Breast Cancer Discrepencies
Breast Cancer Prevalence and BRCA1 Indicators Vary by Ethnic Group
Scientists are making progress against breast cancer as diagnoses are declining and research is revealing how ethnicity may impact prevalence and risk factors.
News about breast cancer is rarely good; however, multiple scientific findings and announcements at the end of 2007 marked improvements in the fight against the disease. This progress culminated in an estimated 34,440 fewer women receiving breast cancer diagnoses in 2007 than the year before. However, the decrease in breast cancer diagnoses and findings about its causes varied by race and ethnicity.
Broad Statistics
According to statistics from the American Cancer Society, 178,480 women were diagnosed with breast cancer instead of 212,920 women in 2006. This decline is believed to result from earlier detection through screening and increased awareness, and improved treatment.
However, disparities exist in breast cancer prevalence among different race and ethnic groups, as well as by socioeconomic status. In particular, African American and Hispanic women have higher mortality rates following a breast cancer diagnosis, as much as 37 percent higher than Caucasian women despite lower incidence rates, per 2006 incidence data from the National Cancer Institute (NCI) and the North American Association of Central Cancer Registries.
As such, targeted research and identification of women at high risk of developing breast cancer can help guide breast cancer screening and risk reduction strategies. Specific study includes that of mutations in the BRCA1 gene that equate to a higher risk of breast and ovarian cancer.
BRCA1 Gene Mutation Findings
According to findings published in the December 2007 issue of the Journal of the American Medical Association, Hispanic women have the highest prevalence of the BRCA1 gene mutation (at 3.5 percent) while Asian American women have the lowest (at 0.5 percent).
This large-scale study examined 3,181 women under age 65 diagnosed during 1996-2005 to determine the prevalence of the BRCA1 gene mutation by race and ethnicity. African American women under the age of 35 years were more than twice as likely to have a BRCA1 gene mutation as young Hispanic women; 16.7 percent of African American women had the mutation and 8.9 percent for Hispanics.
Beyond a stark numbers comparison that highlights how different ethnic groups are affected by breast cancer, the research conclusion indicates how the comparison of prevalence estimates in racial and ethnic groups may facilitate future genetic screening and counseling, and planning for preventative interventions.
Similarly, researchers are examining how a BRCA1 gene mutation leads to breast cancer and/or ovarian cancer. A new study published in the January 2008 issue of Nature Genetics finds that a BRCA1 mutation causes cancer by destabilizing the tumor suppressor gene known as PTEN.
This finding can guide future research target for cancer therapy, particularly as breast cancer tumors linked to BRCA1 mutations are particularly aggressive and quick spreading, according to American Cancer Society statistics and information from the study linking BRCA1 mutations and the PTEN tumor suppressor gene.
What Next?
Research is continually finding new links for breast cancer causes and initiating and validating varying treatments. Direct research efforts and awareness initiatives such as those initiated by organizations such as Susan G. Komen for the Cure focus on breast cancer disparities and differences among racial groups.
Sources:
CA: A Cancer Journal for Clinicians (2006). Trends in Breast Cancer by Race and Ethnicity: 2006 Update.
Journal of American Medical Association (2007). Prevalence of Pathogenic BRCA1 Mutation Carriers in 5 US Racial/Ethnic Groups.
Journal of the National Cancer Institute (2007). Extended Adjuvant Therapy for Breast Cancer - How Much Is Enough?
Nature Genetics (2008). BRCA1 - Sowing the Seeds Crooked in the Furrow.
