Lynch Syndrome and Gynecologic Tumors: Incidence, Prophylaxis, and Management of Patients with Cancer.

This review provides a comprehensive update on recent evidence regarding gynecologic tumors associated with Lynch Syndrome (LS). Endometrial cancer (EC) and ovarian cancer (OC) are the first and second most common gynecologic malignancies in developed countries, respectively, and LS is estimated to be the hereditary cause in 3% of both EC and OC. Despite the increasing evidence on LS-related tumors, few studies have analyzed the outcomes of LS-related EC and OC stratified by mutational variant. This review aims to provide a comprehensive overview of the literature and comparison between updated international guidelines, to help outline a shared pathway for the diagnosis, prevention, and management of LS. Through the widespread adoption of the immunohistochemistry-based Universal Screening, LS diagnosis and identification of mutational variants could be standardized and recognized by international guidelines as a feasible, reproducible, and cost-effective method. Furthermore, the development of a better understanding of LS and its mutational variants will support our ability to better tailor EC and OC management in terms of prophylactic surgery and systemic treatment in the light of the promising results shown by immunotherapy.

Ovarian cancer onset across different BRCA mutation types: a view to a more tailored approach for BRCA mutated patients.

OBJECTIVE: To evaluate the role of different specific types of germline breast cancer susceptibility BRCA mutations on the age of onset of high grade serous ovarian cancer. METHODS: This was a multicenter, international, retrospective cohort of 474 patients diagnosed with recurrent or newly diagnosed high grade serous ovarian cancer, with known germline mutations in BRCA1/2 genes, treated between January 2011 and December 2020 in three academic centers in Europe. Patients were classified into four groups related to the type of BRCA1/2 genes mutation: frameshift, missense, nonsense, and splicing. Data from patients with splicing mutations were removed from the analysis because of the small numbers. The other three groups were compared. RESULTS: Excluding the 29 patients with a splicing mutation, 474 patients were enrolled: 309 (65.2%) with frameshift mutations, 102 (21.5%) with nonsense mutations, and 63 (13.3%) with missense mutations. The BRCA1 gene was affected in 324 (68.4%) cases, while BRCA2 was involved in 150 (31.6%) women (p=0.06). We found a difference of more than 5 years in the age of onset of high grade serous ovarian cancer between BRCA1 and BRCA2 patients (mean 53.3 years vs 58.4 years; p=0.001), with a mean age of 55.1 years. Patients with nonsense germline mutations had the youngest age of onset, while women with frameshift mutations had the oldest age of onset of high grade serous ovarian cancer (mean 52.2 years vs mean 55.9 years), both in the BRCA1 and BRCA2 subgroups. There was no statistically significant difference in age of onset between early and advanced groups (mean 55.8 years vs 55.0 years; p=0.55). CONCLUSION: Different types of germline BRCA mutations could determine different ages for onset of high grade serous ovarian cancer. If confirmed in larger series, this finding might have a clinical impact, potentially leading to a more tailored approach for risk reducing surgery for the prevention of high grade serous ovarian cancer.

Fertility-sparing treatment for endometrial cancer and atypical endometrial hyperplasia in patients with Lynch Syndrome: Molecular diagnosis after immunohistochemistry of MMR proteins.

Introduction: Lynch Syndrome (LS) represents the hereditary condition that is most frequently associated with endometrial cancer (EC). The aim of this study is to assess the presence of Lynch Syndrome (LS) in young women with mismatch repair (MMR)-deficient atypical endometrial hyperplasia (AEH) and non-myoinvasive FIGO G1 endometrioid EC and its possible impact on the outcome of conservative treatment. Methods: Six MMR-deficient cases identified from a previous cohort of 69 conservatively treated patients were selected to be screened for germline mutations in MMR genes. In each patient, the outcomes of conservative treatment for AEH and EEC, including response, relapse, progression, and pregnancy, were assessed. Results: Five out of 6 patients underwent genetic test for LS. Three out of these 5 patients showed a positive genetic test. Patient 1 showed the c.942 + 2 T>A heterozygous variant of MSH2 mutation; after 12 months of complete response, she had relapse and progression of disease. Patient 4 showed the c.2459-1G>C variant of MSH2 mutation; after complete response, she failed to achieve pregnancy; she had relapse after 24 months and underwent hysterectomy. Patient 6 showed the c.803 + 1 heterozygous variant of PMS2 mutation; she had relapse of disease after 18 months from the first complete response and then underwent hysterectomy. Conclusions: In this series, 3 out of 6 women with MMR-deficiency had LS. None of the patients achieved pregnancy, and those who responded to treatment had subsequent relapse of disease. Patients undergoing fertility-sparing treatment for atypical endometrial hyperplasia and endometrial cancer should perform MMR immunohistochemical analysis in order to screen LS.

Distribution of Cerebrovascular Phenotypes According to Variants of the ENG and ACVRL1 Genes in Subjects with Hereditary Hemorrhagic Telangiectasia.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder caused, in more than 80% of cases, by mutations of either the endoglin (ENG) or the activin A receptor-like type 1 (ACVRL1) gene. Several hundred variants have been identified in these HHT-causing genes, including deletions, missense and nonsense mutations, splice defects, duplications, and insertions. In this study, we have analyzed retrospectively collected images of magnetic resonance angiographies (MRA) of the brain of HHT patients, followed at the HHT Center of our University Hospital, and looked for the distribution of cerebrovascular phenotypes according to specific gene variants. We found that cerebrovascular malformations were heterogeneous among HHT patients, with phenotypes that ranged from classical arteriovenous malformations (AVM) to intracranial aneurysms (IA), developmental venous anomalies (DVA), and cavernous angiomas (CA). There was also wide heterogeneity among the variants of the ENG and ACVRL1 genes, which included known pathogenic variants, variants of unknown significance, variants pending classification, and variants which had not been previously reported. The percentage of patients with cerebrovascular malformations was significantly higher among subjects with ENG variants than ACVRL1 variants (25.0% vs. 13.1%, p < 0.05). The prevalence of neurovascular anomalies was different among subjects with different gene variants, with an incidence that ranged from 3.3% among subjects with the c.1231C > T, c.200G > A, or c.1120C > T missense mutations of the ACVRL1 gene, to 75.0% among subjects with the c.1435C > T missense mutation of the ACVRL1 gene. Further studies and larger sample sizes are required to confirm these findings.

Variants of uncertain significance (VUS) in cancer predisposing genes: What are we learning from multigene panels?

One of the main factors influencing the clinical utility of genetic tests for cancer predisposition is the ability to provide actionable classifications (ie pathogenic or benign). However, a large fraction of the variants identified in cancer predisposing genes (CPGs) are of uncertain significance (VUS), and cannot be used for clinical purposes either to identify individuals at risk or to drive treatment. Here we analyze the current status of VUS identification in a subset of 24 CPGs included by the American College of Medical Genetics/Association for Molecular Pathology in the list of genes that should be considered for the return of incidental findings. To this purpose we retrieved published literature using different search strings according to the frequency of the condition and we extracted corresponding data from ClinVar. The total number of VUS has not decreased with time, due to widespread multigene panel testing, and the relative yield of VUS compared to pathogenic variants is higher in more recent studies, which tend to involve series not selected for the presence of specific high risk criteria. In addition, only few studies adopt gene specific interpretation criteria when these are available. Despite the large yield of VUS associated with multigene testing, the data obtained from such studies can be very useful for variant classification, especially for those variants that are more likely to be benign, since these are expected to be detected more frequently in a population that does not show gene specific manifestations. In addition, wider use of gene specific interpretation criteria should be promoted in order to optimize the interpretation process.

Surgical management of BRCA pathogenic variant carriers with breast cancer: a recent literature review and current state of the art.

Surgical management of breast cancer patients carrying pathogenic variants (PV) on breast cancer genes (BRCA) 1 and 2 has changed throughout the last decade due to growing availability of genetic testing, and has shifted towards the diffusion of bilateral mastectomy. Today's scenario however is in further evolution because of emerging data that suggest a personalized modulation of treatment. In this work we aimed to gather recent evidence supporting a prophylactic or conservative surgical approach in order to define the state of the art in today's treatment of BRCA carriers with breast cancer. We reviewed the literature to identify studies providing evidence on surgical treatment in breast cancer patients with BRCA 1 and 2 PVs. We included articles comparing outcomes between patients undergoing breast conserving surgery (BCS) and mastectomy, and articles investigating contralateral risk-reducing mastectomy (CRRM), with a particular focus on recent literature. International guidelines were also reviewed. Optimal surgical management of BRCA PV carriers with breast cancer remains controversial. While the introduction of routine genetic testing has initially led surgeons to favor more radical treatments, recent literature provides evidence that a conservative approach is safe and feasible in selected cases. Guidelines are heterogeneous and provide guidance without constraining the surgeon. Patients should undergo adequate genetic and surgical counseling in order to receive the best tailored surgical treatment. Because guidelines vary in different countries and provide no definite protocol, they highlight the importance of accurate surgical planning. Clinical, familial and psychosocial factors should be taken into account when approaching a BRCA PV carrier with breast cancer, in order to guarantee the best evidence-based patient care in an era of personalized treatment.

Definition and management of colorectal polyposis not associated with APC/MUTYH germline pathogenic variants: AIFEG consensus statement.

An expert consensus panel convened by the Italian Association for Inherited and Familial Gastrointestinal Tumors (Associazione Italiana per lo Studio della Familiarità ed Ereditarietà dei Tumori Gastrointestinali, AIFEG) reviewed the literature and agreed on a number of position statements regarding the definition and management of polyposis coli without an identified pathogenic mutation on the APC or MUTYH genes, defined in the document as NAMP (non-APC/MUTYH polyposis).

Intrafamilial communication of hereditary breast and ovarian cancer genetic information in Italian women: towards a personalised approach.

Genomic testing expansion is accompanied by an increasing need for genetic counselling and intrafamilial communication. Genetic counselling can play an important role in facilitating intrafamilial communication and relationships. We conducted a cross-sectional, multicenter study including 252 Italian women, using a questionnaire divided in two sections, the first one to be filled after the pre-test counselling and the second after receiving BRCA test results. We assessed the factors influencing intrafamilial disclosure of genetic information for hereditary breast and ovarian cancer, family members with whom probands are more prone to share genetic information, and the perceived understanding of information received by counselees during genetic counselling. Women were accompanied to the counselling more often by their husband/partner. Among those with a positive BRCA test result, 49% intended to communicate it to their offspring and 27% to their husband/partner. Younger women, those living with their husband/partner, and those who described family communication as open/profound and spontaneous/sincere had a higher probability of being accompanied during genetic counselling and discuss about it with relatives. Spontaneous/sincere or open/profound family communication and joyful/happy familial relationships were associated with the decision to undergo genetic testing as a responsibility towards relatives. Women had a good understanding of counselling contents (mean score 9.27 in a scale 1-10). Genetic counselling providers should consider that genetic information disclosure does not depend only on the clarity of the information provided, but also on pre-existing intrafamilial communication and relationships, family structure and marital status, indicating the need for a personalised approach accounting for these factors.

Cost-effectiveness analysis of genetic diagnostic strategies for Lynch syndrome in Italy.

Lynch syndrome (LS) is an autosomal dominant condition caused by pathogenic variants in mismatch repair (MMR) genes that predispose individuals to different malignancies, such as colorectal cancer (CRC) and endometrial cancer. Current guidelines recommended testing for LS in individuals with newly diagnosed CRC to reduce cancer morbidity and mortality in relatives. Economic evaluations in support of such approach, however, are not available in Italy. We developed a decision-analytic model to analyze the cost-effectiveness of LS screening from the perspective of the Italian National Health System. Three testing strategies: the sequencing of all MMR genes without prior tumor analysis (Strategy 1), a sequential IHC and MS-MLPA analysis (Strategy 2), and an age-targeted strategy with a revised Bethesda criteria assessment before IHC and methylation-specific MLPA for patients ≥ than 70 years old (Strategy 3) were analyzed and compared to the "no testing" strategy. Quality Adjusted Life Years (QALYs) in relatives after colonoscopy, aspirin prophylaxis and an intensive gynecological surveillance were estimated through a Markov model. Assuming a CRC incidence rate of 0.09% and a share of patients affected by LS equal to 2.81%, the number of detected pathogenic variants among CRC cases ranges, in a given year, between 910 and 1167 depending on the testing strategy employed. The testing strategies investigated, provided one-time to the entire eligible population (CRC patients), were associated with an overall cost ranging between €1,753,059.93-€10,388,000.00. The incremental cost-effectiveness ratios of the Markov model ranged from €941.24 /QALY to €1,681.93 /QALY, thus supporting that "universal testing" versus "no testing" is cost-effective, but not necessarily in comparison with age-targeted strategies. This is the first economic evaluation on different testing strategies for LS in Italy. The results might support the introduction of cost-effective recommendations for LS screening in Italy.

Lynch syndrome with exclusive skin involvement: time to consider a molecular definition?

Muir-Torre syndrome (MTS) is clinically characterized by the occurrence of skin, usually sebaceous, and visceral tumors in the same individual. The most common underlying mechanism is a constitutional defect of the mismatch repair (MMR) genes that cause Lynch syndrome (LS). Herewithin we report on a 76 years-old male patient heterozygous for a pathogenic MSH2 missense substitution who presented with a striking cutaneous phenotype in the absence of typical LS visceral tumors. The patient developed 20 skin tumors, including sebaceous adenomas/carcinomas and keratoacanthomas. Two skin tumors showed immunohistochemical loss of MSH2 and MSH6 expression. There was no apparent family history of neoplasia. Based on the variable involvement of the skin and internal organs, we suggest that the definition of tumor associations that are often observed as variants of inherited tumor syndromes, such as MTS, should be guided by the underlying molecular bases. In addition, the presence of multiple sebaceous tumors, especially if showing MMR deficiency, appears to be a very strong indicator of a constitutional MMR gene defect. The reasons underlying the high phenotypic variability of cutaneous phenotypes associated with constitutional MMR defects are yet to be determined.

Orbital Desmoid-Type Fibromatosis: A Case Report and Literature Review.

PURPOSE: Desmoid-type fibromatosis is a benign fibrous neoplasia originating from connective tissue, fascial planes, and musculoaponeurotic structures of the muscles. Currently, there is no evidence-based treatment approach available for desmoid fibromatosis. In this article, a case of a patient in the pediatric age affected by desmoid fibromatosis localized in the orbit is presented. The aim of the article is to describe this unusual and rare location for the desmoid fibromatosis and outline the principle phases in the decision-making process and the therapeutic alternatives for a patient affected by desmoid fibromatosis. METHODS: The protocol of this review included study objectives, search strategy, and selection criteria. The primary end point of this study was to analyze the head and neck desmoid fibromatosis. The secondary end point was to identify the available therapies and assess their specific indications. RESULTS: The mean age of patients was 18.9 years ranging from 0 to 66, and 52% were female. A bimodal age distribution was observed, and two age peaks were identified: 0-14 years (57%) and 28-42 years (18%). The most common involved areas were the mandible (25%) followed by the neck (21%). In 86% of the cases, the treatment was the surgical resection of the disease, and only in 5% of the cases, the surgical resection was followed by adjuvant radiotherapy. CONCLUSION: The orbital location is extremely rare, especially in the pediatric population. The management of desmoid fibromatosis is based on the function preservation and the maintenance of a good quality of life, but in case of symptomatic patients or aggressive course of the disease or risk of functional damages, the surgical approach may be considered. Therapeutic alternatives to surgical resection are radiotherapy and systemic therapy.

A Specific Mutational Signature Associated with DNA 8-Oxoguanine Persistence in MUTYH-defective Colorectal Cancer.

8-Oxoguanine, a common mutagenic DNA lesion, generates G:C>T:A transversions via mispairing with adenine during DNA replication. When operating normally, the MUTYH DNA glycosylase prevents 8-oxoguanine-related mutagenesis by excising the incorporated adenine. Biallelic MUTYH mutations impair this enzymatic function and are associated with colorectal cancer (CRC) in MUTYH-Associated Polyposis (MAP) syndrome. Here, we perform whole-exome sequencing that reveals a modest mutator phenotype in MAP CRCs compared to sporadic CRC stem cell lines or bulk tumours. The excess G:C>T:A transversion mutations in MAP CRCs exhibits a novel mutational signature, termed Signature 36, with a strong sequence dependence. The MUTYH mutational signature reflecting persistent 8-oxoG:A mismatches occurs frequently in the APC, KRAS, PIK3CA, FAT4, TP53, FAT1, AMER1, KDM6A, SMAD4 and SMAD2 genes that are associated with CRC. The occurrence of Signature 36 in other types of human cancer indicates that DNA 8-oxoguanine-related mutations might contribute to the development of cancer in other organs.

Involvement of MBD4 inactivation in mismatch repair-deficient tumorigenesis.

The DNA glycosylase gene MBD4 safeguards genomic stability at CpG sites and is frequently mutated at coding poly-A tracks in mismatch repair (MMR)-defective colorectal tumors (CRC). Mbd4 biallelic inactivation in mice provided conflicting results as to its role in tumorigenesis. Thus, it is unclear whether MBD4 alterations are only secondary to MMR defects without functional consequences or can contribute to the mutator phenotype. We investigated MBD4 variants in a large series of hereditary/familial and sporadic CRC cases. Whereas MBD4 frameshifts were only detected in tumors, missense variants were found in both normal and tumor DNA. In CRC with double-MBD4/MMR and single-MBD4 variants, transition mutation frequency was increased, indicating that MBD4 defects may affect the mutational landscape independently of MMR defect. Mbd4-deficient mice showed reduced survival when combined with Mlh1-/- genotype. Taken together, these data suggest that MBD4 inactivation may contribute to tumorigenesis, acting as a modifier of MMR-deficient cancer phenotype.

The growing complexity of the intestinal polyposis syndromes.

Familial adenomatous polyposis has been the first form of inherited intestinal polyposis to be recognized. For a long time it has been considered the main polyposis syndrome, associated with an easily recognizable phenotype, with a marginal role attributed to a few very rare hamartomatous conditions. More recently, it has been gradually demonstrated that the intestinal polyposes encompass a range of conditions within a wide spectrum of disease severity, polyp histology, and extraintestinal manifestations. A growing number of genes and phenotypes has been identified, and heterogeneity of somatic molecular pathways underlying epithelial transformation in different syndromes and associated tumors has been documented. Increasing knowledge on the molecular bases and more widespread use of genetic tests has shown phenotypic overlaps between conditions that were previously considered distinct, highlighting diagnostic difficulties. With the advent of next generation sequencing, the diagnosis and the classification of these syndromes will be progressively based more on genetic testing results. However, the phenotypic variability documented among patients with mutations in the same genes cannot be fully explained by different expressivity, indicating a role for as yet unknown modifying factors. Until the latter will be identified, the management of patients with polyposis syndromes should be guided by both clinical and genetic findings.

Cancer risk associated with STK11/LKB1 germline mutations in Peutz-Jeghers syndrome patients: results of an Italian multicenter study.

BACKGROUND: Germline mutations in the STK11/LKB1 gene cause Peutz-Jeghers syndrome, an autosomal-dominantly inherited condition characterized by mucocutaneous pigmentation, hamartomatous gastrointestinal polyposis, and an increased risk for various malignancies. We here report the results of the first Italian collaborative study on Peutz-Jeghers syndrome. AIMS: To assess cancer risks in a large homogenous cohort of patients with Peutz-Jeghers syndrome, carrying, in large majority, an identified STK11/LKB1 mutation. METHODS: One-hundred and nineteen patients with Peutz-Jeghers syndrome, ascertained in sixteen different Italian centres, were enrolled in a retrospective cohort study. Relative and cumulative cancer risks and genotype-phenotype correlations were evaluated. RESULTS: 36 malignant tumours were found in 31/119 (29 STK11/LKB1 mutation carriers) patients. The mean age at first cancer diagnosis was 41 years. The relative overall cancer risk was 15.1 with a significantly higher risk (p < 0.001) in females (22.0) than in males (8.6). Highly increased relative risks were present for gastrointestinal (126.2) and gynaecological cancers (27.7), in particular for pancreatic (139.7) and cervical cancer (55.6). The Kaplan-Meier estimates for overall cumulative cancer risks were 20%, 43%, 71%, and 89%, at age 40, 50, 60 and 65 years, respectively. CONCLUSION: Peutz-Jeghers syndrome entails markedly elevated cancer risks, mainly for pancreatic and cervical cancers. This study provides a helpful reference for improving current surveillance protocols.

Three unrelated patients with congenital anterior pituitary aplasia and a characteristic physical and neuropsychological phenotype: a new syndrome?

Anterior pituitary aplasia (APA) is a very rare cause of congenital-onset multiple pituitary hormone deficiency (CO-MPHD). We report on molecular analysis and clinical follow-up of three previously reported cases of APA [Scommegna et al., 2004], who share a characteristic physical and neuropsychological profile. Mutation analysis of genes encoding transcription factors involved in pituitary development (PROP1, POUF1, HESX1, LHX3, and LHX4) did not demonstrate a any mutation. In order to identify the genetic cause underlying the phenotypes we performed an array-based comparative genomic hybridization (array-CGH), which showed a cryptic interstitial deletion of 9p (200 kb), including the TEK and MOBKL2B, in one patient. Although an apparently identical deletion was carried by the clinically normal father, we assumed that the patient's phenotype might be due to a recessive mutation in the other allele. However, sequence analysis of exons and splice junctions of these genes did not detect pathogenic or predisposing variants in the three patients. We suggest that the constellation of clinical signs in these patients constitutes a previously undescribed syndrome, whose genetic cause has yet to be identified.

Head and neck paragangliomas: genetic spectrum and clinical variability in 79 consecutive patients.

Head and neck paragangliomas (HNPGLs) are neural crest-derived tumors. In comparison with paragangliomas located in the abdomen and the chest, which are generally catecholamine secreting (sPGLs) and sympathetic in origin, HNPGLs are, in fact, parasympathetic in origin and are generally nonsecreting. Overall, 79 consecutive patients with HNPGL were examined for mutations in SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, MAX, and TMEM127 genes by PCR/sequencing. According to a detailed family history (FH) and clinical, laboratory (including metanephrines), and instrumental examinations, patients were divided into three groups: a) patients with a positive FH for HNPGL (index cases only), b) patients with a negative FH and multiple HNPGLs (synchronous or metachronous) or HNPGL associated with an sPGL, and c) patients with negative FH and single HNPGL. The ten patients in group a) proved to be SDHD mutation carriers. The 16 patients in group b) proved to be SDHD mutation carriers. Among the 53 patients in group c), ten presented with germ-line mutations (three SDHB, three SDHD, two VHL, and two SDHAF2). An sPGL was found at diagnosis or followed up in five patients (6.3%), all were SDHD mutation carriers. No SDHC, SDHA, MAX, and TMEM127 mutations were found. In SDHD mutation carriers, none of the patients affected by HNPGL associated with sPGL presented missense mutations. In conclusion, a positive FH or the presence of multiple HNPGLs is a strong predictor for germ-line mutations, which are also present in 18.8% of patients carefully classified as sporadic. The most frequently mutated gene so far is SDHD but others, including SDHB, SDHAF2, and VHL, may also be affected.