Racial and ethnic minorities, women, and the elderly were less likely to enroll in cancer clinical trials than whites, men, and younger patients

According to background information provided by the authors, "Ten years have passed since Congress responded to concerns about unequal access to clinical trials and enacted the National Institutes of Health (NIH) Revitalization Act, which encouraged representation of women and minority patients in NIH-sponsored research. Ensuring broad access to research studies has subsequently been an important aim of national research policy."

Vivek H. Murthy, M.D., M.B.A., and colleagues from the Yale University School of Medicine, New Haven, Conn., analyzed data from participants in therapeutic nonsurgical National Cancer Institute (NCI) Clinical Trial Cooperative Group breast, colorectal, lung, and prostate cancer clinical trials in 2000 through 2002. In a separate analysis, the ethnic distribution of patients enrolled in 2000 through 2002 was compared with those enrolled in 1996 through 1998. The study focused on those four types of cancer trials because they were the four most common causes of cancer-related deaths during the study period.

"From 1996 through 2002, 75,215 patients were enrolled in NCI-sponsored cooperative group nonsurgical treatment trials for breast, lung, colorectal, or prostate cancers. Approximately 3.1 percent of trial participants were Hispanic, 85.6 percent were white, 9.2 percent were black, 1.9 percent were Asian/Pacific Islanders, and 0.3 percent were American Indians/Alaskan Natives," the researchers report. "Trial participants represented approximately 1.7 percent of the total number of incident [new] cancer cases diagnosed during the 2000 through 2002 study period. When all four cancer types were considered in aggregate, Hispanics and blacks were underrepresented," the authors write.

"There was a strong relationship between age and enrollment fraction [number of trial enrollees divided by the estimated U.S. cancer cases in each subgroup], with trial participants 30 to 64 years of age representing 3.0 percent of incident cancer patients in that age group, in comparison to 1.3 percent of 65 - to 74-year-old patients and 0.5 percent of patients 75 years of age and older. … Although the total number of trial participants increased during our study period, the representation of racial and ethnic minorities decreased. In comparison to whites, after adjusting for age, cancer type, and sex, patients enrolled in 2000 through 2002 were 24 percent less likely to be black." The researchers also found that men were more likely than women to enroll in colorectal and lung cancer trials.

"Our study also demonstrates that elderly patients, both minorities and whites, were strikingly underrepresented compared with their younger counterparts. Although the elderly accounted for approximately one third of participants in breast, lung, colorectal, or prostate cancer trials, they accounted for approximately two thirds of patients for these four cancer types," the researchers note.

The researchers point out that several barriers may exist among minority groups to enrollment in clinical trials. "Past and ongoing patterns of discrimination have also resulted in decreased trust in the health care system in general among minority patients. Minorities are more likely to express concerns about exploitation, dishonesty regarding risks of experimental treatment, and motivations of researchers. Other studies have suggested that minority patients may be less likely than whites to be offered trial participation."

In conclusion the authors write, "These findings are of concern given the high profile of minority and elderly under-representation and the efforts that the NCI has made to address this problem. ...Given the substantial cancer burden borne by minorities and the elderly, it is apparent that other policies and initiatives will be required to ensure broad access to trials and broad applicability of their results."

JAMA: The Journal of the American Medical Association