Study: Lifetime breast cancer risk at 82 percent for gene mutation

Thursday, October 23rd 2003, 12:00 am
By: News On 6

WASHINGTON (AP) _ Women who inherit mutations of certain genes are at an 82 percent lifetime risk of developing breast cancer and have a 23 to 54 percent risk of ovarian cancer, according to a study that analyzed the health records of more than a thousand Jewish women.

The study, appearing Friday in the journal Science, also found that exercise and maintaining a healthy weight during adolescence delays the onset of breast cancer even in women who have mutations of the BRCA1 or BRCA2 gene.

Finding that cancer could be delayed, even for high risk women, by exercise and sensible eating during the teen years is ``a source of hope,'' said Mary-Claire King, first author of the study and a professor of genome sciences at the University of Washington, Seattle.

King said the study found that women who exercised actively when they were young _ either dancing, or in team sports, or just walking a lot _ and who maintained a healthy weight through the age of 21, were somewhat protected from breast cancer.

``If they carried the mutation, they still had a very high risk, but their age of diagnosis was pushed to later in life,'' she said.

The study helps to clear up some of the confusion about the risks associated with the BRCA1 and BRCA2 gene mutations, said Dr. Kenneth Offit, a physician and researcher at Memorial Sloan-Kettering Cancer Center in New York.

Earlier studies had suggested that the breast cancer risk from the gene mutations ranged from 25 to 80 percent. The new study firmly nails the lifetime risk at 82 percent. For ovarian cancer, the study found the lifetime risk was 54 percent for BRCA1 and 23 percent for BRCA2 mutations.