(RxWiki News) Thanks to Angelina Jolie, we have been hearing a lot about BRCA1 and BRCA2 gene mutations. But for some patients, these genes alone may not tell the whole story.
A recent study suggests that African-American women and their relatives may benefit from broader genetic screening tests for breast cancer and increased access to genetic counseling.
According to the study, a high percentage of African-American women with breast cancer were found to have BRCA1 and BRCA2 mutations as well as several other types of mutations associated with higher risk of breast cancer.
"Ask an oncologist about genetic tests for breast cancer."
The study was conducted by Jane Churpek, MD, assistant professor of medicine at the University of Chicago Medicine along with collaborators from the University of Chicago and the University of Washington.
The objective of the study was to examine if African-American women had mutations in their genes that could make them more susceptible to breast cancer.
The researchers tested 249 women who had been referred for genetic counseling at the University of Chicago Medical Center. They used a new test called BROCA and looked at 18 genes that may predict the risk of developing breast cancer.
Analysis of the results found that 22 percent (56 patients) of the women screened had at least one mutation that made them more likely to get breast cancer. Of these mutations, 79 percent were in the commonly known BRCA1 and BRCA2 genes, which are associated with a significantly higher risk of developing breast cancer.
The study authors pointed out that women with mutations in the BRCA1 and BRCA2 genes have a 37 to 85 percent chance of developing breast cancer by age 80 as compared to women without these mutations who have a 12 percent chance of developing the cancer.
The researchers also found mutations in other cancer-linked genes, such as CHEK2, PALB2, ATM, and PTEN, in 21 percent of the women screened. In addition, the mutated gene varied from patient to patient due to the high variability in genes among the African-American population.
It is important to note that the patients in this study were not taken from the general population. Most of them had a family history of breast cancer and were referred to the cancer risk clinic for genetic screening.
But the researchers noted that not all patients had such a history. In fact, 40 percent of the 249 women had no family history of breast cancer and yet 12 percent of them had harmful mutations.
"Our study confirms the importance of screening for mutations in breast cancer susceptibility genes in all African-American breast cancer patients diagnosed by age 45, those with a family history of breast or ovarian cancer, or with triple-negative breast cancer before age 60," said Dr. Churpek. "This could identify at-risk family members in time for life-saving interventions and help prevent future cancers for the patients as well."
Adam Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine and dailyRx Contributing Expert said, "The study is sobering and suggests that we should consider genetic susceptibility to breast cancer seriously in African American women. It may also be encouraging in that there are new drugs such as PARP inhibitors (currently being developed) which target DNA repair pathways which could have utility in this patient population."
The study results were presented June 3 at the 2013 Annual Meeting of the American Society of Clinical Oncology in Chicago. All findings should be considered preliminary until published in a peer-reviewed journal.
The research was funded by the National Cancer Institute, Komen for the Cure and the Breast Cancer Research Foundation. No conflicts of interest were reported.