Black women with node-positive breast cancer were less likely to receive tumor gene profiling for treatment decision making compared with women of other ethnicities, according to a new study. However, black women who were node negative were just as likely to receive the test as were other women, suggesting that testing protocols for black women are kept closer to guidelines than for other groups.
The genetic test, known as Oncotype DX (ODX), came into wide use a decade ago as a chemotherapy decision-making tool for patients with estrogen receptor–positive, human epidermal growth factor receptor-2–negative breast cancer, stage I or II, with tumors of 0.5 cm or larger. Current guidelines used by public and private insurers, including Medicare, incorporate ODX testing for these patients who are node negative. Still, there is some evidence suggesting a role for ODX for women with up to three positive nodes, and one major clinical trial is underway to determine whether ODX testing is helpful in these patients.
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Megan C. Roberts, Ph.D., of the University of North Carolina at Chapel Hill, and her colleagues, looked at data for 1,468 women (609 black) from the population-based, phase III Carolina Breast Cancer Study.
Overall in the cohort, 42% of women received ODX testing, and no racial disparities were seen in the likelihood of ODX testing in node-negative women. For patients with node-positive disease, black women were 46% less likely to receive ODX testing than were nonblack women (adjusted risk ratio 0.54, 95% CI 0.35 to 0.84; P = .006).
“Current medical guidelines do not recommend ODX testing in patients with node-positive, early-stage, ER+ breast cancer,” Dr. Roberts and colleagues wrote in their analysis (J Clin Oncol. 2015 Nov 23. doi: 10.1200/JCO.2015.63.2489).
“Therefore, lower rates of ODX testing among black women in our sample reflect their receipt of more guideline-concordant care than nonblack women with node-positive breast cancer. Thus, differential receipt of ODX testing does not necessarily reflect a racial disparity in the quality of care. This paradox illustrates challenges that will accompany the measurement of disparities in the early adoption of new genetic technologies into clinical practice,” the researchers wrote.
They noted as a study limitations the fact that patient preferences regarding ODX could not be accounted for, and that previous studies have suggested these could differ by race.