A tumour tissue sample is collected from a patient at biopsy or during primary surgical cytoreduction and transferred to a lab for DNA analysis and HRD testing. The results of the tests (BRCA mutation and genomic instability) will help with treatment decision-making.
If a patient is being considered for neoadjuvant chemotherapy, it is important to ensure an adequate sample is collected at biopsy to allow testing1–3
DNA is extracted from the formalin-fixed paraffin-embedded (FFPE) ovarian tumour tissue sample and quantified using fluorescence methods to ensure enough genomic material is available2,3 The extracted DNA undergoes multiple steps including fragmentation, purification and amplification to prepare it for analysis2,3 Next-generation sequencing is performed to identify variants of the BRCA1/2 genes and asses a score of genomic instabilty2,3
HRD-positive test result=
BRCA1/2 mutation and/or high genomic instability score.2,3
These tumour tests cannot distinguish between germline and somatic mutations.5,6 If a BRCA mutation is identified, a genetic counsellor should be consulted for germline testing to identify familial risk1
1. Capoluongo E, et al. Semin Oncol 2017;44(3):187–197; 2. Myriad Genetic Laboratories, Inc. Summary of Safety and Effectiveness Data. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf19/P190014B.pdf (Accessed July, 2021); 3. Foundation Medicine, Inc. Summary of Safety and Effectiveness Data. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160018S001b.pdf (Accessed July, 2021); 4. Myriad Genetic Laboratories, Inc. Genetic Testing Process. Available at: https://myriad.com/healthcare-professionals/about-genetic-testing/genetic-testing-process/ (Accessed July, 2021); 5. Myriad Genetic Laboratories, Inc. myChoice® CDx Technical Information. Available at: https://myriad-web.s3.amazonaws.com/myChoiceCDx/downloads/myChoiceCDxTech.pdf (Accessed July, 2021); 6. Foundation Medicine, Inc. FoundationFocus™ CDxBRCA LOH Technical Information Summary. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160018S001c.pdf (Accessed July, 2021)