BRCA1/2 Genetic Test Aids Decision-Making In Breast Cancer Patients

NEW YORK (Reuters Health) - In patients with newly diagnosed breast cancer at high risk for contralateral breast cancer, genetic testing significantly affects their decisions to undergo bilateral mastectomy, according to a prospective trial reported in the May 15th issue of the Journal of Clinical Oncology.

However, the high cost and lack of insurance coverage “threatens to make timely access to genetic testing...an option for the privileged few,” Dr. Mary B. Daly, of Fox Chase Cancer Center in Philadelphia, notes in an accompanying editorial.

The American Society of Clinical Oncology suggests that patients in whom hereditary breast cancer is suspected be referred for genetic testing.

To examine the feasibility of this approach, Dr. Marc D. Schwartz at Georgetown University School of Medicine in Washington, DC, and colleagues enrolled 194 newly diagnosed patients who had at least a 10% probability of carrying a BRCA1/2 mutation as determined by personal and family history. Twenty-seven declined genetic testing. Positive test results were documented in 31 women.

Among those who tested positive, 48% chose bilateral mastectomy, a significantly higher rate than the 24% of those with uninformative results and 4% of those who declined testing (p < 0.001).

According to logistic regression modeling, positive test results were associated with an odds ratio of 3.53 of undergoing bilateral mastectomy. Physician recommendation for genetic testing (odds ratio 3.28) and physician recommendation to consider surgery (odds ratio 5.15) were also independent predictors.

Among patients with uninformative test results, those with a greater family history of breast and ovarian cancer were more likely to choose bilateral surgery. Factors that affected this choice included presence of lobular cancer, previous breast biopsies on the contralateral breast, and failure of routine mammogram to detect the current cancer.

“The impact of testing on the subsequent treatment decisions suggests that testing should be offered to interested high-risk patients,” Dr. Schwartz’s team maintains.

Dr. Daly notes that in some studies the risk for subsequent contralateral breast cancer approaches 60% among mutation carriers with a primary breast cancer. Thus, “the choice to undergo bilateral mastectomy rather than breast-conserving surgery could ultimately translate into improved survival for this population of patients.”

“The fiscal and institutional impediments to widespread availability of genetic counseling and testing for all appropriate candidates should not deter the oncology community from its uptake but, rather, should commit us to the elimination of these barriers,” she concludes.

Source: J Clin Oncol 2004;22. [ Google search on this article ]

MeSH Headings:Breast Neoplasms: Neoplasms: Neoplasms by Site: Genes, BRCA1: DiseasesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.