Background: Universal screening of colorectal cancer (CRC) patients for Lynch syndrome (LS) through MisMatch Repair (MMR) testing is recommended. BRAF V600E mutation and/or MLH1 promoter methylation (Reflex Testing, RefT)generally rule out LS in MLH1-deficient (dMLH1) patients. We estimated the impact of RefTon genetic counseling (GC) and on the diagnostic yield of genetic testing (GT).
View Article and Find Full Text PDFEndometrial cancer (EC) is the most frequent gynecological cancer. The ESGO/ESTRO/ESP 2020 guidelines identify prognostic groups based on morpho-molecular characteristics. This study aims to evaluate the clinical applicability of NGS analysis to define an appropriate risk class and to improve the diagnostic and prognostic stratification of ECs.
View Article and Find Full Text PDFBackground: Germline pathogenic variants (PVs) in BRCA1/2 genes are associated with breast cancer (BC) risk in both women and men. Multigene panel testing is being increasingly used for BC risk assessment, allowing the identification of PVs in genes other than BRCA1/2. While data on actionable PVs in other cancer susceptibility genes are now available in female BC, reliable data are still lacking in male BC (MBC).
View Article and Find Full Text PDFBackground: The distribution of ovarian tumour characteristics differs between germline BRCA1 and BRCA2 pathogenic variant carriers and non-carriers. In this study, we assessed the utility of ovarian tumour characteristics as predictors of BRCA1 and BRCA2 variant pathogenicity, for application using the American College of Medical Genetics and the Association for Molecular Pathology (ACMG/AMP) variant classification system.
Methods: Data for 10,373 ovarian cancer cases, including carriers and non-carriers of BRCA1 or BRCA2 pathogenic variants, were collected from unpublished international cohorts and consortia and published studies.
Epithelial ovarian cancers (EOCs) harboring germline or somatic pathogenic variants in BRCA1 and BRCA2 genes show sensitivity to poly(ADP-ribose) polymerase inhibition. It has been suggested that BRCA1 promoter methylation is perhaps a better determinant of therapy response, because of its intrinsic dynamic feature, with respect to genomic scars or gene mutation. Conflicting evidence was reported so far, and the lack of a validated assay to measure promoter methylation was considered a main confounding factor in data interpretation.
View Article and Find Full Text PDFAims: Next Generation Sequencing (NGS)-based tumour tissue testing poses several challenges. As a first step of its implementation within a regional health service network, an in-house validation study was compared with published recommendations.
Methods: Epithelial ovarian cancer (EOC) formalin-fixed paraffin-embedded specimens stored in the archives of the eight regional pathology units were selected from a consecutive series of patients with known germline status.
Background: Clustered protocadherins (PCDHs) map in tandem at human chromosome 5q31 and comprise three multi-genes clusters: α-, β- and γ-PCDH. The expression of this cluster consists of a complex mechanism involving DNA hub formation through DNA-CCTC binding factor (CTCF) interaction. Methylation alterations can affect this interaction, leading to transcriptional dysregulation.
View Article and Find Full Text PDFThe multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions.
View Article and Find Full Text PDFBackground: Telomere length in peripheral blood leukocytes (PBL-TL) was proposed as a biomarker of cancer risk. Recent scientific evidence suggested PBL-TL plays a diverse role in different cancers. Inconsistent results were obtained on PBL-TL in relation to breast cancer risk and specifically to the presence of BRCA1 and BRCA2 mutations.
View Article and Find Full Text PDFColorectal cancer (CRC) develops through the accumulation of both genetic and epigenetic alterations. However, while the former are already used as prognostic and predictive biomarkers, the latter are less well characterized. Here, performing global methylation analysis on both CRCs and adenomas by Illumina Infinium HumanMethylation450 Bead Chips, we identified a panel of 74 altered CpG islands, demonstrating that the earliest methylation alterations affect genes coding for proteins involved in the crosstalk between cell and surrounding environment.
View Article and Find Full Text PDFFamilial adenomatous polyposis is a Mendelian syndrome in which germline loss-of-function mutations of APC are associated with multiple adenomatous polyps of the large bowel, a multiplicity of extracolonic features, and a high lifetime risk of colorectal cancer. Different APC germline mutations have been identified, including sequence changes, genomic rearrangements, and expression defects. Recently, very rare families have been associated with constitutive large deletions encompassing the APC-5' regulatory region, while leaving the remaining gene sequence intact; the regulatory region contains a proximal and a distal promoter, called 1A and 1B, respectively.
View Article and Find Full Text PDFTo determine prevalence, spectrum and genotype-phenotype correlations of MUTYH variants in Italian patients with suspected MAP (MUTYH-associated polyposis), a retrospective analysis was conducted to identify patients who had undergone MUTYH genetic testing from September 2002 to February 2014. Results of genetic testing and patient clinical characteristics were collected (gender, number of polyps, age at polyp diagnosis, presence of colorectal cancer (CRC) and/or other cancers, family data). The presence of large rearrangements of the MUTYH gene was evaluated by Multiplex Ligation-dependent Probe Amplification analysis.
View Article and Find Full Text PDFNumerous genetic factors that influence breast cancer risk are known. However, approximately two-thirds of the overall familial risk remain unexplained. To determine whether some of the missing heritability is due to rare variants conferring high to moderate risk, we tested for an association between the c.
View Article and Find Full Text PDFBackground/aims: Nearly 15% of all ovarian cancer patients carry a germline BRCA mutation. A pilot project was started at IRCCS AOU San Martino--IST, Genoa, to assess the feasibility and consequences of offering genetic counselling to all ovarian cancer patients during routine oncology appointments. We present early results of this project.
View Article and Find Full Text PDFImportance: Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists.
Objective: To identify mutation-specific cancer risks for carriers of BRCA1/2.
Design, Setting, And Participants: Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations.
The micronucleus test is a well-established DNA damage assay in human monitoring. The test was proposed as a promising marker of cancer risk/susceptibility mainly on the basis of studies on breast cancer. Our recent meta-analysis showed that the association between micronuclei frequency, either at baseline or after irradiation, and breast cancer risk or susceptibility, has been evaluated in few studies of small size, with inconsistent results.
View Article and Find Full Text PDFFamilial adenomatous polyposis (FAP) is a dominantly inherited syndrome leading to the development of multiple intestinal polyps and colorectal cancer. FAP is associated with germline defects of APC tumor suppressor gene; although truncating mutations account for the majority of cases, large APC deletions represent a common disease-causing defect. While a number of intragenic deletions have been well-characterized, sequencing data of breakpoints involved in large APC rearrangements are extremely scanty.
View Article and Find Full Text PDFThe MUTYH DNA glycosylase counteracts mutagenesis by removing adenine misincorporated opposite DNA 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). Biallelic germline mutations in MUTYH cause the autosomal recessive MUTYH-associated polyposis (MAP). The impact on genetic instability of the p.
View Article and Find Full Text PDFThe identification of women with a high probability of being carriers of pathogenic BRCA mutation is not straightforward and a major improvement would be the availability of markers of mutations that could be directly evaluated in individuals asking for genetic testing. The FMR1 gene testing was recently proposed as a candidate prescreening tool because an association between BRCA pathogenic mutations and FMR1 genotypes with 'low alleles' (CGG repeat number <26) was observed. To confirm this hypothesis, we evaluated the distribution of FMR1 alleles and genotypes between BRCA mutation carriers and non-carriers in a cohort of 147 Italian women, free of cancer or affected by breast and/or ovarian cancer, who were tested for the presence of BRCA mutation in a clinical setting.
View Article and Find Full Text PDFBackground: Germline mutations in the BRCA1 and BRCA2 genes are associated with increased risks of breast and ovarian cancers. Although several common variants have been associated with breast cancer susceptibility in mutation carriers, none have been associated with ovarian cancer susceptibility. A genome-wide association study recently identified an association between the rare allele of the single-nucleotide polymorphism (SNP) rs3814113 (ie, the C allele) at 9p22.
View Article and Find Full Text PDFMUTYH-associated polyposis (MAP) is an autosomal recessive condition predisposing to colorectal cancer, caused by constitutional biallelic mutations in the base excision repair (BER) gene MUTYH. Colorectal tumours from MAP patients display an excess of somatic G>T mutations in the APC and KRAS genes due to defective BER function. To date, few extracolonic manifestations have been observed in MAP patients, and the clinical spectrum of this condition is not yet fully established.
View Article and Find Full Text PDFBackground: Few reports have investigated the association of two p53 polymorphisms (Arg72Pro and PIN3-A2) with colorectal cancer (CRC) risk, and no previous study has analyzed their role as susceptibility alleles for colorectal adenoma.
Aim: To explore the impact of the p53 PIN3-Arg72Pro haplotype on colorectal adenoma formation and progression to cancer.
Methods: One hundred and eighty-four colorectal tumor patients (124 with adenomas and 60 with adenocarcinoma) and 188 controls (42 subjects with a clean colon, 54 hospital controls and 92 blood donors) from the Italian population were tested for PIN3-Arg72Pro haplotype status.
Background: We describe a simple tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) for detecting MUTYH mutations, which are associated with colorectal adenomas and colorectal cancer.
Methods: We designed specific T-ARMS-PCR assays for 6 mutations (Y165C, G382D, 1395_7delGGA, Y90X, 1103delC, and R231H) selected on the basis of the frequency of their occurrence. We also designed a set of 3 multiplex T-ARMS PCR assays, each for detection of 2 mutations.
Cancer Epidemiol Biomarkers Prev
August 2005
Familial adenomatous polyposis (FAP) is an autosomal condition caused by inherited mutations in the adenomatous polyposis coli (APC) or in the MYH genes. Clinical trials have established that nonsteroidal anti-inflammatory drugs (NSAID) are effective in preventing the development as well as reducing the size and decreasing the number of adenomas in FAP patients. Our aim was to evaluate the cyclooxygenase-2 (COX-2) expression in surgical specimens from patients with no evidence of germ line APC mutations but carrying germ line MYH mutations.
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