A new risk factor for developing breast cancer has been identified in an Oz research.
According to the study conducted jointly by the Peter MacCallum Cancer Centre, the University of Melbourne and the University of Queensland, the risk factor involves a modification (DNA methylation) to the BRCA1 gene.
BRCA1 is known for its involvement in breast and ovarian cancer. Women with mutations in this gene, which inactivates its function, are predisposed to these diseases.
The DNA methylation modification is known as an epimutation and acts to turn off the BRCA1 gene from its normal protective function against breast cancer.
The study involved women diagnosed with breast cancer before the age of 40 years for whom BRCA1 mutations had not been identified.
The epimutation was found in the blood of some women with breast cancer, especially those who develop the same type of breast cancer that develops in women with a BRCA1 mutation.
However, unlike mutations in the BRCA1 gene, these epimutations appear not to be inherited and the relatives of women with epimutations are not at increased risk of breast or ovarian cancer.
The paper has been published online in the journal Cancer Prevention Research.