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Wilms tumors are commonly associated with predisposition syndromes. Many of these syndromes are associated with specific phenotypic features and are discussed in the related paper from the AACR Pediatric Cancer Working Group. Guidelines for surveillance in this population were published in 2017 but since then several studies have identified new genes with recurrent pathogenic variants associated with increased risk for Wilms tumor development. In general, variants in these genes are less likely to be associated with other phenotypic features. Recently, members of the AACR Pediatric Cancer Working Group met to update surveillance guidelines for patients with a predisposition to Wilms tumors with a review of recently published evidence and risk estimates. Risk estimates for Wilms tumor for the more recently described genes are discussed here along with suggested surveillance guidelines for these populations. Several other emerging clinical scenarios associated with Wilms tumor predisposition are also discussed including patients with family histories of Wilms tumor and no identified causative gene, patients with bilateral tumors, and patients with somatic mosaicism for chromosome 11p15.5 alterations. This perspective serves to update pediatric oncologists, geneticists, radiologists, counselors and other healthcare professionals on emerging evidence and harmonize updated surveillance recommendations in the North American and Australian context for patients with emerging forms of Wilms tumor predisposition.

Children harboring certain germline gene variants have an increased risk of developing myelodysplastic syndrome (MDS) and other hematopoietic malignancies (HM), such as leukemias and lymphomas. Recent studies have identified an expanding number of these predisposition genes, with variants most prevalent in children with MDS but also found in children with other HM. For some hematopoietic malignancy predispositions (HMP), specifically those with a high risk of MDS, early intervention through hematopoietic stem cell transplantation can favorably impact overall survival, providing a rationale for rigorous surveillance. A multidisciplinary panel of experts at the 2023 AACR Childhood Cancer Predisposition Workshop reviewed the latest advances in the field and updated prior 2017 surveillance recommendations for children with HMP. In addition to general guidance for all children with HMP, which includes annual physical examination, education about the signs and symptoms of HM, consultation with experienced providers, and early assessment by a hematopoietic stem cell transplantation specialist, the panel provided specific recommendations for individuals with a higher risk of MDS based on the affected gene. These recommendations include periodic and comprehensive surveillance for individuals with those syndromes associated with higher risk of MDS, including serial bone marrow examinations to monitor for morphologic changes and deep sequencing for somatic changes in genes associated with HM progression. This approach enables close monitoring of disease evolution based on the individual's genetic profile. As more HMP-related genes are discovered and the disorders' natural histories are better defined, these personalized recommendations will serve as a foundation for future guidelines in managing these conditions., (©2024 American Association for Cancer Research.)

Wilms tumors are commonly associated with predisposition syndromes many, but not all, of which include overgrowth. Several of these syndromes also include a risk of other embryonal malignancies - particularly hepatoblastoma. Guidelines for surveillance in this population were published in 2017 and recently members of the AACR Pediatric Cancer Working Group met to update those guidelines with a review of more recently published evidence and risk estimates. This perspective serves to update pediatric oncologists, geneticists, radiologists, counselors and other healthcare professionals on revised diagnostic criteria, review previously published surveillance guidelines and harmonize updated surveillance recommendations in the North American and Australian context for patients with overgrowth syndromes and other syndromes associated with Wilms tumor predisposition.

Purpose: Describe clinical characteristics and outcome of Li-Fraumeni syndrome (LFS)-associated osteosarcomas., Methods: TP53 germline pathogenic/likely pathogenic variant carriers diagnosed with osteosarcoma in France between 1980 and 2019 were identified via the French Li-Fraumeni database at Rouen University Hospital. Sixty-five osteosarcomas in 52 patients with available clinical and histological data were included. The main clinical characteristics were compared with data from National Cancer Institute's SEER (Surveillance, Epidemiology, and End Results) for patients of the same age group., Results: Median age at first osteosarcoma diagnosis was 13.7 years (range: 5.9-36.7). Compared to unselected osteosarcomas, LFS-associated osteosarcomas occurred more frequently in patients less than 10 years of age (23% vs. 9%), and when compared with osteosarcomas in patients less than 25 years were characterized by an excess of axial (16% vs. 10%) and jaw sites (15% vs. 3%) and histology with predominant chondroblastic component and periosteal subtypes (17% vs. 1%). Metastases incidence (25%) was as expected in osteosarcomas. After the first osteosarcoma treatment, the rate of good histologic response (62%) and the 5-year progression-free survival (55%, 95% confidence interval [CI]: 42.6-71.1) were as expected in unselected series of osteosarcomas, whereas the 5-year event-free survival was 36.5% [95% CI: 25.3-52.7] due to the high incidence of second malignancies reaching a 10-year cumulative risk of 43.4% [95% CI: 28.5-57.5]., Conclusion: In osteosarcoma, young age at diagnosis, axial and jaw sites, histology with periosteal or chondroblastic subtype, and synchronous multifocal tumors should prompt suspicion of a germline TP53 mutation. Standard treatments are effective, but multiple malignancies impair prognosis. Early recognition of these patients is crucial for tailored therapy and follow-up., (© 2024 The Author(s). Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

Background: The prognosis for Li-Fraumeni syndrome (LFS) patients with medulloblastoma (MB) is poor. Comprehensive clinical data for this patient group is lacking, challenging the development of novel therapeutic strategies. Here, we present clinical and molecular data on a retrospective cohort of pediatric LFS MB patients., Methods: In this multinational, multicenter retrospective cohort study, LFS patients under 21 years with MB and class 5 or class 4 constitutional TP53 variants were included. TP53 mutation status, methylation subgroup, treatment, progression free- (PFS) and overall survival (OS), recurrence patterns, and incidence of subsequent neoplasms were evaluated., Results: The study evaluated 47 LFS individuals diagnosed with MB, mainly classified as DNA methylation subgroup "SHH_3" (86%). The majority (74%) of constitutional TP53 variants represented missense variants. The 2- and 5-year (y-) PFS were 36% and 20%, and 2- and 5y-OS were 53% and 23%, respectively. Patients who received postoperative radiotherapy (RT) (2y-PFS: 44%, 2y-OS: 60%) or chemotherapy before RT (2y-PFS: 32%, 2y-OS: 48%) had significantly better clinical outcome then patients who were not treated with RT (2y-PFS: 0%, 2y-OS: 25%). Patients treated according to protocols including high-intensity chemotherapy and patients who received only maintenance-type chemotherapy showed similar outcomes (2y-PFS: 42% and 35%, 2y-OS: 68% and 53%, respectively)., Conclusions: LFS MB patients have a dismal prognosis. In the presented cohort use of RT significantly increased survival rates, whereas chemotherapy intensity did not influence their clinical outcome. Prospective collection of clinical data and development of novel treatments are required to improve the outcome of LFS MB patients., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Inversions, i.e. a change in orientation of a segment of DNA, are a recognized cause of human diseases which remain overlooked due to their balanced nature. Inversions can have severe or more subtle impacts on gene expression. We describe two families that exemplify these aspects and underline the need for inversion detection in routine diagnosis. The first family (F1) displayed a sibship with two constitutional mismatch repair deficiency patients and a family history of colon cancer in the paternal branch. The second family (F2) displayed a severe history of Lynch syndrome. These families were analyzed using a whole gene panel (WGP) strategy i.e. including colon cancer genes with their intronic and flanking genomic regions. In F1, a PMS2 inversion encompassing the promoter region to intron 1 and a PMS2 splice variant were found in the maternal and paternal branch, respectively. In F2, we described the first MSH6 inversion, involving the 5' part of MSH6 and the 3' part of the nearby gene ANXA4. Inversion detection mandates genomic sequencing, but makes a valuable contribution to the diagnostic rate. WGP is an attractive strategy as it maximizes the detection power on validated genes and keeps sufficient depth to detect de novo events., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: The interpretation of germline TP53 variants is critical to ensure appropriate medical management of patients with cancer and follow-up of variant carriers. This interpretation remains complex and is becoming a growing challenge considering the exponential increase in TP53 tests. We developed a functional assay directly performed on patients' blood., Methods: Peripheral blood mononuclear cells were cultured, activated, exposed to doxorubicin and the p53-mediated transcriptional response was quantified using reverse transcription-multiplex ligation probe amplification and RT-QMPSF assays, including 10 p53 targets selected from transcriptome analysis, and two amplicons to measure p53 mRNA levels. We applied this blood functional assay to 77 patients addressed for TP53 analysis., Results: In 51 wild-type TP53 individuals, the mean p53 functionality score was 12.7 (range 7.5-22.8). Among eight individuals harbouring likely pathogenic or pathogenic variants, the scores were reduced (mean 4.8, range 3.1-7.1), and p53 mRNA levels were reduced in patients harbouring truncating variants. We tested 14 rare unclassified variants (p.(Pro72His), p.(Gly105Asp), p.(Arg110His), p.(Phe134Leu), p.(Arg158Cys), p.(Pro191Arg), p.(Pro278Arg), p.(Arg283Cys), p.(Leu348Ser), p.(Asp352Tyr), p.(Gly108_Phe109delinsVal), p.(Asn131del), p.(Leu265del), c.-117G>T) and 12 yielded functionally abnormal scores. Remarkably, the assay revealed that the c.*1175A>C polymorphic variant within TP53 poly-adenylation site can impact p53 function with the same magnitude as a null variant, when present on both alleles, and may act as a modifying factor in pathogenic variant carriers., Conclusion: This blood p53 assay should therefore be a useful tool for the rapid clinical classification of germline TP53 variants and detection of non-coding functional variants., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The management of patients with cancer and Li-Fraumeni or heritable TP53-related cancer syndromes is complex because of their increased risk of developing second malignant neoplasms after genotoxic stresses such as systemic treatments or radiotherapy (radiosusceptibility). Clinical decision making also integrates the risks of normal tissue toxicity and sequelae (radiosensitivity) and tumour response to radiotherapy (radioresistance and radiocurability). Radiotherapy should be avoided in patients with cancer and Li-Fraumeni or heritable TP53 cancer-related syndromes, but overall prognosis might be poor without radiotherapy: radioresistance in these patients seems similar to or worse than that of the general population. Radiosensitivity in germline TP53 variant carriers seems similar to that in the general population. The risk of second malignant neoplasms according to germline TP53 variant and the patient's overall oncological prognosis should be assessed during specialised multidisciplinary staff meetings. Radiotherapy should be avoided whenever other similarly curative treatment options are available. In other cases, it should be adapted to minimise the risk of second malignant neoplasms in patients who still require radiotherapy despite its genotoxicity, in view of its potential benefit. Adaptations might be achieved through the reduction of irradiated volumes using proton therapy, non-ionising diagnostic procedures, image guidance, and minimal stray radiation. Non-ionising imaging should become more systematic. Radiotherapy approaches that might result in a lower probability of misrepaired DNA damage (eg, particle therapy biology and tumour targeting) are an area of investigation., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Biallelic pathogenic variants in the NTHL1 (Nth like DNA glycosylase 1) gene cause a recently identified autosomal recessive hereditary cancer syndrome predisposing to adenomatous polyposis and colorectal cancer. Half of biallelic carriers also display multiple colonic or extra-colonic primary tumors, mainly breast, endometrium, urothelium, and brain tumors. Published data designate NTHL1 as an important contributor to hereditary cancers but also underline the scarcity of available informations. Thanks to the French oncogenetic consortium (Groupe Génétique et Cancer), we collected NTHL1 variants from 7765 patients attending for hereditary colorectal cancer or polyposis (n = 3936) or other hereditary cancers (n = 3829). Here, we describe 10 patients with pathogenic biallelic NTHL1 germline variants, that is, the second largest NTHL1 series. All carriers were from the "colorectal cancer or polyposis" series. All nine biallelic carriers who underwent colonoscopy presented adenomatous polyps. For digestive cancers, average age at diagnosis was 56.2 and we reported colorectal, duodenal, caecal, and pancreatic cancers. Extra-digestive malignancies included sarcoma, basal cell carcinoma, breast cancer, urothelial carcinoma, and melanoma. Although tumor risks remain to be precisely defined, these novel data support NTHL1 inclusion in diagnostic panel testing. Colonic surveillance should be conducted based on MUTYH recommendations while extra-colonic surveillance has to be defined., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The detection of copy-number variations (CNVs) from NGS data is underexploited as chip-based or targeted techniques are still commonly used. We assessed the performances of a workflow centered on CANOES, a bioinformatics tool based on read depth information. We applied our workflow to gene panel (GP) and whole-exome sequencing (WES) data, and compared CNV calls to quantitative multiplex PCR of short fluorescent fragments (QMSPF) or array comparative genomic hybridization (aCGH) results. From GP data of 3776 samples, we reached an overall positive predictive value (PPV) of 87.8%. This dataset included a complete comprehensive QMPSF comparison of four genes (60 exons) on which we obtained 100% sensitivity and specificity. From WES data, we first compared 137 samples with aCGH and filtered comparable events (exonic CNVs encompassing enough aCGH probes) and obtained an 87.25% sensitivity. The overall PPV was 86.4% following the targeted confirmation of candidate CNVs from 1056 additional WES. In addition, our CANOES-centered workflow on WES data allowed the detection of CNVs with a resolution of single exons, allowing the detection of CNVs that were missed by aCGH. Overall, switching to an NGS-only approach should be cost-effective as it allows a reduction in overall costs together with likely stable diagnostic yields. Our bioinformatics pipeline is available at: https://gitlab.bioinfo-diag.fr/nc4gpm/canoes-centered-workflow .

Objective: To describe the clinical characteristics and outcome of patients with Li-Fraumeni-associated rhabdomyosarcoma (RMS)., Method: Retrospective analysis of data from 31 French patients with RMS diagnosed before the age of 20 years associated with a TP53 pathogenic germline variant. Cases were identified through the French Li-Fraumeni database. Central histologic review was performed in 16 cases., Results: The median age at diagnosis was 2.3 years, and the median follow-up was 9.1 years (0.3-34.8). The main tumor sites were head and neck (n = 13), extremities (n = 8), and trunk (n = 8). The local pathology report classified the 31 tumors in embryonal (n = 26), alveolar (n = 1), pleomorphic (n = 1), and spindle-cell (n = 1) RMS (missing = 2). After histological review, anaplasia (diffuse or focal) was reported in 12/16 patients. Twenty-five patients had localized disease, three had lymph node involvement, and three distant metastases. First-line therapy combined surgery (n = 27), chemotherapy (n = 30), and radiotherapy (n = 14) and led to RMS control in all, but one patient. Eleven patients relapsed, and 18 patients had second malignancies. The 10-year event-free, progression-free, and overall survival rates were 36% (95% CI: 20-56), 62% (95% CI: 43-77) and 76% (95% CI: 56-88), respectively. The 10-year cumulative risk of second malignancies was 40% (95% CI: 22-60)., Conclusion: The high incidence of multiple primary tumors strongly influences the long-term prognosis of RMS associated with TP53 pathogenic germline variants. Anaplastic RMS in childhood, independently of the familial history, should lead to TP53 analysis at treatment initiation to reduce, whenever possible, the burden of genotoxic drugs and radiotherapy in carriers and to ensure the early detection of second malignancies., (© 2020 Wiley Periodicals LLC.)

Background: Heterozygous germline PMS2 variants are responsible for about 5% of Lynch syndrome (LS) but their prevalence is most likely underestimated because of complicated routine screening caused by highly homologous pseudogenes. Consequently, there is limited knowledge on the implication of the PMS2 gene in LS., Methods: We report 200 PMS2 heterozygous variants identified in 195 French patients, including 112 unique variants classified as class-3/4/5., Results: Genomic rearrangements account for 18% of alterations. The c.137G>T variant was observed in 18% of the patients, but a founder effect could not be clearly identified by haplotype analysis. Among class-4/5 variant carriers, the median age at first tumour onset was 49 years with a predominance of colorectal (80%) and endometrial (8.1%) cancers. Seven patients developed colorectal cancers before the age of 30 with the youngest at the age of 21. Only 6.2% of class-4/5 carriers had a family history fulfilling Amsterdam I/II criteria among patients with available data. Tumours from PMS2 variant carriers exhibited microsatellite instability (96%) and loss of PMS2 expression (76%), confirming the high predictive value of somatic analysis., Conclusion: Our results provide further insight into the role of the PMS2 gene in LS. While PMS2 variants are mostly detected in families not fulfilling Amsterdam criteria, which supports their lower penetrance, they can nevertheless cause early-onset cancers, highlighting the variability of their penetrance., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

We have developed and validated for the diagnosis of inherited colorectal cancer (CRC) a massive parallel sequencing strategy based on: (i) fast capture of exonic and intronic sequences from ten genes involved in Mendelian forms of CRC (MLH1, MSH2, MSH6, PMS2, APC, MUTYH, STK11, SMAD4, BMPR1A and PTEN); (ii) sequencing on MiSeq and NextSeq 500 Illumina platforms; (iii) a bioinformatic pipeline that includes BWA-Picard-GATK (Broad Institute) and CASAVA (Illumina) in parallel for mapping and variant calling, Alamut Batch (Interactive BioSoftware) for annotation, CANOES for CNV detection and finally, chimeric reads analysis for the detection of other types of structural variants (SVs). Analysis of 1644 new index cases allowed the identification of 323 patients with class 4 or 5 variants, corresponding to a 20% disease-causing variant detection rate. This rate reached 37% in patients with Lynch syndrome, suspected on the basis of tumour analyses. Thanks to this strategy, we detected overlapping phenotypes (e.g., MUTYH biallelic mutations mimicking Lynch syndrome), mosaic alterations and complex SVs such as a genomic deletion involving the last BMPR1A exons and PTEN, an Alu insertion within MSH2 exon 8 and a mosaic deletion of STK11 exons 3-10. This strategy allows, in a single step, detection of all types of CRC gene alterations including SVs and provides a high disease-causing variant detection rate, thus optimizing the diagnosis of inherited CRC.

Introduction: Li-Fraumeni syndrome (LFS), due to TP53 germline mutations, is characterised by a remarkably high incidence of multiple primary cancers (MPCs), and the key role of p53 in response to DNA damage questions the contribution of anticancer treatments to MPCs development., Materials and Methods: We first evaluated genotoxicity of X-rays and different classes of conventional chemotherapies, thanks to genotoxicity assays, based on the measurement of transcriptional response to DNA damage and performed in murine splenocytes, either exposed ex vivo or extracted from exposed mice. We then exposed a total of 208 Trp53Δ/Δ, wt/Δ or wt/wt mice to clinical doses of X-rays or genotoxic or non-genotoxic chemotherapies. Tumour development was monitored using whole-body magnetic resonance imaging and pathological examination at death., Results: X-rays and conventional chemotherapies, except mitotic spindle poisons, were found to be genotoxic in both p53 genotoxicity assays. Exposition to X-rays and the topoisomerase inhibitor etoposide, analysed as genotoxic anticancer treatment, drastically increase the tumour development risk in Trp53Δ/Δ and wt/Δ mice (hazard ration [HR] = 4.4, 95% confidence interval [CI] [2.2-8.8], p < 0.001*** and HR = 4.7, 95% CI [2.4-9.3], p < 0.001***, respectively). In contrast, exposure to the non-genotoxic mitotic spindle poison, docetaxel, had no impact on tumour development., Conclusions: This study shows that radiotherapy and genotoxic chemotherapies significantly increase the risk of tumour development in a LFS mice model. These results strongly support the contribution of genotoxic anticancer treatments to MPC development in LFS patients. Therefore, to reduce the risk of MPCs in germline TP53 mutation carriers, radiotherapy should be avoided whenever possible, surgical treatment prioritised, and non-genotoxic treatments considered., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Development of tumours such as adrenocortical carcinomas (ACC), choroid plexus tumours (CPT) or female breast cancers before age 31 or multiple primary cancers belonging to the Li-Fraumeni (LFS) spectrum is, independently of the familial history, highly suggestive of a germline TP53 mutation. The aim of this study was to determine the contribution of de novo and mosaic mutations to LFS., Methods and Results: Among 328 unrelated patients harbouring a germline TP53 mutation identified by Sanger sequencing and/or QMPSF, we could show that the mutations had occurred de novo in 40 cases, without detectable parental age effect. Sanger sequencing revealed two mosaic mutations in a child with ACC and in an unaffected father of a child with medulloblastoma. Re-analysis of blood DNA by next-generation sequencing, performed at a depth above 500X, from 108 patients suggestive of LFS without detectable TP53 mutations, allowed us to identify 6 additional cases of mosaic TP53 mutations, in 2/49 children with ACC, 2/21 children with CPT, in 1/31 women with breast cancer before age 31 and in a patient who developed an osteosarcoma at age 12, a breast carcinoma and a breast sarcoma at age 35., Conclusions: This study performed on a large series of TP53 mutation carriers allows estimating the contribution to LFS of de novo mutations to at least 14% (48/336) and suggests that approximately one-fifth of these de novo mutations occur during embryonic development. Considering the medical impact of TP53 mutation identification, medical laboratories in charge of TP53 testing should ensure the detection of mosaic mutations., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Choriocarcinoma is a highly malignant neoplasm resulting from the malignant transformation of proliferating trophoblastic cells and the molecular mechanisms leading to this transformation remain to be characterized. We report here the first case of a female germline TP53 mutation carrier who developed, as a first tumour, a lung choriocarcinoma, 6 months after a normal delivery. Molecular analyses established the gestational origin of the choriocarcinoma and showed, within the tumour, the presence of the germline mutant TP53 allele and loss of the wild-type allele. Resistance to methotrexate chemotherapy led to perform a surgical resection of the tumour. In agreement with the permissive role of TP53 mutations to oncogenic events, this report strongly suggests that TP53 mutations may promote malignant transformation of proliferating trophoblastic cells. Therefore, female TP53 mutation carriers may have an increased risk of developing gestational choriocarcinoma and might benefit from β-hCG level monitoring after pregnancy.

The POT1 protein binds and protects telomeres. Germline variants in the POT1 gene have recently been shown to be associated with risk of developing tumors in different tissues such as familial chronic lymphocytic leukemia, colorectal, glioma and melanoma tumors. Recently, we uncovered a variant in the POT1 gene (p.R117C) as causative of familial cardiac angiosarcomas (CAS) in Li-Fraumeni-like (LFL) syndrome families. Our in silico studies predicted that this protein had lost the ability to interact with TPP1 and single-stranded DNA. In vitro studies corroborated this prediction and showed that this lack of function leads to abnormally long telomeres. To better understand the POT1 gene and its role with tumorigenesis, we extended the study to LFL (with and without members affected with angiosarcomas (AS)) and sporadic AS and cardiac sarcomas. We found POT1 variants in the 20% of the families with members affected with AS and 10% of sporadic AS and sarcomas. In silico studies predicted that these new variants were damaging in the same manner as previously described for the POT1 p.R117C variants. The wide spectrum of variants in the POT1 gene leading to tumorigenesis in different tissues demonstrates its general importance. Study of the POT1 gene should be considered as routine diagnostic in these cancers.

Background: Sarcomas are rare mesenchymal malignancies whose pathogenesis is poorly understood; both environmental and genetic risk factors could contribute to their aetiology., Methods and Results: We performed whole-exome sequencing (WES) in a familial aggregation of three individuals affected with soft-tissue sarcoma (STS) without TP53 mutation (Li-Fraumeni-like, LFL) and found a shared pathogenic mutation in CDKN2A tumour suppressor gene. We searched for individuals with sarcoma among 474 melanoma-prone families with a CDKN2A -/+ genotype and for CDKN2A mutations in 190 TP53 -negative LFL families where the index case was a sarcoma. Including the initial family, eight independent sarcoma cases carried a germline mutation in the CDKN2A /p16 INK4A gene. In five out of seven formalin-fixed paraffin-embedded sarcomas, heterozygosity was lost at germline CDKN2A mutations sites demonstrating complete loss of function. As sarcomas are rare in CDKN2A /p16 INK4A carriers, we searched in constitutional WES of nine carriers for potential modifying rare variants and identified three in platelet-derived growth factor receptor ( PDGFRA ) gene. Molecular modelling showed that two never-described variants could impact the PDGFRA extracellular domain structure., Conclusion: Germline mutations in CDKN2A /P16 INK4A , a gene known to predispose to hereditary melanoma, pancreatic cancer and tobacco-related cancers, account also for a subset of hereditary sarcoma. In addition, we identified PDGFRA as a candidate modifier gene., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Li-Fraumeni Syndrome (LFS) results from heterozygous germline mutations of TP53, encoding a key transcriptional factor activated in response to DNA damage. We have recently shown, from a large LFS series, that dominant-negative missense mutations are the most clinically severe and, thanks to a new p53 functional assay in lymphocytes, that they alter the p53 transcriptional response to DNA damage more drastically than null mutations. In this study, we first confirmed this observation by performing the p53 functional assay in lymphocytes from 56 TP53 mutation carriers harbouring 35 distinct alterations. Then, to compare the impact of the different types of germline TP53 mutations on DNA binding, we performed chromatin immunoprecipitation-sequencing (ChIP-Seq) in lymphocytes exposed to doxorubicin. ChIP-Seq performed in wild-type TP53 control lymphocytes accurately mapped 1287 p53-binding sites. New p53-binding sites were validated using a functional assay in yeast. ChIP-Seq analysis of LFS lymphocytes carrying TP53 null mutations (p.P152Rfs*18 or complete deletion) or the low penetrant 'Brazilian' p.R337H mutation revealed a moderate decrease of p53-binding sites (949, 580 and 620, respectively) and of ChIP-Seq peak depths. In contrast, analysis of LFS lymphocytes with TP53 dominant-negative missense mutations p.R273H or p.R248W revealed only 310 and 143 p53-binding sites, respectively, and the depths of the corresponding peaks were drastically reduced. Altogether, our results show that TP53 mutation carriers exhibit a constitutive defect of the transcriptional response to DNA damage and that the clinical severity of TP53 dominant-negative missense mutations is explained by a massive and global alteration of p53 DNA binding., (© The Author 2017. Published by Oxford University Press.)

Germline mutations of EXT2, encoding Exostosin Glycosyltransferase 2, are associated with multiple osteochondromas (MO), an autosomal dominant disease characterized by the development of multiple peripheral cartilaginous benign tumors with a weak risk of malignant transformation. We report here a family with a remarkable clinical presentation characterized by the development of isolated chondrosarcomas, mostly located in ribs. Comparative analysis of exomes from two third-degree affected relatives led us to identify a single common disruptive variation, corresponding to a stop mutation (c.237G > A, p.Trp79*; (NM&#95;000401.3); c.138G > A, p.Trp46*; (NM&#95;207122.1)) within exon 2 of the EXT2 gene. Interestingly, no obvious sign of MO was detected in affected members by radiological examination. This report shows that germline mutations of EXT2 can result, not only in the development of multiple benign osteochondromas, but also in the development of isolated malignant cartilaginous tumors including central tumors, and that the presence of germline EXT2 mutation should be considered in patients suspected to have an inherited predisposition to chondrosarcoma, even in the absence of MO. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

The constitutional MisMatch Repair deficiency (CMMRD) syndrome is one of the inherited cancer predisposition syndromes. More than two-third patients belonging to a CMMRD family are diagnosed mainly in the first decade with brain cancers and/or hematological malignancies. This syndrome is due to bi-allelic germline mutations in genes of the MMR pathway (MLH1, MSH2, MSH6 or PMS2). Our family report begins with the index case presenting initially with a medulloblastoma, which was even the two relapses in complete remission, when she was diagnosed for an AML. She died after bone marrow transplantation from toxicity. The family history was progressively established when her uncle was diagnosed for a colonic cancer and a cousin for a brain tumor. Surprisingly, her father had an atypical sarcoma but her brother also presented a lymphoma followed by a gliomatosis cerebri. A new MLH1 bi-allelic mutation was identified in this family. More than the diagnostic difficulties, this family report illustrates the complexity of the microsatellite instability detection in CMMRD patients, which has to be discussed further to a more accurate diagnosis in the pediatric setting, and address the question of the proper diagnostic tool to use in such genetic background with hypermutated tumors.

Whereas most mutations in p53 occur in the DNA-binding domain and lead to its functional inactivation, their relevance in the amino-terminal transactivation domain is unclear. We show here that amino-terminal p53 (ATp53) mutations often result in the abrogation of full-length p53 expression, but concomitantly lead to the expression of the amino-terminally truncated p47 isoform. Using genetically modified cancer cells that only express p47, we demonstrate it to be up-regulated in response to various stimuli, and to contribute to cell death, through its ability to selectively activate a group of apoptotic target genes. Target gene selectivity is influenced by K382 acetylation, which depends on the amino terminus, and is required for recruitment of selective cofactors. Consistently, cancers capable of expressing p47 had a better overall survival. Nonetheless, retention of the apoptotic function appears insufficient for tumor suppression, because these mutations are also found in the germ line and lead to Li-Fraumeni syndrome. These data from ATp53 mutations collectively demonstrate that p53's apoptosis proficiency is dispensable for tumor suppression, but could prognosticate better survival.

Cardiac angiosarcoma (CAS) is a rare malignant tumour whose genetic basis is unknown. Here we show, by whole-exome sequencing of a TP53-negative Li-Fraumeni-like (LFL) family including CAS cases, that a missense variant (p.R117C) in POT1 (protection of telomeres 1) gene is responsible for CAS. The same gene alteration is found in two other LFL families with CAS, supporting the causal effect of the identified mutation. We extend the analysis to TP53-negative LFL families with no CAS and find the same mutation in a breast AS family. The mutation is recently found once in 121,324 studied alleles in ExAC server but it is not described in any other database or found in 1,520 Spanish controls. In silico structural analysis suggests how the mutation disrupts POT1 structure. Functional and in vitro studies demonstrate that carriers of the mutation show reduced telomere-bound POT1 levels, abnormally long telomeres and increased telomere fragility.

The p53 tumor suppressor protein has emerged as a universal sensor of genotoxic stress that regulates the transcription of numerous genes required for appropriate cellular response to DNA damage. Therefore, transcriptional induction of p53 target genes can be considered as a global and early indicator of genotoxic stress. By performing expression microarrays and RNA-Seq analysis on wild-type and mutant TP53 human lymphocytes respectively derived from controls and Li-Fraumeni patients and exposed to different classes of genotoxic agents, we first determined a common p53-dependent transcriptional signature of DNA damage. We then derived a simple and fast assay based on the exposure of wild-type TP53 lymphocytes to physical or chemical agents and on the quantitative measurement of selected p53 target gene transcriptional induction. The specificity of the p53 genotoxicity assay can easily be demonstrated by performing the same experiment in control lymphocytes with heterozygous TP53 mutations, which compromise responses to DNA damage. This assay allowed us to show that most of the drugs commonly used in cancer treatment, except the microtubule poisons, are highly genotoxic. The p53 genotoxicity assay should facilitate the measurement of the genotoxic effects of chemical and physical agents and the identification of drugs that are not genotoxic and do not expose patients to the risk of secondary malignancies, especially those with a constitutional defect in response to DNA damage, such as patients with Li-Fraumeni syndrome., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Purpose: The aim of the study was to update the description of Li-Fraumeni syndrome (LFS), a remarkable cancer predisposition characterized by extensive clinical heterogeneity., Patients and Methods: From 1,730 French patients suggestive of LFS, we identified 415 mutation carriers in 214 families harboring 133 distinct TP53 alterations and updated their clinical presentation., Results: The 322 affected carriers developed 552 tumors, and 43% had developed multiple malignancies. The mean age of first tumor onset was 24.9 years, 41% having developed a tumor by age 18. In childhood, the LFS tumor spectrum was characterized by osteosarcomas, adrenocortical carcinomas (ACC), CNS tumors, and soft tissue sarcomas (STS) observed in 30%, 27%, 26%, and 23% of the patients, respectively. In adults, the tumor distribution was characterized by the predominance of breast carcinomas observed in 79% of the females, and STS observed in 27% of the patients. The TP53 mutation detection rate in children presenting with ACC or choroid plexus carcinomas, and in females with breast cancer before age 31 years, without additional features indicative of LFS, was 45%, 42% and 6%, respectively. The mean age of tumor onset was statistically different (P < .05) between carriers harboring dominant-negative missense mutations (21.3 years) and those with all types of loss of function mutations (28.5 years) or genomic rearrangements (35.8 years). Affected children, except those with ACC, harbored mostly dominant-negative missense mutations., Conclusion: The clinical gradient of the germline TP53 mutations, which should be validated by other studies, suggests that it might be appropriate to stratify the clinical management of LFS according to the class of the mutation., (© 2015 by American Society of Clinical Oncology.)

To identify novel genetic bases of early-onset epithelial ovarian tumors, we used the trio exome sequencing strategy in a patient without familial history of cancer who presented metastatic serous ovarian adenocarcinomas at 21 years of age. We identified a single de novo mutation (c.1157A>G/p.Asn386Ser) within the INHBA gene encoding the βA-subunit of inhibins/activins, which play a key role in ovarian development. In vitro, this mutation alters the ratio of secreted activins and inhibins. In a second patient with early-onset serous borderline papillary cystadenoma, we identified an unreported germline mutation (c.179G>T/p.Arg60Leu) of the INHA gene encoding the α-subunit, the partner of the βA-subunit. This mutation also alters the secreted activin/inhibin ratio, by disrupting both inhibin A and inhibin B biosynthesis. In a cohort of 62 cases, we detected an additional unreported germline mutation of the INHBA gene (c.839G>A/p.Gly280Glu). Our results strongly suggest that inhibin mutations contribute to the genetic determinism of epithelial ovarian tumors., (© 2013 The Authors. *Human Mutation published by Wiley Periodicals, Inc.)

Constitutional mismatch repair-deficiency, due to biallelic mutations of MMR genes, results in a tumour spectrum characterized by leukaemias, lymphomas, brain tumours and adenocarcinomas of the gastro-intestinal tract, occurring mostly in childhood. We report here two families illustrating the phenotypic diversity associated with biallelic MMR mutations. In the first family, two siblings developed six malignancies including glioblastoma, lymphoblastic T cell lymphoma, rectal and small bowel adenocarcinoma with onset as early as 6 years of age. We showed that this dramatic clinical presentation was due to the presence of two complex genomic PMS2 deletions in each patient predicted to result into complete PMS2 inactivation. In the second family, the index case presented with an early form of Lynch syndrome with colorectal adenocarcinomas at ages 17 and 20 years, and urinary tract tumours at the age of 25 years. We identified in this patient two MSH6 mutations corresponding to a frameshift deletion and an in frame deletion. The latter was not predicted to result into complete inactivation of MSH6. These reports show that the clinical expression of biallelic MMR mutations depends on the biological impact of the second MMR mutation and that, in clinical practice, the presence of a second MMR mutation located in trans should also be considered in patients suspected to present a Lynch syndrome with an unusual early-onset of tumours.

In the Li-Fraumeni syndrome (LFS) resulting from germline TP53 mutations, the MDM2 SNP309G allele has been shown to be associated with an earlier age of tumour onset, however the significance of this association is controversial. The 285C variation, also located in the MDM2 promoter, has been shown to reduce the strength of Sp1 binding to MDM2 promoter, antagonizing the effect of the 309G variation. In this study, we investigated the interaction of the MDM2 SNP285 and 309 in a large series of 195 LFS patients. Although we observed a lower mean age of tumour onset in patients with MDM2 SNP309 T/G or G/G genotype (23.1 years) than in patients with T/T genotype (27.3 years), the difference was not statistically significant. In contrast, patients with the 285-309 G-G haplotype develop tumours 5 years earlier than patients harbouring other haplotypes (p = 0.044). This result shows that the MDM2 285-309 G-G is a higher risk haplotype in patients with germline TP53 mutations. This study confirms that the MDM2 309G variation is deleterious when its effect is not neutralized by the 285C variation and illustrates the interfering effects of SNPs located within a gene acting as modifier factor in a Mendelian disease.

Germline alterations of the tumour suppressor TP53 gene are detected approximately in 25% of the families suggestive of Li-Fraumeni syndrome (LFS), characterised by a genetic predisposition to a wide tumour spectrum, including soft-tissue sarcomas, osteosarcomas, premenopausal breast cancers, brain tumours, adrenocortical tumours, plexus choroid tumours, leukaemia and lung cancer. The aim of this study was to determine the contribution of germline copy number variations (CNVs) to LFS in families without detectable TP53 mutation. Using a custom-designed high-resolution array CGH, we evaluated the presence of rare germline CNVs in 64 patients fulfilling the Chompret criteria for LFS, but without any detectable TP53 alteration. In 15 unrelated patients, we detected 20 new CNVs absent in 600 controls. Remarkably, in four patients who had developed each brain tumour, the detected CNV overlap the KDM1A, MTA3, TRRAP or SIRT3 genes encoding p53 partners involved in histone methylation or acetylation. Focused analysis of SIRT3 showed that the CNV encompassing SIRT3 leads to SIRT3 overexpression, and that in vitro SIRT3 overexpression prevents apoptosis, increases G2/M and results in a hypermethylation of numerous genes. This study supports the causal role of germline alterations of genes involved in chromatin remodelling in genetic predisposition to cancer and, in particular, to brain tumours.

In contrast to other tumor suppressor genes, the majority of TP53 alterations are missense mutations. We have previously reported that in the Li-Fraumeni syndrome (LFS), germline TP53 missense mutations are associated with an earlier age of tumor onset. In a larger series, we observed that mean age of tumor onset in patients harboring dominant negative missense mutations and clearly null mutations was 22.6 and 37.5 years, respectively. To assess the impact of heterozygous germline TP53 mutations in the genetic context of the patients, we developed a new functional assay of the p53 pathway on the basis of induction of DNA damage in Epstein-Barr-virus-immortalized lymphocytes, followed by comparative gene-expression profiling. In wild-type lymphocytes, we identified a core of 173 genes whose expression was induced more than twofold, of which 46 were known p53 target genes. In LFS lymphocytes with canonical missense mutations, the number of induced genes and the level of known p53 target genes induction were strongly reduced as compared with controls and LFS lymphocytes with null mutations. These results show that certain germline missense TP53 mutations, such as those with dominant negative effect, dramatically alter the response to DNA damage. This probably explains why TP53 alterations are predominantly missense mutations., (© 2012 Wiley Periodicals, Inc.)

Germline genetics, gender and hormonal-signaling pathways are all well described modifiers of cancer risk and progression. Although an improved understanding of how germline genetic variants interact with other cancer risk factors may allow better prevention and treatment of human cancer, measuring and quantifying these interactions is challenging. In other areas of research, Information Theory has been used to quantitatively describe similar multivariate interactions. We implemented a novel information-theoretic analysis to measure the joint effect of a high frequency germline genetic variant of the p53 tumor suppressor pathway (MDM2 SNP309 T/G) and gender on clinical cancer phenotypes. This analysis quantitatively describes synergistic interactions among gender, the MDM2 SNP309 locus, and the age of onset of tumorigenesis in p53 mutation carriers. These results offer a molecular and genetic basis for the observed sexual dimorphism of cancer risk in p53 mutation carriers and a model is proposed that suggests a novel cancer prevention strategy for p53 mutation carriers.

Huntingtin-interacting protein 1 (HIP1) is frequently overexpressed in prostate cancer. HIP1 is a clathrin-binding protein involved in growth factor receptor trafficking that transforms fibroblasts by prolonging the half-life of growth factor receptors. In addition to human cancers, HIP1 is also overexpressed in prostate tumors from the transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse model. Here we provide evidence that HIP1 plays an important role in mouse tumor development, as tumor formation in the TRAMP mice was impaired in the Hip1null/null background. In addition, we report that autoantibodies to HIP1 developed in the sera of TRAMP mice with prostate cancer as well as in the sera from human prostate cancer patients. This led to the development of an anti-HIP1 serum test in humans that had a similar sensitivity and specificity to the anti-alpha-methylacyl CoA racemase (AMACR) and prostate-specific antigen tests for prostate cancer and when combined with the anti-AMACR test yielded a specificity of 97%. These data suggest that HIP1 plays a functional role in tumorigenesis and that a positive HIP1 autoantibody test may be an important serum marker of prostate cancer.

Since chromosomal instability (CIN) is a hallmark of most cancer cells, it is essential to identify genes whose alteration results into this genetic instability. Using a yeast CIN indicator strain, we show that inactivation of the YMR131c/RRB1 gene, which is involved in early ribosome assembly and whose expression is induced when the spindle checkpoint is activated, alters chromosome segregation and blocks mitosis at the metaphase/anaphase transition. We demonstrate that RRB1 interacts with YPH1 (yeast pescadillo homologue 1) and other members of the Yph1 complex, RPL3, ERB1 and ORC6, involved in ribosome biogenesis and DNA replication. Transient depletion of the human homologues GRWD, Pescadillo, Rpl3, Bop1 and Orc6L resulted in an increase of abnormal mitoses with appearance of binucleate or hyperploid cells, of cells with multipolar spindles and of aberrant metaphase plates. If deregulation of proteins involved in ribosome biogenesis, commonly observed in malignant tumors, could contribute to cancer through an aberrant protein synthesis, our study demonstrates that alteration of proteins linking ribosome biogenesis and DNA replication may directly cause CIN.

The Rapp-Hodgkin syndrome (RHS, MIM 129400) corresponds to a rare form of anhydrotic ectodermal dysplasia, which shares some features with the ectrodactyly, ectodermal dysplasia and cleft lip/palate syndrome (EEC, MIM 604292) resulting from TP63 mutations. We report here, in two unrelated patients with RHS, the identification of two distinct TP63 mutations, corresponding to a novel frameshift mutation (1709DelA, exon 14) located downstream the sterile alpha motif (SAM) domain and to a missense mutation (R279H, exon 7) within the DNA binding domain. Functional analysis of the R279H mutation, which had previously been reported in several EEC families, shows that this mutation disrupted the dominant negative activity of the DeltaNp63alpha and gamma isoforms on the transcriptional activity of TP53. This report shows, on a molecular basis, that RHS is also an EEC-like syndrome resulting from mutations of the TP63 gene, and highlights the wide phenotypic spectrum associated to TP63 mutations.