Hispanic women in the USA have the highest risk of developing breast cancer while Asian American women have the lowest. A study of many US racial and ethnic groups found that Hispanic 3.5% of Hispanic women who were examined have the BRCA1 gene mutation which is linked to breast cancer, while the prevalence for Asian women in the USA is 0.5%, according to an article published in the Journal of the American Medical Association (JAMA).
Women who have a mutation in the BRCA1 gene – a gene that suppresses tumors – have a higher chance of developing ovarian and breast cancers. Those who carry the mutated gene run a 65% chance of developing breast cancer by the age of 70 and a 39% chance of developing ovarian cancer, the authors explain.
BRCA1 mutations are very rare. However, they are more commonly found among people who have several relatives who have/had breast or ovarian cancer, early-onset breast cancer, or are of Ashkenazi Jewish ancestry. The authors write that there is very little data on BRCA1 mutations among racial/ethnic minority populations.
Esther M. John, Ph.D., Northern California Cancer Center, Fremont, Calif., and team looked at the prevalence of BRCA1 mutations among African American, Asian American and Hispanic women – all of them had breast cancer. They were compared to non-Hispanic white women with and without Ashkenazi Jewish ancestry. The patients, all of them under 65 at diagnosis, were enrolled at the Northern California site of the Breast Cancer Family Registry (n = 3,181) during 1996-2005.
The researchers found the following prevalence of the mutated BRCA1 gene
— Women with Ashkenazi Jewish ancestry 8.3%
— Hispanic women 3.5%
— Non-Hispanic white women without Ashkenazi Jewish ancestry 2.2%
— African American women 1.3%
— Asian American women 0.5%
In all the racial/ethnic groups the prevalence estimates went down with age at diagnosis and were higher among patients whose family history included relatives with breast or ovarian cancer, compared with those who had no family history of breast or ovarian cancer.
16.7% of African American women who had breast cancer and were aged under 35 had the BRCA1 mutation, compared to 8.9% of Hispanic women, 7.2% of non-white Hispanic women (without Ashkenazi Jewish ancestry) and 2.4% of Asian American women.
The researchers concluded “The present study included multiple racial/ethnic groups, therefore allowing direct comparison of carrier prevalence estimates. Since certain mutations may be unique to specific populations, the full spectrum of mutations needs to be determined. Such information may facilitate mutation screening in a clinical setting and is needed to guide resource allocation for genetic testing, genetic counseling, and planning of preventive interventions in all population subgroups.”
“Prevalence of Pathogenic BRCA1 Mutation Carriers in 5 US Racial/Ethnic Groups”
Esther M. John, PhD; Alexander Miron, PhD; Gail Gong, PhD; Amanda I. Phipps, MPH; Anna Felberg, MS; Frederick P. Li, MD; Dee W. West, PhD; Alice S. Whittemore, PhD
JAMA. 2007;298(24):2869-2876.
Written by – Christian Nordqvist