Incidence Patterns and Trends of Chordoma in the United States: a Population-Based Analysis of over 6,000 Cases.

Introduction:Chordoma is a rare malignant bone tumor arising from notochordal remnants, with unknown etiology and limited descriptive characterization. Methods:Data from the North American Association of Central Cancer Registries, covering 93% of the U.S. population, were used to estimate age-standardized incidence rates and trends from 2003 to 2022 by demographic and clinical factors. Trends were quantified using Joinpoint regression. Data from 21 Surveillance, Epidemiology, and End Results (SEER) registries were used to estimate relative survival for cases diagnosed from 2003 to 2021. Results:A total of 6260 chordoma cases were diagnosed during 2003-2022. Cranial tumors were most frequent (38.7%), followed by sacral (32.7%) and spinal (25.4%) sites. The age-standardized incidence rate was 0.097 per 100,000, increasing with age and peaking at 80-84 years. Overall, incidence rates were higher in males than females (0.1173 versus 0.0800), with the divergence emerging after age 35. Incidence rates were comparable across racial and ethnic populations, except among non-Hispanic Black individuals, whose rates were 56% lower than those of non-Hispanic White individuals (95% CI = 0.39 to 0.49). Incidence rates were highest in the Northeast and metropolitan areas. From 2003 to 2022, incidence rose 1.47% annually (95% CI = 0.61-2.39), with steeper increases among younger individuals, women, and localized/cranial tumors. Among 2170 SEER cases, 5-year relative survival was 83.3%, varying by race/ethnicity and region. For distant-stage disease, survival ranged from 68.6% for cranial tumors to 38.3% for sacral tumors. Conclusion:Chordoma incidence and survival vary by demographic and clinical factors, suggesting differences in detection, healthcare access, and underlying etiology.