Clinical trials of pancreatic cancer fail to include and report on representative proportions of non-white patients at every study phase, researchers suggested.
This discrepancy is troubling in that certain racial and ethnic minorities get pancreatic cancer more often, are diagnosed at a younger age, and die sooner, noted Kelly Herremans, MD, of the University of Florida College of Medicine in Gainesville.
"Currently there's a heightened awareness of racial and ethnic disparities in society, particularly in healthcare," Herremans said during a press briefing held in advance of the annual meeting.
Using data from the registry at she and her colleagues analyzed data on 8,429 participants in 207 U.S. trials of treatments for pancreatic ductal adenocarcinoma, a malignancy known to be lethal, with a 5-year survival rate of just 9%. The trials in the study spanned from 2007 to 2020.
The investigators then looked at incident pancreatic ductal adenocarcinoma cases from the .
The results showed that compared with the proportion of U.S. incident cases across various racial/ethnic groups, patients from minorities making up a substantial portion of the U.S. population were underrepresented in trials:
- Blacks: 8.2% of trial participants versus 12.4% of incident cases
- Hispanics: 6.0% versus 8.5%
- Asians or Pacific Islanders: 2.4% versus 3.3%
- American Indians and Alaska Natives: 0.3% versus 0.4%
Not unexpectedly, white patients were overrepresented, accounting for 84.7% of all trial participants but 82.3% of total U.S. incident cases. In all, 54.8% of trial participants were male, and 45.2% were female, although 48.4% of incident cases occur in women, Herremans reported.
"Although the incidence of pancreatic cancer is higher in men, women are, not surprisingly, underrepresented in trials. We found that fewer than half of participants were women and that was statistically significant," she said.
In other discrepancies, while gender was reported in 99% of trials, race and ethnicity were reported in only 49.3% and 34.7%, respectively.
Furthermore, Black participants were less likely to be included in phase III trials (2.7%) than in phase I (9.9%) and II (9.8%) trials.
Diversity is an important element in clinical trials because of racial differences in tumor biology, Herremans explained: Black patients, for instance, have different rates of both somatic and germline mutations when compared with other racial subgroups and may respond differently to therapeutics.
The study also found that Black patients with pancreatic cancer were more likely to be enrolled in early-phase trials of safety and efficacy than in later-phase trials of therapeutic standard of care.
She noted that the diversity gap in clinical trials is often attributed to reluctance on the part of minorities to enroll because of past unjust treatment, as in the infamous Tuskegee Syphilis Study that withheld penicillin from poor Black men for many years in order to study the long-term impact of syphilis. "But recent research has shown that Black and Hispanic patients are just as willing as white patients to participate," Herremans said.
She said the enduring lack of accurate representation may be a result of systemic racism and provider biases that interfere with recruitment, as well as restrictive inclusion criteria that turn away individuals with conditions more common in minorities such as obesity and diabetes.
Although the problem is multifaceted and regulations have been put in place to counter it, "it's unfortunate that we still haven't made much headway in diversity in clinical trials over the last 15 years," Herremans said. "We need to have an accurate representation of the entire population in studies."
Asked about possible recruitment solutions, she said the first step is for researchers and physicians to recognize bias in themselves: "A lot of providers don't recognize their bias, and bias training may be a way to combat this."
Another key issue is the need for a more diverse research and physician workforce, she added. "Currently only 2.3% of U.S. oncologists are Black and 5.8% are Hispanic."
Trial participation should be made available to all racial and ethnic groups, Herremans emphasized. "Clinical trials really need to recruit in locations with racially and ethnically diverse populations. This will help facilitate community engagement and improve diversity in trials."
Asked for his perspective, Robert H. Vonderheide, MD, DPhil, director of the Abramson Cancer Center at the University of Pennsylvania's Perelman School of Medicine in Philadelphia, who was not involved with the study, called the data "emblematic" of what's happening in clinical trials. "This is part of a larger national problem, on which not much progress has been made," he told 鶹ý.
Vonderheide noted that Blacks make up only about 5% of enrollment in cancer trials but about 13.4% of the population. "That is unacceptable," he said.
He pointed out that in cancer drug trials conducted in 2018 and 2019 with 8,700 patients, only 4% of the participants were Black. "That percentage hasn't changed in 10 years -- this is a multifactorial problem and requires a multifaceted solution," he said.
Vonderheide added that there is renewed interest in addressing the issue of minority participation, and that his center will be presenting positive results from a community engagement program for recruiting Black patients, at the American Society of Clinical Oncology annual meeting next month.
Disclosures
Herremans reported fundeding by a T3 fellowship grant.
She disclosed no competing interests.
Vonderheide disclosed no competing interests relevant to his comments.
Primary Source
Digestive Disease Week
Herremans K, et al "Trials and tribulations: Diversity and inclusion in pancreatic ductal adenocarcinoma clinical trials" DDW 2021; Abstract 901.