By Guest Writer - February 23, 2021
February marks Black History Month and an important time to reflect on cancer disparities in the Black community, especially when it comes to differences in genetic testing.
Black women with breast cancer have a higher mortality rate than white women and are more likely to be diagnosed with the more aggressive triple negative pathology. Black men with prostate cancer are more likely to have advanced or metastatic disease at diagnosis compared to white men. They also carry a higher risk of dying from their disease.
These disparities extend to genetic testing for hereditary cancer risks. The first genetic tests , which identify BRCA1 and BRCA2 genes, became available in the 1990s to women with a personal or family history of breast cancer. Approximately 10% of all breast cancers have an underlying hereditary cause, and these two genes constitute the majority of cases. It is important to identify women who have mutations of genes that increase the risk of breast cancer. Women can use this knowledge for many important reasons, such as identifying breast cancer at an earlier, more favorable stage with more frequent and comprehensive imaging, pursuing preventative mastectomy to reduce the risk of ever developing breast cancer and helping inform risks to their other family members.
Past research has shown that Black women report favorable attitudes and have high interest in genetic testing. However, genetic testing for inherited cancers happen less often in Blacks compared to whites. According to the 2020 Cancer Disparities Progress Report by the American Association for Cancer Research, 65% of young white women with breast cancer were offered genetic testing, whereas only 36% of young Black women with breast cancer were offered this same testing. Despite national guidelines advising all women diagnosed with breast cancer under age 45 to have genetic testing, it appears that only about one-third of Black women are receiving this medically necessary test. This is important as certain Black populations have higher risks to have hereditary forms of breast cancer. Approximately 25% of Bahamian women carry a harmful BRCA1 or BRCA2 gene mutation.
When undergoing genetic testing, Black women are more likely to receive a Variant of Uncertain Significance (VUS) than white women. A VUS indicates that a genetic change was identified but cannot reliably be determined whether it does or does not associate with cancer. Large genetic databases have data from mostly white populations, which means that Black individuals are more likely to receive uncertain results when undergoing genetic testing. These disparities also apply to Black men; genetic testing in Black men with prostate cancer is less likely to detect harmful genetic changes than in white men.
It is important to put an end to racial inequalities in genetics. We must raise awareness of hereditary cancer and the need for every person who qualifies for genetic testing to receive that testing.
This article was guest written by Sarah Burke, MS, CGC, a genetics counselor at Moffitt Cancer Center