The use of heuristics in genetic testing decision-making: A qualitative interview study

Background Decision-making concerning predictive genetic testing for hereditary cancer syndromes is inherently complex. This study aims to investigate what kind of complexities adults undergoing genetic counseling in Switzerland experience, how they deal with them, and what heuristics they use during the decision-making process. Methods Semi-structured qualitative interviews with eighteen Swiss adults seeking genetic counseling for hereditary cancer syndrome genetic testing and two counseling physicians were conducted and analyzed using a grounded theory approach. Results Counselees stated that once they were aware of their eligibility for genetic testing they perceived an inevitable necessity to make a decision in a context of uncertainties. Some counselees perceived this decision as simple, others as very complex. High emotional involvement increased perceived complexity. We observed six heuristics that counselees used to facilitate their decision: Anticipating the test result; Focusing on consequences; Dealing with information; Interpreting disease risk; Using external guidance; and (Re-)Considering the general uncertainty of life. Limitations Our findings are limited to the context of predictive genetic testing for hereditary cancer syndromes. This qualitative study does not allow extrapolation of the relative frequency of which heuristics occur. Conclusions The use of heuristics is an inherent part of decision-making, particularly in the complex context of genetic testing for inherited cancer predisposition. However, some heuristics increase the risk of misinterpretation or exaggerated external influences. This may negatively impact informed decision-making. Thus, this study illustrates the importance of genetic counselors and medical professionals being aware of these heuristics and the individual manner in which they might be applied in the context of genetic testing decision-making. Findings may offer practical support to achieve this, as they inductively focus on the counselees’ perspective.

Complete Response of a Colonic High-Grade Neuroendocrine Carcinoma to Platinum-Based Therapy: Insights from Comprehensive Genomic Profiling

Background Comprehensive genomic profiling (CGP) is an essential tool in precision medicine, providing diagnostic, prognostic, and predictive (therapeutic) information that enables personalized optimal care for cancer patients. We present the case of a 54-year-old woman with stage IV large-cell neuroendocrine carcinoma (LCNEC) of the colon with liver and nodal metastases with complete response to therapy and demonstrate the value of CGP in identifying potential targets for treatment in these tumors. Results CGP performed on the tumor showed pathogenic mutations in multiple oncogenes and tumor suppressor genes including BRCA1, BAP1, and BRAF, high tumor mutation burden (TMB), and high microsatellite instability (MSI-H). Treatment with platinum-based therapy resulted in a complete radiographic response of the metastases, with no evidence of recurrence after 6.5 years. Assessment by Medical Genetics did not identify any evidence of hereditary cancer syndrome. The dramatic response to therapy is likely due to loss of BRCA1 and/or BAP1 function, as deleterious mutations in both genes predict response to platinum-based therapy through exploitation of deficient homologous recombination repair (HRR). The information provided by CGP also suggested potential tumor sensitivity to poly(ADP-Ribose) polymerase inhibitors (PARPi), immunotherapy (IT) and BRAF/MEK inhibitor therapy, should the tumor recur. Conclusion This case highlights the value of CGP in guiding diagnosis and management of rare and aggressive tumors.

Fertility Counseling in Survivors of Cancer in Childhood and Adolescence: Time for a Reappraisal?

Genetic predisposition could have an important role in the pathogenesis of cancers in children and adolescents. A recent study by our group showed that, among female survivors of cancers in childhood and adolescence, the proportion of cases involving a possible genetic predisposition was sizable (at least one in five). Our sample is too small to be representative of the general population, but it gave us an opportunity to reappraise this issue. Women with a genetic predisposition can transmit the risk of cancer to their offspring, and their awareness of this may influence their reproductive and fertility preservation choices. In our experience, a predisposition to cancer receives little attention in the fertility counseling and decision-making process unless a patient already has a definitive molecular diagnosis of a hereditary cancer syndrome. We feel it is essential to empower women on this issue, particularly as there are ways to overcome the problem, including preimplantation genetic testing (PGT-M) in definitively diagnosed cases, egg donation and adoption. In the context of fertility counseling for survivors of cancer in childhood and adolescence who have reached adulthood, the risk of transmitting a predisposition to cancer should be discussed with patients, if relevant and desired.

Genetic Characterization of Hereditary Cancer Syndromes Based on Targeted Next-Generation Sequencing

A hereditary cancer syndrome is a genetic predisposition to cancer caused by a germline mutation in cancer-related genes. Identifying the disease-causing variant is important for both the patient and relatives at risk in cancer families because this could be a guide in treatment and secondary cancer prevention. In this study, hereditary cancer panel harboring cancer-related genes was performed on MiSeq Illumina NGS system from peripheral blood samples. Sequencing files were fed into a cloud-based data analysis pipeline. Reportable variants were classified according to the American College of Medical Genetics and Genomics guidelines. Three hundred five individuals were included in the study. Different pathogenic/likely pathogenic variants were detected in 75 individuals. The majority of these variants were in the <i>MUTYH</i>, <i>BRCA2</i>, and <i>CHEK2</i> genes. Nine novel pathogenic/likely pathogenic variants were identified in <i>BRCA1</i>, <i>BRCA2</i>, <i>GALNT12</i>, <i>ATM</i>, <i>MLH1</i>, <i>MSH2</i>, <i>APC</i>, and <i>KIT</i> genes. We obtained interesting and novel variants which could be related to hereditary cancer, and this study confirmed that NGS is an indispensable method for the risk assessment in cancer families.

Multicancer hereditary syndrome testing: Genetic counselors’ perspectives.

106 Background: The accessibility of cancer hereditary syndrome testing has increased, and the cost has declined significantly in the past few years. We conducted a national, quantitative survey of genetic counselors (GCs) to assess their perspectives on what influences hereditary cancer genetic testing decisions and practices, with a focus on cost. This survey was funded by NIH, conducted by UCSF TRANSPERS, and supported by the National Society of Genetic Counselors(NSGC). Methods: The survey was developed through literature review, expert interviews, and a pilot. Sent to the NSGC Cancer Special Interest Group via email. Chi-square tests were used to examine variability. Results: The survey response rate was 56% (202/363). Multiple hereditary cancer syndrome tests are discussed often/always by 86% of genetic counselors (GCs).The existence of an institutional protocol on multiple hereditary cancer syndrome testing was reported by 35.4% of GCs. When asked about GC counseling encounters, GCs report insurance rarely/never pays for: 25.2% pre-test in-person,39.7% for pre-test tele-genetics, 35.4% post-test in-person, and 52.9% post-test tele-genetics. GCs rated clinical factors higher than cost as influencing decision for multiple hereditary syndrome cancer testing (table); the total cost of the test was least important. These patterns were similar across the GCs institution types and years in practice. Conclusions: We found consistent use of multiple hereditary cancer syndrome tests, with less focus on cost, out-of-pocket, and insurance coverage and more of a focus on clinical indicators. GCs reported challenges with reimbursement for GC counseling encounters. The shift toward more genetic counseling encounters via tele-genetics necessitates evaluation of insurance reimbursement.[Table: see text]

Current Testing Guidelines: A Retrospective Analysis of a Community-Based Hereditary Cancer Program

It is estimated that 5% to 10% of all cancers are related to a hereditary cancer syndrome. However, specific cancers, such as pancreatic and ovarian cancers, are related to hereditary cancer syndromes 15% to 20% of the time. Genetic testing guidelines for hereditary cancer syndromes are frequently reviewed and updated by the National Comprehensive Cancer Network (NCCN). The purpose of this retrospective analysis is to identify carriers of pathogenic variants or hereditary cancer syndrome who do not meet NCCN criteria for testing and compare the results with previous studies. The data obtained can be used to provide recommendations to assess current guidelines for testing and evaluate the benefit of comprehensive panel testing vs. standard testing for specific hereditary cancer syndromes. This project is a retrospective review of clinical histories of patients who had multigene panel testing between September 2015 and February 2019 through a cancer outreach and risk assessment (CORA) program. Frequencies analyses were performed to analyze results. A total of 233 individuals were included in the analysis: 171 met BRCA1/2 testing criteria, 66 met Lynch syndrome criteria, and 4 met polyposis criteria. Of the individuals meeting established criteria for testing, 39 were identified with pathogenic variants. However, only 10 of these individuals were identified with a pathogenic variant associated with the criteria for which they met. Genetic testing that is limited to only those patients with genes associated with hereditary cancer syndromes may lead to exclusion of other potentially actionable genes, which may impair a patient’s ability to receive additional screening or preventative measures.

WRN Germline Mutation Is the Likely Inherited Etiology of Various Cancer Types in One Iranian Family

BackgroundFamilial cancers comprise a considerable distribution of colorectal cancers (CRCs), of which only about 5% occurs through well-established hereditary syndromes. It has been demonstrated that deleterious variants at the newly identified cancer-predisposing genes could describe the etiology of undefined familial cancers.MethodsThe present study aimed to identify the genetic etiology in a 32-year-old man with early onset familial CRC employing several molecular diagnostic techniques. DNA was extracted from tumoral and normal formalin-fixed-paraffin-embedded (FFPE) blocks, and microsatellite instability (MSI) was evaluated. Immunohistochemistry staining of MMR proteins was performed on tumoral FFPE blocks. Next-generation sequencing (NGS), multiplex ligation-dependent amplification (MLPA) assay, and Sanger sequencing were applied on the genomic DNA extracted from peripheral blood. Data analysis was performed using bioinformatics tools. Genetic variants interpretation was based on ACMG.ResultsMSI analysis indicated MSI-H phenotype, and IHC staining proved no expressions of MSH2 and MSH6 proteins. MLPA and NGS data showed no pathogenic variants in MMR genes. Further analysis of NGS data revealed a candidate WRN frameshift variant (p.R389Efs*3), which was validated with Sanger sequencing. The variant was interpreted as pathogenic since it met the criteria based on the ACMG guideline including very strong (PVS1), strong (PS3), and moderate (PM2).ConclusionWRN is a DNA helicase participating in DNA repair pathways to sustain genomic stability. WRN deficient function may contribute to CRC development that is valuable for further investigation as a candidate gene in hereditary cancer syndrome diagnosis.

RARE-24. IDENTIFYING INDIVIDUALS WITH PRIMARY CENTRAL NERVOUS SYSTEM TUMORS AT RISK FOR HEREDITARY CANCER SYNDROMES USING THE UTAH POPULATION DATABASE

Background CNS tumors are the most common solid tumors and the deadliest cancers in children. Approximately 10% of children with a CNS tumor harbor a hereditary cancer syndrome (HCS), but many will not be tested for a HCS. The Utah Population Database (UPDB) contains comprehensive cancer registry data for Utah families and can determine multigenerational cancer pedigrees across an archive of 5.8 million individuals. We hypothesize that the UPDB can identify children and families with HCSs not previously identified. Methods We queried the UPDB for individuals ages 0–39 diagnosed with a primary CNS tumor (malignant and benign) between 1966–2017 and generated cancer pedigrees of 3 generations or more for probands, extending to at least third-degree relatives. Specialized software calculated a familial standardized incidence ratio (FSIR) to determine families with excess clustering of CNS tumors. Clinical cancer genetics experts reviewed pedigrees to confirm patterns of HCS. Results We identified 4,634 CNS tumors in 4,550 individuals, of whom 2,233 (49%) reside in high-quality pedigrees containing ≥2 grandparents, at least 1 from both maternal and paternal sides. To identify families with excess clustering of CNS tumors, we selected pedigrees with an FSIR P&lt;0.05 and ≥2 affected patients, resulting in 161 high-risk families with a mean of 170 (median 96) relatives per pedigree of 3–6 generations. Among these 161 families, there were 2,017 unique relatives (first-third degree) of CNS probands with 2,355 tumors (any site), for a per pedigree average of 14.7 tumors in 12.5 relatives. Review of the 10 highest risk pedigrees indicated that 4 meet HCS criteria, including Li-Fraumeni (n=2), von Hippel-Lindau (n=1), and rhabdoid tumor predisposition (n=1). Conclusion The UPDB can produce multigenerational cancer pedigrees that identify individuals and families at risk of harboring a HCS who warrant germline testing. These findings should encourage clinicians to perform thorough family history screening.

The contribution of Lynch syndrome to early onset malignancy in Ireland

Background Lynch syndrome (LS) is an autosomal dominant hereditary cancer syndrome responsible for 2–4% of hereditary colorectal cancers (CRC). Mismatch repair protein deficiency (dMMR) is a characteristic feature of LS. It has been associated with a poor response to standard chemotherapy in metastatic colorectal cancer (mCRC). There is currently no LS database to monitor trends of disease in Ireland. We aim to centralise LS data in Ireland to assess the burden of LS in Ireland and guide improvements in prevention and treatment of LS-associated cancer. Methods A retrospective review was carried out including all medical records for LS patients from two of the three cancer genetics clinics in Ireland between 2000 and 2018 was carried out. Clinicopathological data of probands (n = 57) and affected family members including demographics, mutation status, cancer diagnosis and outcome was recorded. Statistical analysis was carried out using SPSS software. Results Fifty-seven families including three-hundred and forty-five individuals affected by cancer were identified. The most common cancers recorded were colorectal (53%), breast (12%) and endometrial (10%). One-hundred and thirty-eight confirmed carriers were identified: 65 path_MLH1 (47%), 43 path_MSH2 (31%), 11 path_MSH6 (8%), 17 path_PMS2 (12%) and two path_EPCAM (1%). Cancer type varied significantly by gene. Median age of first diagnosis was 44.5 years (range 23–81). Half of all deceased patients (n = 11) in this group died within 2.5 years of first diagnosis. These deaths were directly related to cancer in 59% of cases. Conclusions Under diagnosis of LS misses a powerful preventive and therapeutic opportunity. LS causes early onset dMMR cancer diagnoses with substantial societal impact. Implementation of ICBs into treatment policy for this small cohort of dMMR mCRC is an achievable therapeutic goal that may significantly improve survival. A prospective database for LS in Ireland is necessary to maximise prevention in this population.

Hereditary Leiomyomatosis and Renal Cell Cancer: Recent Insights Into Mechanisms and Systemic Treatment

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare autosomal dominant hereditary cancer syndrome characterized by a predisposition to cutaneous leiomyomas, uterine leiomyomas, and renal cell carcinoma (RCC). It is known to be caused by germline mutations of the fumarate hydratase (FH) gene, which encodes an enzyme component of the citric acid cycle and catalyzes the conversion of fumarate to L-malate. Currently, there is no standardized treatment for HLRCC, which may be due in part to a lack of understanding of the underlying mechanisms. Here, the underlying molecular mechanisms by which the inactivation of FH causes HLRCC are discussed. Additionally, potential therapeutic pharmacological strategies are also summarized to provide new perspectives for the prevention and treatment of HLRCC.