Dr. James Flanagan, a Breast Cancer Campaign scientific fellow in the Department of Surgery and Cancer at Imperial College London, uncovered the first strong evidence that molecular or "epigenetic" changes in a gene can be associated with breast cancer risk.
The study involved 640 women with breast cancer and 741 controls who enrolled in three previous studies -- the earliest of which began in 1992.
The researchers analyzed blood samples that the women donated on average three years before being diagnosed with breast cancer to find out whether the alteration of single genes by a process called methylation can predict whether women have an increased breast cancer risk.
The study, published in Cancer Research, found the women with the highest level of methylation on one area of the gene ATM were twice as likely as women with the lowest level to get breast cancer. The result was particularly clear in blood samples taken from women age 60 and under, the study said.