Chemotherapy type can be personalized to decrease harmful side effects for Black patients with breast cancer

Newswise — INDIANAPOLIS — Researchers at the Indiana University Melvin and Bren Simon Comprehensive Cancer Center and the IU School of Medicine have discovered that Black patients with breast cancer who are treated with a chemotherapy called docetaxel experience less of a harmful side effect called peripheral neuropathy. Their findings represent an important shift in knowledge about a patient population who’ve historically been underrepresented in breast cancer research.

Taxane-based chemotherapies are the primary curative therapy for breast cancer, but they can lead to taxane-induced peripheral neuropathy (TIPN). Neuropathy symptoms include numbness, tingling and pain in the hands and feet, which can become debilitating and impact the ability to deliver planned doses of curative chemotherapy.

Results of the clinical study EAZ171, by the ECOG-ACRIN Cancer Research Group (ECOG-ACRIN), found that patients with breast cancer treated with docetaxel every three weeks had less TIPN and fewer dose reductions compared to those who received weekly doses of the chemotherapy paclitaxel. The results will be presented by Tarah J. Ballinger, MD, today at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago. Ballinger is the Vera Bradley Foundation Scholar in Breast Cancer Research at the IU Simon Comprehensive Cancer Center and an associate professor at the IU School of Medicine.

Chosen from more than 5,000 research abstracts that are part of the meeting, the study is part of the ASCO press program and among fewer than 0.5% that will be highlighted for media. Additionally, the findings are published today in the Journal of Clinical Oncology; Bryan P. Schneider, MD, Vera Bradley Professor of Oncology at the IU School of Medicine, is corresponding author.

“Black women have much higher rates of neuropathy, and that neuropathy tends to be more severe and more impactful. We're seeing more dose reductions in Black women and ultimately reduced survival because of this,” Ballinger said. “Our goal was to specifically focus on Black women for whom this toxicity is more serious and more impactful, and to find ways to intervene specifically for Black patients.”

“Given the disparities that we see with Black patients in terms of survival and toxicity, we felt compelled to address this head-on and design a clinical trial built specifically for this population so that we could try to better personalize our medications and try to improve outcomes in all ways,” said Schneider, who led the clinical trial. Schneider and Ballinger are investigators at the Vera Bradley Foundation Center for Breast Cancer Research at the IU Simon Comprehensive Cancer Center.

Notably, the study is among the first National Cancer Institute cooperative group trials to focus enrollment solely on a minority population that has disparate outcomes. The trial enrolled only women who self-identified as Black or African American.

“That's really important because in previous trials, Black women have been underrepresented so our standard of care is based on women who are not Black,” Ballinger said. “We know that Black women have a different disease biology, they have different risk factors, they respond differently to chemotherapy, and they have higher rates of neuropathy. Now we have this whole data set that applies specifically to those patients. We were able to do that because of a lot of involvement from Black women and Black patient advocates.”

Researchers collaborated with Black patient advocates in the trial design and patient recruitment, specifically with guidance from the Indianapolis-based organization Pink-4-Ever Ending Disparities. Focus groups helped inform the study’s design, recruitment and educational materials, which included a social media campaign that featured Black women with breast cancer.

“This study is critically important,” said Lisa Hayes, Pink-4-Ever executive director. “Pink-4-Ever helped recruit breast cancer survivors for the focus groups that led to the design of the study. They played a role in improving treatment and hopefully improving outcomes for other Black women with these kinds of studies, which is what will eventually improve breast cancer outcomes for Black women.”

EAZ171 enrolled 249 Black patients with 121 receiving at least one dose of paclitaxel and 118 receiving one dose of docetaxel. The severity of side effects was graded on a scale of one to four, with four being the most severe and life-altering. Grade 2-4 peripheral neuropathy was significantly higher in patients receiving paclitaxel than those receiving docetaxel as reported by both physicians (44% vs. 29%) and patients (40% vs. 24%). Patients receiving paclitaxel required more dose reductions due to peripheral neuropathy (28% vs. 9%) or due to any cause (39% vs. 25%) compared to patients receiving docetaxel.

The study also sought to determine if two inherited gene alterations predicted which patients would have less peripheral neuropathy. While inherited gene alterations were more common in patients who developed TIPN, the data was not statistically significant.

“EAZ171 is really exciting because it shows us that we can do better in terms of designing and delivering research trials that ask questions that are important and necessary for underrepresented populations,” Ballinger said. “This starts us down a whole line of research where we stop just describing that there's a disparity in breast cancer outcomes, and we actually start to change our practice so that we're intervening on it.”

This study was built on more than a decade of research at the IU Simon Comprehensive Cancer Center. In addition, it drew from the results of a previous ECOG-ACRIN clinical trial, E5103, a 5,000-patient, NCI-sponsored study led by Kathy Miller, MD, associate director of clinical research at the cancer center and the Ballvé Lantero Professor of Oncology at IU School of Medicine. The study laid the groundwork for Schneider’s research to determine the association of genetics with treatment efficacy and chemotherapy-induced toxicities. While performing an analysis, his research team discovered that Black women with breast cancer had a higher risk of developing neuropathy as a side effect of chemotherapy.

EAZ171 was designed and conducted by ECOG-ACRIN with funding from the National Cancer Institute, part of the National Institutes of Health. Additional support was provided by Susan G. Komen and the Vera Bradley Foundation for Breast Cancer.

Media contact: Candace Gwaltney, [email protected], (317) 278-4322

About the IU Simon Comprehensive Cancer Center 

The Indiana University Melvin and Bren Simon Comprehensive Cancer Center is the state's only National Cancer Institute-designated Comprehensive Cancer Center and one of only 57 in the nation. The prestigious comprehensive designation recognizes the center's excellence in basic, clinical, and population research, outstanding educational activities, and effective community outreach program across the state. It is also one of only 33 members of the National Comprehensive Cancer Network. As a member, the center's physicians have a role in determining the recognized standard of clinical care for cancer patients. The center is the central hub for cancer research and education across Indiana University. 

About the IU School of Medicine

The IU School of Medicine is the largest medical school in the U.S. and is annually ranked among the top medical schools in the nation by U.S. News & World Report. The school offers high-quality medical education, access to leading medical research and rich campus life in nine Indiana cities, including rural and urban locations consistently recognized for livability. According to the Blue Ridge Institute for Medical Research, the IU School of Medicine ranks No. 13 in 2023 National Institutes of Health funding among all public medical schools in the country.