Persistent Race-Associated Disparities in Genetic Testing of Patients with Breast Cancer

Web Exclusives

Triple-negative breast cancer (TNBC) is disproportionately prevalent among African-American populations, and in women with BRCA1 germline mutations. Results of genetic testing may influence treatment approaches and surgical choices that are considered risk-reducing, despite the increasing availability of targeted therapy such as PARP inhibitors that are an option for BRCA mutation carriers.

Bayard and colleagues evaluated patterns in genetic testing and outcomes for treated TNBC patients by analyzing the prospectively maintained databases from 1998 to 2018 at 2 academic cancer programs located in urban regions of New York City and Detroit. The median follow-up was 3.73 years. They compared patients diagnosed before and after the 2013 Supreme Court ruling that expanded testing availability by banning gene patenting.

In total, 810 patients were included in the analysis, with 600 from New York City and 200 from Detroit; the study included 202 African-American patients and 488 white patients.

Patients undergoing genetic testing were generally younger than those who did not; there was a statistically significant difference in the median age of patients undergoing genetic testing (50 years) and that of the cohort of those who did not receive genetic testing (62 years). White patients were more likely to undergo genetic testing than African-American patients, receiving testing at a rate of 42% compared with 23.8% (P <.0001). These rates were more similar to the subanalysis of patients living in New York City, where 42.8% of whites and 25.6% of African Americans received genetic testing, than in Detroit, where 38.6% of whites and 22.3% of African Americans underwent genetic testing.

The frequencies of pathogenic BRCA mutations were not significantly different between African-American (14.6%) and white (29.3%) patients.

Compared with genetic testing rates before 2013, when 18.3% of African-American patients and 40.7% of white patients received tests, genetic testing disparities after mid-2013 decreased among diagnosed patients with 31.4% of African-American patients compared with 44.0% of white patients (P <.0001).

Among cohorts of patients with BRCA, BRCA variants of uncertain significance, non-BRCA mutations, and patients without genetic mutations, no differences were observed in local or distant recurrence-free survival. When stratified by white compared with African-American identity, this outcome equivalence was consistent.

In TNBC patients, genetic testing has increased since the landmark 2013 Supreme Court decision banning gene patenting. However, race-associated disparities persist. It should be noted that genetic testing results are not reflective of survival outcomes, regardless of race. Currently, patients who have received genetic testing results are more likely to undergo risk-reducing mastectomy. This study highlights the need to focus on genetic testing disparities that will become increasingly crucial as researchers develop mutation-associated targeted therapies and precision medicine is more frequently adopted.

Source:

Bayard S, Chen Y, Fasano GA, et al. Racial disparities in genetic testing of breast cancer patients. Presented at: American Society of Clinical Oncology 2021 Annual Meeting, June 4-8. Abstract 10591.

Related Items


Subscribe Today!

To sign up for our newsletter or print publications, please enter your contact information below.

I'd like to receive: