High-penetrance Cancer Susceptibility Genes Research Articles

Classification of Variants of Reduced Penetrance in High Penetrance Cancer Susceptibility Genes: Framework for Genetics Clinicians and Clinical Scientists by CanVIG-UK (Cancer Variant Interpretation Group-UK)

PurposeCurrent practice is to report and manage likely pathogenic/pathogenic variants in a given cancer susceptibility gene (CSG) as though having equivalent penetrance, despite increasing evidence of inter-variant variability in risk associations. Using existing variant interpretation approaches, largely based on full-penetrance models, variants where reduced penetrance is suspected may be classified inconsistently and/or as variants of uncertain significance (VUS). We aimed to develop a national consensus approach for such variants within the Cancer Variant Interpretation Group UK (CanVIG-UK) multidisciplinary network. MethodsA series of surveys and live polls were conducted during and between CanVIG-UK monthly meetings on various scenarios potentially indicating reduced penetrance. These informed the iterative development of a framework for the classification of variants of reduced penetrance by the CanVIG-UK Steering and Advisory Group (CStAG) working group. ResultsCanVIG-UK recommendations for amendment of the 2015 ACMG/AMP variant interpretation framework were developed for variants where (A) Active evidence suggests a reduced penetrance effect size (e.g. from case-control or segregation data) (B) Reduced penetrance effect is inferred from weaker/potentially-inconsistent observed data. ConclusionsCanVIG-UK propose a framework for the classification of variants of reduced penetrance in high-penetrance genes. These principles, whilst developed for CSGs, are potentially applicable to other clinical contexts.

Comprehensive assessment of germline pathogenic variant detection in tumor-only sequencing

Background:Tumor-only sequencing, implemented for the identification of somatic variants, is oftentimes used for the detection of actionable germline variants. We sought to determine whether tumor-only sequencing assays are suitable for detection of actionable germline variants, given their importance for the delivery of targeted therapies and risk-reducing measures.Patients and methods:The detection of germline variants affecting moderate- and high-penetrance cancer susceptibility genes (CSGs) by tumor-only sequencing was compared to clinical germline testing in 21 333 cancer patients who underwent tumor and germline testing using the Food and Drug Administration (FDA)-authorized Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Targets (MSK-IMPACT) assay. Seven homologous recombination deficiency (HRD), two DNA damage response (DDR) and four mismatch repair (MMR) genes, as well as NF1, RB1 and TP53 were included in the analysis. FDA-authorized and New York State Department of Health-approved sequencing methods for germline, tumor/normal and tumor-only sequencing assays and analytical pipelines were employed.Results:In patients who underwent tumor and germline sequencing, as compared to clinical genetic testing, tumor-only sequencing failed to detect 10.5% of clinically actionable pathogenic germline variants in CSGs, including 18.8%, 12.8% and 7.3% of germline variants in MMR, DDR and HRD genes, respectively. The sensitivity for detection of pathogenic germline variants by tumor-only sequencing was 89.5%. Whilst the vast majority of pathogenic germline exonic single-nucleotide variants (SNVs) and small indels were detected by tumor-only sequencing, large percentages of germline copy number variants, intronic variants and repetitive element insertions were not detected.Conclusions:Tumor-only sequencing is adequate for the detection of clinically actionable germline variants, particularly for SNVs and small indels; however, a small subset of alterations affecting HRD, DDR and MMR genes may not be detected optimally. Therefore, for high-risk patients with negative tumor-only sequencing results, clinical genetic testing could be considered given the impact of these variants on therapy and genetic counseling.

Germline Cancer Susceptibility Gene Testing in Unselected Patients with Hepatobiliary Cancers: A Multi-Center Prospective Study.

Data from germline testing in unselected patients with hepatobiliary cancers are limited. Identification of germline predisposition can have important implications on cancer treatment and family counseling. To determine prevalence of pathogenic germline variants (PGV) in patients with hepatobiliary cancer, we undertook a prospective multi-site study of germline sequencing using a >80-gene next-generation sequencing platform among patients with hepatobiliary cancers receiving care at Mayo Clinic Cancer Centers between April 1, 2018 and March 31, 2020. Patients were not selected on the basis of stage, family cancer history, ethnicity, or age. Family cascade testing was offered at no cost. Of 205 patients, the median age was 65 years, 58.5% were male, 81% were White, and 64.4% had cholangiocarcinoma, 21.5% hepatocellular carcinoma, 7.8% gallbladder cancer, and 4.3% carcinoma of ampulla of Vater. PGV were found in 15.6% (n = 32) of patients, including 23 (71%) in moderate and high penetrance cancer susceptibility genes. A total of 75% of patients with a positive result would not have been detected using guidelines for genetic evaluation. Prevalence of PGV was 15.7% in intrahepatic cholangiocarcinoma, 17% in extrahepatic cholangiocarcinoma, 15.9% in hepatocellular cancer, and 33% in carcinoma of ampulla of Vater. On the basis of these genetic findings, 55% were potentially eligible for approved precision therapy and/or clinical treatment trials. Universal multi-gene panel testing in hepatobiliary cancers was associated with detection of heritable mutations in over 15% of patients most of whom would not have been tested using current guidelines. Germline testing should be considered in all patients with hepatobiliary cancers. PREVENTION RELEVANCE: Universal multi-gene testing in hepatobiliary cancers was associated with heritable mutations in over 15% of patients, most of whom would not have been tested using current guidelines. 55% were potentially eligible for approved precision therapy and/or clinical treatment trials. Germline testing should be considered in all patients with hepatobiliary cancers.

A Case-Based Approach to Understanding Complex Genetic Information in an Evolving Landscape.

The rapid integration of highly sensitive next-generation sequencing technologies into clinical oncology care has led to unparalleled progress, and yet these technological advances have also made genetic information considerably more complex. For instance, accurate interpretation of genetic testing for germline/inherited cancer predisposition syndromes and somatic/acquired pathogenic variants now requires a more nuanced understanding of the presence and incidence of clonal hematopoiesis and circulating tumor cells, with careful evaluation of pathogenic variants occurring at low variant allele frequency required. The interplay between somatic and germline pathogenic variants and awareness of distinct genotype-phenotype manifestations in various inherited cancer syndromes are now increasingly appreciated and can impact patient management. Through a case-based approach, we focus on three areas of particular relevance to the treating clinician oncologist: (1) understanding clonal hematopoiesis and somatic mosaicism, which can be detected on germline sequencing and lead to considerable confusion in clinical interpretation; (2) implications of the detection of a potentially germline pathogenic variant in a high-penetrance cancer susceptibility gene during routine tumor testing; and (3) a review of gene-specific risks and surveillance recommendations in Lynch syndrome. A discussion on the availability and difficulties often associated with direct-to-consumer genetic testing is also provided.

High prevalence of actionable germline variants in unselected endometrial cancer (EC) patients.

5577 Background: The use of upfront germline genetic testing for cancer patients to identify hereditary syndromes and to aid in treatment decision making has increased dramatically. Recent evidence suggests that such testing should be considered for all solid tumors. In EC, mismatch repair deficiency (MMRd) has emerged as an important molecular marker for treatment with checkpoint inhibitors. MMRd is the hallmark of Lynch syndrome (LS), the most common hereditary cause of EC. Therefore, identifying LS not only affords opportunities for cancer prevention but also for making treatment decisions for women who already have EC. Although tumor-based screening is highly effective, some LS diagnoses will be missed. Upfront multi-gene panel testing (MGPT) for EC has been evaluated as an alternative approach to identifying LS with the potential to simultaneously find actionable germline variants in other cancer susceptibility genes (CSGs). Our objective was to determine the frequency and types of actionable germline variants in a large, unselected group of women with EC. Methods: Prospective germline MGPT for 47 CSGs was performed for 961 unselected EC cases. Patients diagnosed from 2017-2020 were enrolled at nine different institutions. Clinicopathologic data were abstracted from patients’ records. Results: 101 likely pathogenic (LP) or pathogenic variants (PV) were identified in 98 women (10.2%). LP/PVs in LS genes were most common: 29 LS cases were identified (3.02%, 95% CI 2.1 - 4.3%). MGPT found 9 cases (one-third of LS cases) that were not identified by tumor screening: 6 were from institutions that do not perform tumor screening and 3 had normal immunohistochemistry. There were 72 LP/PVs found in 17 different CSGs. 21 patients (2.1%) had LP/PVs in high penetrance CSGs other than the LS genes, 19 of which were in genes associated with breast and/or ovarian cancer (4 in BRCA1, 6 in BRCA2, 6 in BRIP1, 2 in PALB2, 1 in RAD51C). BRCA1/2 PVs (1.04% of the study population, 95% CI 0.6 - 1.9%) were significantly more frequent in women with type II cancers than the rest of the cohort (P =.005, HR 2.00, 95% CI 1.16 - 4.75). 21 additional LP/PVs were found in moderate risk CSGs ( ATM, CHEK2, NBN, NF1). Conclusions: Upfront MGPT in an unselected EC population improved LS diagnosis and identified an additional 2% of patients with LP/PVs in highly penetrant CSGs. The enrichment of germline BRCA1/2 PVs in type II cancers is consistent with prior reports that non-endometrioid tumors are frequently deficient in homologous recombination. Germline BRCA mutation is a known predictive biomarker in ovarian cancer and an attractive therapeutic target in EC. Knowing germline status at the time of diagnosis facilitates further delineation of germline/phenotype associations, and it defines a genetic syndrome allowing for cancer prevention. Upfront MGPT in EC provides clinically impactful information and should be adopted into routine clinical care. Clinical trial information: NCT03460483.

Germline Cancer Susceptibility Gene Testing in Unselected Patients With Colorectal Adenocarcinoma: A Multicenter Prospective Study

Hereditary factors play a role in the development of colorectal cancer (CRC). Identification of germlinepredisposition can have implications on treatment and cancer prevention. This study aimedto determine the prevalence of pathogenic germline variants (PGVs) in CRC patients using a universal testing approach, association with clinical outcomes, and the uptake of family variant testing. We performed a prospective multisite study of germline sequencing using a more than 80-gene next-generation sequencing platform among CRC patients (not selected for age or family history) receiving care at Mayo Clinic Cancer Centers between April 1, 2018, and March 31,2020. Of 361 patients, the median age was 57 years (SD, 12.4 y), 43.5% were female, 82% were white, and 38.2% had stage IV disease. PGVs were found in 15.5% (n= 56) of patients, including 44 in moderate- and high-penetrance cancer susceptibility genes. Thirty-four (9.4%) patients had incremental clinically actionable findings that would not have been detected by practice guideline criteria or a CRC-specific gene panel. Only younger age at diagnosis was associated with the presence of PGVs (odds ratio, 1.99; 95% CI, 1.12-3.56). After a median follow-up period of 20.7 months, no differences in overall survival were seen between those with or without a PGV (P= .2). Eleven percent of patients had modifications in their treatment based on genetic findings. Family cascade testing was low (16%). Universal multigene panel testing in CRC was associated with a modest, but significant, detection of heritable mutations over guideline-based testing. One in 10 patients had changes in their management based on test results. Uptake of cascade family testing was low, which is a concerning observation that warrants further study.

Upfront Multigene Panel Testing for Cancer Susceptibility in Newly Diagnosed Endometrial Cancer Patients: A Prospective Cohort Study

Background: Lynch syndrome (LS) is the most common cause of hereditary endometrial cancer (EC). Screening EC patients for LS varies by institution and current strategies employ tumor testing and/or family history approaches. Ultimately a LS diagnosis is made by genetic testing. In this study, we evaluated upfront multi-gene panel testing (MGPT) in unselected ECs for improved identification of LS and to determine the frequency of pathogenic variants (PVs) in other cancer susceptibility genes (CSGs).  Methods: EC patients were prospectively enrolled at nine Ohio institutions, 10/1/2017 - 12/31/2020. All patients had clinical germline testing for forty-seven CSGs. Mismatch repair (MMR) immunohistochemistry (IHC), MLH1 methylation and clinicopathologic data were abstracted from patients’ records. Detailed family history data were obtained for all subjects.  Findings: 29 of 961 EC patients (3·1%, 95% CI 2·1 – 4·3%) were found to have LS. <i>PMS2</i> PVs were most frequent (11/29), followed by MSH6 (10/29), <i>MSH2</i> (6/29), and  <i>MLH1</i> (2/29). Tumor IHC was concordant for all <i>MLH1</i> and  <i>MSH2</i>, and 9/10 MSH6 heterozygotes. For  <i>PMS2</i>, tumor IHC and germline status concordance was 80% and family history was not predictive of LS. An additional 68 (7·1%) women had likely pathogenic (LP) or PVs in 16 other CSGs. Twenty-one patients had LP/PVs in high penetrance CSGs. Of note, 10 patients (1·04%) had PVs in <i>BRCA1</i> or <i>BRCA2</i>, with a significant excess of type-II ECs among  <i>BRCA</i> heterozygotes.    Interpretation: Prospective MGPT in a large, unselected EC cohort revealed that a majority of LS diagnoses are attributable to low-penetrance genes. MGPT substantially increased LS diagnoses by capturing patients who had equivocal IHC findings or for whom tumor screening was not performed. The finding that 97/961 (10%) women in this cohort have actionable CSG variants supports a role for upfront MGPT for all women with EC.  Funding: This research was funded by an Ohio State University James Comprehensive Cancer Center Statewide Pelotonia Cancer Impact Award. Declaration of Interest: HH is on the scientific advisory boards for Invitae Genetics, Promega, and Genome Medical. HH has stock/stock options in Genome Medical and GI OnDemand, outside of the submitted work. DC is a COVID response consultant for Kane Logistics, he receives honoraria as Deputy Editor of Gynecologic Oncology and as an author for Up to Date, and he also holds patents: 1) “MicroRNA-based methods and compositions for the diagnosis, prognosis and treatment of ovarian cancer using a real-time PCR platform” Patent number 9,499,869 B2, issued November 22, 2016 Cohn DE, Alder HJ, Croce C, Resnick KE; 2) “Chimeric VEGF peptides” Patent number 8,080,253 B2, issued December 20, 2011 Kaumaya PTP, Cohn DE, all outside of the submitted work. JMs wife is employed by Pfizer Inc. JN declares consulting roles for AstraZeneca, Curio, and Clovis Oncology; speakers’ bureau for Clovis oncology and Merck; and has received a research grant from Zodus Medical Inc, all outside of the submitted work. CB has received honoraria as a speaker for OncLive and for an oral boards review course by Perinatal services, outside of the submitted work. SS reports speakers’ bureaus for AstraZeneca and Merck, outside of the submitted work. KR’s partner is SS with previously listed disclosures. PJG received an award from Promega, outside of the submitted work. MDL, RP, CC, AC, AS, DB, SW, SA, EJ, AC, and RN declare no competing interests. Ethical Approval: The study was approved by the Institutional Review Boards (IRBs) at each participating center with OSU serving as IRB of record.

Abstract PD10-05: Universal genetic testing in breast cancer patients: A multi-center prospective study

Abstract Background: Hereditary factors play a key role in the risk of developing breast cancers. Identification of a germline predisposition can have important implications for treatment decisions, risk-reducing interventions, cancer screening, and testing for family members. Aim: To determine the prevalence of pathogenic or likely pathogenic germline mutations (P/LP) using a “universal” testing approach and uptake of no-cost cascade family testing in patients with breast cancer. Methods: We undertook a prospective multi-site study of germline genetic alterations among breast cancer patients receiving care at Mayo Clinic cancer centers in Rochester, MN; Eau Claire, WI; Jacksonville, FL and Phoenix, AZ between April 1, 2018 and March 31, 2020. Patients with a new or active breast cancer diagnosis (all stages) irrespective of cancer family history were tested with a >80-gene next generation sequencing panel.Results: Of 390 patients, the median age was 58 years (SD 12.3), 1% were male, 85% were white and 28% had advanced (stage 3-4) disease. P/LP were found in 12.1% (n=47) of patients, including 29 in moderate and high penetrance cancer susceptibility genes. 13 (3.3%) patients had mutations in BRCA1 or 2, while 33 (8.4%) had mutations in BRCAness (ATM, BAP1, BARD1, BLM, BRCA1, BRCA2, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C, RAD51D, WRN) associated genes. Of the P/LP findings the most frequent aberrations were in BRCA2 (13.5%), BRCA1 (11.5%), CHEK2 (11.5%), MUTYH (11.5%), and WRN (9.6%). Variants of uncertain significance were found in 209 (53.6%) including 26 (6.6%) with concurrent P/LP and VUS. 37 (9.4%) patients had mutations associated with published management recommendations, precision therapies and/or clinical trial eligibility. 10 (2.6%) patients had P/LP that would not have met current screening guidelines, including 4 with moderate or high penetrance mutations. Patients with younger age of diagnosis were less likely than patients with older age of diagnosis to have a P/LP mutation (OR= 0.47, 95%CI: 0.25-0.90 p = 0.020). Only 10 (21%) patients with P/LP had family members undergo familial site- specific testing at no cost.Conclusions: In this prospective multi-center study of unselected breast cancer patients, universal multi-gene panel testing found that 1 in 8 patients harbor P/LP germline variants. Current guidelines were able to identify the majority of patients with P/LP mutations. Familial site specific testing is greatly under-utilized even when cost is not a barrier. Multigene panels impact cancer patient care by identifying precision medicine treatment interventions, and guiding long-term medical management and preventive surveillance. Citation Format: Brenda Ernst, Natalie Ertz-Archambault, Deborah J Rhodes, Donald W Northfelt, Myra Wick, Douglas L Riegert-Johnson, Scott Okuno, Katie Kunze, Michael Golafshar, Cindy M Azevedo, PLS Uson Junior, ED Esplin, Robert Nussbaum, Margaret Klint, Sarah Mantia, Megan Hager, Keith Stewart, Niloy Jewel Samadder. Universal genetic testing in breast cancer patients: A multi-center prospective study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD10-05.

Comparison of Universal Genetic Testing vs Guideline-Directed Targeted Testing for Patients With Hereditary Cancer Syndrome

Hereditary factors play a key role in the risk of developing several cancers. Identification of a germline predisposition can have important implications for treatment decisions, risk-reducing interventions, cancer screening, and germline testing. To examine the prevalence of pathogenic germline variants (PGVs) in patients with cancer using a universal testing approach compared with targeted testing based on clinical guidelines and the uptake of cascade family variant testing (FVT). This prospective, multicenter cohort study assessed germline genetic alterations among patients with solid tumor cancer receiving care at Mayo Clinic cancer centers and a community practice between April 1, 2018, and March 31, 2020. Patients were not selected based on cancer type, disease stage, family history of cancer, ethnicity, or age. Germline sequencing using a greater than 80-gene next-generation sequencing platform. Proportion of PGVs detected with a universal strategy compared with a guideline-directed approach and uptake of cascade FVT in families. A total of 2984 patients (mean [SD] age, 61.4 [12.2] years; 1582 [53.0%] male) were studied. Pathogenic germline variants were found in 397 patients (13.3%), including 282 moderate- and high-penetrance cancer susceptibility genes. Variants of uncertain significance were found in 1415 patients (47.4%). A total of 192 patients (6.4%) had incremental clinically actionable findings that would not have been detected by phenotype or family history-based testing criteria. Of those with a high-penetrance PGV, 42 patients (28.2%) had modifications in their treatment based on the finding. Only younger age of diagnosis was associated with presence of PGV. Only 70 patients (17.6%) with PGVs had family members undergoing no-cost cascade FVT. This prospective, multicenter cohort study found that universal multigene panel testing among patients with solid tumor cancer was associated with an increased detection of heritable variants over the predicted yield of targeted testing based on guidelines. Nearly 30% of patients with high-penetrance variants had modifications in their treatment. Uptake of cascade FVT was low despite being offered at no cost.

Germline alterations in patients with biliary tract cancers: A spectrum of significant and previously underappreciated findings.

With limited information on germline mutations in biliary tract cancers, this study performed somatic and germline testing for patients at Memorial Sloan Kettering Cancer Center with known biliary tract carcinoma with the aim of determining the frequency and range of pathogenic germline alterations (PGAs). Patients with biliary tract carcinoma were consented for somatic tumor and matched blood testing of up to 468 genes via the Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets next-generation sequencing platform. A germline variant analysis was performed on a panel of up to 88 genes associated with an increased predisposition for cancer. Demographic and diagnostic details were collected. Germline mutations were tested in 131 patients. Intrahepatic cholangiocarcinoma was the most common cancer (63.4%), and it was followed by gallbladder adenocarcinoma (16.8%), extrahepatic cholangiocarcinoma (16%), and otherwise unspecified biliary tract cancer (3.8%). Known and likely PGAs were present in 21 patients (16.0%), with 9.9% harboring a PGA in a high/moderate-penetrance cancer predisposition gene. Among high-penetrance cancer susceptibility genes, PGAs were most commonly observed in BRCA1 and BRCA2 (33.3%), which made up 5.3% of the entire cohort, and they were followed by PALB2, BAP1, and PMS2. Mutations in ATM, MITF, and NBN, moderate-penetrance cancer susceptibility genes, were identified in 1 patient each. There was no observed difference in the types of mutations among the subtypes of biliary tract cancer. The frequency of PGAs found was comparable to existing data on the prevalence of germline mutations in other solid tumor types with matched tumor analysis. This provides support for the role of the BRCA1/2, ATM, and BAP1 genes in biliary tract cancer susceptibility.

Psychosocial Effects of Multigene Panel Testing in the Context of Cancer Genomics.

In recent years, with both the development of next-generation sequencing approaches and the Supreme Court decision invalidating gene patents, declining costs have contributed to the emergence of a new model of hereditary cancer genetic testing. Multigene panel testing (or multiplex testing) involves using next-generation sequencing technology to determine the sequence of multiple cancer-susceptibility genes. In addition to high-penetrance cancer-susceptibility genes, multigene panels frequently include genes that are less robustly associated with cancer predisposition. Scientific understanding about associations between many specific moderate-penetrance gene variants and cancer risks is incomplete. The emergence of multigene panel tests has created unique challenges that may have meaningful psychosocial implications. Contrasted with the serial testing process, wherein patients consider the personal and clinical implications of each evaluated gene, with multigene panel testing, patients provide broad consent to whichever genes are included in a particular panel and then, after the test, receive in-depth genetic counseling to clarify the distinct implications of their specific results. Consequently, patients undergoing multigene panel testing may have a less nuanced understanding of the test and its implications, and they may have fewer opportunities to self-select against the receipt of particular types of genetic-risk information. Evidence is conflicting regarding the emotional effects of this testing.

Personalised medicine and population health: breast and ovarian cancer.

It has been suggested that a personalised approach to cancer prevention and screening might lead to a new paradigm for cancer control. Various aspects include testing for high-penetrance cancer susceptibility genes and generating personal risks scores, based on panels of single nucleotide polymorphisms. These tests can categorize women into various groupings of risk for cancer prevention (surgery and chemoprevention) cancer screening and prevention of cancer recurrence. In this review, I investigate various claims and come to the conclusion that the approach may be beneficial for the occasional patient but is unlikely to have any impact on reducing the burden of cancer incidence and mortality as whole. Challenges include meeting a high uptake of the test in the population, developing an effective and acceptable intervention and the willingness of healthy women to follow health care provider recommendations. The review focuses onstrategies to reduce mortality from breast and ovarian cancer but is potentially applicable to other cancer sites, such as colon, prostate, andendometrial.

Real-Time Genomic Characterization of Metastatic Pancreatic Neuroendocrine Tumors Has Prognostic Implications and Identifies Potential Germline Actionability.

We assessed the usefulness of real-time molecular profiling through next-generation sequencing (NGS) in predicting the tumor biology of advanced pancreatic neuroendocrine tumors (panNETs) and in characterizing genomic evolution. Patients with metastatic panNETs were recruited in the routine clinical practice setting (between May 2014 and March 2017) for prospective NGS of their tumors as well as for germline analysis using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) sequencing platform. When possible, NGS was performed at multiple time points. NGS was performed in 96 tumor samples from 80 patients. Somatic alterations were identified in 76 of 80 patients (95%). The most commonly altered genes were MEN1 (56%), DAXX (40%), ATRX (25%), and TSC2 (25%). Alterations could be defined in pathways that included chromatin remodeling factors, histone methyltransferases, and mammalian target of rapamycin pathway genes. Somatic loss of heterozygosity was particularly prevalent (50 of 96 samples [52%]), and the presence of loss of heterozygosity resulted in inferior overall survival (P < .01). Sequencing of pre- and post-treatment samples revealed tumor-grade progression; clonal evolution patterns were also seen (molecular resistance mechanisms and chemotherapy-associated mutagenesis). Germline genetic analysis identified clinically actionable pathogenic or likely pathogenic variants in 14 of 88 patients (16%), including mutations in high-penetrance cancer susceptibility genes (MEN1, TSC2, and VHL). A clinical NGS platform reveals pertubations of biologic pathways in metastatic panNETs that may inform prognosis and direct therapies. Repeat sequencing at disease progression reveals increasing tumor grade and genetic evolution, demonstrating that panNETs adopt a more aggressive behavior through time and therapies. In addition to frequent somatic mutations in MEN1 and TSC2, germline mutations in these same genes underlie susceptibility to panNETs and highlight the need to re-evaluate whether germline genetic analysis should be performed for all patients with panNETs.

Time to incorporate germline multigene panel testing into breast and ovarian cancer patient care.

Genetic evaluation is increasingly becoming an integral part of the management of women with newly diagnosed breast and ovarian cancer (OC), and of individuals at high risk for these diseases. Genetic counseling and testing have been incorporated into oncological care to help and complete management and treatment strategies. Risk assessment and early detection strategies in individuals with BRCA1/2 mutations and with Lynch syndrome have been quite extensively studied, whereas much less is known about the management of mutation carriers with less common high-penetrance cancer susceptibility genes (PTEN, TP53, STK11, CDH1), and particularly those who carry mutations in moderate-penetrance genes (e.g., PALB2, CHEK2, ATM, NF1, RAD51C, RAD51D, BRIP1). The latter patient groups represent important ongoing research opportunities to enable informed counseling about appropriate clinical management. We summarize the current guidelines for the management of high and moderate-penetrance mutations for breast and OC susceptibility. Continuous updating of guidelines for proper clinical management of these individuals is ongoing because of rapid advances in technology and knowledge in this field. Thus, we exhort the use of multigene panels for the assessment of cancer risk beyond the classic predisposition syndromes as a new standard of care in cancer genetics. We further support an increase of genetic counselors in Europe and use of their expertise to support genetic testing in specialist multidisciplinary teams.

Perceptions of genetic testing among patients undergoing genetic counseling.

e13107Background: The utility of genetic testing for germline mutations in high-penetrance cancer susceptibility genes is well established. However, the clinical utility of mutations in more moderate-penetrance genes is less clear. The aim of this study was to examine factors that motivate patients to choose panel testing over traditional BRCA1/2 testing and if the perception of utility is consistent between patients and genetic counselors. Methods: Adults presenting for genetic counseling at an academic center were invited to complete a survey to identify psychological, medical and social factors which influence patient decision-making. Additional variables included age, personal and family history of cancer, and previous knowledge of BRCA1/2 and panel testing. Genetic counselors completed a survey indicating how strongly they felt the individual would benefit from panel testing, rated on a scale from 1 (little benefit) to 5 (strong benefit). Results: Forty-one women completed surveys, 36 (87.8%) with a ...

Development of Genetic Testing for Breast, Ovarian and Colorectal Cancer Predisposition: A Step Closer to Targeted Cancer Prevention

Individuals who inherit a high penetrance cancer susceptibility gene represent a population in which cancer diagnoses occur at younger ages and much more frequently than in the general population. Screening regimens aimed at early detection of cancer may reduce cancer mortality but in order to reduce cancer incidence, surgery and medical therapies have been advocated. In high genetic risk patients, either surgical or medical intervention may provide long term protection against cancer and at young ages co-morbidities will be low. The use of genetic testing for high risk predisposition genes to refine risk estimates and inform choices about cancer prevention is now readily available in many countries and routinely used to target cancer prevention strategies. Surgical approaches to cancer prevention are currently the mainstay in many conditions where a high risk is identified but medical prevention strategies also have demonstrated some efficacy in lowering cancer risk. Using the genetic status of an individual to target cancer treatment and prevent recurrence is increasingly gaining momentum as clinical trials involving known high risk gene carriers are now being conducted using both established cytotoxic drugs and novel targeted agents. Translation of new mechanistic insights into beneficial clinical care strategies requires more research. Robust evidence supporting medical approaches to cancer prevention in particular will require well designed large international collaborative clinical trials.

Architecture of inherited susceptibility to common cancer

This Timeline article looks back at 40 years of research into the inherited genetic basis of cancer and the insights these studies have yielded. Early epidemiological research provided evidence for the 'two-hit' model of cancer predisposition. During the 1980s and 1990s linkage and positional cloning analyses led to the identification of high-penetrance cancer susceptibility genes. The past decade has seen a shift from models of predisposition based on single-gene causative mutations to multigenic models. These models suggest that a high proportion of cancers may arise in a genetically susceptible minority as a consequence of the combined effects of common low-penetrance alleles and rare disease-causing variants that confer moderate cancer risks.

Familial testicular germ cell tumors in adults: 2010 summary of genetic risk factors and clinical phenotype

Familial aggregations of testicular germ cell tumor (FTGCT) have been well described, suggesting the existence of a hereditary TGCT subset. Approximately 1.4% of newly diagnosed TGCT patients report a positive family history of TGCT. Sons and siblings of TGCT patients have four- to sixfold and eight- to tenfold increases in TGCT risk respectively. Segregation analyses suggest an autosomal recessive mode of inheritance. Linkage analyses have identified several genomic regions of modest interest, although no high-penetrance cancer susceptibility gene has been mapped yet. These data suggest that the combined effects of multiple common alleles, each conferring modest risk, might underlie familial testicular cancer. Families display a mild phenotype: the most common number of affected families is 2. Age at diagnosis is 2-3 years younger for familial versus sporadic cases. The ratio of familial seminoma to nonseminoma is 1.0. FTGCT is more likely to be bilateral than sporadic TGCT. This syndrome is cancer site specific. Testicular microlithiasis is a newly recognized FTGCT component. Candidate gene-association studies have implicated the Y chromosome gr/gr deletion and PDE11A gene mutations as genetic modifiers of FTGCT risk. Two genomewide association studies of predominantly sporadic but also familial cases of TGCT have implicated the KIT-ligand, SPRY4, and BAK1 genes as TGCT risk modifiers. All five loci are involved in normal testicular development and/or male infertility. These genetic data provide a novel insight into the genetic basis of FTGCT, and an invaluable guide to future TGCT research.

Screening and Prevention of Hereditary Gynecologic Cancers

Endometrial and ovarian cancer are the fourth and fifth most common malignancies in women, with approximately 40,000 new endometrial and 25,000 new ovarian cancers expected to be diagnosed in the Unites States this year. While the majority of these cancers will occur in the absence of a family history, approximately 5% of endometrial cancers and 10% of ovarian cancers will be the result of inherited defects in high-penetrance cancer susceptibility genes. With the identification and subsequent availability of clinical genetic testing for mutations in the genes associated with hereditary breast-ovarian cancer and the Lynch/hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, targeted risk-reduction using intensive screening, chemoprevention, and prophylactic surgery has become possible for women at inherited risk of gynecologic malignancies. We review the options for gynecologic cancer risk reduction in women with an inherited mutation in BRCA1, BRCA2, or one of the mismatch repair (MMR) genes associated with Lynch/HNPCC syndrome. Additionally, we outline ongoing questions and areas for future research.