The impact of clinical trial protocols on patient care systems

Racial and Ethnic Inequities in US Oncology Clinical Trial Participation From 2017 to 2022

Importance

There is increasing recognition from regulatory agencies that racial and ethnic representation in clinical trials is inadequate and linked to health inequities. The extent of racial inequities in clinical trial participation is unclear because prior studies have synthesized enrollment data from published trials, which often do not report participant race and ethnicity.

Objective

To evaluate racial and ethnic inequities in oncology clinical trial participation in a contemporary cohort of patients with cancer before and during the COVID-19 pandemic.

Design, Setting, and Participants

This cohort study used a nationwide electronic health record-derived deidentified database, which includes data for approximately 280 US cancer clinics (approximately 800 sites of care). The study included Latinx, non-Latinx Black (hereinafter, Black), and non-Latinx White (reference; hereinafter, White) patients aged 18 years or older who had been diagnosed with advanced non-small cell lung cancer, metastatic colorectal cancer, metastatic breast cancer, multiple myeloma, or metastatic pancreatic cancer between January 1, 2017, and June 30, 2022 (follow-up through December 31, 2022). Data analysis was performed between August 1, 2022, and February 7, 2023.

Exposures

Electronic health record-documented race and ethnicity.

Main Outcomes and Measures

The main outcome was oncology trial participation (ie, receipt of a clinical study drug). Stratified cause-specific hazard models were used to estimate adjusted hazard ratios (HRs) and 95% CIs for likelihood of participation. Participation was assessed overall, by cancer type, and by period of diagnosis (2017-2019 vs 2020-2022).

Results

Of the 50 411 patients in this study, 28 878 (57.3%) were women and 21 533 (42.7%) were men. Black and Latinx patients were younger than White patients, with a median age of 65 (IQR, 57-72), 64 (IQR, 54-73), and 68 (IQR, 60-76) years, respectively. Oncology trial participation was lower among Black patients (307 of 6912 [4.4%]) and Latinx patients (166 of 3973 [4.2%]) relative to White patients (2858 of 39 526 [7.2%]) over the entire study period. Inequities in participation were observed across the 5 cancer types studied, with notably large inequities observed among Black patients (HR, 0.54 [95% CI, 0.36-0.81]) and Latinx patients (HR, 0.46 [95% CI, 0.27-0.77]) with metastatic pancreatic cancer. Moreover, inequities between Black and White patients in terms of participation widened among those diagnosed in the COVID-19 era (2020-2022: HR, 0.49 [95% CI, 0.40-0.60] vs 1.00 [95% CI, 0.93-1.09]) relative to those diagnosed before the pandemic (2017-2019: HR, 0.61 [95% CI, 0.53-0.70] vs 1 [reference]).

Conclusions and Relevance

The findings of this cohort study suggest that oncology trial participation was lower among Black and Latinx patients relative to White patients across all 5 cancer types examined. These findings, including potentially widening inequities in the COVID-19 era, support the need for regulatory guidance to improve enrollment of participants from historically excluded racial and ethnic populations in clinical trials.

Barriers to recruiting underrepresented populations to cancer clinical trials: a systematic review

Racial and ethnic minorities, older adults, rural residents, and individuals of low socioeconomic status are underrepresented among participants in cancer-related trials. The authors conducted a systematic review to determine the barriers to participation of underrepresented populations in cancer-related trials. Their search included English-language publications that reported original data on the recruitment of underrepresented groups to cancer treatment or prevention trials between 1966 and December 2005 in multiple electronic databases. They also hand-searched titles in 34 journals from January 2003 to December 2005 and they examined reference lists for eligible articles. Titles and abstracts were reviewed to identify relevant studies. Data on barriers to participation were synthesized both qualitatively and based on statistically significant associations with trial enrollment. Of 5257 studies that were cited, 65 studies were eligible for inclusion in the current analysis, including 46 studies on recruitment into cancer therapeutic trials, 15 studies on recruitment into prevention trials, and 4 studies on recruitment into both prevention and treatment trials. Numerous factors were reported as barriers to participation in cancer-related trials. However, only 20 of the studies reported statistically significant associations between hypothesized barriers and enrollment. The available evidence had limitations in quality regarding representativeness, justification of study methods, the reliability and validity of data-collection methods, potential for bias, and data analysis. The results indicated that underrepresented populations face numerous barriers to participation in cancer-related trials. The current systematic review highlighting the literature on recruitment of underrepresented populations to cancer trials and may be used as the evidence base toward developing an agenda for etiologic and intervention research to reduce the disparities in participation in cancer-related trials.

Patients' perceptions of physicians communication and outcomes of the accrual to trial process

The purpose of this study was to examine the relations among patients' perceptions of their physicians' communicative behavior during the informed consent interview, the patient's feeling of being confirmed by the physician and satisfied with care delivered by the physician, and the patient's decision to participate in a clinical trial or not. Respondents included 130 cancer patients who were eligible for a clinical trial and who had recently discussed trial participation with their physicians. Results indicated that a linear combination of the variables physician affiliative style, physician dominant or controlling style, patient satisfaction, patient confirmation, patient preference for decision making, patient desire for information, and patient age discriminate between patients who agree to participate in clinical trials and patients who refuse to participate. Physicians' affiliative communicative behaviors and patient satisfaction were clearly important to patients who agreed to participate. Motivations for patients who declined to participate in trials were less clear. Implications for physicians who offer clinical trials to their patients are that specific communication skills may enhance their patients' satisfaction and may help increase enrollment in clinical trials.