To explore the issue further, Dr. Florez and her colleagues analyzed enrollment data from all U.S. cancer therapy trials completed between 2003 and 2016, winding up with more than 55,000 participants.
Of those patients, 83 percent were white, 6 percent were black, just over 5 percent were Asian, almost 3 percent were Hispanic, and around 2 percent were classified as “other,” researchers found.
The Hispanic numbers are particularly troubling, given that they currently make up 16 percent to 20 percent of the U.S. population and that proportion is increasing, Florez said.
“That’s one-third of the U.S. population, and we have close to zero information about how to treat cancer in those patients,” Duma said.
Researchers also found that only 36 percent of patients were aged 65 and older, even though cancer risk increases dramatically with age.
Finally, women were underrepresented in clinical trials for melanoma (just 35 percent), lung cancer (39 percent), and pancreatic cancer (40 percent).
Not including these folks in clinical trials means that doctors are not fully equipped to treat all the various types of cancer that can strike different groups, said Dr. Christopher Li, a research professor of epidemiology with Fred Hutchinson Cancer Research Center in Seattle.
“If these populations are underrepresented in clinical trials, there will also be an underrepresentation of the types of cancer that we know disproportionately affect them,” Li said. For example, black and Hispanic women are much more likely to be diagnosed with aggressive breast cancer.
“Therefore, we will have less knowledge around the effectiveness of treatment that might be specific for these different forms of the disease,” Li continued.