Cancer Advances: Study of Genetic Counseling and Testing Shows Breast Cancer Patients with BRCA1 and BRCA2 Gene Mutations Twice as Likely to Have Both Breasts Removed

Posted online on April 5, 2004 on www.jco.org

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Breast cancer patients who have mutations in their BRCA1 and BRCA2 genes - the genes responsible for suppressing tumor growth - have an elevated risk of developing cancer in the opposite breast - as high as 60% by some estimates - for at least 10 years after their original diagnosis. For women with these mutations who have early stage breast cancer, surgery to remove the tumor followed by radiation is an appropriate treatment, but it does not reduce the risk of cancer developing in the opposite breast.

A new study published in the Journal of Clinical Oncology (JCO) shows that newly diagnosed breast cancer patients who test positive for BRCA1 and BRCA2 mutations after receiving genetic counseling are more likely to choose to have both breasts removed (double mastectomy) to help reduce the risk of cancer in the opposite breast.Genetic counseling involves the advice of a specially trained counselor who can help patients understand their genetic background and how it affects their risk of cancer. Women at high risk for breast cancer, as well as those already diagnosed with the disease, may choose to undergo genetic testing to see if they have a mutation in their BRCA1 and BRCA2 genes. The new study found that knowing this information can help patients - together with their physicians - make decisions about treatment.Researchers at Georgetown University provided free genetic counseling to 167 patients newly diagnosed with breast cancer, with test results available in about two weeks. Thirty-one women tested positive for BRCA1 or BRCA2 mutations, while tests in the other 136 patients found no mutation or a mutation of unknown significance. Of these women, 48% of patients who received a positive BRCA1 or BRCA2 test chose to have an immediate double mastectomy, compared to 24% of women in whom no significant mutation was detected.

What Does This Mean for Patients?

Women diagnosed with breast cancer at a young age or with a family history of breast cancer should discuss with their doctors whether genetic counseling and testing are appropriate. Choosing to undergo genetic testing for mutations in BRCA1 or BRCA2 genes soon after a diagnosis may affect a woman's decision about treatment.While genetic counseling and testing have become more widely available in the United States, patients may face delays in getting an appointment to see a genetic counselor or obtaining insurance approval. Although such delays can be frustrating for patients who want to begin treatment in a timely manner, genetic counseling and testing provides women with important information that can significantly impact their treatment decision. Women who want to use the results of BRCA1 and BRCA2 testing to make treatment decisions should ask their physician about the possibility of rapid testing, as well as the associated costs.