Study: Racial disparities in BRCA testing: Why?

IN DEPTH REVIEW OF RESEARCH

Study background:

Black and White non-Jewish/non-Hispanic women have similar chances of carrying a BRCA mutation. A recent study suggests that young black women with breast cancer are about twice as likely to carry a BRCA mutation compared to non-Hispanic white women. However, many studies have shown that black women do not get tested for BRCA as often as white women do. Researchers do not understand why this racial disparity exists.

When researchers of this study explored a possible explanation for this disparity, they noted that racial groups could be segregated unevenly in U.S. cities, suggesting that black women and white women may not be seeing the same healthcare providers. Anne Marie McCarthy and her colleagues at Harvard Medical School and other institutions published research in the Journal of Clinical Oncology to determine if black and white women are seeing different types health care providers and whether or not this accounts for the racial disparity in BRCA testing.  

Researchers of this study wanted to know:

Why are black women not receiving BRCA testing as often as white women?

Population(s) looked at in the study:

The women in this study were between 18-64 years old, from Florida and Pennsylvania, and were diagnosed with localized or invasive breast cancer between 2007-2009. A total of 3,016 women (69% white and 31% black) were surveyed, with a response rate of 61%. Physicians were also surveyed; their response rate was 29% (808 oncologists and 732 surgeons).

Study findings: 

1. The care of black and white women with breast cancer is highly segregated across surgeons and oncologists.
   • Oncologists and surgeons who cared for the most black patients were younger and more likely to be female.
2. A physician recommendation was strongly associated with BRCA testing. For unknown reasons, surgeons and oncologists were about 1.5 times less likely to recommend BRCA testing to their black patients than their white patients.
   • Surgeons and oncologists who cared for more black patients did not differ in their attitude towards BRCA testing compared to surgeons and oncologists who saw more white patients.   
   • The characteristics of the surgeons and oncologists (age, sex, U.S.-trained, employment type, and when they graduated from medical school) did not explain the racial disparity in BRCA testing recommendations between black and white women.
3. Black women with breast cancer were less likely than white women to have BRCA testing.
   • About one-quarter of black women had BRCA testing compared to almost one-half of white women.

Limitations:

While 61% of women who qualified for the study responded to the survey, the characteristics of the respondents, including age, race and year of diagnosis, differed from the women who did not respond. Black women were also less likely than white women to provide data about their physicians. Because this data was based on a survey, some bias could exist in the women’s answers. For example, women who were tested may have been more likely to remember that their physician recommended testing than women who chose not to undergo testing.

This was a population-based study, meaning that not all the women involved met guidelines for genetic testing—the results might be different if study participants included only women who met guidelines for genetic testing. Additionally, researchers could not compare women who received care at academic centers versus non-academic centers. This study only looked at oncologists and surgeons. Other types of doctors could be involved, although in the researchers’ experience, few patients receive breast cancer care from health care providers other than oncologists and surgeons.

Finally, this study included only women from Florida and Pennsylvania. The researchers state that while those populations are large and diverse, it is possible that the patterns in those states are not the same as what may be seen in other areas in the U.S.

Conclusions:

This study suggests that although black and white women do not see the same health care providers (some providers see more black women than white and vice versa because of the area in which they practice), that does not explain why black women have BRCA testing less often than white women. This study did reaffirm that fewer black women are receiving recommendations to get BRCA testing than white women. The researchers suggest this may be because family cancer history information may be less complete among black women. This could stem from either less awareness of cancer diagnoses in other family members, or healthcare providers not asking about family history as often for black women as they do for white women. Even though black women have a similar, if not higher chance of carrying a BRCA as a non-Jewish white women, when researchers applied the 2007 BRCA risk assessment guidelines to their study population, they found that a lower proportion of black women were classified as “high risk” compared to white women. Using the current criteria, which includes women diagnosed with breast cancer before age 45 (previous guidelines included patients before age 40) and women with triple-negative breast cancer before age 60, might increase the number of black women who would meet national guidelines for testing.

Because the study did not include discussion about genetic counseling, it is unknown whether these patients saw genetic counselors, and whether seeing a genetic counselor increased genetic testing.  

Ultimately, more work needs to be done to understand why this racial disparity in BRCA testing between black and white women exists. Until then, healthcare providers should be more conscious to fully assess BRCA risk for black women, who should question their health care providers if they believe they may be at genetic risk for breast cancer.

Posted July 21, 2016

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