Health Disparities Emerge Around Cancer Screening Eligibility

October 07, 2021 - According to the results of a simulated pancreatic cancer clinical trial screening, Black patients were significantly more likely than White patients to be excluded from clinical trials due to a wide range of eligibility criteria, creating health disparities.

Clinical trials determine the safety and efficacy of cancer treatments and play an important role in the approval process by the United States Food and Drug Administration. Previous research has indicated that racial and ethnic minorities are extremely underrepresented in clinical trials.

Clinical trials that do not include diverse populations do not represent the full picture of how patients respond to various medications, explained the study’s lead author, Andrea N. Riner, MD, MPH, a research fellow and general surgery resident at the University of Florida in Gainesville.

“Inequitable representation of participants leaves gaps in our knowledge, limits opportunities to receive investigational therapeutics, and subsequently perpetuates disparities in survivorship,” Riner said in a press release.

In the study, Riner and colleagues at Virginia Commonwealth University (VCU) examined the criteria typically used to determine whether a patient will qualify for a trial. Riner explained that many trials use criteria that have been in place for a long time. However, depending on several factors, the criteria may not be medically justifiable.

The team simulated a screening process for a pancreatic cancer clinical trial, using data from patients with pancreatic ductal adenocarcinoma who received care at VCU Massey Cancer Center in Richmond, Virginia, from 2010-2019. 

They compiled common eligibility criteria for Phase 2 and Phase 3 pancreatic cancer trials listed on ClinicalTrials.gov and modeled inclusion and exclusion based upon clinical variables determined from billing codes and medical records.

The criteria that had the highest tendency to exclude Black patients was related to nutrition and infectious diseases. They included:

• Albumin, a marker of nutrition (14.07 percent of Black patients were excluded, compared to 7.91 percent of White patients)
• Hepatitis B (1.742 percent of Black patients were excluded, compared to 0 percent of White patients.)
• Hepatitis C (9.06 percent of Black patients were excluded, compared to 3.43 percent of White patients.)

Several other criteria also disproportionately excluded Black patients, creating health disparities. However, the results did not reach statistical significance. The only criteria that excluded more White patients than Black was a history of prior cancer treatment. Fourteen percent of White patients were excluded based on previous cancer treatment compared to 9.06 percent of Black patients.

“The results of our study confirmed our suspicion that standard criteria lead to significantly fewer Black patients being eligible for pancreatic cancer clinical trials than white patients,” Riner said. “We are creating bias in who may even qualify to participate, and we are sometimes doing so without a truly valid medical reason to exclude someone.”

According to Riner, this study could be used to create modifications in current clinical trial enrollment requirements.

Riner said those modifications should be made on a trial-by-trial basis given the range of therapeutics being pursued. For example, chemotherapy trials often require different criteria than immunotherapy trials based upon how the drugs work.

“These decisions could be made between the sponsor of the trial and an advisory board of medical experts that would be able to decide which criteria are absolutely necessary,” Riner continued.

“Alternative eligibility criteria can improve the diversity of participants, provide more equitable access to investigational therapeutics, and reduce disparities in survivorship, without compromising patient safety or study results.”

One limitation of the study was that the data was based on information from a single cancer center, so the results may not be generalizable to the broader public. Additionally, based on the demographics of the patients in the study, researchers only compared patients from Black and White populations.