Beyond BRCA1 and BRCA2: Deleterious Variants in DNA Repair Pathway Genes in Italian Families with Breast/Ovarian and Pancreatic Cancers.

The 5-10% of breast/ovarian cancers (BC and OC) are inherited, and germline pathogenic (P) variants in DNA damage repair (DDR) genes BRCA1 and BRCA2 explain only 10-20% of these cases. Currently, new DDR genes have been related to BC/OC and to pancreatic (PC) cancers, but the prevalence of P variants remains to be explored. The purpose of this study was to investigate the spectrum and the prevalence of pathogenic variants in DDR pathway genes other than BRCA1/2 and to correlate the genotype with the clinical phenotype. A cohort of 113 non-BRCA patients was analyzed by next-generation sequencing using a multigene panel of the 25 DDR pathways genes related to BC, OC, and PC. We found 43 unique variants in 18 of 25 analyzed genes, 14 classified as P/likely pathogenic (LP) and 28 as variants of uncertain significance (VUS). Deleterious variants were identified in 14% of index cases, whereas a VUS was identified in 20% of the probands. We observed a high incidence of deleterious variants in the CHEK2 gene, and a new pathogenic variant was detected in the RECQL gene. These results supported the clinical utility of multigene panel to increase the detection of P/LP carriers and to identify new actionable pathogenic gene variants useful for preventive and therapeutic approaches.

Positive margins (R1) risk factors in breast cancer conservative surgery.

BACKGROUND: The primary goal in conservative breast cancer surgery is the complete excision of the tumor, but at the same time attempting to obtain a satisfactory postoperative esthetic result. The notion of "No Ink on Tumor" that indicates exclusively the presence of tumor cells on the inked surface of the surgical specimen is now the gold standard; however, the problem of the free margin is still a fundamental topic of debate that has not yet found a definitive solution. METHODS: Our retrospective analysis takes into account 1440 patients undergoing breast conservative surgery, from October 2004 to November 2018, all treated at the breast unit of our institution. RESULTS: Positive margins (R1) rate was 10.2% (147 cases out of 1440). Overall survival was 95% at 5 years and 89% at 10 years. No differences in mortality and local recurrence rate between R0 and R1 patients were found. Half of the R1 patients underwent secondary surgery with enlargement of margins, while in the other half we performed direct mastectomy. Among the analyzed variables, age, histological size, histological type, grading, multifocality, lympho-vascular invasion and lymph node status were significantly correlated with the R1 status. The multivariate analysis shows  the association of age and surgical technique (oncoplastic) with R1 status. CONCLUSION: Further studies will allow the creation of a statistical model, for better pre-operative prediction of patients with higher risk of R1 and better selection of patients to be candidates for conservative surgery.

Rapid detection of copy number variations and point mutations in BRCA1/2 genes using a single workflow by ion semiconductor sequencing pipeline.

Molecular analysis of BRCA1 (MIM# 604370) and BRCA2 (MIM #600185) genes is essential for familial breast and ovarian cancer prevention and treatment. An efficient, rapid, cost-effective accurate strategy for the detection of pathogenic variants is crucial. Mutations detection of BRCA1/2 genes includes screening for single nucleotide variants (SNVs), small insertions or deletions (indels), and Copy Number Variations (CNVs). Sanger sequencing is unable to identify CNVs and therefore Multiplex Ligation Probe amplification (MLPA) or Multiplex Amplicon Quantification (MAQ) is used to complete the BRCA1/2 genes analysis. The rapid evolution of Next Generation Sequencing (NGS) technologies allows the search for point mutations and CNVs with a single platform and workflow. In this study we test the possibilities of NGS technology to simultaneously detect point mutations and CNVs in BRCA1/2 genes, using the OncomineTM BRCA Research Assay on Personal Genome Machine (PGM) Platform with Ion Reporter Software for sequencing data analysis (Thermo Fisher Scientific). Comparison between the NGS-CNVs, MLPA and MAQ results shows how the NGS approach is the most complete and fast method for the simultaneous detection of all BRCA mutations, avoiding the usual time consuming multistep approach in the routine diagnostic testing of hereditary breast and ovarian cancers.

Role of frozen section in sentinel lymph node biopsy for breast cancer in the era of the ACOSOG Z0011 and IBCSG 23-10 trials.

BACKGROUND: Intraoperative frozen sections (FS) of sentinel lymph nodes (SLN) were evaluated to avoid the need for deferred axillary lymph node dissection (ALND) in patients with early breast cancer (EBC). However, FS has low sensitivity for detecting micro-metastases (<2 mm), resulting in patients who later undergo deferred ALND. The aim of the study was to determine the best clinical approach for selecting patients who would derive real benefit from ALND, as well as to minimize the functional and psychological damage caused by delayed surgery, and the risk of undertreating EBC patients. METHODS: This study evaluated 1453 patients with early breast cancer (EBC) who underwent SLN biopsy, FS and definitive evaluation. Causes of discrepancies between SLN biopsy and FS results and the need for further surgery were evaluated. RESULTS: A total of 1226 (86%) patients underwent FS; of these patients, 146 (11.9%) were false negatives. The global sensitivity of FS in detecting both macro and micrometastases was 53.7%. Although ACOSOG Z0011 criteria found that ALND could be avoided in 236 patients, 40 (17%) of these had >3 positive axillary lymph nodes. In contrast, application of the IBCSG 23-10 trial criteria, found that only three patients (3.1%) had >3 positive axillary lymph nodes. CONCLUSIONS: FS has a low sensitivity in detecting micrometastases (19%), but a reasonable sensitivity for macrometastases (75%). Most false negatives were smaller metastases (mean 2.1 mm) and more likely in patients with infiltrating lobular carcinoma. Retrospective modelling of the IBCSG 23-10 criteria reduced the percentage of patients requiring deferred surgery from 12% to 4%. Guidelines recommend irradiation of lymph node drainage stations in patients with ≥4 axillary metastatic lymph nodes. Omission of ALND from 40% of patients who met Z0011 criteria would have resulted in their undertreatment. This risk decreases to 3% by omitting axillary clearing only in patients with micrometastases.