The study, published by The New York Breast Cancer Study Group in the Oct. 24 edition of Science, also found that many women with these inherited mutations come from families with few if any reports of breast or ovarian cancer.

The good news from the study is that even among women at very high risk, exercise and healthy weight as an adolescent delayed the onset of breast cancer.

"It was a surprise, but a source of hope, to learn that factors over which we have some control made a difference in the age at which these highest-risk women developed breast cancer," said the lead author, Mary-Claire King, Ph.D. King is American Cancer Society Professor of Genome Sciences and Medicine at the University of Washington in Seattle and a pioneer in the study of the link between inherited genetic alterations and disease. "Women with inherited mutations were at extremely high risk, but exercise and appropriate weight during their adolescent years clearly delayed the onset of breast cancer."

"The possibility that lifestyle changes such as increased exercise and weight control could modify the impact of genetic risk has very intriguing implications, not only for BRCA-related cancers but for other breast cancers as well," said Dr. Larry Norton, head of the Division of Solid Tumor Oncology and Norna S. Serafim Chair in Clinical Oncology at Memorial Sloan-Kettering Cancer Center.

The research was conducted with financial support from The Breast Cancer Research Foundation of New York.

Previous studies had suggested widely varying estimates of breast cancer risk ranging from 25 percent to 80 percent among women with BRCA1 and BRCA2 mutations. In order to resolve these discrepancies and accurately calc
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Contact: Walter Neary
wneary@u.washington.edu
206-685-3841
University of Washington
23-Oct-2003