Internal Overview of Prostatic Cancer Cases and Quality of BRCA1 and BRCA2 NGS Data from the FFPE Tissue

Background: Comprehensive genomic profiling (CGP) has gained an important role in patients with advanced prostate cancer following the introduction of PARP inhibitors in daily clinical practice. Here, we report an overview of CGP results, specifically of BRCA1 and BRCA2 HRD-repair system genes, from patients with prostate cancer analyzed in our institution, and we compare our results with those available from more recent scientific literature. Methods: The study cohort consisted of 70 patients. Somatic DNA was extracted from Formalin-Fixed Paraffin-Embedded (FFPE) tissue using a MagCore Genomic DNA FFPE One-Step Kit for MagCore System. The DNA was quantified by EasyPGX^® Real-Time qPCR and EasyPGX^® Analysis Software (version 4.0.13). Tissue somatic DNA libraries were prepared with Myriapod^® NGS BRCA1-2 panel-NG035 and sequenced in a Mi-Seq^® System. The sequence alignment in hg19 and the variant calling were performed using Myriapod^® NGS Data Analysis Software version 5.0.8 NG900-SW 5.0.8 with a software detection limit (LoD) of 95%. Variants with a coverage of 500 and VAF% ≥ 5 were evaluated. Results: Tumor tissue NGS was unsuccessful in 46/70 patients (66%). Mutations of the BRCA2 gene were detected in 4 of the samples: (1) BRCA2 ex10 c.1244A>G p.His415Arg VAF = 51.03%; (2) BRCA2 ex11 c.5946delT p.Ser1982fs VAF = 72.1%; (3) BRCA2 ex11 c.3302A>G p.His1101Arg VAF = 52.9%; and (4) BRCA2 ex11 c.3195_3198delTAAT p.Asn1066fs VAF = 51.1%. Conclusions: The results from our internal overview seem to support the data and to confirm the performance of the technical issues reported in the literature. Considering the advanced age of our patients, with 84% of men over the age of 65, the application of alternative and less invasive procedures such as liquid biopsy, could be a more suitable solution for some cases.