Nearly all patients with HR-positive breast cancer are treated with endocrine therapy, yet Black women are 4 times more likely to die of this disease compared with White women.
Black women with breast cancer treated with neoadjuvant endocrine therapy were more likely to benefit than White women if treated at an earlier disease stage. However, Black women were less likely to benefit compared with White women if treated at a later disease stage.1
These findings were presented at the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved by Veronica Jones, MD.
Regardless of race, nearly all patients with hormone receptor (HR)–positive breast cancer are treated with endocrine therapy. According to Jones, Black women are still 4 times more likely to die of this disease than White women.
“Our findings suggest that neoadjuvant endocrine therapy alone may not be the best approach in Black women who present with more advanced tumors,” said Jones, an assistant professor in the Department of Surgery, Division of Breast Surgery at City of Hope, in a press release.
Currently, failure of treatment with endocrine therapy cannot be predicted as 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,” Jones noted.
Investigators, including Jones, aimed to examine the differences in outcomes between Black and White women treated with neoadjuvant endocrine therapy. A cohort of patients from the National Cancer Database was identified and included 3521 White women and 365 Black women with stage I to III HR-positive breast cancer who received neoadjuvant endocrine therapy. Patients must have had a tumor stage, nodal status, and presence of metastases that was known following treatment.
At the time of the diagnosis, findings showed that Black women were 1.6 times more likely to have cancer detected in lymph nodes and 1.5 times more likely to have stage III disease vs White women.
A longer duration of endocrine therapy was also given to Black women compared with White women, with a median duration of 128 days and 114 days, respectively. Black women were 1.5 times more likely to receive longer than 24 weeks of neoadjuvant endocrine therapy. Additionally, when examining both Black and White women, 0.8% of tumors were either downstaged to an in situ lesion or eliminated following neoadjuvant endocrine therapy.
Black women were 2.9 times more likely to experience tumor downstaging or elimination than White women, with all of the downstaged tumors originally diagnosed as being stage I or II. All but 2 tumors (0.9%)which were diagnosed as stage II or III ended up upstaging to stage IV. Black women were also 2.6 times more likely to experience tumor upstaging than what was seen in White women.
These findings suggest different health outcomes for patients with HR-positive breast cancer, especially in Black women. This research exposes an area in the field where precision medicine may be beneficial.
“While lower-stage cancers in Black women responded better to endocrine therapy compared to White women, higher-stage cancers in Black women did more poorly in response to endocrine therapy,” Jones added. “This suggests a different tumor biology that may impact the treatment we give.”
Next, Jones along with her colleagues will investigate how mutations and gene expression profiles are different between breast tumors from Black and White women. The goal of this study is to see how the amount of available targeted therapies for these patients could expand. This will be especially beneficial research for Black women, as they have been historically underrepresented in clinical trials.
“This project is a critical step in unpacking the heterogeneity of [HR] tumor biology,” Jones said. “It brings into question how we can more effectively manage this disease to mitigate breast cancer racial disparities.”