BRCA-associated hereditary male cancers: can gender affect the prevalence and spectrum of germline pathogenic variants?

Introduction: Although hereditary male neoplasms are quite rare, individuals harbouring germline BRCA1/2 pathogenic variants (PVs) may have a risk of developing tumours associated with Hereditary Breast and Ovarian Cancer (HBOC) syndrome, including male breast (MBC), prostate (PCa) and pancreatic (PC) cancers, and melanoma. Women and men showed a comparable genetic architecture of cancer susceptibility, but there are some gender-specific features. Since little is known about cancer genetic susceptibility in male population, our study was aimed at investigating the frequency of BRCA1/2 PVs in men with HBOC syndrome-associated tumors, in order to understand whether differences in gender may reflect in the prevalence and spectrum of germline alterations. Patients and methods: We retrospectively collected and analysed clinical information of 352 HBOC-associated male cancer patients genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis, enrolled, from February 2018 to January 2024, at the "Regional Center for the prevention, diagnosis and treatment of rare and heredo-familial tumors of adults" of the University-Hospital Policlinico "P. Giaccone" of Palermo (Italy). Results: Our investigation revealed that 7.4% of patients was carrier of a germline BRCA PV, with an almost total prevalence of BRCA2 alterations. In particular, 65.4% of BRCA-positive patients developed MBC, 19.2% had PC, 11.6% developed PCa, and only 3.8% had melanoma. Specifically, MBC individuals showed a BRCA-associated genetic predisposition in 17% of cases, whereas patients with PCa or PC exhibited a lower frequency of BRCA2 PVs, taking into account the current national criteria for access to germline genetic testing. Discussion: Our study showed a high heterogeneity in prevalence of germline BRCA2 PVs among men which could reflect a potential gender-specific genetic heterogeneity. Therefore, BRCA-associated male tumours could be due to BRCA2 PVs different from those usually detected in women. In the event that it is demonstrated, in future, that male cancers are genetically distinct entities from those female this could improve personalized risk evaluation and guide therapeutic choices for patients of both sexes, in order to obtain a gender equality in cancer care.

Clinical relevance of exosome-derived microRNAs in Ovarian Cancer: Looking for new tumor biological fingerprints.

Specific tumor-derived extracellular vesicles, called exosomes, are considered as potential key players in cross-talk between immune system and tumor microenvironment in several solid tumors. Different studies highlighted the clinical relevance of exosomes in ovarian cancer (OC) for their role in early diagnosis, prognosis, chemoresistance, targeted therapy. The exosomes are nanosize vesicles carrying lipids, proteins, and nucleic acids. In particular, exosomes shuttle a wide spectrum of microRNAs (miRNAs) able to induce phenotypic reprogramming of target cells, contributing to tumor progression. In this review, we will discuss the promising role of miRNAs shuttled by exosomes, called exosomal miRNAs (exo-miRNAs), as potential biomarkers for early detection, tumour progression and metastasis, prognosis, and response to therapy in OC women, in order to search for new potential biological fingerprints able to better characterize the evolution of this malignancy and provide a clinically relevant non-invasive approach useful for adopting, in future, personalized therapeutic strategies.

Theranostic biomarkers and PARP-inhibitors effectiveness in patients with non-BRCA associated homologous recombination deficient tumors: Still looking through a dirty glass window?

Breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2) deleterious variants were the first and, still today, the main biomarkers of poly(ADP)ribose polymerase (PARP)-inhibitors (PARPis) benefit. The recent, increased, numbers of individuals referred for counseling and multigene panel testing, and the remarkable expansion of approved PARPis, not restricted to BRCA1/BRCA2-Pathogenic Variants (PVs), produced a strong clinical need for non-BRCA biomarkers. Significant limitations of the current testing and assays exist. The different approaches that identify the causes of Homologous Recombination Deficiency (HRD), such as the germline and somatic Homologous Recombination Repair (HRR) gene PVs, the testing showing its consequences, such as the genomic scars, or the novel functional assays such as the RAD51 foci testing, are not interchangeable, and should not be considered as substitutes for each other in clinical practice for guiding use of PARPi in non-BRCA, HRD-associated tumors. Today, the deeper knowledge on the significant relationship among all proteins involved in the HRR, not limited to BRCA, expands the possibility of a successful non-BRCA, HRD-PARPi synthetic lethality and, at the same time, reinforces the need for enhanced definition of HRD biomarkers predicting the magnitude of PARPi benefit.

BRCA1/2 variants of unknown significance in hereditary breast and ovarian cancer (HBOC) syndrome: Looking for the hidden meaning.

Hereditary breast and ovarian cancer syndrome is caused by germline mutations in BRCA1/2 genes. These genes are very large and their mutations are heterogeneous and scattered throughout the coding sequence. In addition to the above-mentioned mutations, variants of uncertain/unknown significance (VUSs) have been identified in BRCA genes, which make more difficult the clinical management of the patient and risk assessment. In the last decades, several laboratories have developed different databases that contain more than 2000 variants for the two genes and integrated strategies which include multifactorial prediction models based on direct and indirect genetic evidence, to classify the VUSs and attribute them a clinical significance associated with a deleterious, high/low or neutral risk. This review provides a comprehensive overview of literature studies concerning the VUSs, in order to assess their impact on the population and provide new insight useful for the appropriate patient management in clinical practice.

Not all KIT 557/558 codons mutations have the same prognostic influence on recurrence-free survival: breaking the exon 11 mutations in gastrointestinal stromal tumors (GISTs).

Background: Although the gastrointestinal stromal tumor (GIST) genotype is not currently included in risk-stratification systems, a growing body of evidence shows that the pathogenic variant (PV) type and codon location hold a strong prognostic influence on recurrence-free survival (RFS). This information has particular relevance in the adjuvant setting, where an accurate prognostication could help to better identify high-risk tumors and guide clinical decision-making. Materials and Methods: Between January 2005 and December 2020, 96 patients with completely resected GISTs harboring a KIT proto-oncogene receptor tyrosine kinase (KIT) exon 11 PV were included in the study. We analyzed the type and codon location of the PV according to clinicopathological characteristics and clinical outcome; the metastatic sites in relapsed patients were also investigated. Results: Tumors harboring a KIT exon 11 deletion or deletion/insertion involving the 557 and/or 558 codons, showed a more aggressive clinical behavior compared with tumors carrying deletion/deletion/insertion in other codons, or tumors with duplication/insertion/single-nucleotide variant (SNV) (7-year RFS: 50% versus 73.1% versus 88.2%, respectively; p < 0.001). Notably, among 18 relapsed patients with 557 and/or 558 deletion or deletion/insertion, 14 patients (77.8%) harbored deletions simultaneously involving 557 and 558 codons, while only 4 patients (22.2%) harbored deletions involving only 1 of the 557/558 codons. Thus, when 557 or 558 deletions occurred separately, the tumor showed a prognostic behavior similar to the GIST carrying deletions outside the 557/558 position. Remarkably, patients with GISTs stratified as intermediate risk, but carrying the 557/558 deletion, showed a similar outcome to the high-risk patients with tumors harboring deletions in codons other than 557/558, or duplication/insertion/SNV. Conclusion: Our data support the inclusion of the PV type and codon location in routine risk prediction models, and suggest that intermediate-risk patients whose GISTs harbor 557/558 deletions may also need to be treated with adjuvant imatinib like the high-risk patients.

Prevalence and Spectrum of Germline BRCA1 and BRCA2 Variants of Uncertain Significance in Breast/Ovarian Cancer: Mysterious Signals From the Genome.

About 10-20% of breast/ovarian (BC/OC) cancer patients undergoing germline BRCA1/2 genetic testing have been shown to harbor Variants of Uncertain Significance (VUSs). Since little is known about the prevalence of germline BRCA1/2 VUS in Southern Italy, our study aimed at describing the spectrum of these variants detected in BC/OC patients in order to improve the identification of potentially high-risk BRCA variants helpful in patient clinical management. Eight hundred and seventy-four BC or OC patients, enrolled from October 2016 to December 2020 at the "Sicilian Regional Center for the Prevention, Diagnosis and Treatment of Rare and Heredo-Familial Tumors" of University Hospital Policlinico "P. Giaccone" of Palermo, were genetically tested for germline BRCA1/2 variants through Next-Generation Sequencing analysis. The mutational screening showed that 639 (73.1%) out of 874 patients were BRCA-w.t., whereas 67 (7.7%) were carriers of germline BRCA1/2 VUSs, and 168 (19.2%) harbored germline BRCA1/2 pathogenic/likely pathogenic variants. Our analysis revealed the presence of 59 different VUSs detected in 67 patients, 46 of which were affected by BC and 21 by OC. Twenty-one (35.6%) out of 59 variants were located on BRCA1 gene, whereas 38 (64.4%) on BRCA2. We detected six alterations in BRCA1 and two in BRCA2 with unclear interpretation of clinical significance. Familial anamnesis of a patient harboring the BRCA1-c.3367G>T suggests for this variant a potential of pathogenicity, therefore it should be carefully investigated. Understanding clinical significance of germline BRCA1/2 VUS could improve, in future, the identification of potentially high-risk variants useful for clinical management of BC or OC patients and family members.

Hereditary Breast and Ovarian Cancer in Families from Southern Italy (Sicily)-Prevalence and Geographic Distribution of Pathogenic Variants in BRCA1/2 Genes.

Recent advances in the detection of germline pathogenic variants (PVs) in BRCA1/2 genes have allowed a deeper understanding of the BRCA-related cancer risk. Several studies showed a significant heterogeneity in the prevalence of PVs across different populations. Because little is known about this in the Sicilian population, our study was aimed at investigating the prevalence and geographic distribution of inherited BRCA1/2 PVs in families from this specific geographical area of Southern Italy. We retrospectively collected and analyzed all clinical information of 1346 hereditary breast and/or ovarian cancer patients genetically tested for germline BRCA1/2 PVs at University Hospital Policlinico "P. Giaccone" of Palermo from January 1999 to October 2019. Thirty PVs were more frequently observed in the Sicilian population but only some of these showed a specific territorial prevalence, unlike other Italian and European regions. This difference could be attributed to the genetic heterogeneity of the Sicilian people and its historical background. Therefore hereditary breast and ovarian cancers could be predominantly due to BRCA1/2 PVs different from those usually detected in other geographical areas of Italy and Europe. Our investigation led us to hypothesize that a higher prevalence of some germline BRCA PVs in Sicily could be a population-specific genetic feature of BRCA-positive carriers.

BRCA1/2 pathogenic variants in triple-negative versus luminal-like breast cancers: genotype-phenotype correlation in a cohort of 531 patients.

BACKGROUND: Several available data suggest the association between specific molecular subtypes and BRCA1/2 mutational status. Previous investigations showed the association between BRCA1/2 pathogenic variants (PVs) in specific genomic regions and phenotypic variations of cancer relative risk, while the role of PV type and location in determining the breast cancer (BC) phenotypic features remains still unclear. The aim of this research was to describe the germline BRCA1/2 PVs in triple-negative breast cancer (TNBC) versus luminal-like BC and their potential leverage on BC phenotype. PATIENTS & METHODS: We retrospectively collected and analyzed all clinical information of 531 patients with BC genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis at University Hospital Policlinico "P. Giaccone" of Palermo (Sicily) from January 2016 to February 2020. RESULTS: Our results corroborate the evidence that BRCA1-related tumors often have a profile which resembles the TNBC subtype, whereas BRCA2-associated tumors have a profile that resembles luminal-like BC, especially the Luminal B subtype. Interestingly, our findings suggest that the PVs identified in TNBC were not largely overlapping with those in luminal-like tumors. Differences in the frequency of two PVs potentially associated with different molecular tumor subtypes were observed. BRCA1-633delC was detected with relatively higher prevalence in patients with TNBC, whereas BRCA2-1466delT was found mainly in Luminal B tumors, but in no TNBC patient. CONCLUSION: Future studies examining the type and location of BRCA1/2 PVs within different molecular subtypes are required to verify our hypothesis and could provide an interesting insight into the complex topic of genotype-phenotype correlations. Additionally, a more in-depth understanding of the potential correlations between BRCA PVs and clinical and phenotypic features of hereditary BC syndrome patients could be the key to develop better strategies of prevention and surveillance in BRCA-positive carriers without disease.