Black women with breast cancer fare worse than other women when treated with early chemotherapy, according to new research from the Yale Cancer Center.
Typically, black, Hispanic and Asian women are more likely to undergo neoadjuvant chemotherapy, or chemotherapy prior to surgery, than white women because they are more likely to develop advanced-stage breast cancer. But the new study found that black women are less likely to benefit from the treatment.
The finding is significant because it proves further research is needed, and could impact how future research and treatment options are pursued for black women, said Brigid Killelea, the study’s first author and associate professor of surgery at Yale School of Medicine.
“African American women didn’t respond as well to the chemotherapy when a pathologist looked at the tumors under a microscope after [subsequent] surgery,” she said. “We were surprised to see such a significant finding.”
For the study, Yale researchers examined the National Cancer Data Base to focus on racial disparities in the use and outcome of neoadjuvant chemotherapy in 27,300 women with stage I to stage III cancer. All of the women in the study were diagnosed in 2010 or 2011.
Of those 27,300 women, there were 17,970 known outcomes and a third of them— 5,944 women—had a pathologic complete response (pCR), meaning there was no residual invasive disease in the breast following chemotherapy, according to the study.
Compared with white women, black women—but not Hispanic or Asian women—had a lower rate of pCR, the study found.
Black women had a 43 percent rate of pCR for certain types of cancers, known as ER/PR-negative and HER2-positive, compared with 54 percent of white women who had no cancer following chemotherapy for those types of tumors.
Black women also had a 37 percent rate of pCR after using early chemotherapy to treat breast cancer tumors known as triple-negative. By comparison, white women with that type of tumor had a 43 percent rate of cancer absence following the chemotherapy, according to the study.
The difference remained even when data was adjusted for women’s age, cancer stage, geographic region, insurance status, income and other factors, the study found.
“Even when we controlled for the fact that minority women often present with more advanced-stage, higher-grade tumors, and more aggressive types of breast cancer overall, our team was surprised to find that black women did not respond as well to neoadjuvant chemotherapy compared to other racial groups,” Killelea said.
Minority women tend to be underrepresented in treatment clinical trials, she said, which could change in light of the study.
“These findings are very important,” she said. “We need to pay close attention to these racial disparities and make sure we’re encouraging black women, and Hispanic women, to participate in clinical trials.”
Researchers aren’t sure but think biologic differences in chemo sensitivity, treatment disparities or socioeconomic factors—which could not be adjusted for in the study—may be reasons why black women tend to fare worse.
The study, which recently appeared in the Journal of Clinical Oncology, should spur further research, said Dr. Andrew Salner, director of the Helen & Harry Gray Cancer Center and medical director at the Hartford HealthCare Cancer Institute, both at Hartford Hospital.
“This was a really interesting study,” he said, in that it controlled for many variables to focus specifically on racial disparities. “There’s obviously more research and work that needs to be done, but it begins to get to the issue.”
There are questions the study can’t answer, he said, such as whether black women had different chemotherapy, different doses of chemo, or other medical conditions or factors that affected their outcomes.
But pinpointing that the rate of cancer eradication varied between black women and other racial groups is an important step that could inform treatment decisions going forward, he said.
“That was an important question to answer,” Salner said. “This was an important study. It opens up a bunch of other interesting questions.”