A study led by City of Hope, one of the largest cancer research and treatment organizations in the United States, found that Black women with Stage 1 or 2 breast cancer were almost three times more likely than white women to have tumor shrinkage from hormone therapy delivered prior to surgery, yet Black women were more likely than their white counterparts to have worse outcomes when this type of endocrine therapy before surgery was used at a later stage of disease. The results will be presented at the virtual 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved, held Sept. 16 to 19, 2022.
In more than 70% of all breast cancer cases, tumors have either estrogen or progesterone hormone receptor sensitivity. Hormone receptor-positive breast cancer is usually treated with endocrine therapy, where medicines target the receptors. Yet, even within this breast cancer subgroup, the disease is varied and should not be treated with relative uniformity, noted Veronica Jones, M.D., a breast cancer expert who also studies cancer health disparities at City of Hope. AACR chose to highlight Jones' data in its press program for the conference.
Black women are four times more likely than white women to die of hormone receptor-positive breast cancer. While neoadjuvant endocrine therapy appeared to benefit Black women with Stage 1 and 2 breast cancer, our findings suggest that it was not beneficial in Black women with more advanced tumors. This finding may offer insight into its role in the adjuvant setting as well."
Veronica Jones, Assistant Professor, City of Hope's Division of Breast Surgery
To examine health outcome differences between Black and white women, Jones and colleagues analyzed 3,521 white women and 365 Black women with Stage 1 through 3 hormone receptor-positive breast cancer from the National Cancer Database. They analyzed changes in tumor size and nodal status after neoadjuvant endocrine therapy, which is treatment before surgery, while also considering duration of treatment.
In current medical practice, endocrine treatment failure cannot be predicted; it is detected when the disease recurs. Little is known about the contribution of endocrine therapy resistance to the mortality disparity seen in Black women.
The researchers found that at diagnosis, Black women were 1.6 times more likely to have cancer detected in lymph nodes and 1.5 times more likely to have Stage 3 disease compared to white women. Black women were 1.5 times more likely to receive neoadjuvant endocrine therapy for longer than 24 weeks.
Because the findings suggest different health outcomes in hormone receptor-positive breast cancer in Black women, it exposes an area where precision medicine can be beneficial. City of Hope harnesses leading-edge, genomic-driven insights and highly specialized oncologists to improve patient outcomes and quality of life. The institution is dedicated to reaching diverse, underserved populations so that they have access to precision medicine.
"We need to do a better job distinguishing these tumors based on their genetic profile to identify the best treatments," Jones said. "In order to address the question of tumor biology, City of Hope is using RNA sequencing to look closer at genomic differences in hormone receptor-positive breast cancer across races."
These discoveries may help expand the repertoire of targeted therapies available to breast cancer patients, especially for Black women who have been historically underrepresented in clinical trials.
For people with breast cancer now, Jones said, "Recently the CDK4/6 inhibitor abemaciclib has been approved in the adjuvant treatment of locally advanced tumors and should be considered for all women, including Black women with higher-stage breast cancer."
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