The Challenge of Making Cancer Trials More Diverse

Patients from racial and ethnic minority groups remain underrepresented in biomedical research.¹

In an attempt to rectify this disparity, the US Food and Drug Administration (FDA) has called for study sponsors to develop and implement plans to enroll more participants from underrepresented racial and ethnic populations on research studies.

However, data suggest that, when it comes to cancer patients, investigators are a long way from reaching the FDA’s objective.

Diversity Has Not Improved in Cancer Trials

In a recent study, researchers examined cancer trial participation by race and ethnicity in a nationwide, patient-level, deidentified database extracted from electronic health records.² The researchers focused on patients from about 800 sites who were diagnosed with the most common cancers between January 1, 2017, and June 30, 2022.

The database included 50,411 Latino, Black, and White adults diagnosed with advanced non-small cell lung cancer (n=20,961), metastatic colorectal cancer (n=10,596), metastatic breast cancer (n=9912), multiple myeloma (n=4348), and metastatic pancreatic cancer (n=4594).

Over the entire study period, trial participation was lower among Black (4.4%) and Latino patients (4.2%) relative to White patients (7.2%). In an adjusted analysis, there was a significantly lower risk of participation among Black patients (hazard ratio [HR], 0.57; 95% CI, 0.51-0.65) and Latino patients (HR, 0.54; 95% CI, 0.46-0.63).

Lower participation among Black and Latino patients relative to White patients was seen across all cancer types except multiple myeloma, for which the difference between White and Latino patients was not significant.

In an exploratory analysis, the researchers also looked at whether there were differences in clinical trial enrollment disparities in the pre-pandemic (2017-2019) and pandemic (2020-2022) eras.

Inequities in trial participation between Black and White patients widened during the first 2 years of the COVID-19 pandemic (HR, 0.49; 95% CI, 0.40-0.60) in comparison with the pre-pandemic years (HR, 0.61; 95% CI, 0.53-0.70). For White patients, trial participation did not meaningfully change in the pandemic era compared to the pre-pandemic years.

The researchers concluded that racial and ethnic inequities in cancer trial participation persisted from 2017 to 2022 and, despite policies to lessen barriers for participants, this disparity widened during the pandemic.

Studies involving the 5 cancer types noted above are not the only ones in which diversity remains an unattained goal. A presentation at this year’s Society of Gynecologic Oncology Annual Meeting on Women’s Cancer revealed that racial and ethnic minority groups are similarly underrepresented in clinical trials for gynecologic cancers.³

The researchers analyzed 252 trials with published results and at least 1 performance site in the United States. The trials were all registered at ClinicalTrials.gov from October 2007 through March 2020. Of 13,497 participants, most (82.7%) were White. Among the remaining patients, 7.0% were Asian, 5.6% were Latina, 4.5% were Black, and 0.3% were American Indian or Alaska Native.

Compared to White patients, under-enrollment in ovarian cancer trials was more than 8-fold higher for Latina patients, more than 7-fold higher for Black patients, and about 7-fold higher for American Indian/Alaska Native patients.

For uterine cancer trials, under-enrollment was nearly 2-fold higher for American Indian/Alaska Native patients, nearly 3-fold higher for Asian patients, and more than 7-fold higher for Latina patients.

Community Engagement Can Increase Minority Enrollment

Inequities in trial participation are more complex than suggested by accrual tallies and hazard ratios, said Oluwadamillola “Lola” Fayanju, MD, from the University of Pennsylvania in Philadelphia, during a presentation at the Society of Surgical Oncology Annual Meeting 2023.⁴

For example, Dr Fayanju reported that Black and Latino patients are overrepresented in first-in-human trials and in trials that do not require informed consent, but they are underrepresented in the trials that are most likely to provide personal benefit (ie, phase 3 trials).

“We know that one of the strategies we can use to improve representation of diverse individuals in trials is to simply have more diverse people being treated at the kinds of centers that also offer high-level treatment and where trials are likely to take place,” Dr Fayanju noted.

In 2014, at Penn Abramson Cancer Center, 19% of people living in the catchment area were Black, but Black patients represented only 11% of patients who received cancer care there.⁵ The percentages of Black participants on trials was 12.2% for therapeutic trials, 8.3% for non-therapeutic interventional trials, and 13.0% for non-interventional trials.

From 2014-2018, the center implemented a program that included protocol-specific plans to encourage trial enrollment among Black patients, wellness fairs held in partnership with faith-based organizations, programs with ride-sharing services to mitigate transportation barriers, culturally tailored messaging about trials, and patient education by nurse navigators regarding cancer and clinical trials.

By 2018, the percentage of Black patients seen at Penn Abramson Cancer Center (16.2%) nearly matched the percentage of Black cancer patients in the catchment area (16.5%).

Over the 5-year period, cancer trial accrual increased by 41.5%, from 9308 participants to 13,170. Enrollment of Black patients improved for all trial types, including therapeutic (23.9%), non-therapeutic interventional (33.1%), and non-interventional (22.5%) studies.

Dr Fayanju concluded that clinical investigators should focus less on increasing numbers and more on facilitating informed choices about cancer and clinical research, providing opportunities for diverse communities to inform health professionals of their needs, and respectfully responding to those needs in trial design and implementation.

Trust and Fairness Are Key

Earning patient trust and promoting fairness may provide the best opportunities for increasing the proportion of minority patients on clinical trials, according to researchers.⁶

“I think that’s why it’s so important to have people at the table conducting research, seeking funding, generating hypotheses, who have a multiplicity of perspectives, a multiplicity of backgrounds, who are diverse in many ways, to ensure that there is really a kind of altruism in all forms represented with regards to how research is conducted and performed,” Dr Fayanju said at a roundtable discussion on diversity in clinical trials that was hosted by the Society for Immunotherapy of Cancer.⁷

As Dr Fayanju described, community-focused outreach and making the logistics of participating in trials more convenient for patients are among the strategies that can improve the health of patients in marginalized communities and provide equitable access to cutting-edge cancer research.

Disclosures: Dr Fayanju disclosed a relationship with Gilead Sciences, Inc.

References

1. Diversity plans to improve enrollment of participants from underrepresented racial and ethnic populations in clinical trials: Draft guidance for industry. US Food and Drug Administration. Published April 14, 2022. Accessed September 6, 2023.

2. Pittell H, Calip GS, Pierre A, et al. Racial and ethnic inequities in US oncology clinical trial participation from 2017 to 2022. JAMA Netw Open. 2023;6(7):e2322515. doi:10.1001/jamanetworkopen.2023.22515

3. Richardson MT, Barry D, Steinberg JR, et al. Underrepresentation of non-White enrollment in gynecologic oncology: An analysis of over 350 clinical trials. SGO 2023. March 25-28, 2023.

4. Fayanju O. Strategies to increase enrollment of diverse populations in clinical trials. SSO 2023. March 22-25, 2023.

5. Guerra CE, Sallee V, Hwang W-T, et al. Accrual of Black participants to cancer clinical trials following a five-year prospective initiative of community outreach and engagement.  J Clin Oncol. 2021;39(15_suppl):100-100. doi:10.1200/JCO.2021.39.15_suppl.100 

6. Schwartz AL, Alsan M, Morris AA, Halpern SD. Why diverse clinical trial participation matters. N Engl J Med. 2023;388:1252-1254. doi:10.1056/NEJMp2215609

7. Virtual roundtable on diversity in clinical trial enrollment. Society for Immunotherapy of Cancer. July 25, 2023. Accessed September 6, 2023.

This article originally appeared on Cancer Therapy Advisor