We investigate the prevalence of germline mutations in cancer predisposition genes in patients with pancreatic ductal adenocarcinoma (PDAC) or suspected related hereditary syndromes.
we enrolled for ...NGS with an Illumina TrueSight Cancer panel comprising 19 CPGs and 113 consecutive subjects referred to cancer genetic clinics for metastatic PDAC, early onset PDAC, suspected hereditary syndrome, or positive family history.
Overall, 23 (20.1%) subjects were carriers of 24 pathogenetic variants (PVs). We found 9 variants in
(37.5%), 6 in
(25%), 3 in
(12.5%), 2 in
(8.3%), 1 in
(4.1%), 1 in
(4.1%), 1 in
(4.1%), and 1 in
(4.1%). A double PV (
plus
) was found in 1 subject. We observed a nearly 30% (16/55) mutational rate in the subgroup of subjects tested for the suspected syndromes (PDAC and other synchronous or metachronous tumors or an indicative family history), and the frequency was significantly higher than that in patients with only metastatic PDAC (
= 0.05). In our cohort, 39 variants of unknown significance (VUS) were identified, most of which (16/39, 41%) in genes belonging to the Lynch syndrome spectrum.
A clinically relevant proportion of pancreatic cancer is associated with mutations in known predisposition genes. Guidelines instructing on an adequate selection for accessing genetic testing are eagerly needed. The heterogeneity of mutations identified in this study reinforces the value of using a multiple-gene panel in pancreatic cancer.
Several unclassified variants (UVs) have been identified in splicing regions of disease-associated genes and their characterization as pathogenic mutations or benign polymorphisms is crucial for the ...understanding of their role in disease development. In this study, 24 UVs located at BRCA1 and BRCA2 splice sites were characterized by transcripts analysis. These results were used to evaluate the ability of nine bioinformatics programs in predicting genetic variants causing aberrant splicing (spliceogenic variants) and the nature of aberrant transcripts. Eleven variants in BRCA1 and 8 in BRCA2, including 8 not previously characterized at transcript level, were ascertained to affect mRNA splicing. Of these, 16 led to the synthesis of aberrant transcripts containing premature termination codons (PTCs), 2 to the up-regulation of naturally occurring alternative transcripts containing PTCs, and one to an in-frame deletion within the region coding for the DNA binding domain of BRCA2, causing the loss of the ability to bind the partner protein DSS1 and ssDNA. For each computational program, we evaluated the rate of non-informative analyses, i.e. those that did not recognize the natural splice sites in the wild-type sequence, and the rate of false positive predictions, i.e., variants incorrectly classified as spliceogenic, as a measure of their specificity, under conditions setting sensitivity of predictions to 100%. The programs that performed better were Human Splicing Finder and Automated Splice Site Analyses, both exhibiting 100% informativeness and specificity. For 10 mutations the activation of cryptic splice sites was observed, but we were unable to derive simple criteria to select, among the different cryptic sites predicted by the bioinformatics analyses, those actually used. Consistent with previous reports, our study provides evidences that in silico tools can be used for selecting splice site variants for in vitro analyses. However, the latter remain mandatory for the characterization of the nature of aberrant transcripts.
Background
Approximately 10% of patients with breast cancer who are treated with breast-conserving surgery (BCS) develop an ipsilateral-breast tumor recurrence (IBTR). The optimal local therapy for ...women with BRCA-associated breast carcinoma remains controversial. We report the outcome of BCS in BRCA mutation carriers followed at a single institution.
Methods
A total of 54 women with BRCA1/2-associated breast cancer treated with BCS and whole breast radiotherapy were matched for age, tumor size, and time of surgery with 162 patients with sporadic breast cancer who had the same treatment between February 1994 and October 2007. Primary end points were cumulative incidence of IBTR and contralateral breast cancer (CBC). Median follow-up was 4 years for both groups.
Results
Median age was 36 and 37 years for mutation carriers and controls, respectively; mean tumor size was 1.8 cm in carriers and 1.9 cm in controls. Ten-year cumulative incidence of IBTR was 27% for mutation carriers and 4% for sporadic controls (hazard ratio 3.9; 95% confidence interval 1.1–13.8;
P
= 0.03). Ten-year cumulative incidence of CBC was 25% for mutation carriers and 1% for sporadic controls (
P
= 0.03).
Conclusions
Our data suggest that IBTR risk after BCS in BRCA1/2 mutation carriers is increased compared with patients who have sporadic breast cancer. Likewise, the risk of CBC seems to be increased in this group. These risks and the likelihood of developing new primary tumors should be discussed with carriers interested in breast conservation as well as when choosing risk-reducing strategies.
Abstract
Abstract
Objective
The aim of this study is to evaluate male awareness of developing prostate cancer (PCa) in families with germline DNA‐repair genes (DRG) variants.
Materials and methods
...Data were collected from a prospective, monocentric cohort study. The study was conducted in a university hospital with a multidisciplinary approach to the patient (collaboration of the Departments of Oncology, Urology, Pathology, Radiology, and Medical Genetics Laboratory). We recruited healthy males, relatives of families of women with breast or ovarian cancer who tested positive for pathogenic variants (PVs) or likely pathogenic variants (LPVs) in DRGs. A dedicated PCa screening was designed and offered to men aged 35 to 69 years, based on early visits with digital rectal examination (DRE), prostate health index (PHI) measurement, multiparametric magnetic resonance imaging (mpMRI) and, if necessary, targeted/systematic prostate biopsies. The primary endpoint was to evaluate the willingness of healthy men from families with a DRG variants detected in female relatives affected with breast and/or ovarian cancer to be tested for the presence of familial PVs. The secondary endpoints were the acceptance to participate if resulted positive and compliance with the screening programme.
Results
Over 1256 families, of which 139 resulted positive for PVs in DRGs, we identified 378 ‘healthy’ men aged between 35 and 69 years old. Two hundred sixty‐one (69.0%) refused to be tested for DRG variants, 66 (17.5%) declared to have been previously tested, and 51 (13.5%) males were interested to be tested. Between those previously tested and those who accepted to be tested, 62 (53.0%) were positive for a DRG variant, and all of them accepted to participate in the subsequent surveillance steps. The main limitation is that is a single‐centre study and a short follow‐up.
Conclusions
All men tested positive for a DRG variants agreed to go under the surveillance scheme. However, only 31% of ‘men at risk’ (i.e., relative of a DRG variant carrier) expressed their willingness to be tested for the familial DRG variant. This observation strongly supports the urgent need to implement awareness of genetic risk for PCa within the male population.
The identification of founder mutations in cancer predisposing genes is important to improve risk assessment in geographically defined populations, since it may provide specific targets resulting in ...cost-effective genetic testing. Here, we report the characterization of the BRCA1 c.190T>C (p.Cys64Arg) mutation, mapped to the RING-finger domain coding region, that we detected in 43 hereditary breast/ovarian cancer (HBOC) families, for the large part originating from the province of Bergamo (Northern Italy). Haplotype analysis was performed in 21 families, and led to the identification of a shared haplotype extending over three BRCA1-associated marker loci (0.4 cM). Using the DMLE+2.2 software program and regional population demographic data, we were able to estimate the age of the mutation to vary between 3,100 and 3,350 years old. Functional characterization of the mutation was carried out at both transcript and protein level. Reverse transcriptase-PCR analysis on lymphoblastoid cells revealed expression of full length mRNA from the mutant allele. A green fluorescent protein (GFP)-fragment reassembly assay showed that the p.Cys64Arg substitution prevents the binding of the BRCA1 protein to the interacting protein BARD1, in a similar way as proven deleterious mutations in the RING-domain. Overall, 55 of 83 (66%) female mutation carriers had a diagnosis of breast and/or ovarian cancer. Our observations indicate that the BRCA1 c.190T>C is a pathogenic founder mutation present in the Italian population. Further analyses will evaluate whether screening for this mutation can be suggested as an effective strategy for the rapid identification of at-risk individuals in the Bergamo area.
Monoallelic germ-line deleterious mutations of PALB2 (partner and localizer of BRCA2) are associated with breast cancer risk and have been found in several populations, with carrier frequencies of ...~1-2%. Initially, these mutations were considered to have moderate penetrance, but accumulating evidence now indicates that they are associated with much higher risk.
In this study, we sequenced the PALB2 coding regions unlinked to BRCA (breast cancer) genes in 575 probands from Italian breast cancer families recruited in Milan.
We found 12 carriers (2.1%) of deleterious mutations, and none of the mutations was found in 784 controls collected in Milan. One of these mutations, the c.1027C>T (p.Gln343X), was found to be recurrent in the province of Bergamo in northern Italy, being detected in 6/113 (5.3%) familial breast cancer cases and 2/477 (0.4%) controls recruited in this area (Fisher's exact test: P < 0.01).
Our data provide confirmatory findings that, in the Italian population also, deleterious mutations of PALB2 are relatively frequent predisposing factors for breast cancer and may be associated with high risk of the disease.
Breast cancer can be caused by germline mutations in several genes that are responsible for different hereditary cancer syndromes. Some of the genes causing the Fanconi anemia (FA) syndrome, such as ...BRCA2, BRIP1, PALB2, and RAD51C, are associated with high or moderate risk of developing breast cancer. Very recently, SLX4 has been established as a new FA gene raising the question of its implication in breast cancer risk. This study aimed at answering this question sequencing the entire coding region of SLX4 in 526 familial breast cancer cases from Italy. We found 81 different germline variants and none of these were clearly pathogenic. The statistical power of our sample size allows concluding that in Italy the frequency of carriers of truncating mutations of SLX4 may not exceed 0.6%. Our results indicate that testing for SLX4 germline mutations is unlikely to be relevant for the identification of individuals at risk of breast cancer, at least in the Italian population.
A growing number of sequence changes of unknown clinical significance are being identified in the BRCA1 gene. However, these variants cannot be used for identification and surveillance of at-risk ...individuals unless their pathogenic role can be demonstrated. The frequency of these variants makes research on this subject a relevant topic in the field of predisposition to breast and ovarian cancers. Herein, we investigate the pathogenicity of the BRCA1 p.Val1688del (c.5181_5183delGTT) variant, which recurs in our population.
Recent studies have drawn attention to different strategies that, if considered singly, do not usually provide sufficient power to firmly state for or against causality, thus forcing to a re-evaluation of the literature on each specific variant. To increase the power of our study, we used a recently described strategy that integrates data from multiple independent evidences. By this approach, we analyzed data from the comprehensive study of 12 breast/ovarian cancer families carrying p.Val1688del.
We succeeded in integrating five independent evidences of disease causality including segregation, tumor pathology, and evolutionary and epidemiologic data. Under this model, we obtained a final score of 349,000:1 in favor of disease causality. This result largely matches established cutoffs, and thus is readily translatable into a clear clinical message.
We show that p.Val1688del is a pathogenic mutation deriving from a common founder. Notably, this study alone increases by 15% the number of BRCA1-positive families in our patients' cohort, thus substantially contributing to explain many of the families wherein prediction of a BRCA1 mutation contrasted with the absence of a molecular recognizable defect.
Pancreatic cancer (PC) surveillance of high-risk individuals (HRI) is becoming more common worldwide, aiming at anticipating PC diagnosis at a preclinical stage. In 2015, the Italian Registry of ...Families at Risk of Pancreatic Cancer was created. We aimed to assess the prevalence and incidence of pancreatic findings, oncological outcomes, and harms 7 years after the Italian Registry of Families at Risk of Pancreatic Cancer inception, focusing on individuals with at least a 3-year follow-up or developing events before.
HRI (subjects with a family history or mutation carriers with/without a family history were enrolled in 18 centers). They underwent annual magnetic resonance with cholangiopancreatography or endoscopic ultrasound (NCT04095195).
During the study period (June 2015-September 2022), 679 individuals were enrolled. Of these, 524 (77.2%) underwent at least baseline imaging, and 156 (29.8%) with at least a 3-year follow-up or pancreatic malignancy/premalignancy-related events, and represented the study population. The median age was 51 (interquartile range 16) years. Familial PC cases accounted for 81.4% of HRI and individuals with pathogenic variant for 18.6%. Malignant (n = 8) and premalignant (1 PanIN3) lesions were found in 9 individuals. Five of these 8 cases occurred in pathogenic variant carriers, 4 in familial PC cases (2 tested negative at germline testing and 2 others were not tested). Three of the 8 PC were stage I. Five of the 8 PC were resectable, 3 Stage I, all advanced cases being prevalent. The 1-, 2-, and 3-year cumulative hazard of PC was 1.7%, 2.5%, and 3%, respectively. Median overall and disease-free survival of patients with resected PC were 18 and 12 months (95% CI not computable). Considering HRI who underwent baseline imaging, 6 pancreatic neuroendocrine neoplasms (1 resected) and 1 low-yield surgery (low-grade mixed-intraductal papillary mucinous neoplasm) were also reported.
PC surveillance in a fully public health care system is feasible and safe, and leads to early PC or premalignant lesions diagnoses, mostly at baseline but also over time.
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