Minority Women with Breast Cancer Show More Variants of Uncertain Significance

In a study published in the Journal of Cancer Education, researchers observed a high frequency of pathogenic or likely pathogenic variants among non-Hispanic black and non-Hispanic white women and observed more variants of uncertain significance results among minority women.

Researchers did not detect a difference in hereditary breast and ovarian cancer (HBOC) genetic testing among young patients with breast cancer, based upon race or ethnicity. However, they did indicate that these findings underscore the need for targeted genetic counseling education, specifically among young minority women, given the uncertainty about the clinical implications of pathogenic or likely pathogenic variants in moderate penetrance genes and variants of uncertain significance. 

“This study underscores the importance of increasing awareness of the importance of genetic testing among young minority women with breast cancer,” Safiya George, PhD, dean of Florida Atlantic University’s Christine E. Lynn College of Nursing, said in a press release. “It also signals that these patients’ healthcare providers and future healthcare providers of this population need to be reminded and/or made aware of the critical need for them to receive this important multigene panel testing.”

In this retrospective study of 1,503 diverse patients with breast cancer who were diagnosed at age ≤ 50 years from January 2007 to December 2017, 46.1% of the cohort completed HBOC genetic testing. Of the cohort, 424% were non-Hispanic white, 13.3% were no-Hispanic black, 25.5% were Hispanic, 9.9% were Asian, and 8.9% were other or unknown race/ethnicity. The completion of genetic testing was associated with younger age, family history of breast cancer, and earlier stage, but not race, ethnicity, or health insurance status.

Black patients were found to have the highest frequency of pathogenic or likely pathogenic variants (18.6%), and Hispanic and Asian patients had the most variants of uncertain significance (19% and 21.9%, respectively). Moreover, the percentage of women undergoing genetic testing increased over time from 15.3% in 2007 to a peak of 72.8% in 2015. Across the same time period, there was a significant increase observed in pathogenic or likely pathogenic and variants of uncertain significance results.

“Since the burden of breast cancer is particularly high among young black women, with a mortality rate that is 2 times greater among young women of European ancestry, there is a need to engage more young black breast cancer patients in genetic counseling education and the importance of having HBOC genetic testing performed,” the authors wrote. 

Additionally, women with metastatic breast cancer were found to be more than 60% less likely to undergo genetic testing when compared to women with stage 1 disease and women who were older at breast cancer diagnosis were also less likely to have genetic testing. Furthermore, compared to those with stage 1 breast cancer, patients who had stage 0 or stage 4 disease at diagnosis were less likely to complete genetic testing. However, the odds of a young women completing genetic testing increased almost three times if she had a family history of breast cancer. 

Lead author and an assistant professor in Florida Atlantic University’s Christine E. Lynne College of Nursing, Tarsha Jones, PhD, indicated that next steps include conducting a future study that looks at the possible impact of receiving pathogenic or likely pathogenic genetic testing results and promoting family risk communication since pathogenic variants can be inherited. 

References:

1. Jones T, Trivedi MS, Jiang X, et al. Racial and Ethnic Differences in BRCA1/2 and Multigene Panel Testing Among Young Breast Cancer Patients. Journal of Cancer Education. doi:10.1007/s13187-019-01646-8.

2. Study Examines Genetic Testing in Diverse Young Breast Cancer Patients over a Decade [news release]. Published January 28, 2020. newswise.com/articles/study-examines-genetic-testing-in-diverse-young-breast-cancer-patients-over-a-decade?sc=sphr&xy=10019792. Accessed February 18, 2020.