Hereditary Cancer Predisposition Syndromes Research Articles

DICER1-associated embryonal rhabdomyosarcoma and adenosarcoma of the gynecologic tract: Pathology, molecular genetics, and indications for molecular testing.

Gynecologic sarcomas are uncommon neoplasms, the majority occurring in the uterus. Due to the diverse nature of these, the description of "new" morphological types and the rarity of some of them, pathological diagnosis and treatment is often challenging. Finding genetic alterations specific to, and frequently occurring, in a certain type can aid in the diagnosis. DICER1 is a highly conserved ribonuclease crucial in the biogenesis of microRNAs and mutations in DICER1 (either somatic or germline) have been detected in a wide range of sarcomas including genitourinary embryonal rhabdomyosarcomas (ERMS) and adenosarcomas. Importantly, DICER1-associated sarcomas share morphological features irrespective of the site of origin such that the pathologist can strongly suspect a DICER1 association. A review of the literature shows that almost all gynecologic ERMS reported (outside of the vagina) harbor DICER1 alterations, while approximately 20% of adenosarcomas also do so. These two tumor types exhibit significant morphological overlap and DICER1 tumor testing may be helpful in distinguishing between them, because a negative result makes ERMS unlikely. Given that germline pathogenic DICER1 variants are frequent in uterine (corpus and cervix) ERMS and pathogenic germline variants in this gene cause a hereditary cancer predisposition syndrome (DICER1 syndrome), patients diagnosed with these neoplasms should be referred to medical genetic services. Cooperation between pathologists and geneticists is crucial and will help in improving the diagnosis and management of these uncommon sarcomas.

Genitourinary manifestations of hereditary cancer predisposition syndromes in children.

Several hereditary cancer predisposition syndromes are associated with genitourinary (GU) manifestations in children. The GU manifestation may be the first symptom of a more global syndrome to arise, which places the pediatric urologist in a unique position to impact the health of the child. Some GU manifestations are pathognomonic for a particular hereditary cancer predisposition syndrome, which can prompt genetic testing and enhanced surveillance for other features of the condition. In other cases, knowledge of an underlying hereditary cancer predisposition syndrome alters treatment decisions. This review focuses on hereditary cancer predisposition syndromes that impact the GU tract and are likely to be seen by a pediatric urologist.

Lynch Syndrome and Breast Cancer: Case Reports and Literature Review

In the era of advanced cancer genomics, our knowledge of hereditary cancer mutations continues to expand. Lynch syndrome is one of the hereditary cancer predisposition syndromes associated with an increased lifelong risk of several types of cancer development, such as colorectal, endometrial, ovarian and other. This unique syndrome is an autosomal dominant inherited disease caused by mutations on EPCAM gene or on mismatch repair genes, which lead to microsatellite instability. In this article we will present three such cases visiting our clinic. They had breast cancer and a familial or personal history of malignancy. This article summarizes what we consider important about Lynch syndrome and breast cancer.

Abstract 5587: Characterization of shared immunogenic frameshift mutations in microsatellite unstable cancers to guide the design of off-the-shelf immunotherapies

Abstract Microsatellite instability-high (MSI-H) cancers are an important model for evaluating neoantigen-based immunotherapies, given their high loads of tumor-specific antigens, evidence of T cell infiltration and exceptional response rates to checkpoint blockade. Importantly, MSI-H tumors are enriched in short nucleotide insertion/deletions in microsatellite regions (“hot spots”) within open reading frames, potentially leading to frameshift mutations shared across patients with MSI-H tumors and Lynch Syndrome, a hereditary cancer predisposition syndrome with MSI-H phenotype. We hypothesized that MSI-H tumors are enriched in recurrent frameshift mutations encoding immunogenic neoantigens and pre-selection of an optimal set of recurrent frameshift mutations, based on the multiplicity of encoded neoepitopes, diversity of interaction with common major histocompatibility complex (MHC) alleles and immunogenicity, will inform the design of off-the-shelf immune therapies for patients with MSI-H phenotype. Utilizing the whole-exome sequencing information available at The Cancer Genome Atlas, we evaluated the neoantigen profiles of patients with colorectal (n=461), stomach (n=443) and endometrial carcinoma (n=560) (COAD, STAD and UCEC, respectively) according to the aforementioned criteria and identified 37, 23 and 9 frameshift mutations encoding potentially immunogenic neoantigens, which were shared across the MSI-H population in COAD, STAD and UCEC, respectively. In an array of immunological assays utilizing peripheral blood mononuclear cells (PBMCs) from healthy donors, we characterized the immunogenicity of the neoantigens derived from the 9 frameshift peptides shared in MSI-H UCEC to assess the extent and specificity of the engendered T cell immunity. We found that each frameshift peptide could elicit antigen-specific CD8+ T cell responses in a subset of subjects tested, which suggests that MSI-H UCEC patients have an increased frequency of high-quality T cell epitopes derived from shared frameshift peptides, binding to a broad spectrum of MHC alleles, capable of inducing CD8+ T responses. Currently, utilizing blood and tissue specimens from patients with MSI-H COAD, STAD and UCEC, we are interrogating (1) the expression levels and frequencies of the selected shared neoantigens, (2) whether these neoantigens are presented in the context of MHC and (3) can elicit endogenous T cell responses. Findings from this research will guide the selection of shared neoantigens eliciting antitumor T cell immunity in patients with MSI-H tumors and will ultimately lay the foundation for common neoantigen-based, off-the-shelf cancer immunotherapy designs, which can be utilized in therapeutic and preventative settings in MSI-H cancers and Lynch Syndrome, respectively. Citation Format: Cansu Cimen Bozkus, Vladimir Roudko, Theofani Orfanelli, Stephanie Blank, Benjamin Greenbaum, Nina Bhardwaj. Characterization of shared immunogenic frameshift mutations in microsatellite unstable cancers to guide the design of off-the-shelf immunotherapies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5587.

Prevalence of germline mutations in BRCA1/2 in patients from northeastern Brazil.

e13603 Background: Identifying carriers of hereditary cancer predisposition syndromes (HCPS) improves prevention and treatment. However, due to the elevated cost of genetic testing, information on the prevalence and incidence of HCPS is scarce, depriving patients of assertive treatment―a scenario observed worldwide, especially in regions like Northeastern Brazil. In this study, we determined the prevalence of hereditary breast and ovarian cancer (HBOC) in patients from Ceará (Brazil) based on NCCN criteria. Methods: The patients (n = 267) were evaluated using NGS gene panels, while retrospective data were analyzed statistically with the chi-squared test, Fisher’s test and multinomial logistic regressions ( p< 0.05; SPSS 20.0). Results: BRCA1/2 was detected in 21.3% (57/267) of the sample, but BRCA1 was more prevalent than BRCA2 (70%; 40/57 vs 30%; 17/57) ( p< 0.001). Having two or more primary tumors ( p= 0.031) or primary ovarian cancer ( p= 0.029) was associated with the pathogenic mutation BRCA1/2. The latter was detected in patients with bilateral tumors (40%) and male breast cancer (45%), and in patients under 45 years (67%), with familial breast cancer (27%) and familial ovarian cancer (41%). In the multivariate analysis, the triple-negative phenotype was strongly associated with mutated BRCA1/2 ( p= 0.003). Conclusions: The prevalence of HBOC in our sample is compatible with rates reported worldwide. The study variables (bilaterality, male sex, age < 45 years, family history of breast or ovarian cancer, and triple-negative phenotype) reinforce the diagnostic criteria published by the NCCN.

Neuroimaging Findings in Children with Constitutional Mismatch Repair Deficiency Syndrome

Constitutional mismatch repair deficiency is a hereditary childhood cancer predisposition syndrome characterized by brain tumors and colorectal and hematologic malignancies. Our objective was to describe the neuroimaging findings in patients with constitutional mismatch repair deficiency. This retrospective study included 14 children with genetically confirmed constitutional mismatch repair deficiency who were referred to 2 tertiary pediatric oncology centers. Fourteen patients from 11 different families had diagnosed constitutional mismatch repair deficiency. The mean age at presentation was 9.3 years (range, 5-14 years). The most common clinical presentation was brain malignancy, diagnosed in 13 of the 14 patients. The most common brain tumors were glioblastoma (n = 7 patients), anaplastic astrocytoma (n = 3 patients), and diffuse astrocytoma (n = 3 patients). Nonspecific subcortical white matter T2 hyperintensities were noted in 10 patients (71%). Subcortical hyperintensities transformed into overt brain tumors on follow-up imaging in 3 patients. Additional non-neoplastic brain MR imaging findings included developmental venous anomalies in 12 patients (85%) and nontherapy-induced cavernous hemangiomas in 3 patients (21%). On brain MR imaging, these patients have both highly characteristic intra-axial tumors (typically multifocal high-grade gliomas) and nonspecific findings, some of which might represent early stages of neoplastic transformation. The incidence of developmental venous anomalies is high in these patients for unclear reasons. Awareness of these imaging findings, especially in combination, is important to raise the suspicion of constitutional mismatch repair deficiency in routine diagnostic imaging evaluation or surveillance imaging studies of asymptomatic carriers because early identification of the phenotypic "gestalt" might improve outcomes.

A Multi-Institutional Cohort of Therapy-Associated Polyposis in Childhood and Young Adulthood Cancer Survivors.

Prior small reports have postulated a link between gastrointestinal polyposis and childhood and young adulthood cancer (CYAC) treatment (therapy-associated polyposis; TAP), but this remains a poorly understood phenomenon. The aim of this study was to describe the phenotypic spectrum of TAP in a multi-institutional cohort. TAP cases were identified from eight high-risk cancer centers. Cases were defined as patients with ≥10 gastrointestinal polyps without known causative germline alteration or hereditary colorectal cancer predisposition syndrome who had a history of prior treatment with chemotherapy and/or radiotherapy for CYAC. A total of 34 TAP cases were included (original CYAC: 27 Hodgkin lymphoma, three neuroblastoma, one acute myeloid leukemia, one medulloblastoma, one nephroblastoma, and one non-Hodgkin lymphoma). Gastrointestinal polyposis was first detected at a median of 27 years (interquartile range, 20-33) after CYAC treatment. A total of 12 of 34 (35%) TAP cases had ≥50 colorectal polyps. A total of 32 of 34 (94%) had >1 histologic polyp type. A total of 25 of 34 (74%) had clinical features suggestive of ≥1 colorectal cancer predisposition syndrome [e.g., attenuated familial adenomatous polyposis (FAP), serrated polyposis syndrome, extracolonic manifestations of FAP, mismatch repair-deficient colorectal cancer, or hamartomatous polyposis] including 8 of 34 (24%) with features of multiple such syndromes. TAP is an apparently acquired phenomenon that should be considered in patients who develop significant polyposis without known causative germline alteration but who have had prior treatment for a CYAC. Patients with TAP have features that may mimic various hereditary colorectal cancer syndromes, suggesting multiple concurrent biologic mechanisms, and recognition of this diagnosis may have implications for cancer risk and screening.

Distinct clinical phenotype and genetic testing strategy for Lynch syndrome in China based on a large colorectal cancer cohort.

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) predisposition syndrome. We performed a large-scale study to assess a screening strategy for identifying LS in Chinese CRC patients in routine clinical testing. A total of 4,195 eligible CRCs were universally screened. Then, 8.7% of CRCs were detected with dMMR. The incidence of LS was 2.7% (115 of 4,195) in this cohort; among patients over 70 years of age, only 0.3% (2 of 678) were diagnosed as LS. Then, 17.4% of LS cases showed large genomic deletions/duplications. LS probands developed CRCs predominantly at proximal colon location. The frequency of BRAF V600E mutation among Chinese CRCs was significantly lower than that among Western populations, and MLH1 promoter methylation significantly improved the efficiency of genetic screening for LS among MLH1-deficient patients. A comprehensive molecular testing strategy that includes detection of large genomic rearrangements is imperative for the diagnosis of LS. Among CRC patients aged 70 years or younger, a selective strategy for LS screening might be considered for routine clinical testing.

Group plus \u201cmini\u201d individual pre-test genetic counselling sessions for hereditary cancer shorten provider time and improve patient satisfaction

BackgroundGenetic counselling (GC) is an integral component in the care of individuals at risk for hereditary cancer predisposition syndromes (CPS). In many jurisdictions, access to timely counselling and testing is limited by financial constraints, by the shortage of genetics professionals and by labor-intensive traditional models of individual pre and post-test counselling. There is a need for further research regarding alternate methods of GC service delivery and implementation. This quality improvement project was initiated to determine if pretest group GC followed immediately by a ‘mini’ individual session, would be acceptable to patients at risk for hereditary breast and colon cancer.MethodsPatients on waitlists for GC at the Provincial Medical Genetics Program in St. John’s, NL, Canada (n = 112), were contacted by telephone and offered the option of a group counselling session (GGC), followed by a “mini” individual session, versus (TGC) traditional private appointments. GGC sessions consisted of a cancer genetics information session given to groups of 6–20 followed by brief 20 min “mini” individual sessions with the patient and genetic specialist. TGC individual appointments provided the same cancer genetics information and counselling to one patient at a time in the classic model. All but 2 participants selected group+mini session. A de-identified confidential 12-item, Likert scale survey was distributed at the conclusion of mini-sessions to measure perceptions of GGC and satisfaction with this counselling model.ResultsSixty participants completed questionnaires. The majority of participants strongly agreed that they were comfortable with the group session (58/60); the explanation of cancer genetics was clear (54/59); they understood their cancer risks (50/60); and they would recommend such a session to others (56/59). 38/53 respondents disagreed or strongly disagreed that they would prefer to wait for a traditional private appointment. All 5 participating genetic counselors reported a preference for this model. At the end of the pilot project, the waitlist for counselling/testing was reduced by 12 months.ConclusionsGroup pre-test genetic counselling combined with immediate “mini” individual session is strongly supported by patients and reduces wait times. Additional formal investigation of this approach in larger numbers of patients is warranted.

Abstract P6-08-34: Genetic testing for hereditary breast cancer in Brazilian public health system: The experience of tumor board reference in a cancer center

Abstract Introduction: In Brazil, genetic testing for hereditary cancer predisposition syndromes, including Hereditary Breast Cancer (HBC), is not covered by the public health system (SUS) and was only incorporated in most private health insurance (PHI) plans after 2013. Nonetheless, considering that only 22% of the Brazilian population has access to private health system and the high cost of genetic testing in private laboratories, the majority of Brazilian women at risk for HBC do not have access to a genetic diagnosis. In this context, we have implemented at A.C.Camargo Cancer Center (ACCCC – a reference Cancer Center in Brazil which serves both the private and public health systems) a pilot program that offers genetic testing for SUS patients at risk for HBC. The goal of this study is to present the adopted clinical criteria and the corresponding detection rate of pathogenic variants in HBC genes observed in our cohort in comparison to detection rates observed in private health scenario. Methods: Since 2018, 34 cases of breast cancer patients from SUS under medical follow-up at ACCCC and at risk for HBC were discussed in multidisciplinary Tumor Board meetings. The Tumor Board team consists of health care professionals from different specialties, including medical oncologists, surgeons, pathologists, molecular biologists, and clinical geneticists. The clinical criteria defined for referring patients to genetic testing were: (1) personal history of triple negative breast cancer (TNBC) in any age; (2) personal history of non-TNBC developed before 30 years old, positive family history of cancer, and a PENN II model prediction of >15% risk in carry a BRCA1/2 mutation; and (3) personal history of BC in any age and a PENN II model prediction of >30% risk in carry a BRCA1/2 mutation. Detection rates of SUS patients were compared to BRCA1/2 results obtained during the same period from the ACCCC Laboratory of Genomics Diagnostics that serves manly PHI and private patients. Genetic tests were performed using different gene panels containing 26 or 94 genes. Results: Pathogenic (P) and likely pathogenic (LP) variants were detected in 38% of SUS patients (13/34), with a higher proportion of BRCA1 carriers (69% - 9 patients) than of BRCA2 (1 patient). Aside BRCA1/2 mutations that were detected in 10 patients (29%), P/LP variants were also identified in BRIP1, CHEK2, and PALB2 (1 patient each). The rate for BRCA1/2 P/LP variants in PHI cohort was 9.8% (23/234 patients), with a lower proportion of BRCA1 carriers (22%) than of BRCA2 (40%). It was identified a high rate of P/LP variants in TNBC from SUS cohort (62% - 10/16 cases) and a marked association of BRCA1 and TNBC, with 80% (8/10) of hereditary TNBC having BRCA1 mutations. The mean turnaround time for genetic test results was 4 months, varying from 2 to 8 months. From 11 patients with P/LP variants that already received the genetic test result, 5 underwent prophylactic contralateral mastectomy and/or bilateral salpingo-oophorectomy. Conclusions: The introduction of genetic testing for HBC made possible to tailor preventative measures for women at high risk, including prophylactic surgery and screening protocols. However, in many developing countries, the high cost of genetic tests and the lack of national policies prevent its application in clinical practice for the majority of the population. By defining more stringent clinical criteria for HBC genetic test, we detected a mutation rate three times as high as that detected in the private health scenario. With the continuity our study, we expect to contribute to the development of national standards for HBC screening and to encourage the implementation of consistent and cost-effective genetic testing under the real-life conditions of our public health system, maximizing the benefit for the population with the available resources. Citation Format: Dirce M Carraro, Giovana T Torrezan, Karina M Santiago, Maria\ Nirvana da Cruz Formiga, Solange M Sanches, Fabiana BA Makdissi, Breast Cancer Tumor Board Team. Genetic testing for hereditary breast cancer in Brazilian public health system: The experience of tumor board reference in a cancer center [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-08-34.

Dissemination of Genetic Information in Swiss Families with Lynch Syndrome: A Qualitative Exploratory Study

In Switzerland, out of respect for privacy and in accordance with federal laws regarding genetic testing, information sharing about hereditary cancer predisposition syndromes is initiated solely by the proband and never from the medical clinic. Thus, an essentially medical task, communication of cancer risk and possible testing, is always delegated, at least initially, to the patient. In order to explore this communication process, its associated difficulties and possibilities for improvements, we have conducted a study with Lynch syndrome families in Western Switzerland. Semi-structured interviews were conducted with 19 participants (12 female, 7 male), either in person or by telephone. We specifically explored whether participants considered transmission of genetic information a medical or personal responsibility. Other recurrent themes were also identified, including family wisdom and superstitions, emotional responses, and parent-child guilt. The identification of a cancer predisposition and the request to communicate this with family members remained a traumatic experience for many. However, within this group, which may be biased towards better communicators, the information was shared with at risk relatives. Despite inherent difficulties, the majority wish to retain the responsibility for contacting family members. This suggests that in Switzerland, and possibly in other countries with similar rules/attitudes towards privacy, efforts to improve cascade screening should be directed towards facilitating intra-familial communication.

Somatic mismatch repair testing in evaluation of Lynch syndrome: The gap between preferred and current practices.

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome primarily defined by increased risk for colorectal and uterine cancers. Individuals with germline pathogenic variants in the mismatch repair (MMR) genes (MLH1, MSH2/EPCAM, MSH6, and PMS2) are diagnosed with LS and recommended high-risk screening protocols to increase prevention and early detection of LS-related cancers. Tumor testing can help identify those at high risk for LS, but sometimes creates uncertainty with discordant screening and germline results, or unexplained mismatch repair deficiency (UMMRD). Somatic testing for MMR genes may help resolve UMMRD, potentially clarifying LS status and modifying cancer surveillance. However, guidelines for such testing are currently limited. This survey of cancer genetic counselors (GCs) aimed to examine current versus preferred ordering practices and interpretation of somatic MMR testing results in LS evaluation. Two hundred eligible GCs practicing in the United States and Canada were recruited from the National Society of Genetic Counselors. Participants answered questions regarding ordering practices, barriers to somatic MMR testing, theoretical scenarios, and desire for further guidelines. Statistical analysis was performed using chi-square, Fisher's exact, and Wilcoxon rank-sum tests, while themes were identified from free-text responses. Most respondents did not include somatic MMR testing in the LS work-up, despite three-quarters reporting they were 'somewhat comfortable' or 'extremely comfortable' with interpreting these results. Approximately half of participants indicated interest in ordering concurrent somatic MMR and germline testing for each of the four theoretical scenarios. Over three-quarters of individuals reported barriers to ordering somatic MMR testing, with cost and coordinating tissue samples most commonly cited. The frequently reported laboratory- and insurance-related barriers may contribute to the gap between preferred and current ordering practices for somatic MMR testing. Nearly all respondents endorsed additional guidelines for this testing, which could reduce barriers and inform screening recommendations for patients with UMMRD and their family members.

Genetic testing for hereditary gastrointestinal cancer syndromes: Interpreting results in today's practice.

Advances in genomics have led to the discovery of multiple predisposition genes linked to increased risk for gastrointestinal (GI) cancer. The goal of this review is to assist physicians and allied health care professionals in understanding the current paradigm shift in clinical genetic testing for hereditary GI cancer predisposition syndromes; with a focus on multigene panel testing (MGPT) and test results interpretation. Additionally, this review introduces direct-to-consumer and at-home genetic testing. Both delivery models are increasing in popularity and clinicians will be expected to address results from patients who utilize these approaches. Technological advancement and reduced costs have transformed the genetic testing approach from single syndrome genetic testing to broad-based MGPT. MGPT has the benefit of aiding in efficient genetic diagnosis; however, clinicians should be knowledgeable of possible results including variants of uncertain significance, secondary findings, and pathogenic variants within high- and low-to-moderate risk genes, as well as genes for which risks are ill-defined. The landscape of clinical cancer genetics continues to evolve rapidly. Timely updates are critical to ensure the medical community is familiar with current considerations and ongoing challenges regarding genetic testing for hereditary GI cancer susceptibility.

Abstract 2032: Investigating the contribution of mTORC1-dependent signaling in the microenvironment to cancer onset in Li-Fraumeni syndrome

Abstract We are investigating the role of stromal mTORC1 signaling in the development of malignancy in individuals with Li-Fraumeni Syndrome (LFS). LFS is a hereditary cancer predisposition syndrome that is associated with germline mutations in TP53. Individuals with LFS are faced with a significant lifetime risk of developing a wide spectrum of early-onset malignancies, thus necessitating the identification of pharmacologic agents to prevent tumour onset. Chemical inhibitors of the mTORC1 pathway have been shown to promote lifespan extension and delay or even prevent tumour onset in LFS mouse models. These findings are noteworthy, since they suggest that mTORC1 signaling plays a central role in favoring tumorigenesis in LFS. mTORC1 signaling has been implicated in promoting the pro-tumorigenic senescence-associated secretory phenotype (SASP). The SASP constitutes the release of soluble factors, such as cytokines, growth factors, and proteases from senescent cells into the microenvironment, thus promoting oncogenesis in a paracrine manner. Mutant p53 has also been shown to promote the secretion of a variety of pro-tumorigenic factors from various cell types. We believe that mTORC1 signaling in LFS stromal cells favors the production and secretion of pro-tumorigenic factors, which may induce changes in the surrounding tissue to promote development of a precancerous niche, thus favoring tumorigenesis. Our objectives are to investigate the contribution of stromal cells and stromal secreted factors in favoring tumorigenesis in LFS, and to investigate the role of mTORC1 signaling in favoring these altered stromal phenotypes. To determine whether patient-derived LFS fibroblasts with TP53 mutations secrete more pro-tumorigenic cytokines than non-LFS fibroblasts, we performed protein arrays with conditioned media (CM) from fibroblast cultures. We saw that LFS fibroblasts secrete markedly higher levels of pro-tumorigenic, SASP-related cytokines. Next, we treated spheroids formed from cancer cells of a common LFS subtype (osteosarcoma) with CM from LFS and non-LFS fibroblast cultures. LFS fibroblast CM had a robust pro-proliferative effect on spheroids, while non-LFS fibroblast CM inhibited spheroid growth. To further address these aims in vivo, we co-injected LFS fibroblasts with cancer cells of a common LFS subtype [rhabdomyosarcoma (RMS)] into Nude mice. We found that tumours formed from the co-injection of RMS cells with LFS fibroblasts grew to be larger than tumours formed from co-injection with non-LFS fibroblasts. Thus far, we have observed that LFS stromal constituents favor cancer cell proliferation in vitro and in vivo. We are currently investigating the role that mTORC1 signaling plays in these processes by repeating these studies following chemical and genetic perturbation of mTORC1 signaling in the LFS fibroblasts. Citation Format: Camilla Giovino, Nish Patel, Sangeetha Paramathas, Gaetano Zafarana, Ran Kafri, David Malkin. Investigating the contribution of mTORC1-dependent signaling in the microenvironment to cancer onset in Li-Fraumeni syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2032.

Adequacy of self-reported family history in electronic health record for genetic risk assessment for Lynch syndrome.

1515 Background: Self-reported family cancer history (FCH) is one of the key indicators of hereditary cancer risk. Studies have shown that accurate FCH documentation by healthcare providers is suboptimal, but data regarding patient-provided FCH are limited. We evaluated the quality of FCH as entered by the patient into the electronic health record (EHR) to determine its adequacy for Lynch syndrome (LS) risk assessment. Methods: At our tertiary referral cancer center, FCH is self-reported via an online questionnaire sent prior to appointment, which is reviewed/updated by clinic nurse during initial visit and then imported into EHR review of systems. Records of all new patients from September 2016 to August 2017 were retrospectively reviewed and analyzed. FCH quality was estimated by calculating rates of reporting of 3 FCH variables required for PREMM5, a risk-prediction model for LS. Parameters required for the model were sex, age, personal history of cancer, and for FCH, degree of kinship (first/second degree), cancer site/type, and age at diagnosis. Results: Of 47,647 unique patients, 47.5% reported FCH for 1 or more relative (46.1% were first degree, 64.8% second degree, 3.0% other, and 2.4% missing). A cancer type/site was specified for 88.8% reporting FCH. Age at diagnosis was listed for 21.7% of the relatives’ cancers. Overall, only 20.9% provided all 3 FCH data elements required for running PREMM5 (9.9% of the total sample, n=4738). Fewer men (9.5%) than women (28.1%) provided all 3 FCH elements. Furthermore, 46.7% of breast cancer patients, 21.9% of gastrointestinal cancer patients, 47.2% and 23.1% of patients seen for cancer prevention screening and endoscopy respectively, reported 3 FCH elements. Lower rates were observed for other cancers. Conclusions: Patient self-reported FCH is suboptimal for estimation of LS risk and genetic counseling referral. Future steps to optimize online patient-facing FCH collection to enable routine automated risk-assessment in an essentially provider-free setting may include, patient education regarding importance of FCH, EHR prompts for FCH completion, and implementation of algorithms in EHRs using FCH to identify patients at risk for hereditary cancer predisposition syndromes.

"I remember how I felt, but I don't remember the gene": Families' experiences of cancer-related genetic testing in childhood.

Genetic testing in children for hereditary cancer predisposition syndromes (CPSs) involves unique psychosocial and family-systems considerations. This retrospective study explored the perspectives and emotional reactions of parents and young adults about cancer-related genetic counseling and testing offered to children in the family. Families were eligible if they had considered genetic testing for a child (≤18 years) within the family. Parents and young adults ≥16 years participated in semistructured interviews that we coded and identified key themes. We also quantitively assessed emotional distress, quality of life, impact of receiving genetic cancer risk information, and service-related satisfaction. From 35 interviews (26 parents, nine young adults), we identified themes spanning families' experiences from referral to genetic services to the longer term impact of receiving information about family cancer risk from testing of children. Supported by quantitative data, families generally described positive experiences of genetic services and reported benefits to genetic testing. Nevertheless, families faced unique emotional and relational challenges that changed over the family lifecycle. Those challenges differed according to whether the child was asymptomatic or had a cancer diagnosis at testing. Parents of children with cancer described genetic consultations as a secondary concern to the immediate stressors of their child's treatment. We conclude that the successful integration of cancer genetics into pediatric cancer care requires specialist pediatric genetic counseling and psychosocial support services that are able to respond to families' changing needs.

Lynch Syndrome: From Screening to Diagnosis to Treatment in the Era of Modern Molecular Oncology.

Lynch syndrome is a hereditary cancer predisposition syndrome caused by germline alterations in the mismatch repair genes and is the most common etiology of hereditary colorectal cancer. While Lynch syndrome was initially defined by the clinical Amsterdam criteria, these criteria lack the sensitivity needed for clinical utility. This review covers the evolution of screening for Lynch syndrome from the use of tumor microsatellite instability and/or somatic alterations in mismatch repair protein expression by immunohistochemistry to the newest methods using next-generation sequencing. Additionally, it discusses the clinical implications of the diagnosis of Lynch syndrome as it affects cancer therapeutics and the role of screening in noncolorectal Lynch-associated cancers. As molecular oncology continues to evolve, it is crucial to remain current on the increasing complexity of Lynch syndrome diagnostics and treatment options.

Abstract P4-03-07: Analysis of hereditary cancer syndromes by using a panel of genes: Novel and multiple pathogenic mutations

Abstract BACKGOUND: Hereditary cancer predisposition syndromes are believed to be responsible for approximately 5-10% of all diagnosed cancer cases. In the past, single genes analysis of certain high risk genes was used for the determination of the genetic cause of cancer heritability in certain families. The selection of genes was mainly based on the family history of the individuals analyzed and included only highly associated genes (e.g. the BRCA1 and BRCA2 genes for families with breast cancer history. Nowadays though, the application of Next Generation Sequencing (NGS) technology has facilitated multigene panel analysis and is widely used in clinical practice, for the identification of individuals with cancer predisposition gene mutations. AIM: The aim of this study was to investigate the extent and nature of mutations in 36 genes implicated in hereditary cancer predisposition in individuals referred for testing in our lab. MATERIALS & METHODS: In total, 1197 individuals were referred for testing in our lab in the past four years from Greece, Romania and Turkey. The analysis of genes involved in hereditary cancer predisposition was performed using two NGS approaches. The first 451 individuals were analyzed using an amplicon based sequencing method (26 gene panel), while the following 746 individuals were analyzed using a capture based method (33 gene panel). Genomic DNA was enriched for targeted regions of 36 genes involved in hereditary predisposition to cancer included in both versions of the panel (APC, BMPR1A, BRCA1, BRCA2, CDH1, CDK4, CDKN2A, EPCAM, MEN1, MLH1, MSH2, MSH6, MUTYH, PALB2, PMS2, PTEN, RET, SMAD4, STK11, TP53, VHL, ATM, BRIP1, CHEK2, NBN, RAD51C, RAD51D, BARD1, BLM, CHEK1, ABRAXAS1 (FAM175A), MRE11 (MRE11A), NF1, RAD50, RAD51B, XRCC2). Sequencing was carried out using the Illumina NGS technology. Reads were aligned to the reference sequence (GRCh37), and sequence changes were identified and interpreted in the context of a single clinically relevant transcript. The presence of large genomic rearrangements was investigated by computational analysis of NGS results and the use of MLPA for 13 genes. All clinically significant observations were confirmed by orthogonal technologies. RESULTS: In total, a pathogenic mutation was identified in 259 of the 1197 individuals (21.6%) analyzed while a VUS was identified in 35.7% of the cases. Clinically significant mutations were identified in 29 of the genes analyzed. Concerning the mutation distribution among individuals with positive findings, 44.7% of them were located in BRCA1/2 genes whereas 20.9%, 19.9%, and 14.5% in high, moderate and low risk genes respectively. In addition to BRCA1 and BRCA2 genes other highly mutated genes were CHEK2 (10.6%), PALB2 (7.1%), MUTYH (7.1%) and ATM (4.3%). Of note is that 25 of the 259 positive individuals (9.7%) carried clinically significant mutations in two different genes and 5.8% had a large genomic rearrangement (LGR). CONCLUSIONS: Our results support the clinical significance of analysis of a panel of genes involved in hereditary cancer predisposition. In our cohort, analysis of this panel allowed for the identification of 8.3% additional pathogenic variants in moderate/low risk genes, enabling personalized management of these individuals. Citation Format: Tsoulos N, Tsaousis GN, Papadopoulou E, Agiannitopoulos K, Pepe G, Kambouri S, Apessos A, Diamantopoulos N, Floros T, Iosifidou R, Katopodi O, Koumarianou A, Markopoulos C, Papazisis K, Venizelos V, Xanthakis I, Xepapadakis G, Banu E, Eniu DT, Negru S, Stanculeanu DL, Ungureanu A, Ozmen V, Tansan S, Tekinel M, Yalcin S, Nasioulas G. Analysis of hereditary cancer syndromes by using a panel of genes: Novel and multiple pathogenic mutations [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-03-07.

Updates on progress in cancer screening for children with hereditary cancer predisposition syndromes.

A significant proportion of pediatric cancer occurs in children with hereditary cancer predisposition syndromes. Their survival may be significantly improved and/or late effects diminished through screening for their greatly elevated cancer risks. Here, an overview of new developments in the field of pediatric cancer surveillance is provided. Consensus-based screening guidelines have been developed for most syndromes associated with childhood cancer risks. Studies evaluating the clinical utility of these screening regimens have also been emerging. This review focuses on three conditions for which consensus screening recommendations have been evolving in response to new evidence: Beckwith-Wiedemann syndrome, Li-Fraumeni syndrome, and constitutional mismatch repair deficiency syndrome. For each condition, recently proposed screening guidelines and relevant evidence are described and potential future directions for improving cancer surveillance practices are anticipated. Also, the implications of several recent studies exploring the psychosocial aspects of screening in these conditions are discussed. Significant strides have been made in cancer surveillance for children with hereditary cancer predisposition syndromes. A continued emphasis on consensus-driven screening guidelines and collaborative research evaluating the clinical utility of recommended screening methodologies will lead to further improvements in the clinical outcomes of these vulnerable children.

Recent advances in Lynch syndrome.

Lynch syndrome is one of the most common hereditary cancer predisposition syndromes and is associated with increased risks of colorectal and endometrial cancer, as well as multiple other cancer types. While the mechanism of mismatch repair deficiency and microsatellite instability and its role in Lynch-associated carcinogenesis has been known for some time, there have been significant advances recently in diagnostic testing and the understanding of the molecular pathogenesis of Lynch tumors. There is also an increased awareness that the clinical phenotype and cancer risk varies by specific mismatch repair mutation, which in turn has implications on surveillance strategies for patients. Even the treatment of Lynch-associated cancers has changed with the addition of immunotherapy for advanced disease. This progress report aims to review some of the many advances in epidemiology, molecular pathogenesis, diagnosis, clinical phenotype, cancer surveillance, treatment, and chemo- and immune-prevention strategies in the Lynch syndrome field over the past 5years.