A new study has found that Asian Americans have the lowest prevalence (0.5 percent) of the cancer-associated gene mutation BRCA1.
For the study, Esther M. John, Ph.D., of the Northern California Cancer Center, Fremont, Calif., and colleagues examined the prevalence of BRCA1 mutations in Hispanic, African American and Asian American female breast cancer patients compared with non-Hispanic white patients with and without Ashkenazi Jewish ancestry.
The patients, younger than 65 years at diagnosis, were enrolled at the Northern California site of the Breast Cancer Family Registry during the period 1996-2005.
In patients without reported Ashkenazi Jewish ancestry, estimated mutation prevalence was highest in Hispanic patients (3.5 percent), followed by non-Hispanic white patients (2.2 percent), African American patients (1.3 percent), and Asian American patients (0.5 percent).
Patients with Ashkenazi Jewish ancestry had a prevalence of 8.3 percent. Within each racial/ethnic group, prevalence estimates decreased with age at diagnosis and were higher in patients who reported a family history of breast or ovarian cancer than in those who did not.
The prevalence of BRCA1 mutations was particularly high in African American patients diagnosed before age 35 years (16.7 percent), compared with young Hispanics (8.9 percent), non-white Hispanics without Ashkenazi Jewish ancestry (7.2 percent), and Asian Americans (2.4 percent).
"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," the researchers said.
"Such information may facilitate mutation screening in a clinical setting and is needed to guide resource allocation for genetic testing, genetic counselling, and planning of preventive interventions in all population subgroups," they added.
The study is published in the Journal of the American Medical Association.