Same mutations linked to breast cancer risk found in black, white women

Both Black and White women have the same genetic mutations linked to breast cancer, according to a recently published study in JAMA Oncology.¹

The study, led by a team of researchers from the Basser Center for BRCA at Penn Medicine’s Abramson Cancer Center in Philadelphia, Pennsylvania, evaluated nearly 30,000 patients and found about 5% of Black and White women have the same genetic mutations that are associated with an increased risk of breast cancer.

This study follows a 2020 study that investigated breast cancer risk in Black women, however, there was no direct comparison to White women. According to Penn Medicine, Black women are more likely to be diagnosed with breast cancer before the age of 50 or with estrogen receptor (ER)–negative and triple-negative breast cancer compared to non-Hispanic White women. Prior to this study, the consensus was unclear on whether these disparities are related to racial differences in germline genetic pathogenic variants (PVs) associated with breast cancer genes, as well as if race should influence approaches for genetic testing.

“The findings challenge past, smaller studies that found Black women face a greater genetic risk and the suggestion that race should be an independent factor when considering genetic testing,” said first author Susan Domchek, MD, executive director, Basser Center for BRCA. “We shouldn’t make changes to testing guidelines based on race alone. Rather, our efforts should focus on ensuring equal access to and uptake of testing to minimize disparities in care and outcomes.”

The study examined data from 7 population-based studies in the CARRIERS consortium, a group of 17 epidemiology studies in the U.S. focused on who develops breast cancer. Investigators recorded the incidence of PVs in 12 genes associated with breast cancer risk.

Results demonstrated that among 3,946 Black and 25,287 non-Hispanic White women, there was no statistically significant difference in PVs by race, with 5.65% of Black women vs 5.06% percent of White women having PVs in the 12 genes. For both White and Black women, younger age and ER-negative breast cancer were found to be risk factors in the most impactful genes, such as BRCA1, BRCA2, and PALB2. Investigators also found that Black women are much less likely to receive genetic counseling and testing compared to White women, which can be attributed to access to care and differences in physician recommendations.

In an effort to lessen this gap, the Basser Center launched its Black & BRCA initiative in 2020, bringing resources and support to the Black community for genetic counseling and testing, as well as providing tools to collect family history, addressing myths, and educating providers, according to Penn Medicine.

“At a time when Black men and women are more likely to be diagnosed with cancer at later stages when it is less treatable, Black & BRCA seeks to empower people to understand their family health history and take action to prevent cancer from one generation to the next,” Domchek said.

Reference

1. Black and white women have same mutations linked to breast cancer risk - penn medicine. Accessed November 8, 2021. https://www.pennmedicine.org/news/news-releases/2021/june/black-and-white-women-have-same-mutations-linked-to-breast-cancer-risk