New Test for Predicting Breast Cancer
(Ivanhoe Newswire) – One in eight women will be affected by breast cancer in their lifetime. A new study finds a new test that can predict the presence of BRCA mutations.
A new multiple gene expression profile test predicted the presence of harmful BRCA1 or BRCA2 mutations in otherwise healthy women carrying the mutations.
“This novel technology aims to provide a layer of information regarding the cell functionality aspect of BRCA mutations that could greatly enhance the doctor's ability to identify high-risk carriers," Asher Y. Salmon, M.D., a breast cancer specialist at the Hadassah Hebrew University Medical Center in Jerusalem, Israel was quoted as saying.
Women who have a mutated BRCA1 gene have an increased risk for developing breast cancer or ovarian cancer. Scientists are investigating ways to detect these genetic mutations so women who carry the genes can take measures to reduce their risk of cancer.
"The current tool for mutation detection is gene sequencing, which is expensive, time-consuming and, in many cases, lacking clear and decisive clinical decision making information. In many cases, the current sequencing tool identifies a mutation, but we do not know if the mutation is neutral or harmful,” Dr. Salmon was quoted as saying.
Dr. Salmon says that emerging evidence has revealed that cells with a mutation in one of the BRCA1 or BRCA2 genes have a gene expression profile when exposed to causes of DNA damage, like radiation. Researchers collected white blood cells from 9 healthy women with a mutated BRCA1 gene and 8 healthy women with a mutated BRCA2 gene. Dr. Salmon cultured the cells and then exposed them to radiation. Then, they extracted the RNA from the cells and compared it to the RNA from identical white blood cells from 10 healthy women without a mutation.
Close to 1,500 genes were differentially expressed between non-carriers and carriers. The list got narrowed down to 18 genes that were mostly differentiated between the 2 groups. Then, they narrowed it down further with a validation study of a model using 21 of the new genes and 5 control genes to predict the risk. Blood samples were used from an independent group of 40 women, who were carriers of mutated BRCA1 and BRCA2 and 17 non-carrier women. The model had a sensitivity of 95 percent and specificity of 88 percent.
"In wealthy societies, it can become a screening tool for identifying individuals with a very high susceptibility for carrying a mutation, and full sequencing can be reserved only for them. In societies in which sequencing is not feasible, this test can substitute for it with a very high accuracy rate,” Dr. Salmon concluded.
Dr. Salmon and his colleagues are conducting a large validation study in North America and Europe to analyze the efficacy of the test in heterogeneous populations.
SOURCE: Cancer Prevention Research: A Journal of the American Association for Cancer Research, January 2013