Seven new studies were presented at the 2015 SABCS they demonstrated the increased sensitivity of panel testing, patient stress, and HRD.
Multiplex Identification of Genetic Etiologies Among Women with Bilateral Breast Cancer Using a 28-Gene Hereditary Cancer Panel
Jeffery N Weitzel, MD (City of Hope), presented outcomes data on 135,609 consecutive cases that underwent testing with Myriad myRisk 28-gene hereditary cancer panel. 4,865 patients from that cohort were diagnosed with two primary breast cancers, 12.4% of which were diagnosed with at least one pathogenic variant. The study found that women tested with a multiplex panel were identified at a high percentage including women over the age of 50. The study also found that women with two primary breast cancers were twice as likely to have more than one pathogenic variant. To read more click here.
Interim Analysis of Multiplex Gene Panel Testing for Inherited Susceptibility to Breast Cancer
Gregory E Idos, MD (USC Norris Comprehensive Cancer Center, Keck School of Medicine), presented data from a multicenter prospective cohort study of patients undergoing cancer-risk assessment using the Myriad myRisk 28-gene hereditary cancer panel. 332 patients who were suspicious of hereditary breast/ovarian cancer syndrome underwent testing by meeting the standard criteria for genetic testing or are predicted to have a >2.5% probability of inherited susceptibility to cancer. This diverse cohort found 11.1% of participants tested positive for a deleterious mutation, 4.3% of which tested positive for a non-BRCA1/2 mutations. To read more click here.
The Patient Experience in a Prospective Trial of Multiplex Gene Panel Testing for Cancer Risk
Allison W Kurian, MD (Stanford University Cancer Institute), presented data examining 332 patients suspicious of breast/ovarian cancer syndrome were tested with the Myriad myRisk 28-gene hereditary cancer panel. Patients were evaluated by determining the MICRA score three months following the hereditary cancer test the mean score was 2 out of a possible 30 signifying low distress. Of the participants 82% wanted to know all of their multigene panel results even if the clinical relevance was not fully understood and 87% of participants never regretted their decision to undergo panel testing. To read more click here.
Characterization of Li-Fraumeni Syndrome Using a 28-Gene Hereditary Cancer Panel
Theresa Rich, MS (Myriad Genetics Laboratories), presented data examining patients with a pathogenic variant in TP53 identified from 135,609 consecutive cases tested with the Myriad myRisk 28-gene hereditary cancer panel. In examining patient clinical data it was found that a high proportion (only 54% of individuals with likely germline pathogenic variants presented some clinical concern for LFS) of likely germline TP53 pathogenic variant carriers would not have been identified as at risk for LFS based on NCCN guidelines. Around 1/3 of the detected TP53 pathogenic variants displayed allelic imbalance and the clinical presentation was distinct from the likely germline carriers. To read more click here.
Predisposing Germline Mutations in an Unselected Academic Breast Cancer (BC) Cohort
Judy E Garber MD, PhD, (Dana-Farber Cancer Institute), presented data on new invasive breast cancer patients seen at the Dana-Farber Cancer Institute between January 1, 2010 and July 31, 2012, who were tested with the Myriad myRisk 28 gene hereditary cancer panel. In this single institution 10.7% of new breast cancer patients tested positive for germline mutation of a breast cancer predisposition gene. The data further demonstrated that of those with a breast cancer predisposition gene 6.1% tested positive for a pathogenic variant in BRCA1/2, while 4.1% tested positive for a pathogenic variant of another breast cancer predisposition gene. To read more click here.
Several studies related to myChoice HRD were presented at the San Antonio Breast Cancer Symposium last week. Melinda L Telli, MD (Stanford University), reviewed data showing that Homologous Recombination Deficiency (HRD) predicts response to platinum-based therapy in patients with triple negative breast cancer. To read more click here. Roisin M Connolly, MB, BCh (Johns Hopkins Medicine), presented a study supporting Homologous Recombination Deficiency (HRD) as a predictive biomarker of response to neoadjuvant platinum in HER2-negative breast cancer. To read more click here.
Additionally, event-free survival data for the CALGB 40603 trial was reported, showing no survival benefit of platinum use in patients with triple-negative breast cancer. The discussant for this session, Dr. Angela DeMichele (University of Pennsylvania), stated that a biomarker may help identify which patients are more likely to benefit from platinum use. Data on myChoice HRD as a predictive biomarker in this cohort will be presented in 2016.