BRCA 1/2 mutations by next-generation sequencing testing in 200 Romanian high-risk patients with breast cancer.

e13116 Background: To determine types and frequencies of BRCA 1 (B1) or BRCA2 (B2) mutations in high-risk Romanian breast cancer patients, as there is no data published in this population. Methods: This prospective study evaluates the germline BRCA1/BRCA2 mutations in 200 Romanian high-risk breast cancer patients tested between February 2015-January 2017 at IOCN. Inclusion criteria selected patients diagnosed with breast cancer before 40 years, triple negative breast cancer under the age of 50, or having conventional family history criteria. All patients signed an informed consent. BRCA1/BRCA2 testing was performed using an AmpliSeq-based sequencing analysis, on the Ion Torrent Personal Genome Machine (Life Technologies) at RCFG. The pathogenic mutations were validated using Sanger technology. MLPA was performed for all 200 patients. Results: We analyzed 200 high-risk breast cancer patients and found 32 (16%) patients with pathogenic mutations, 23 (11.5%) patients with B1 and 9 (4.5%) patients with B2 mutations. The majority of patients (99.5%) presented normal MLPA results; only one sample (0.5%) presented a deletion at CHEK2-9(10). The frequency of class 5 mutations identified in B1 gene were c.1687C > T (1%), c.181T > G (2%), c.3607C > T (3.5%), c.4218delG (0.5%), c.5329_5330insC (c.5266dupC) (4.5%) and for the B2 gene c.1528G > T (0.5%), c.4022C > G (0.5%), c.7007G > A (0.5%), c.8695C > T (0.5%), c.9253 delA (0.5%), c.9371A > T (2%). Conclusions: Frequency of deleterious BRCA mutations in our cohort was 11.5% for BRCA1 and 4.5% for BRCA2. This prospective study presents the first extensive results on frequency and types of germline BRCA1/2 mutations in Romanian high-risk breast cancer patients. Clinical trial information: NCT02317120. [Table: see text]