‘It’s a Crisis’: Research Reveals Breast Cancer Disparities

Non-Hispanic Black women have worse breast cancer treatment outcomes than their peers, according to research presented at the 2022 San Antonio Breast Cancer Symposium. The study analyzed outcomes for more than 4,000 patients with early-stage hormone receptor-positive, HER2-negative (HR+/HER2-), lymph node-positive disease.

The research adds to existing evidence of discrepancies in Black and other patients’ outcomes. Although the rate of breast cancer in Black women is 4% lower than in white women in the U.S., the mortality rate is 40% higher in Black women, noted study presenter Yara Abdou, MD, assistant professor at the University of North Carolina at Chapel Hill and Lineberger Comprehensive Cancer Center.

“It’s a crisis. We really need to understand what’s happening, and the only way we can understand what’s happening is if we have more Black women in clinical trials,” Jasmine Souers, president and CEO of The Missing Pink, told Patient Power. Souers is a breast cancer survivor who advocates for people of color with breast cancer.

Learn More About the RxPONDER Trial

The new study included women who were part of the RxPONDER clinical trial, a study originally intended to assess whether certain patients could skip chemotherapy after surgery.

The RxPONDER trial enrolled women with HR+/HER2- breast cancer to evaluate the clinical utility of the Oncotype DX test, also known as the 21-gene recurrence score (RS). These women had RS scores between zero and 25, signifying they faced a low to intermediate risk.

Following surgery, half of the women received just hormone therapy, also called endocrine therapy, and the other half also received chemotherapy. The study showed that postmenopausal women experienced no benefit when chemotherapy was added, but premenopausal women did. For the study presented at this year’s SABCS, Dr. Abdou and her colleagues further analyzed these data to determine if race affected treatment outcome as well.

The researchers analyzed outcomes after five years, finding that 91.5% of white women were alive and had not experienced a recurrence or been diagnosed with a new cancer, a measure called invasive disease-free survival (IDFS). In contrast, IDFS was 87.2% for non-Hispanic Black women.

It was “probably one of the most important presentations that we will hear here,” said Eric P. Winer, MD, director of Yale Cancer Center in New Haven, Connecticut, physician-in-chief at Smilow Cancer Network,and president of the American Society of Clinical Oncology, during the question-and-answer period.

“A very plausible hypothesis, particularly given the pervasive nature of the disparities in outcomes in white versus Black women with breast cancer, is that structural racism is playing a significant role,” wrote Dr. Winer in a request for comment about the study.

Where Do These Differences Come From?

These worse outcomes existed despite striking similarities between the groups of women, explained Dr. Abdou. The patients had similarly sized tumors and numbers of lymph nodes positive for cancer. They also had similar scores on the Oncotype DX test measuring their risk of recurrence.

Other factors did not affect the impact of race, including whether the patients received chemotherapy as well as hormone therapy, menopausal status, age, and tumor grade. These outcome differences could not be explained by treatment compliance, which did not significantly vary between groups. Non-Hispanic Black patients were more likely to accept the treatments they were assigned than non-Hispanic white patients and just as likely to remain on hormone therapy. One year later, 96% were still on hormone therapy, while 94.8% of non-Hispanic white patients were. Dr. Abdou said that longer follow-up beyond the one-year mark are needed to confirm these findings, however.

The one factor that did influence the effect of race was body mass index (BMI). Non-Hispanic Black women in the study were more likely to have a higher BMI than their peers. When adjusted for BMI, the effect of race decreased but did not disappear.

“In the context of the trial, the difference in the risk of disease recurrence persisted despite the fact that the trial should have eliminated differences in treatment and access to care,” wrote Dr. Winer. “While higher body mass index in non-Hispanic Black women appears to account for some of the difference in outcome, it is by no means the full explanation. We need to understand the disparities, and we must take action. It is simply unacceptable and unconscionable to sit silently.”

A Call for Greater Clinical Trial Diversity

Black patients continue to be underrepresented in clinical trials. Studies show that many Black women who have metastatic breast cancer never even receive information from their care team about clinical trials.

Of the participants in the RxPONDER study, just 6.1% were non-Hispanic Black women. Because of the low number of events among this group, “any apparent treatment differences by race should be considered hypothesis-generating,” Dr. Abdou said.

“We need to make sure that we’re being intentional about increasing the diversity in clinical trials,” Souers said. “It’s imperative, and it’s a benefit to all of us. It means more effective treatments, better data. And obviously, it means women who are able to live longer and have better quality of life.”