ionizing radiation or genetic mutations such as p53. Current treatment of these cancers includes surgical resection, external-beam radiotherapy (EBRT), and adjuvant chemotherapy, dependent on location, histology, time since diagnosis, and other factors. Previous research supports an association between race and survival in children for brain malignancies generally; given racial disparities in healthcare delivery exist, we sought to bridge this gap to identify pitfalls in pediatric astrocytoma treatment due to its prevalence.

Methods: We analyzed 5-year relative survival rates in children under 15 with localized diffuse or anaplastic astrocytomas from 2000-2018 using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program. The tumor classification used ICD-O-3 codes 9400-9401, 9410-9411, and 9420. Racial groups included were Hispanic, Non-Hispanic Asian/Pacific Islander (NHAPI), Non-Hispanic Black (NHB), and Non-Hispanic White (NHW). Incidence for Hispanics and Non-Hispanics was based on the North American Association of Central Cancer Registries Hispanic Latino Identification Algorithm. Analysis of variance (ANOVA) and subsequent post-hoc two-sample T-tests were performed to assess associations between race and relative survival.

Results: The ANOVA assuming that mean survival is equal across racial groups was statistically significant (p=3.9552-8) with an alpha level of 0.05. Post-hoc two-sample t-tests assuming unequal variances showed significantly different survival rates of NHAPI when compared to Hispanics, NHB, and NHW (p=0.01925, p=0.01888, p=0.00142, respectively where alpha=0.025).

Conclusion: Non-Hispanic Asians/ Pacific Islanders have significantly worse survival compared to any other racial group examined. This varies from adult and pediatric research which associate lower survival in Black populations compared to White populations with the same brain tumor.These findings identify a unique racial difference not before described in the pediatric population and emphasize the need for closer inspection of neuro-oncological treatment practices.