Study demonstrates BRACAnalysis testing for women with breast carcinoma in situ

Myriad Genetics, Inc. announced today that an article entitled "Prevalence of BRCA1 and BRCA2 Mutations In Women With Carcinoma In Situ of the Breast Referred for Genetic Testing" will appear in the December 2010 issue of the journal Cancer Prevention Research. The study demonstrated that BRACAnalysis^® testing of at risk women with breast carcinoma in situ may provide valuable information to guide the physician's medical and surgical strategies for their patients.

Among women referred to Myriad for testing, the authors examined 7,295 non-Ashkenazi women diagnosed with CIS. Approximately 6% of these women had deleterious mutations in either the BRCA1 or BRCA2 genes regardless of personal and/or family history of invasive cancer. Results of the data showed that 10.3% of the CIS patients with both a personal and family history of invasive cancer had BRCA1/2 deleterious mutations. 

"This data confirms what physicians have long suspected," stated Mark C. Capone, President of Myriad Genetic Laboratories. "A significant percentage of women with breast carcinoma in situ who have a family history of breast cancer have mutations in the BRCA genes. These women are at particularly high risk for invasive cancers of the breast and ovary. BRACAnalysis^® testing helps to identify these women and provides their physician with critical information so that strategies can be designed to lower their cancer risks."

In patients referred for genetic testing, early-onset CIS is associated with a likelihood of carrying BRCA1/2 mutation. When a family history of breast and/or ovarian cancer are also present, testing women with early-onset CIS may increase the likelihood of BRCA1/2 mutation detection, and the opportunity for carriers to consider invasive cancer prevention strategies.

Carcinoma in situ of the breast is an increasingly common diagnosis in American women. Between 1980 and 2001, age-adjusted rates of CIS have increased approximately seven-fold. According to the American Cancer Society, 62,280 new cases of CIS were expected to be diagnosed last year, and CIS accounts for nearly 25% of all new breast cancer diagnoses. Women diagnosed with CIS of the breast have a significantly higher risk of invasive breast cancer compared to the general population.

The current market opportunity for BRACAnalysis^® testing among pre-symptomatic women and patients with cancer is estimated to be $800 million annually. Considering the 62,000 newly diagnosed cases of breast carcinoma in situ and the CIS survivors, the Company now estimates that the market opportunity will increase by $100 million annually to a total annual market potential of over $900 million in the United States.

Professional medical society guidelines, such as the American Society of Clinical Oncologists (ASCO), the Society of Gynecologic Oncologists (SGO), and the American College of Obstetricians and Gynecologists (ACOG), articulate risk factors for BRCA gene mutations, which include, among others, breast cancer occurring before age 50, personal or family history of ovarian cancer at any age, personal or family history of male breast cancer, Ashkenazi Jewish ancestry with breast cancer at any age, or the presence of a known BRCA mutation in the family.