Descriptive Epidemiology of Cranial Chordomas in the United States

Background Chordomas account for 1 to 4% of all bone malignancies and 0.5% of primary intracranial central nervous system tumors. Our prior epidemiology literature is based on more limited population data. The purpose of this study is to provide the largest and most inclusive population-based study of descriptive epidemiology of cranial chordomas.

Methods The Centers for disease Control and Prevention (CDC) and National Program of Cancer Registries (NPCR) were queried for chordoma in cranial, spinal, and sacral locations. Age-adjusted incidence per 100,000 population was calculated by age, sex, race, and ethnicity. Annual percentage change was calculated using JointPoint.

Results

Overall incidence: From 2001 to 2014, a total of 3,788 chordomas were diagnosed in the United States: 1,517 (40%) cranial, 997 (26%) spinal, and 1,274 (34%) sacral chordomas. For cranial chordomas, the average annual age-adjusted incidence was 0.037 (95% CI, 0.033–0.037) resulting in an annual mean of ∼108 new cranial chordomas diagnosed per year. In 2001, there was an age-adjusted incidence rate of 0.030 and in 2014 the rate was 0.041 which represented an annual percentage change (APC) of 2.23% (95% CI, 1.3–3.2) during the study period. For chordomas in all locations, the average age-adjusted incidence was 0.092 (95% CI, 0.089–0.095) resulting in an annual mean of ∼289 chordomas diagnosed per year. In 2001, the age-adjusted incidence rate was 0.086 and in 2014 it was 0.104 which represented an annual percentage change of 1.41 (95% CI, 0.4–2.5).

Incidence by demographics for cranial chordomas: For cranial chordomas, the incidence increases from a nadir of 0.01 (95% CI, 0.01–0.02) to a peak of 0.067 (95% CI, 0.007–0.054) in the 70- to 79-year-old age group. The average age-adjusted incidence for males is 0.04 (95% CI, 0.037–0.043), and that for females is 0.031 (95% CI, 0.028–0.033) with an incidence rate ratio (IRR) of 1.14 for males, p = 0.003.

From 2001 to 2014, the rate of cranial chordoma in white patients was 0.038 (95% CI, 0.034–0.0389), 0.022 (95% CI, 0.018–0.027) in black patients, and 0.043 (95% CI, 0.034–0.052) in Asian or Pacific Islander.

Conclusion The incidence of all chordomas is increasing APC (+2.23%). The incidence also increases with age up to the 70- to 79-year-old age group and with male gender. Asian Pacific Islander race is associated with highest incidence of cranial chordoma. This study presents the most comprehensive evaluation of descriptive epidemiology of cranial chordomas.

No conflict of interest has been declared by the author(s).