Although women of African descent experience a higher incidence and mortality from triple-negative breast cancer than women of other races or ethnicities, research findings presented by Hall et al at the 2022 ASCO Annual Meeting showed that the magnitude of gene-specific risks of triple-negative breast cancer was similar across different racial and ethnic groups (Abstract 10517).
“The standard belief has always been that the BRCA1 gene is the major gene associated with triple-negative breast cancer, but work from our own and other groups suggested there is an expanded array of genes that were also associated with this cancer subtype,” said Michael J. Hall, MD, MS, lead author of the study and Chair of the Department of Clinical Genetics at Fox Chase Cancer Center. “In our earlier research, we showed that other genes in addition to BRCA1 are also associated with increased risk of triple-negative breast cancer.”
Triple-negative breast cancer accounts for about 10% to 15% of all breast cancers. The term triple-negative breast cancer means the cancer cells don’t have estrogen or progesterone receptors or the protein HER2, potential points of attack that physicians can use to fight cancer, so there are fewer treatment options.
In the current study, Dr. Hall and collaborators expanded on their earlier findings to examine how the magnitude of gene-specific risk of triple-negative breast cancer varies by race/ethnicity. To do this, they examined clinical and genetic records from women referred for multigene cancer panel testing and then used risk modeling to determine whether there was a gene-ancestral interaction.
“The reason to ask this is we know triple-negative breast cancer is a lot more common in African American women. While in general we think these high-risk genetic mutations are evenly distributed in the population by race/ethnicity, we wanted to see if variations in race/ethnicity-specific risks existed and could be explained by gene-specific variability in risk,” said Dr. Hall.
Through this study, researchers confirmed that increased risk of triple-negative breast cancer was highest in patients with pathogenic variants of the gene BRCA1. Additionally, increased risk was associated with mutations in the genes BARD1, PALB2, RAD51C, RAD51D, and BRCA2.
“When we broke down those overall associations of risk by each racial group, we didn’t see any strong evidence of variability by race,” said Dr. Hall. “In other words, the gene-specific risk of triple-negative breast cancer was similar across the different racial groups we examined.”
Disclosure: For full disclosures of the study authors, visit coi.asco.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.