Less than 5 percent of the participants in federally funded clinical trials are non-white, and less than 2 percent of clinical cancer research studies focus on non-white ethnic or racial groups, UC Davis researchers have found.
Researches said the findings, published online last month in Cancer are worrisome given the increase in cancer cases among the country’s diverse populations, especially in states with large ethnic populations, like California.
Clinical trials are considered essential for the discovery and development of better drugs and treatments for cancer. Participation in trials has been shown to lower cancer mortality in patients with some types of tumors.
However, according to researchers at the UC Davis Comprehensive Cancer Center, ethnic adults are nearly completely absent from clinical trials going on today, despite a 20 year old Congressional mandate that all research funded by the National Institutes of Health include a representative number of minority participants.
Researchers examined online citations from medical publications to determine how frequently data based on minorities in clinical trials were reported and analyzed.
Professor Moon Chen, the study’s lead researcher, said a greater emphasis on minority-focused research and recruitment of racially diverse participants is needed, akin to efforts decades ago to include more women.
“The proportion of minorities in clinical research remains very low and is not representative of the U.S. population with cancer,” said Chen, the cancer center’s associate director for cancer control. “What is needed is deliberate effort. Minorities are not hard to reach. They are hardly reached.”
Chen and his colleagues searched NIH online data – ClincalTerials.gov – to determine the number of clinical trials with an emphasis on a particular ethnic population. They found that only about 150 trials, out of about 10,000, or less than 2 percent, met the criteria.
The study’s authors concluded that the overall participation of adult minorities is not proportional to their representation in the U.S. population. For example, blacks experience the highest incidence of cancer (593.7 cases per 100,000 people) but, along with Hispanics, have the lowest rates of cancer clinical trials participation at 1.3 percent.
By contrast, researchers found that in clinical trials involving patients under age 15, minority representation among children is excellent, either equal to or greater than their proportion of the population.
“The record of participation by racial/ethnic populations in pediatric clinical trials suggests that a comparable record is potentially achievable in clinical trials for adults,” the authors stated in the study.
Karen Kelly, a co-author and associate director for clinical research at the UC Davis Comprehensive Cancer Center, said the value of participation by ethnic groups is well documented, citing as an example the development of an oral treatment for lung cancer that resulted from observing lung tumors in Asians.
“In lung cancer, it opened our eyes,” said Kelly. “Clinical trials in diverse populations can help us understand the biology of disease, and why a drug may produce a higher response rate and higher toxicity in one group than in another. Moreover by targeting the population most likely to benefit from a novel treatment we can accrue patients more quickly to clinical trials that will lead to faster results.”
The authors acknowledged that barriers, such as mistrust, costs, transportation and cultural differences, contribute to the lower minority participation rate, but suggest that using more “culturally sensitive” educational materials and “specially trained patient navigators” could make a difference.
“The solution is not changing the attitudes of minorities but rather in ensuring access to health research,” the authors argued. Clinical trials should be designed to include and focus on specific populations, and scientific journals should insist on appropriate representation and analyses of NIH-funded research by race and ethnicity, they concluded.
“Whatever happens in the laboratory or in the clinic needs to be applied to solving real-world problems, and those relate to the disproportionate effects of cancer and other diseases on racial and ethnic minorities,” said Chen.