According to the Los Angeles County Department of Public Health, breast cancer is the leading cause of premature cancer death and the second most common cause of cancer death, behind ling cancer in the county. Many are aware that certain genes, such as BRCA1 and BRCA2, are related to increased breast cancer risk. Women who carry either the BRCA1 or BRCA2 gene are five times more likely to carry the gene than non-carriers. Now, researchers have identified another gene, known as the Abraxas mutation, interacts with BRCA1 and BRCA2 genes to increase breast cancer risk. The results of their study were published in the February 22 edition of Science Translational Medicine.
The researchers screened 125 Northern Finnish breast cancer families (families with a familial history of breast cancer) for the Abraxas mutation and found that three of them (2.4%) had the mutation. Although the mutation did not appear to be common, it is important to note that the mutation was not found in any woman without cancer in the study group. The mutation does not appear to be common — it was found in 2.4 percent of families with a history of breast cancer. But importantly, the mutation was not found in anyone without breast cancer in the study. The researchers concluded that they had found another gene that increases the susceptibility of breast cancer.
Abraxas is now added to the number of genes that increase breast cancer risk, which now number more than a dozen. The research also adds additional evidence that more than one gene is responsible for increased risk, For example, only about 20% women with a family history of breast cancer carry the BRCA1 and BRCA2 genes, clearly demonstrating that other genes are involved.
The researchers also evaluated 991 breast cancer patients in Finland and compared them to 868 control women who did not have breast cancer. They discovered that one of the breast cancer patients carried the Abraxas mutation; however, none of the control women carried the mutation.
The researchers determined that the Abraxas mutation prevents cells from repair damaged DNA; this results in an increased risk of the cells becoming malignant. They also noted that the gene might also increase the risk of other cancers. This theory was supported by the finding that one of the breast cancer patients in the study also had endometrial cancer (cancer of the lining of the uterus). They also noted that women who carried the Abraxas mutation were diagnosed with breast cancer in their mid-forties, which was comparable to the age at diagnosis for women with the BRCA1 and BRCA2 mutations.
The importance of identifying genes, which increase cancer risk is important for two reasons: (1) If women who are at significantly increased risk are aware of that increased risk, they can make decisions regarding removal of their breast tissue or other risk-lowering measures; and (2) As genetic research progresses, it may become possible to reduce or eliminate the harmful impact of these genes.