Elisa De Paolis1, Maria De Bonis2, Paola Concolino3, Alessia Piermattei4, Anna Fagotti5, Andrea Urbani6, Giovanni Scambia7, Angelo Minucci8, Ettore Capoluongo9. 1. Molecular Diagnostic and Genomic Laboratory, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: elisa.depaolis@guest.policlinicogemelli.it. 2. Molecular Diagnostic and Genomic Laboratory, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: maria.debonis@guest.policlinicogemelli.it. 3. Molecular Diagnostic and Genomic Laboratory, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: paola.concolino@policlinicogemelli.it. 4. Division of Oncological Gynecology, Department of Women's and Children's Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: alessia.piemattei@policlinicogemelli.it. 5. Division of Oncological Gynecology, Department of Women's and Children's Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; Catholic University of the Sacred Heart, 00168 Rome, Italy. Electronic address: anna.fagotti@policlinicogemelli.it. 6. Molecular Diagnostic and Genomic Laboratory, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; Catholic University of the Sacred Heart, 00168 Rome, Italy. Electronic address: andrea.urbani@policlinicogemelli.it. 7. Division of Oncological Gynecology, Department of Women's and Children's Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: giovanni.scambia@policlinicogemelli.it. 8. Molecular Diagnostic and Genomic Laboratory, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy. Electronic address: angelo.minucci@policlinicogemelli.it. 9. Department of Molecular Medicine and Medical Biotechnology, Federico II University, 80131 Naples, Italy; Federico II University, CEINGE, Advanced Biotechnology, 80131 Naples, Italy. Electronic address: ettoredomenico.capoluongo@unina.it.
Abstract
BACKGROUND AND AIMS: With the introduction of Olaparib as target therapy for High Grade Serous Ovarian Cancer (HGSOC) patients with germline and somatic BRCA1/2 mutations, the genetic test performed on tumor tissue has become important like the germline test. In somatic testing the evaluation of Large Genomic Rearrangements (LGRs) represents the main challenge. We describe a droplet digital PCR (ddPCR) assay for the evaluation of target BRCA1 LGRs on blood and formalin-fixed paraffin-embedded (FFPE)/Fresh Frozen Tissue (FFT) samples. MATERIALS AND METHODS: We analyzed blood, FFPE and FFT samples in a validation setting of n = 78 HGSOC patients. We applied the ddPCR to BRCA1 exons 2, 20 and 21 as some of the most common BRCA1 exons involved in LGRs in our cohort of patients. RESULTS: The ddPCR custom assays allowed the identification of LGRs in all sample types, including FFPE specimens. Moreover, we were able to clearly detect LGRs accounted as somatic event. CONCLUSION: The introduction of ddPCR in a comprehensive workflow, encompassing both germline and somatic tests, represents an improvement in BRCA1/2 testing. ddPCR can overcome challenges related to BRCA testing, especially on FFPE analysis. Finally, ddPCR represents a promising alternative strategy to the established standard methods currently used in clinical setting.
BACKGROUND AND AIMS: With the introduction of Olaparib as target therapy for High Grade Serous Ovarian Cancer (HGSOC) patients with germline and somatic BRCA1/2 mutations, the genetic test performed on tumor tissue has become important like the germline test. In somatic testing the evaluation of Large Genomic Rearrangements (LGRs) represents the main challenge. We describe a droplet digital PCR (ddPCR) assay for the evaluation of target BRCA1 LGRs on blood and formalin-fixed paraffin-embedded (FFPE)/Fresh Frozen Tissue (FFT) samples. MATERIALS AND METHODS: We analyzed blood, FFPE and FFT samples in a validation setting of n = 78 HGSOC patients. We applied the ddPCR to BRCA1 exons 2, 20 and 21 as some of the most common BRCA1 exons involved in LGRs in our cohort of patients. RESULTS: The ddPCR custom assays allowed the identification of LGRs in all sample types, including FFPE specimens. Moreover, we were able to clearly detect LGRs accounted as somatic event. CONCLUSION: The introduction of ddPCR in a comprehensive workflow, encompassing both germline and somatic tests, represents an improvement in BRCA1/2 testing. ddPCR can overcome challenges related to BRCA testing, especially on FFPE analysis. Finally, ddPCR represents a promising alternative strategy to the established standard methods currently used in clinical setting.