Hispanic people have a disproportionately high incidence of liver cancer compared with other groups but are under-represented in Phase 3 trials for the disease.
Hispanic individuals are known to be under-represented in studies of cancers of the breast, prostate, lung and colorectum. It is particularly important that this population be fairly represented in clinical trials of therapy for liver cancer because they have high incidence of the disease and rates of death due to this malignancy, and they are the second largest ethnic subpopulation in the US.
Tim F. Greten, MD, and colleagues investigated whether enrollment of Hispanic patients in liver cancer trials is adequate and reported their findings in the Journal of Hepatocellular Research. Using published data from trials conducted over the past decade, they found that Hispanic individuals are disproportionately under-represented in multinational Phase 3 clinical trials for liver cancer, despite having the highest relative incidence rates among the four major racial or ethnic groups in the United States.
“Hispanic individuals are severely under-represented in multinational Phase 3 clinical trials for advanced liver cancer,” Dr. Greten says. “That raises concerns about the generalizability of trial results to the Hispanic population and highlights potential disparities in access to innovative treatments.”
Liver Cancer Incidence Vs Clinical Trial Enrollment
“To compare cancer incidence rates among different racial and ethnic groups, we relied on data from the National Cancer Institute’s SEER and the CDC’s United States Cancer Statistics (USCS) database,” says Dr. Greten. “To assess enrollment rates in multinational Phase 3 clinical trials for advanced liver cancer, we conducted a systematic search of relevant clinical trials from July 2012 to July 2022. We filtered to include only Phase 3 trials seeking FDA approval for liver cancer treatments.”
Ultimately, 13 clinical trials met the researchers’ criteria.
“We collected data on the racial and ethnic characteristics of the trial participants from the published version of the studies and the information available for each study on the clinicaltrials.gov database,” says Dr. Greten. “Specifically, we sought to compare the incidence rates of liver cancer in different racial and ethnic groups and contrast these rates with the enrollment rates of those groups in clinical trials.”
Hispanic Individuals Under-Represented Compared With Others
“What we found is that Hispanic individuals have a disproportionately high incidence of liver cancer compared with other ethnic and racial groups in the United States. Despite this, they are severely under-represented in Phase 3 clinical trials for advanced liver cancer,” says Dr. Greten. “The metrics for Difference in Incidence by Race and Ethnicity (D-IRE) and the Ratio of Incidence by Race and Ethnicity (R-IRE) emphasize the significant gap in ethnic and racial representation that currently exists (Figure).”
According to the researchers’ analysis, the median D-IRE for Hispanic individuals is -31.3% and the R-IRE is 0.04, confirming the under-representation in trials. In contrast, non-Hispanic White and Asian individuals have positive D-IRE values, indicating overrepresentation in liver cancer trials.
Real-World Implications of the Analysis
“Physicians need to be aware of these disparities and advocate for more inclusive trial recruitment to ensure that all patients, regardless of their racial or ethnic background, have equal access to emerging therapies through inclusion in clinical trials,” says Dr. Greten. “Improving representation in clinical trials can reduce health care disparities by ensuring that all patients have equitable access to the latest treatments, potentially improving their outcomes and quality of life.” Ultimately, greater inclusion of Hispanic patients in clinical studies will lead to a more comprehensive understanding of how liver cancer treatments affect this population, potentially resulting in a better prognosis.
Future research, according to Dr. Greten, should prioritize efforts to increase the representation of Hispanic individuals in liver cancer trials. Studies also are needed to understand the root causes of under-representation, including barriers at the patient, health care provider, and trial design levels; develop interventions to address these barriers and increase participation; and explore the impact of under-representation on treatment outcomes.