Cranial Chondrosarcomas: Descriptive Epidemiology from the Years 2001 to 2014 in The United States

Background Chondrosarcoma is a rare bony cancer with scantly reported epidemiological factors in the United States. Prior epidemiological studies have drawn data from limited datasets or have reported chondrosarcomas together with other types of cancer, making it difficult to ascertain epidemiological factors with an acceptable level of certainty specifically about chondrosarcomas. This study draws from the Centers for Disease Control and Prevention (CDC) and National Program of Cancer Registries (NPCR), which includes 99% of the U.S. population.

Methods The CDC and NCPR databases were queried for chondrosarcoma based on ICD-O-3 histological codes. Race, sex, age, and ethnicity per age-adjusted incidence per 100,000 were calculated. JointPoint was used to calculate annual percentage change.

Results Overall incidence: A total of 10,231 chondrosarcomas were diagnosed in the United States between 2001 and 2014. The average age-adjusted incidence was 0.234 (95% CI, 0.229–0.238). An average of 731 chondrosarcomas were diagnosed annually. Of the total number of chondrosarcomas, 764 (7.46%) were found to be cranial in nature, while the rest were extracranial. For cranial chondrosarcomas, the average annual age-adjusted incidence was 0.018 (95% CI, 0.016–0.019). An average of ∼55 new cases of cranial chondrosarcoma were diagnosed annually. In 2003, there was a significantly lower rate of diagnosis of cranial chondrosarcomas, with a rate ratio of 0.693 (95% CI, 0.482–0.969). In 2013, there was a significantly higher rate of diagnosis of cranial chondrosarcomas, with a rate ratio of 1.373 (95% CI, 1.074–1.735). In 2001, there was an age-adjusted incidence rate of 0.015 and in 2014 the rate was 0.019 which represented an annual percentage change (APC) of 2.24% (95% CI, −0.14 to 4.67%).

Incidence by demographics for cranial chondrosarcomas: The distribution of the incidence of cranial chondrosarcoma by age (groups of 5 years) is roughly normal with the peak incidence of 0.025 (95% CI, 0.020–0.031) occurring from 45 to 49 years of age. The average age-adjusted incidence for males is 0.016 (95% CI, 0.014–0.018) and that for females is 0.019 (95% CI, 0.017–0.021) with no statistically significant difference between the two. The rate ratio of cranial chondrosarcoma in white patients to the total population was 1.054 (95% CI, 0.947–1.172), in black patients to the total population was 0.589 (95% CI, 0.436–0.779), and in Asian/Pacific Islander to the total population was 0.617 (95% CI, 0.396–0.924).

Conclusion The incidence of cranial chondrosarcoma was stable from 2001 to 2014 (APC was nonsignificant), with a single low point in 2003 and a single high point in 2013. Black and Asian/Pacific Islander patients have a slightly decreased incidence of cranial chondrosarcoma compared with the overall population. This study presents the most accurate descriptive epidemiology of cranial chondrosarcomas in the United States to date.

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