Factors Influencing Adherence to the Risk Management Program for Women With a Genetic Predisposition to Breast Cancer: Real-World Data from a French Multicenter Program.

BACKGROUND: Risk management programs targeting women with genetic predispositions to breast cancer (BC), eg, BRCA1 and BRCA2, are effective assuming full adherence with the program protocol. However, high risk to BC in women and equal access to care may not result in high and uniform adherence with the program. OBJECTIVE: To elucidate factors influencing adherence with screening program in women with genetic predispositions to BC. MATERIAL AND METHODS: We retrieved data from a multicenter pathogenic-related BC surveillance program across 4 French regions. We used multilevel logistic modeling to analyze factors of adherence with the program, with "on-time" or postponed screening as the dependent variable. RESULTS: Seven hundred and seventy-eight participants were followed for a 4.7-year median. We observed 2796 annual screening rounds and 5.4% postponed rounds with a 6-month margin. Women with prevalent BC and carriers of BRCA1 and BRCA2 mutations did not have on-time annual screenings any more than women low cancer risk. Better adherence was observed with screenings after the 2nd round, with higher total number of rounds. Having one or more recalls was significantly associated with worse adherence. No contextual factors affected adherence. Furthermore, postponed rounds increased between 2018 and 2020 compared to 2015 and 2017. CONCLUSION: Having a higher BC risk status does not result in better adherence to the risk management program. However, factors directly related to screening rounds reduced postponements. Future research should address the benefits of screening-related organizational factors that contribute to adherence improvement.

Low risk of embryonic and other cancers in PIK3CA-related overgrowth spectrum: Impact on screening recommendations.

The PIK3CA-related overgrowth spectrum (PROS) encompasses various conditions caused by mosaic activating PIK3CA variants. PIK3CA somatic variants are also involved in various cancer types. Some generalized overgrowth syndromes are associated with an increased risk of Wilms tumor (WT). In PROS, abdominal ultrasound surveillance has been advocated to detect WT. We aimed to determine the risk of embryonic and other types of tumors in patients with PROS in order to evaluate surveillance relevance. We searched the clinical charts from 267 PROS patients for the diagnosis of cancer, and reviewed the medical literature for the risk of cancer. In our cohort, six patients developed a cancer (2.2%), and Kaplan Meier analyses estimated cumulative probabilities of cancer occurrence at 45 years of age was 5.6% (95% CI = 1.35%-21.8%). The presence of the PIK3CA variant was only confirmed in two out of four tumor samples. In the literature and our cohort, six cases of Wilms tumor/nephrogenic rests (0.12%) and four cases of other cancers have been reported out of 483 proven PIK3CA patients, in particular the p.(His1047Leu/Arg) variant. The risk of WT in PROS being lower than 5%, this is insufficient evidence to recommend routine abdominal imaging. Long-term follow-up studies are needed to evaluate the risk of other cancer types, as well as the relationship with the extent of tissue mosaicism and the presence or not of the variant in the tumor samples.

Modulation of DNA Methylation/Demethylation Reactions Induced by Nutraceuticals and Pollutants of Exposome Can Promote a C > T Mutation in the Breast Cancer Predisposing Gene PALB2

Background: Deregulation of DNA methylation/demethylation reactions may be the source of C > T mutation via active deamination of 5-methylcytosine to thymine. Exposome, that is to say, the totality of exposures to which an individual is subjected during their life, can deregulate these reactions. Thus, one may wonder whether the exposome can induce C > T mutations in the breast cancer-predisposing gene PALB2. Methods: Our work is based on the exposure of MCF10A mammary epithelial cells to seven compounds of our exposome (folate, Diuron, glyphosate, PFOA, iron, zinc, and ascorbic acid) alone or in cocktail. The qMSRE and RMS techniques were used to study the impact of these exposures on the level of methylation and mutation of the PALB2 gene. Results: Here, we have found that exposome compounds (nutriments, ions, pollutants) promoting the cytosine methylation and the 5-methylcytosine deamination have the ability to promote a specific C > T mutation in the PALB2 gene. Interestingly, we also noted that the addition of exposome compounds promoting the TET-mediated conversion of 5-methylcytosine (Ascorbic acid and iron) abrogates the presence of C > T mutation in the PALB2 gene. Conclusions: Our study provides a proof of concept supporting the idea that exposomes can generate genetic mutation by affecting DNA methylation/demethylation.

Mutation of the proline P81 into a serine modifies the tumour suppressor function of the von Hippel-Lindau gene in the ccRCC.

BACKGROUND: The von Hippel-Lindau disease is an autosomal dominant syndrome associated with tumour formation in various tissues, such as retina, central nervous system, kidney, and adrenal glands. VHL gene deletion or mutations support the development of various cancers. Unclassified VHL variants also referred as "of unknown significance" result from gene mutations that have an unknown or unclear effect on protein functions. The P81S mutation has been linked to low penetrance Type 1 disease but its pathogenic function was not clearly determined. METHODS: We established a stable cell line expressing the pVHL213 (c.241C>T, P81S) mutant. Using biochemical and physiological approaches, we herein analysed pVHL folding, stability and function in the context of this VHL single missense mutation. RESULTS: The P81S mutation mostly affects the non-canonical function of the pVHL protein. The cells expressing the pVHL213P81S acquire invasive properties in relation with modified architecture network. CONCLUSION: We demonstrated the pathogenic role of this mutation in tumour development in vhl patients and confirm a medical follow up of family carrying the c.241C>T, P81S.

Minors at risk of von Hippel-Lindau disease: 10 years' experience of predictive genetic testing and follow-up adherence.

Von Hippel-Lindau (VHL) disease is one of the most common cancer predisposition syndromes. Penetrance is high with around 20% of children presenting detectable and curable manifestations of the disease at 15 years old. VHL predictive genetic testing (PGT) is recommended during childhood from age 5 years in France. Insufficient compliance to surveillance of VHL pathogenic variant (PV) carriers is associated with severe outcome. PGT experienced by children and their parents is probably critical in influencing future acceptance of the result and adherence to surveillance. We conducted a retrospective study on minors tested (aged 5 to 16 years old) from 2010 to 2020, in a multidisciplinary oncogenetics consultation which follows a 3-step protocol based on psychological familial support. The objectives were to assess the adherence to follow-up within the National Expert Center for inherited predispositions to renal tumors (PREDIR) network of VHL PV carriers and its benefit through tumor detection and medical interventions. A VHL PGT was carried out in 34 children. Among the 16 children diagnosed as VHL PV carriers addressed to the PREDIR network, none had discontinued surveillance after a median of 41 months. Follow-up examinations detected 11 tumors in 6 children, 4 have been surgically treated. All had a favorable outcome. Our data suggest that a specific and adapted procedure for PGT in at-risk VHL children as well as a follow-up, organized within a specialized expert network, fosters a complete adherence to the surveillance protocol and thus lead to a favorable clinical outcome.

A de novo pathogenic variant in the MSH6 gene in a 52 years-old woman.

Lynch syndrome (LS) is a condition which predisposes individuals primarily to early-onset colorectal and endometrial cancer. LS is characterized by a germline pathogenic variant in one of the MMR (MisMatch Repair) gene, inducing a phenotype of microsatellite instability in the tumor, which may be associated with a loss of expression of MMR proteins detected by standard immunohistochemistry on tumor tissue. Most of the time, LS is inherited from a parent in whom the condition may not be known due to incomplete penetrance, but de novo pathogenic variant is a rare occurrence. Here, we describe the case of a 52-year-old woman with no family history of LS, referred to the genetics department for colorectal cancer at the age of 50. Genetic analysis revealed a de novo germline pathogenic variant in the MSH6 gene. To date, this case is only the second report of a de novo pathogenic variant in the MSH6 gene in Lynch syndrome. De novo mutations have been extensively studied over the past years, but little is known about their origin and mechanism of occurrence in MMR genes. However, knowledge of mutation status allows better cancer risk management for the patient and an appropriate genetic testing and counseling for her family.

Classification of 101 BRCA1 and BRCA2 variants of uncertain significance by cosegregation study: A powerful approach.

Up to 80% of BRCA1 and BRCA2 genetic variants remain of uncertain clinical significance (VUSs). Only variants classified as pathogenic or likely pathogenic can guide breast and ovarian cancer prevention measures and treatment by PARP inhibitors. We report the first results of the ongoing French national COVAR (cosegregation variant) study, the aim of which is to classify BRCA1/2 VUSs. The classification method was a multifactorial model combining different associations between VUSs and cancer, including cosegregation data. At this time, among the 653 variants selected, 101 (15%) distinct variants shared by 1,624 families were classified as pathogenic/likely pathogenic or benign/likely benign by the COVAR study. Sixty-six of the 101 (65%) variants classified by COVAR would have remained VUSs without cosegregation data. Of note, among the 34 variants classified as pathogenic by COVAR, 16 remained VUSs or likely pathogenic when following the ACMG/AMP variant classification guidelines. Although the initiation and organization of cosegregation analyses require a considerable effort, the growing number of available genetic tests results in an increasing number of families sharing a particular variant, and thereby increases the power of such analyses. Here we demonstrate that variant cosegregation analyses are a powerful tool for the classification of variants in the BRCA1/2 breast-ovarian cancer predisposition genes.

Osteosarcoma without prior retinoblastoma related to RB1 low-penetrance germline pathogenic variants: A novel type of RB1-related hereditary predisposition syndrome?

BACKGROUND: Retinoblastoma (Rb) is a rare intraocular malignant tumor in children with high overall survival. Predisposition to Rb is linked to RB1 germline mutations with high penetrance, but rare RB1 low-penetrance variants are also known. Rb survivors are at risk of second primary malignancies (SPMs), mostly osteosarcoma and soft-tissue sarcoma. Nevertheless, the risk of primary osteosarcoma developing without prior Rb has not been reported in RB1 germline mutation carriers. METHODS: We report a patient in whom osteosarcoma developed at age 17 as a first primary malignancy within a family context of sarcoma. RESULTS: Unexpectedly, genetic testing identified a low-penetrance germline mutation in RB1 [NM_000321.2: c.45_76dup; p.(Pro26Leufs*50)]. In eight additional similar cases from published and unpublished reports of families, first primary osteosarcomas and sarcomas mostly developed in RB1 low-penetrance mutation carriers without prior Rb. CONCLUSION: We propose that first primary sarcoma and osteosarcoma could be a novel clinical presentation of a RB1-related hereditary predisposition syndrome linked to RB1 low-penetrance germline mutations. In these families, careful screening of primary non-Rb cancer and SPMs is required by maintaining enhanced clinical vigilance. Implementing lifelong periodic whole-body MRI screening might be a complementary strategy for unaffected carrier relatives in these families.

Endoscopic Phenotype of Monoallelic Carriers of MUTYH Gene Mutations in the Family of Polyposis Patients: A Prospective Study.

BACKGROUND: Almost no prospective data on endoscopy in MUTYH monoallelic carriers are available. OBJECTIVE: This study aimed to define the prevalence of colorectal and duodenal adenomas in a population of people presenting with a single mutation of the MUTYH gene and being first-degree relatives of biallelic MUTYH mutation carriers. DESIGN: This study is a prospective cohort evaluation. PATIENTS: Patients were first-degree relatives of a patient who had polyposis with biallelic MUTYH mutation and carrying a single gene mutation of the gene from 12 French centers. SETTINGS: This is a multicenter study. INTERVENTION: Detailed data on life habits (tobacco, alcohol, and nonsteroidal anti-inflammatory drugs), extraintestinal manifestations, and germline analysis were recorded. Complete endoscopic evaluation (colonoscopy and upper endoscopy) with chromoendoscopy was performed. RESULTS: Sixty-two patients were prospectively included (34 women (55%), mean age of 54, range 30-70 years). Thirty-two patients (52%) presented with colorectal polyps at colonoscopy. Of these patients with polyps, 15 (25%) had only adenomas, 8 (13%) had only hyperplastic polyps, 1 (1%) had sessile serrated adenomas, and 8 (13%) had adenomas and/or sessile serrated adenomas. We detected, in total, 29 adenomas with low-grade dysplasia, 5 adenomas with high-grade dysplasia, and 6 sessile serrated adenomas. Fourteen patients (23%) presented with a single adenoma, and 10 (16%) had 1 to 5 adenomas. No patient had more than 5 adenomas. At upper endoscopy, 3 had a limited number of fundic gland polyps; none had duodenal adenomas. The 2 main missense mutations c.1145G>A, p.Gly382Asp and c.494A>G, p.Tyr165Cys were associated with the development of colorectal adenomas/serrated polyps in these monoallelic carriers. LIMITATIONS: This study was limited by the small number of patients. CONCLUSIONS: This prospective study provides unique prospective data suggesting that monoallelic mutation carriers related to patients with polyposis show no colorectal polyposis and have very limited upper GI manifestations justifying an endoscopic follow-up. See Video Abstract at http://links.lww.com/DCR/A862.

Landscape of pathogenic variations in a panel of 34 genes and cancer risk estimation from 5131 HBOC families.

PURPOSE: Integration of gene panels in the diagnosis of hereditary breast and ovarian cancer (HBOC) requires a careful evaluation of the risk associated with pathogenic or likely pathogenic variants (PVs) detected in each gene. Here we analyzed 34 genes in 5131 suspected HBOC index cases by next-generation sequencing. METHODS: Using the Exome Aggregation Consortium data sets plus 571 individuals from the French Exome Project, we simulated the probability that an individual from the Exome Aggregation Consortium carries a PV and compared it to the estimated frequency within the HBOC population. RESULTS: Odds ratio conferred by PVs within BRCA1, BRCA2, PALB2, RAD51C, RAD51D, ATM, BRIP1, CHEK2, and MSH6 were estimated at 13.22 [10.01-17.22], 8.61 [6.78-10.82], 8.22 [4.91-13.05], 4.54 [2.55-7.48], 5.23 [1.46-13.17], 3.20 [2.14-4.53], 2.49 [1.42-3.97], 1.67 [1.18-2.27], and 2.50 [1.12-4.67], respectively. PVs within RAD51C, RAD51D, and BRIP1 were associated with ovarian cancer family history (OR = 11.36 [5.78-19.59], 12.44 [2.94-33.30] and 3.82 [1.66-7.11]). PALB2 PVs were associated with bilateral breast cancer (OR = 16.17 [5.48-34.10]) and BARD1 PVs with triple-negative breast cancer (OR = 11.27 [3.37-25.01]). Burden tests performed in both patients and the French Exome Project population confirmed the association of PVs of BRCA1, BRCA2, PALB2, and RAD51C with HBOC. CONCLUSION: Our results validate the integration of PALB2, RAD51C, and RAD51D in the diagnosis of HBOC and suggest that the other genes are involved in an oligogenic determinism.

Contribution of germline deleterious variants in the RAD51 paralogs to breast and ovarian cancers.

RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) have recently been involved in breast and ovarian cancer predisposition: RAD51B, RAD51C, and RAD51D in ovarian cancer, RAD51B and XRCC2 in breast cancer. The aim of this study was to estimate the contribution of deleterious variants in the five RAD51 paralogs to breast and ovarian cancers. The five RAD51 paralog genes were analyzed by next-generation sequencing technologies in germline DNA from 2649 consecutive patients diagnosed with breast and/or ovarian cancer. Twenty-one different deleterious variants were identified in the RAD51 paralogs in 30 patients: RAD51B (n = 4), RAD51C (n = 12), RAD51D (n = 7), XRCC2 (n = 2), and XRCC3 (n = 5). The overall deleterious variant rate was 1.13% (95% confidence interval (CI): 0.72-1.55%) (30/2649), including 15 variants in breast cancer only cases (15/2063; 0.73% (95% CI: 0.34-1.11%)) and 15 variants in cases with at least one ovarian cancer (15/570; 2.63% (95% CI: 1.24-4.02%)). This study is the first evaluation of the five RAD51 paralogs in breast and ovarian cancer predisposition and it demonstrates that deleterious variants can be present in breast cancer only cases. Moreover, this is the first time that XRCC3 deleterious variants have been identified in breast and ovarian cancer cases.

BRCA1 allele-specific expression in genetic predisposed breast/ovarian cancer.

Germline allele specific expression (ASE), resulting in a lowered expression of one of the BRCA1 alleles, has been described as a possible predisposition marker in Hereditary Breast or Ovarian Cancer (HBOC), usable for molecular diagnosis in HBOC. The main objective of this prospective case-control study was to compare the proportion of ASE between controls without familial history of breast or ovarian cancer, and HBOC cases without BRCA1 or BRCA2 deleterious mutation. BRCA1 ASE evaluated on three SNPs among controls and HBOC patients without deleterious mutation were assessed by pyrosequencing. The allelic ratios and the proportion of ASE were compared between controls and cases using a Student's t test and a Fisher exact test, respectively. The linearity and reproducibility of the ASE dosage was demonstrated with R2 > 0.99 and a coefficient of variation below 10 %, and ASE was detected in two positive controls harbouring BRCA1 truncated mutations. In the heterozygote population, composed of 99/264 controls (37.5 %) and 96/227 patients (42.3 %), we detected a 5 % ASE without truncated mutations, in each population. We failed to detect any significant difference of ASE between controls and patients. So far, BRCA1 Allelic specific expression is not usable in routine diagnosis as a possible predisposition marker in HBOC patients except for the detection of truncated mutations.

Otopalatodigital spectrum disorders: refinement of the phenotypic and mutational spectrum.

Otopalatodigital spectrum disorders (OPDSD) constitute a group of dominant X-linked osteochondrodysplasias including four syndromes: otopalatodigital syndromes type 1 and type 2 (OPD1 and OPD2), frontometaphyseal dysplasia, and Melnick-Needles syndrome. These syndromes variably associate specific facial and extremities features, hearing loss, cleft palate, skeletal dysplasia and several malformations, and show important clinical overlap over the different entities. FLNA gain-of-function mutations were identified in these conditions. FLNA encodes filamin A, a scaffolding actin-binding protein. Here, we report phenotypic descriptions and molecular results of FLNA analysis in a large series of 27 probands hypothesized to be affected by OPDSD. We identified 11 different missense mutations in 15 unrelated probands (n=15/27, 56%), of which seven were novel, including one of unknown significance. Segregation analyses within families made possible investigating 20 additional relatives carrying a mutation. This series allows refining the phenotypic and mutational spectrum of FLNA mutations causing OPDSD, and providing suggestions to avoid the overdiagnosis of OPD1.

Clinical relevance of 8q23, 15q13 and 18q21 SNP genotyping to evaluate colorectal cancer risk.

To determine if the at-risk single-nucleotide polymorphism (SNP) alleles for colorectal cancer (CRC) could contribute to clinical situations suggestive of an increased genetic risk for CRC, we performed a prospective national case-control study based on highly selected patients (CRC in two first-degree relatives, one before 61 years of age; or CRC diagnosed before 51 years of age; or multiple primary CRCs, the first before 61 years of age; exclusion of Lynch syndrome and polyposes) and controls without personal or familial history of CRC. SNPs were genotyped using SNaPshot, and statistical analyses were performed using Pearson's χ(2) test, Cochran-Armitage test of trend and logistic regression. We included 1029 patients and 350 controls. We confirmed the association of CRC risk with four SNPs, with odds ratio (OR) higher than previously reported: rs16892766 on 8q23.3 (OR: 1.88, 95% confidence interval (CI): 1.30-2.72; P=0.0007); rs4779584 on 15q13.3 (OR: 1.42, CI: 1.11-1.83; P=0.0061) and rs4939827 and rs58920878/Novel 1 on 18q21.1 (OR: 1.49, CI: 1.13-1.98; P=0.007 and OR: 1.49, CI: 1.14-1.95; P=0.0035). We found a significant (P<0.0001) cumulative effect of the at-risk alleles or genotypes with OR at 1.62 (CI: 1.10-2.37), 2.09 (CI: 1.43-3.07), 2.87 (CI: 1.76-4.70) and 3.88 (CI: 1.72-8.76) for 1, 2, 3 and at least 4 at-risk alleles, respectively, and OR at 1.71 (CI: 1.18-2.46), 2.29 (CI: 1.55-3.38) and 6.21 (CI: 2.67-14.42) for 1, 2 and 3 at-risk genotypes, respectively. Combination of SNPs may therefore explain a fraction of clinical situations suggestive of an increased risk for CRC.

Renal cell tumour characteristics in patients with the Birt-Hogg-Dubé cancer susceptibility syndrome: a retrospective, multicentre study.

BACKGROUND: The Birt-Hogg-Dubé syndrome is a rare cancer susceptibility syndrome characterised by renal tumours, lung cysts and pneumothoraces, and fibrofolliculomas. It is caused by dominantly inherited mutations in FLCN. Our objective was to report renal tumour characteristics in a large series of patients with the Birt-Hogg-Dubé syndrome. METHODS: We studied French Birt-Hogg-Dubé patients with a history of renal tumour. RESULTS: We included 33 patients with 21 distinct germline FLCN mutations. Median age at diagnosis of first renal tumour was 46, and age varied from 20 to 83. Twenty cases had one renal tumour, the remainder had two or more tumours. Most cases (23/33, 70%) had oncocytoma or renal cell carcinoma of the chromophobe or hybrid chromophobe-oncocytoma type, three had clear cell carcinoma (9%), and the other seven had carcinoma of papillary, undifferentiated or undetermined histology. Four cases had metastatic disease, although none died of it. CONCLUSIONS: Age at renal tumour diagnosis was highly variable, highlighting the need for regular surveillance from young adulthood to old age. Most cases had tumour types classically associated with Birt-Hogg-Dubé, i.e. oncocytoma or renal cell carcinoma of the chromophobe or hybrid type. Nevertheless, 9% had clear cell renal cell carcinoma. Geneticists, urologists and oncologists should therefore be alert to the possibility of Birt-Hogg-Dubé in patients with renal cell carcinoma of clear cell histology, especially if there are associated manifestations. Finally, the behaviour of metastatic carcinoma seemed more indolent than in sporadic renal cancers.

Involvement of germline DDX1-MYCN duplication in inherited nephroblastoma.

This report concerns a 3-year-old girl with prenatal bilateral nephroblastomatosis and a family history of nephroblastoma. This girl had a chromosome 8 pericentric inversion inherited from her father. This inversion was observed in healthy individuals of the family and was absent in other individuals suffering from embryonic kidney tumor. We then supposed that another genetic anomaly predisposed her to tumorogenesis. Additional cryptic imbalances are reported in cases of apparently balanced chromosomal rearrangements with an abnormal phenotype. Array-CGH analysis showed a 569 kb duplication at 2p24.3 including the DDX1 and MYCN genes. This duplication was inherited from the patient's father who also had a nephroblastoma. A link between germline MYCN duplication and the occurrence of other embryonic cancers such as neuroblastoma has already been described. We supposed that germline DDX1-MYCN duplication could also be involved in the apparition of nephroblastomas.