, results of a population-based study suggest.
Adjusted incidence rates of CNS tumors were significantly higher among children from the U.S. Surveillance, Epidemiology, and End Results (SEER) database than among children from a cancer registry in Hong Kong.
Anthony P. Y. Liu, MBBS, MMedSc, of St. Jude Children’s Research Hospital in Memphis, Tenn., and colleagues reported these findings in.
The Hong Kong cohort originally included 526 patients, but only 508 of them were included in the comparison with the SEER patients. The SEER cohorts included 447 patients of API descent and 5,047 patients of all ethnicities.
In all cohorts, patients were younger than 18 years of age and had been diagnosed with a primary CNS tumor during 1999-2016.
Age-, sex-, and study period–adjusted incidence rates of CNS tumors were significantly higher in the SEER cohorts than in the Hong Kong cohort (P < .001). The adjusted incidence rates were:
- 2.51 per 100,000 children in the Hong Kong cohort.
- 3.26 per 100,000 children among APIs in the SEER cohort.
- 4.10 per 100,000 children among all ethnicities in the SEER cohort.
Incidence rates of most tumor types were significantly lower in the Hong Kong cohort than in the entire SEER cohort. This includes choroid plexus tumors (0.08 vs. 0.16; P = .045), ependymomas (0.18 vs. 0.31; P = .005), and glial and neuronal tumors (0.94 vs. 2.61; P < .001). However, incidence rates of germ cell tumors were significantly higher in the Hong Kong cohort (0.57 vs. 0.24; P < .001).
For the most part, there were no significant differences in incidence by histology between the Hong Kong cohort and the API SEER cohort. The exception was glial and neuronal tumors, for which the incidence rate was lower in the Hong Kong cohort than in the API SEER cohort (0.94 vs. 1.74; P < .001).
The 5-year overall survival rate was significantly lower in the Hong Kong cohort than in the API and entire SEER cohorts – 66.8% , 75.3%, and 78.7%, respectively (P < .001). This appears to be driven by inferior survival among Hong Kong patients with glial and neuronal tumors. For other tumor types, there were no significant differences in survival across the cohorts.
“Dr. Liu and colleagues have conducted a very nice epidemiological study, and their results suggest that the incidence of pediatric brain tumors is much lower in Hong Kong compared to the incidence in the United States,” noted Eric Bouffet, MD, of the University of Toronto.
“These results are intriguing, and it is clear that large epidemiological studies are needed to better understand the impact of ethnic, genetic, and socio-environmental factors linked to the incidence of childhood cancer, and in particular childhood brain tumors,” Dr. Bouffet added.
“My suspicion is that the lower incidence of brain tumors in Hong Kong may relate to the omission of patients who did not have a biopsy from the dataset,” said David Ziegler, MD, PhD, of the University of New South Wales in Kensington, Australia.
Dr. Liu and colleagues acknowledged that this study had limitations. The Hong Kong data do not represent the entire Chinese population, the SEER registry represents only 34.6% of the U.S. population, and the SEER registry has substandard ancestry designation for APIs. In addition, neither dataset included information on disease progression/recurrence or treatment details.
The study was supported by the American Lebanese Syrian Associated Charities and the Children’s Cancer Foundation, Hong Kong. Study authors disclosed relationships with MSD Oncology, Genentech, and Kazia Pharmaceutical.
Dr. Ziegler reported having no conflicts of interest. Dr. Bouffet disclosed relationships with Bristol-Myers Squibb and Roche.
SOURCE: Liu APY et al. JCO Glob Oncol. 2020 May 11. .