A blood test that spots changes in a specific gene could reveal a woman's risk for breast cancer years before the disease has a chance to develop.
Women with the highest level of methylation on one area gene were more likely to develop cancer than those with the lowest level of methylation because high levels of methylation signal high levels of DNA flaws.

Scientists from Imperial College (London, UK) analyzed blood samples from breast cancer patients and women without breast cancer. The samples from the breast cancer patients were collected an average of three years before they were diagnosed with the disease. Samples were from a case-control study derived from a cohort of high-risk breast cancer families and nested case-control studies in two prospective cohorts. Bisulfite pyrosequencing was used to quantify methylation from 640 incident cases of invasive breast cancer and 741 controls.

The objective was to find out if the alteration of ataxia telangiectasia mutated (ATM) genes by a process called methylation could predict a woman's breast cancer risk. The analysis of the blood samples identified alterations in the ATM gene that did not occur because of having active cancer or cancer treatments. This result was particularly pronounced in blood samples taken from women under the age of 60.
This blood test used in combination with other breast cancer risk assessment tools such as genetic testing and risk factor profiling, could help identify women at higher risk. This early warning could be used to monitor these patients and one day perhaps even prevent them from developing breast cancer. The study identifies a significant association between breast cancer risk and gene-specific methylation in leucocyte DNA measured in prediagnostic blood samples from cases in prospective cohorts and using pyrosequencing, which is a highly quantitative method.

James Flanagan, PhD, the senior author of the study said, "We know that genetic variation contributes to a person's risk of disease. With this new study, we can now also say that epigenetic variation, or differences in how genes are modified, also has a role. So far, we have found alterations in one small region of a gene that appear to associate with risk of disease, and so the next step with this epigenetic research is a genome-wide approach to try and find all the associated genes" The study was published on May 1, 2012, in the journal Cancer Research.

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