annual income reported by the sample is $32,000, with 42 percent reporting incomes of $30,000 or less, 49 percent reporting incomes of between $30,000 and $50,000, and 9 percent reporting incomes of greater than $50,000.

BCPT recently yielded data suggesting that tamoxifen may be an effective chemopreventive agent for women at increased risk of breast cancer. This trial, however, which included more than 13,000 women, performed extremely poorly with respect to the accrual of ethnic minorities. Of the 13,266 women enrolled in the trial, 12,630 (95.2 percent) were white, 275 (2.1 percent) were African American, 163 (1.2 percent) were Hispanic, 112 (0.8 percent) were Asian or Pacific Islander, and 33 (0.2 percent) were Native American. According to SEER program data (Miller et al., 1996), African-American women make up 8.2 percent of the population with breast cancer, and Hispanic women make up 3.2 percent of the population with breast cancer. Therefore, for African Americans and Hispanics, the rates of accrual to BCPT were fourfold and almost threefold less, respectively, than the national breast cancer incidence. Asian Americans, Pacific Islanders, and Native Americans were slightly underrepresented in this study, according to national incidence data.

As is the case with the CCOP and MBCCOP prevention trials, the committee finds that the rate of accrual of ethnic minorities into large NIH-sponsored prevention trials in most cases lagged behind that into treatment trials. Especially for African-American and Hispanic populations, the rate of accrual of these groups appeared to be several fold less than the incidence of the various types of cancer in these groups.

How Can Low Ethnic Minority Accrual Be Addressed?

The data presented above indicate that NCI has done well in ensuring the proportional representation of ethnic minority individuals in clinical treatment trials. NCI has not enjoyed the same success, however, in accrual the of ethnic minorities in prevention trials. These data underscore the difficulties that researchers face in recruiting and retaining ethnic minority research participants. As noted above, issues of community mistrust of the medical and scientific establishments, researcher reluctance to extend extra effort to recruit ethnic minority and medically underserved populations, and greater costs associated with recruitment are all significant factors in the low rates of accrual. The same difficulties may apply to the recruitment of medically underserved populations, but data are lacking to draw appropriate conclusions. According to NCI's analyses and the experiences of other researchers, several additional factors may contribute to these disparities.

Comorbidity appears to be an important factor that potentially limits



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