Looking at a subgroup analysis of patients with hormone receptor-positive and HER2-negative breast cancer on endocrine therapy, researchers saw promising results but worrying disparities between non-Hispanic White patients and non-Hispanic Black patients.
Kevin Kalinsky, MD, MS, associate professor in the department of hematology and medical oncology at Emory University School of Medicine, and the Louisa and Rand Glenn Family chair in Breast Cancer Research, director of the Glenn Family Breast Center, and director of Breast Medical Oncology at the Winship Cancer Institute, discusses the disparities seen between non-Hispanic Black women and non-Hispanic White women with hormone receptor (HR)-positive HER2-negative breast cancer on endocrine therapy.
In a subgroup analysis of 5,000 patients with HR-positive/HER2-negative breast cancer either on chemotherapy plus endocrine therapy or endocrine therapy alone, patients had better results, including disease free survival (DFS), on endocrine therapy but these results did not extend to all patients equally. While 6% of the patients involved were non-Hispanic Black women, this still underscored the under representation of this patient population in clinical trials. Moreover, this patient group had poorer results when compared with non-Hispanic White patients.
In an interview with Targeted OncologyTM Kalinsky discussed how these results open more questions for researchers to answer. He added that they need to understand why these disparities exist and address the poor results for this patient population.
0:08 | This is despite having a higher rate of non-Hispanic black vs non-Hispanic white women agreeing to their randomization and despite the fact that at 1 year we saw that patients were equally adherent to their endocrine therapy in both of those subgroups. We also did note that non-Hispanic Black women had a higher rate of grade 3 tumors, and a higher BMI, and that magnitude of difference when we look at invasive [DFS] and distant relapse-free survival between the 2 groups when we incorporated the body mass index into the multivariable analysis the magnitude of that benefit had dampened a bit.
0:52 | I think that this was a, hopefully, informative analysis. There are several questions that come out of this; specifically, why is this happening? And there are additional studies that will be reviewing adherence beyond a year and looking at other social determinants of health. These results are like what was seen in [TAILORx trial [NCT00310180]] within the first 5 years of follow up in that analysis in a node-negative population, so there does seem to be this consistent finding. I just think that the next steps are for us to continue to understand why this is happening.