Photo by Esther Dyson
Preparing drug for a trial
ATLANTA—New research suggests some racial/ethnic minority groups are underrepresented in clinical trials for cancer patients in the US.
African-American and Hispanic patients were underrepresented in the trials studied, while Asian and non-Hispanic white patients were not.
Patients belonging to other racial/ethnic groups were not studied in detail.
The research also showed that elderly patients were less likely than other age groups to enroll in a cancer trial.
However, the percentage of elderly patients in the trials studied (36%) was more than double the percentage of elderly individuals in the US population (15.2%).
This research was presented at the 10th AACR Conference on The Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved (abstract A26).
“Clinical trials are crucial in studying the effectiveness of new drugs and ultimately bringing them to the market to benefit patients,” said Narjust Duma, MD, of the Mayo Clinic in Rochester, Minnesota.
“However, many clinical trials lack appropriate representation of certain patient populations. As a result, the findings of a clinical trial might not be generalizable to all patients.”
Dr Duma and her colleagues analyzed enrollment data from all cancer therapeutic trials reported as completed on clinicaltrials.gov from 2003 to 2016. These trials included 55,689 subjects, and the racial/ethnic breakdown of the group was as follows:
- Non-Hispanic white—83%
- African-American—6%
- Asian—5.3%
- Hispanic—2.6%
- “Other”—2.4%.
According to the US Census Bureau, as of July 1, 2016, the estimated total US population was 323,127,516. The racial/ethnic breakdown of that population is as follows:
- White alone (excluding Hispanics/Latinos)—61.3%
- Hispanic/Latino*—17.8%
- Black/African-American alone—13.3%
- Asian alone—5.7%
- American Indian/Alaska Native—1.3%
- Native Hawaiian/Other Pacific Islander—0.2%
- Two or more races—2.6%.
Dr Duma and her colleagues said their study suggests African-American and Hispanic representation in cancer trials has declined in recent years, when compared to historical data from 1996 to 2002.
In the 1996-2002 period, African-Americans represented 9.2% of patients in cancer trials (vs 6% in 2003-2016), and Hispanics represented 3.1% (vs 2.6% in 2003-2016).
On the other hand, the recruitment of Asians in cancer trials has more than doubled, from 2% in the historical data to 5.3% in the current data.
The current study also showed that elderly patients (age 65 and older) represented 36% of the subjects enrolled in cancer trials. In comparison, 15.2% of the total US population is 65 or older.
Previous research suggested the elderly are often underrepresented in clinical trials, despite the fact that most cancer cases are diagnosed in individuals age 65 and older, according to the National Cancer Institute’s Surveillance, Epidemiology and End Results database.
Dr Duma said the increasing use of genetic information in clinical trials may be decreasing the numbers of ethnic minorities and elderly patients. In recent years, researchers have sought to study drugs that treat cancers by targeting certain mutations. In order to identify the patients who are most likely to respond to the drugs, many trials now require molecular testing of tumors.
“This is leading to significant advances,” Dr Duma said. “However, it is vastly more expensive to run these trials, often leaving a limited budget to recruit patients or do outreach to the elderly or minorities.”
“Also, this type of testing can only be conducted at the major cancer centers. The mid-sized, regional hospitals are excluded because they don’t have the capacity, and, sadly, this leaves us farther away from these populations.”
Dr Duma added that cultural biases may also make minorities less likely to enroll in clinical trials. Previous research has indicated that members of certain minority groups may be less likely to trust healthcare providers.
Language barriers may also be a factor for minority patients, and the elderly may be dissuaded by difficulty in traveling to and from major cancer centers, Dr Duma noted.
She identified a few potential ways to narrow the gap of participation in clinical trials:
- Increase clinical trial partnerships between major cancer centers and satellite hospitals. Dr Duma suggested that patients could be enrolled at their local hospital and undergo treatment there, while data could be sent to the partnering cancer center.
- Targeted interventions, such as Spanish interpreters, could be used to help enroll minority patients in clinical trials.
- Healthcare providers should be mindful of the need to enroll more patients from underrepresented populations and should be willing to discuss risks and benefits with patients.
Dr Duma said the main limitation of this study is that race and ethnicity are generally self-reported, which could lead to some inconsistencies in data.
*The US Census Bureau notes that Hispanics may be of any race, so they are also included in applicable race categories.