Capturing evolving definitions of 12 select rare CNS tumors: a timely report from CBTRUS and NCI-CONNECT

Purpose: Incidence, prevalence, and survival are population-based statistics describing cancer burden. The National Cancer Institute's (NCI) Comprehensive Oncology Network Evaluating Rare CNS Tumors (NCI-CONNECT) specializes in tumor biology and outcomes for 12 rare CNS tumor types selected for their importance in adults, research interest, or potential for targeted treatment. The aim of this study was to update incidence, prevalence, and survival statistics for these tumors.

Methods: The Central Brain Tumor Registry of the United States (CBTRUS) database, a combined dataset of Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology and End Results (SEER) data, was used to calculate average annual age-adjusted incidence rates (AAAIR) per 100,000 population overall and by sex, race-ethnicity, and age for diagnosis years 2008-2019. Incidence time trends were calculated for diagnosis years 2004-2019. NPCR data were used to calculate relative survival rates. Point prevalence on December 31, 2019 was estimated using annual age-specific incidence and survival.

Results: AAAIR was 1.47 per 100,000 for these tumors combined, with highest incidence in ependymomas (AAAIR = 0.41/100,000). Most tumor types were more common in males, adults (ages 40 + years) or children (ages < 15 years), and non-Hispanic White individuals. Ependymomas were the most prevalent tumor type (19,320 cases) followed by oligodendrogliomas (14,900 cases). Ependymomas had the highest five-year survival (90.6%) and primary CNS sarcomas the lowest (7.7%).

Conclusions: These data provide means to measure the impact of clinical care and evaluate new therapies and the evolving histopathology definitions in rare CNS tumor types.