July 18, 2016
2 min read

Hispanic, younger children underrepresented in pediatric oncology trials

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Underrepresentation of Hispanic patients and children aged 0 to 4 years occurred frequently in phase 1 trials, according to a meta-analysis of trials conducted by Children’s Oncology Group and Pediatric Brain Cancer Consortium.

Children with lymphohematopoietic malignancies also appeared underrepresented, whereas children with solid tumors were overrepresented.

Approximately 60% of pediatric patients with cancer join clinical trials of all phases; however, limited data exist on racial, ethnic and age-based representation in trial populations.

“It is encouraging that most groups have been proportionally represented in pediatric oncology trials,” Rebecca D. Pentz, PhD, professor of research ethics at Emory University School of Medicine, told HemOnc Today. “However, we found that certain groups continue to be underrepresented, particularly Hispanic children.”

Pentz and colleagues accessed deidentified data sets from phase 1 trials conducted between 2000 and 2008 by Children’s Oncology Group and Pediatric Brain Cancer Consortium. These data represented 1,348 children with 128 lymphohematopoietic or solid tumor malignancies (lymphohematopoietic, n = 126; solid tumor, n = 1,222).

The data included patients’ race or ethnicity, date of birth, date of diagnosis and date of trial enrollment. The researchers divided patients into four age groups: 0 to 4 years, 5 to 9 years, 10 to 14 years and 15 to 19 years.

Pentz and colleagues used the SEER database to establish expected age, race, ethnicity and sex proportions of 27,766 children the same International Classification of Diseases for Oncology diagnostic codes.

Solid tumors accounted for 63% (n = 17,565) of pediatric cancer diagnoses and lymphohematopoietic malignancies counted for 36.7% (n = 10,201) diagnoses in the United States during the study period.

The highest expected proportion of cancers occurred in children aged 0 years to 4 years (36.5%), followed by those aged 15 years to 19 years (25%).

Boys had a higher expected proportion of diagnoses than girls (56% vs. 44%). Non-Hispanic white pediatric patients comprised the largest expected racial/ethnic cohort (54%), followed by Hispanic children (27%).

Researchers then compared these data with the those of children enrolled in clinical trials using 2-side t tests and chi-square tests, were an alpha of .05 was considered significant.

Clinical trial enrollment comprised 5% of all expected cases, with a median time to enrollment of 16 months.

The researchers observed significant overrepresentation of patients with solid tumors in phase 1 trials (observed vs. expected, 90.6% vs. 63%), whereas patients with lymphohematopoietic malignancies were significantly underrepresented (9.3% vs. 37%).

Patients aged 0 years to 4 years with solid tumors were underrepresented on trials (11% vs. 34%), although overrepresentation occurred in the 5-to-9-years age group (30.4% vs. 17%).

The researchers observed similar underrepresentation among patients aged 0 years to 4 years with lymphohematopoietic malignancies (16% vs. 40%).

Hispanic children were underrepresented in solid tumor (12% vs. 24%) and lymphohematopoietic (19.4% vs. 33%) trials.

Hispanic children remained the most underrepresented ethnic group overall (2%), and for boys (9% vs. 21%) and girls (6% vs. 18%).

Hispanic boys aged 5 years to 9 years were overrepresented (20% vs. 11%). Non-Hispanic white boys and girls aged 0 years to 4 years were significantly underrepresented (6% vs. 19% and 6% vs. 16%).

Underrepresentation further occurred in non-Hispanic black boys (9% vs. 18%) and girls (9% vs. 16%).

The researchers identified the relatively small number of observed and expected numbers in certain subgroups as a potential study limitation.

“Given these consistent findings, research needs to be done to determine the barriers to clinical trials encountered by Hispanic children, so that these barriers can be targeted,” Pentz said. – by Cameron Kelsall

For more information:

Rebecca D. Pentz, PhD, can be reached at rpentz@emory.edu

Disclosure: Pentz reports travel expenses from the Children’s Oncology Group. Please see the full study for a list of all other researchers’ relevant financial disclosures.