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Introduction About 5%–10% of the hereditary breast and/or ovarian cancer (BC/BOC) is associated with an autosomal dominant genetic susceptibility due to highly penetrant mutations of the BRCA1/2 genes. In particular, BRCA1/2 gene mutations are found in 25%–30% of the BC families subjected to genetic testing. These numbers suggest the possible involvement of other genes in BC/BOC genetic predisposition and a fraction of these cases remains to be assigned to specific genetic factors. Here we report on the application of the NGS multigene panel to a group of BRCA1/2 mutation negative BC/BOC cases, in order to identify germline mutations that could further explain BC/BOC genetic susceptibility. Material and methods We selected a group of 27 BRCA1/2 negative BC and BOC families on the basis of a clear dominant inheritance pattern and/or a moderate/high BRCAPro score. We performed a genomic screening by a comprehensive multi-gene custom panel of 29 cancer-related genes, using Ion Torrent platform (Thermo Fisher Scientific). Results and discussions In three cases (11%) we found mutations described as pathogenic (https://www.ncbi.nlm.nih.gov/clinvar/) in ATM, MUTYH and PALB2 genes. In the series analysed, the most frequently altered genes were APC and ATM (15%) but were also identified mutations in MSH6 and TP53 (11%), MUTYH and RAD51B (7%), MRE11, EPCAM, BRIP1, CHEK2, PALB2, BARD1, STK11 and RAD50 (4%). In particular, we found six genomic variants of uncertain significance (VUS) in MSH6, ATM, BRIP1, RAD50 and APC genes; nine genomic variants of conflicting interpretations of pathogenicity in MUTYH, MRE11, TP53, APC, MSH6, CHEK2, EPCAM and ATM genes and eight genomic variants not reported in ClinVar in APC, RAD51B, STK11, TP53, ATM and BARD1 genes predicted deleterious by in silico analysis. Their biological significance and involvement in the development of the pathology is still unknown today. Only six patients were negative for the presence of mutations in the 29 genes analysed. Conclusion Preliminary results of this study suggest that NGS could offer a great contribution to identify the genetic component of susceptibility to BC/BOC and could potentially be used with implications for clinical management and counselling of patients and their families. Moreover, our results suggest that multigene testing approach may benefit appropriately selected patients, especially those with increased risk of BC/BOC development.

Introduction Colorectal carcinoma (CRC) is one of the most commonly diagnosed cancers worldwide. The metastatic disease contributes to the high mortality rate reported for such tumours. Significant benefit on overall survival was brought about the introduction of monoclonal antibodies anti-EGFR and anti-VEGF used in combination with chemotherapy in metastatic CRC (mCRC). While anti-VEGF treatment does not require biomarker-based selection criteria, the potential efficacy of anti-EGFR antibodies is neglected to patients with activating mutations in KRAS and NRAS (RAS) genes, whose molecular analysis became a clinical routine. The advent of Next Generation Sequencing (NGS) instruments, able to reach quick testing of multiple clinically-relevant hotspots, yet maintaining precision and low costs, allows the simultaneous determination of the mutation status of an expanding number of genes. Despite only few of these molecular biomarkers have gained clinical utility in the routine oncological practice, the acquisition of more complex cancer mutational patterns may provide more efficient tumour characterisation for prognostic and predictive purposes and highlight actionable targets. Material and methods We sequenced 639 mCRC samples by IT-PGM platform using a panel of hotspots and targeted regions of 22 genes (including RAS) commonly involved in CRCs. MSI analyses on 89 patients have been performed with a single fluorescent system comprising BAT25 and BAT26 mononucleotide repeats. Results and discussions We identified recurrent mutations (≥1%) in 12/22 genes, being KRAS, TP53 and PIK3CA the most frequently mutated ones. Statistical analysis, indicated that the mutation associations follow a non-random distribution. Categorization of the cases on the base of KRAS and p53 mutation status led us the definition of 8 Mutation Association Patterns (MAPs) characterised by specific mutation associations. Analysis of the clinicopathological data available for 89 out of 639 cases indicates interesting trends for the associations of MAPs with specific parameters, some of which reached statistical significance. Conclusion Application of NGS gene panel as a routine for the characterisation of RAS/BRAF status required for predictive purposes in CRC patients, may provide additional prognostic/predictive information, with no significant extra-costs.