The Tumor BRACAnalysis CDx companion diagnostic test significantly improved the detection of cancer-causing BRCA1/2 mutations by 44% in women with ovarian cancer. Data from this new study were presented at the European Society for Medical Oncology (ESMO) 2014 Congress in Madrid, Spain.

“Several previous clinical studies have demonstrated that patients with germline or somatic BRCA1/2 mutations respond to certain DNA-damaging medicines such as the platinum drugs,” said Colin Hayward, MD, European medical director at Myriad Genetics. “Tumor BRACAnalysis CDx also has the potential to greatly expand the number of ovarian cancer patients who may respond to treatment with PARP inhibitors.”

This study evaluated 131 previously untreated patients with high-grade ovarian cancer. Blood samples were tested for germline (hereditary) BRCA mutations. In addition, tumor samples were obtained from patients receiving surgery and were tested for both somatic (tumor) and germline BRCA mutations. The data analysis included 92 patients who completed testing for both germline and somatic mutations.

The results show that the Tumor BRACAnalysis CDx test identified 28.3% of women with either germline or somatic BRCA1/2 mutations. In contrast, blood germline testing only identified the 19.6% of patients with germline BRCA1/2 mutations. The somatic mutations identified by Tumor BRACAnalysis CDx testing represent a 44% increase in the detection of cancer-causing BRCA mutations over germline testing.

“In this study, tumor analysis identified substantially more patients with BRCA1/2 mutations than germline blood testing alone,” said Melinda Yates, PhD, of the MD Anderson Cancer Center in Houston, Texas, and a study investigator. “The logical path forward is to use tumor testing to identify the greatest number of patients with BRCA1/2 mutations.”