Study on Racial and Ethnic Disparities in Pediatric Cancer Identify Difference in Risk Between Patient Subgroups

Findings from a study that examined age-specific incidence of pediatric cancers by a narrow vs broad age groupings have identified that pediatric patients who are of a racial or ethnic minority have different risks vs White children for several disease types.^1,2

Findings from the study identified that Black pediatric patients and young adults had a significant reduction in incidence of acute lymphoid leukemia (ALL; incidence rate ratio [IRR], 0.52; 95% CI, 0.49-0.55) vs White patients. This was most significantly observed in patients who were 1 to 7 years of age, as well as those who were ages 16 to 20.

Moreover, Hispanic patients have had a notable reduction in overall incidence of both Hodgkin lymphoma (IRR, 0.50; 95% CI, 0.48-0.52) and astrocytoma (IRR, 0.54; 95% CI, 0.52-0.56). However, this population also experienced an increased risk of developing ALL (IRR, 1.46; 95% CI, 1.42-1.51) vs non-Hispanic White patients. This risk was most notable among patients who were between the ages of 10 and 23 years. Moreover, investigators noted a significant risk reduction in multiple tumor types in Asians and Pacific Islanders as well as Indigenous Americans and Alaskan Natives.

“There are significant racial and ethnic disparities in the incidence of some childhood cancer types,” Erin L. Marcotte, PhD, MPH, an assistant professor in the Department of Pediatrics, a faculty member of epidemiology and clinical research, and an executive committee member of the Brain Tumor Program at the University of Minnesota Medical School, stated in a press release. “Additionally, unlike in cancers that occur in older adults, the incidence of cancer among children and young adults has striking variations by age at diagnosis and studying these variations has often led to a deeper understanding of causes of childhood cancer.”

The rationale for the study developed after investigators observed that incidence rates of pediatric cancer in the United States are commonly reported in 5-year age groups, which could obscure the variation in incidence observed by a single year of age. This combined with incidence variation by racial and ethnic populations being presented in broad categories as opposed to narrow age ranges inspired investigators to launch the study.

Investigators utilized data from the Surveillance, Epidemiology, and End Results database from 2000 to 2017 to assess the frequency and age-adjusted incidence of certain cancer types among individuals from birth to 39 years of age.

Additional findings from the study identified that Black pediatric patients experienced a comparable incidence of non-Hodgkin lymphoma with White patients, although Black young adults were at a higher risk vs White young adults beginning at age 28. Black pediatric patients were also found to be at a higher risk for developing nephroblastoma before the age of 5 vs their White counterparts.

“Some of the patterns we observed may be due to racial and ethnic differences in known childhood cancer risk factors, such as exposure to infections and congenital anomalies. We also know that the causes of each type of childhood and young adult cancer may vary depending on the age at which it occurs. For instance, exposure to Epstein-Barr virus is associated with Hodgkin lymphoma diagnosed in children younger than age 10, but not at older ages. Thus Epstein-Barr virus exposure may explain the higher risk of Hodgkin lymphoma among Hispanic children younger than age 10,” Marcotte concluded.

In closing, investigators believe that the findings of this study may help to play a role in reducing racial and ethnic disparities in cancer risk among pediatric and young adult populations.

References

1. Marcotte EL, Domingues AM, Sample JM, et al. Racial and ethnic disparities in pediatric cancer incidence among children and young adults in the United States by single year of age. Cancer. June 21, 2021. doi:10.1002/cncr.33678
2. Study reveals racial and ethnic disparities in childhood cancers by single year of age. News release. Wiley. June 21, 2021. Accessed July 27, 2021. https://bit.ly/2TJhHKg