Cancer patients' experience of receiving variant of uncertain significance results: An Asian perspective.

Due to a lack of ancestry-matched, functional, and segregation data, Asians have a higher rate of receiving a variant of uncertain significance (VUS) result following panel testing. Managing VUS results presents challenges, as it often leads to increased anxiety and distress among cancer patients undergoing genetic testing. This exploratory study aims to investigate the experience of Asian cancer patients upon receiving a VUS result. A qualitative, semi-structured interview study was conducted, involving cancer patients who had received a VUS result through the Cancer Genetics Service of the National Cancer Centre Singapore. Twenty participants were interviewed, and their responses were transcribed and analyzed using thematic analysis to identify key themes. Thematic analysis revealed five major themes: (1) VUS results are interpreted as uncertain outcomes; (2) a VUS result provides relief and prompts positive behavioral adjustments; (3) patients employ fatalism and religion as coping mechanisms to navigate uncertainty; (4) genetic counselors, family, and the community offer reassurance and support; (5) patients value updates on variant classifications for future management. While this novel study provides unique insights into the perspectives of Asian patients who receive VUS results, it also highlights patients' effective management of VUS results and uncertainty, which has implications for improving counseling practices in Asia. Emphasis must be placed on accurate interpretation and clear communication of VUS results to dispel the possibility of misconceptions, misdiagnosis, and mismanagement in cancer care.

Investigation into the origins of an ancient BRCA1 founder mutation identified among Chinese families in Singapore.

Identification of ancestry-specific pathogenic variants is imperative for diagnostic, treatment, management and prevention strategies, and to understand penetrance/modifiers on risk. Our study aimed to determine the clinical significance of a recurrent BRCA1 c.442-22_442-13del variant of unknown significance identified among 13 carriers from six Chinese families, all with a significant history of breast and/or ovarian cancer. We further aimed to establish whether this was due to a founder effect and explore its origins. Haplotype analysis, using nine microsatellite markers encompassing 2.5 megabase pairs around the BRCA1 locus, identified a common haploblock specific to the variant carriers, confirming a founder effect. Variant age was estimated to date back 77.9 generations to 69 bc using the Gamma approach. On principal component analysis using single nucleotide polymorphisms merged with 1000 Genomes dataset, variant carriers were observed to overlap predominantly with the southern Han Chinese population. To determine pathogenicity of the variant, we assessed the functional effect on RAD51 foci formation as well as replication fork stability upon induction of DNA damage and observed an impaired DNA repair response associated with the variant. In summary, we identified an ancient Chinese founder mutation dating back 77.9 generations, possibly common among individuals of southern Han Chinese descent. Using evidence from phenotypic/family history studies, segregation analysis and functional characterization, the BRCA1 variant was reclassified from uncertain significance to pathogenic.

Understanding patients' views and willingness toward the use of telehealth in a cancer genetics service in Asia.

Telehealth is a growing field, its pertinence magnified by COVID-19 causing the accelerated digitalization of the world. Given the significant global demand to provide telehealth services, it is important to explore patient receptiveness toward this alternative service model, particularly from regions where it has yet to be implemented. We conducted a cross-sectional study to understand the views and willingness of patients toward the use of telehealth for cancer genetic counseling. A survey was completed by 160 patients of the National Cancer Centre Singapore, and descriptive statistics were used to analyze the data. The study found that 95.6% (n = 153/160) of participants did not have prior telehealth experience. Most participants were willing or neutral toward having genetic counseling by phone (n = 114/160, 71.3%) and video (n = 106/160, 66.3%). However, majority prefer in-person appointments for first (n = 127/160, 79.4%) and follow-up (n = 97/160, 60.6%) visits over telehealth. Majority agreed that a phone/video consultation would meet most of their needs but voiced concerns regarding privacy and sharing of information (n = 79/160, 49.4% for phone; n = 74/160, 46.3% for video) and whether their emotional needs could be met (n = 61/160, 38.1%). Participants' age, employment status, income, mode of transportation to the appointment, and whether special arrangements were made to attend the in-person appointment were associated with receptivity to telehealth genetic counseling (p ≤ .05 for all). This study adds diversity to existing literature and demonstrates that patients from Asia are generally willing and accepting of the use of telehealth in a cancer genetics service. This will help meet increasing global demand of telehealth consultations in the post-pandemic new norm. Furthermore, it will also provide services for underserved populations and patients requiring urgent testing in a timely manner. Further studies are needed to explore the cost-effectiveness and fair billing methods, as well as willingness and acceptability of telehealth genetic counseling in post-COVID times.

Use of telephone intake for family history taking at a cancer genetics service in Asia.

Family history taking is a fundamental part of genetic counseling, and however, it is also a time-consuming process. To cope with the increasing demands at the Cancer Genetics Service in Singapore, alternative methods to collect patients' family history were implemented to reduce the duration of the initial consultation and increase the clinic's capacity. Two interventions were performed in this study, where a family history questionnaire and telephone intakes (telephone calls to collect patient family history) were implemented prior to a cancer genetics consultation. The primary outcome of this study is the duration of the initial consultation in relation to both interventions while the secondary outcome is the clinic attendance rate before and after implementing the telephone intake. The impact of interventions was evaluated with a Plan-Do-Study-Act (PDSA) methodology. The use of a family history questionnaire could not be evaluated due to poor patient response while the telephone intake was found to be feasible among the local population. Two improvements were observed after the implementation of telephone intake: (a) a significant reduction in the duration of the initial consultation from 60 to 45 min (p = .001) and (b) a significant increase of 29.7% in clinic attendance (p = .01). This study demonstrates that collecting family history information ahead of genetic counseling via telephone intake is a useful measure in improving clinic capacity, which potentially resulting in optimization of clinical resources.

An in-depth exploration of the post-test informational needs of BRCA1 and BRCA2 pathogenic variant carriers in Asia.

INTRODUCTION: Identification of one's status as a BRCA1/2 pathogenic variant carrier often marks the start of navigating challenging decisions related to cancer risk management and result disclosure. Carriers report unmet informational needs, but studies have yet to explore the specific aspects of and how best to fulfill these needs. This study aims to explore the informational needs of BRCA1/2 pathogenic variant carriers in Asia to inform for the design of educational materials to support risk management decision-making. METHODS: Semi-structured in-depth interviews were conducted with two male and 22 female English-speaking BRCA1/2 pathogenic variant carriers, aged 29-66 years, identified through the Cancer Genetics Service at the National Cancer Centre Singapore. A grounded theory approach with thematic analysis was undertaken to extract dominant themes. RESULTS: Four themes were identified: (i) proactive online information seeking behaviors (ii) personalized informational needs; (iii) challenges in sharing the results; and (iv) lack of genetic awareness. DISCUSSION: Participants highlight challenges with sharing their result arising from significant post-result informational needs, which have manifested into proactive online information-seeking behaviors. They desire for an online source of information, where content is personalized, reliable and local. Participants foresee the potential of an online resource to raise genetic awareness. This suggests the use of a culturally tailored online-based genetics resource, to promote result disclosure, empower risk-management decisions and raise genetic literacy rates. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s13053-020-00154-x.

Evaluation of the relative effectiveness of the 2017 updated Manchester scoring system for predicting BRCA1/2 mutations in a Southeast Asian country.

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes have significant clinical implications for both risk-reducing and early surveillance management. The third and most recent revision of the Manchester scoring system (MSS3) used to distinguish patients indicated for germline BRCA1/2 testing included further adjustments for triple negative breast cancer, high-grade serous ovarian cancer and human epidermal growth factor 2 (HER2) receptor status. This study aims to evaluate the relative effectiveness of MSS3 in a Southeast Asian population. METHODS: All patients in our centre were tested using next-generation sequencing (NGS) panels that included full gene sequencing as well as coverage for large deletions/duplications in BRCA1/2. We calculated MSS1-3 scores for index patients between 2014 and 2017 who had undergone BRCA1/2 genetic testing and recorded their genetic test results. MSS1-3 outcomes were compared using receiver operating characteristic analysis, while associations with predictors were investigated using Fisher's exact test and logistics regression. Calculations were performed using Medcalc17. RESULTS: Of the 330 included patients, 47 (14.2%) were found to have a germline mutation in BRCA1 or BRCA2. A positive HER2 receptor was associated with a lower likelihood of a BRCA1/2mutation (OR=0.125, 95% CI 0.016 to 0.955; P=0.007), while high-grade serous ovarian cancer was conversely associated with an increased likelihood of a BRCA1/2 mutation (OR=5.128, 95% CI 1.431 to 18.370; P=0.012). At the 10% threshold, 43.0% (142/330) of patients were indicated for testing under MSS3, compared with 35.8% (118/330) for MSS1% and 36.4% (120/330) for MSS2. At the 10% threshold, MSS3 sensitivity was 91.5% and specificity 65.0%, significantly better than the previous MSS1 (P=0.037) and MSS2 (P=0.032) models. CONCLUSION: Our results indicate that the updated MSS3 outperforms previous iterations and relative to the Manchester population, is just as effective in identifying patients with BRCA1/2 mutations in a Southeast Asian population.

The influence of Malay cultural beliefs on breast cancer screening and genetic testing: A focus group study.

OBJECTIVE: Malays comprise an Asian cultural group reported to have low breast cancer screening uptake rates and poor cancer outcomes. Little is known about Malay cultural factors influencing beliefs and practice of cancer screening and genetic testing. Our study aims to explore health beliefs of Malay women around breast cancer screening and genetic testing. METHODS: We conducted focus groups among healthy English-speaking Malay women in Singapore, aged 40 to 69 years, using a structured guide developed through literature review, expertise input and participant refinement. Thematic analysis was conducted to extract dominant themes representing key motivators and barriers to screening and genetic testing. We used grounded theory to interpret results and derive a framework of understanding, with implications for improving uptake of services. RESULTS: Five focus groups (four to six participants per group) comprising 27 women were conducted to theme saturation. Major themes were (a) spiritual and religious beliefs act as barriers towards uptake of screening and genetic testing; (b) preference for traditional medicine competes with Western medicine recommendations; (c) family and community influence health-related decisions, complexed by differences in intergenerational beliefs creating contrasting attitudes towards screening and prevention. CONCLUSIONS: Decisions to participate in breast cancer screening and genetic testing are influenced by cultural, traditional, spiritual/religious, and intergenerational beliefs. Strategies to increase uptake should include acknowledgement and integration of these beliefs into counseling and education and collaboration with key influential Malay stakeholders and leaders.

Factors influencing the decision to share cancer genetic results among family members: An in-depth interview study of women in an Asian setting.

OBJECTIVE: Reluctance to share hereditary cancer syndrome genetic test results with family is reported among Asian patients. This study aims to explore patient factors influencing result sharing with family, to improve overall testing uptake. METHODS: Participants were women with a personal/family history of breast and/or ovarian cancer who received a positive, negative, or variant of uncertain significance test result. In-depth interviews were conducted to theme saturation to explore facilitators and barriers for sharing results with family. Grounded theory with thematic analysis was applied in analysis and interpretation. RESULTS: Twenty-four women participated. Three themes representing facilitators emerged for all results categories: family closeness, involvement of families in the testing process, and perception of low emotional impact of results. In the positive result category, 2 facilitator themes emerged: presence of actionable results and perception of family members' acceptance. In the negative and variant of uncertain significance result categories, 2 themes representing barriers to sharing emerged: perception of no genetic or medical implication for family and result ambiguity. CONCLUSION: Facilitators and barriers for result sharing are similar to those among Western women. A framework to explain Asian patients' decision-making process identifies optimal counselling opportunities to enhance communication with family.

Impact of subsidies on cancer genetic testing uptake in Singapore.

PURPOSE: Previous reports cite high costs of clinical cancer genetic testing as main barriers to patient's willingness to test. We report findings of a pilot study that evaluates how different subsidy schemes impact genetic testing uptake and total cost of cancer management. METHODS: We included all patients who attended the Cancer Genetics Service at the National Cancer Centre Singapore (January 2014-May 2016). Two subsidy schemes, the blanket scheme (100% subsidy to all eligible patients), and the varied scheme (patients received 50%-100% subsidy dependent on financial status) were compared. We estimated total spending on cancer management from government's perspective using a decision model. RESULTS: 445 patients were included. Contrasting against the blanket scheme, the varied scheme observed a higher attendance of patients (34 vs 8 patients per month), of which a higher proportion underwent genetic testing (5% vs 38%), while lowering subsidy spending per person (S$1098 vs S$1161). The varied scheme may potentially save cost by reducing unnecessary cancer surveillance when first-degree relatives uptake rate is above 36%. FINDINGS: Provision of subsidy leads to a considerable increase in genetic testing uptake rate. From the government's perspective, subsidising genetic testing may potentially reduce total costs on cancer management.

Impact of Appointment Waiting Time on Attendance Rates at a Clinical Cancer Genetics Service.

The increase in demand for clinical cancer genetics services has impacted the ability to provide services timeously. Given limited resources, this often results in extended appointment waiting times. Over the last 3 years, the Cancer Genetics Service at the National Cancer Centre Singapore has continued to experience a steady increase in demand for its service. Nevertheless, significant no-show rates have been reported. This study sought to determine whether an association exists between appointment waiting times and attendance rates. Data was gathered for all participants meeting inclusion criteria. Attendance rates and appointment waiting times were calculated. The relationship between mean waiting times for those who did and did not attend their scheduled appointments was evaluated using Welch's t test and linear regression model. The results showed a significant difference in mean appointment waiting times between patients who did and did not attend (32.66 versus 43.50 days respectively; p < 0.0001). Furthermore, patients who waited for longer than 37 days were significantly less likely to attend. No-show rates increased as the waiting time increased, at a rate of 19.60% per 20 days and 21.40% per 30 days. In conclusion, appointment waiting time is a significant predictor for patient attendance. Strategies to ensure patients receive an appointment within the necessary timeframe at the desired setting are important to ensure that individuals at increased cancer risk attend their appointments in order to manage their cancer risks effectively.

Mutation spectrum of POLE and POLD1 mutations in South East Asian women presenting with grade 3 endometrioid endometrial carcinomas.

OBJECTIVE: Somatic POLE mutations have been found in a subset of endometrioid ECs particularly in FIGO grade 3 tumors while POLD1 mutations are reportedly rare in ECs. While it has been suggested that POLE mutation confers good prognosis, the data remains conflicting. Our study aims to determine the mutation spectrum of somatic and germline POLE and POLD1 gene mutations in South East Asian (SEA) women with FIGO grade 3 endometrioid ECs. METHODS: Forty-seven patients diagnosed with FIGO grade 3 endometrioid EC, diagnosed between 2009 and 2013 were included. Next generation sequencing (NGS) using formalin fixed embedded (FFPE) tissue was utilized to sequence tumor and matched normal tissue. Tumors were also assessed for other clinicopathologic and microsatellite status phenotype. Survival curves for pathogenic somatic POLE mutated and wild-type tumors were estimated by Kaplan-Meier method. RESULTS: Pathogenic POLE (somatic or germline) and POLD1 (germline) mutations were detected in 29.7% (14/47) and 4.3% (2/47) patients, respectively. Three pathogenic germline mutations; one POLE and two POLD1 mutations were novel. Pathogenic germline and somatic POLE and POLD1 mutations were associated with 100% recurrence free survival. In contrast, among the wild-type POLE and POLD1 patients, 25% (8/32) had recurrence with 15.6% (5/32) subsequently dying of the disease. Somatic POLE-mutated tumors were more commonly associated with microsatellite stable (MSS) ECs (83% vs 49%; p=0.04) and peritumoral lymphocytic infiltration (75% vs 42%; p=0.05). All tumors with tumoral infiltrating lymphocytes exhibited peritumoral lymphocytic infiltrate but not vice versa. CONCLUSION: Mutations in POLE and POLD1 in SEA women with grade 3 endometrioid ECs are associated with improved recurrence free survival. Notably, germline mutations in either POLE/POLD1 were seen in 8.5% of patients who will require appropriate genetic counseling regarding risk of developing colorectal carcinoma and on the need for additional surveillance for colonic changes. MSS and peritumoral lymphocytic infiltration may be useful histological features for distinguishing POLE mutated grade 3 endometrioid ECs.

Missed diagnosis or misdiagnosis: Common pitfalls in genetic testing.

Genetic testing has the power to identify individuals with increased predisposition to disease, allowing individuals the opportunity to make informed management, treatment and reproductive decisions. As genomic medicine continues to be integrated into aspects of everyday patient care and the indications for genetic testing continue to expand, genetic services are increasingly being offered by non-genetic clinicians. The current complexities of genetic testing highlight the need to support and ensure non-genetic professionals are adequately equipped with the knowledge and skills to provide services. We describe a series of misdiagnosed/mismanaged cases, highlighting the common pitfalls in genetic testing to identify the knowledge gaps and where education and support is needed. We highlight that education focusing on differential diagnoses, test selection and result interpretation is needed. Collaboration and communication between genetic and non-genetic clinicians and integration of genetic counsellors into different medical settings are important. This will minimise the risks and maximise the benefits of genetic testing, ensuring adverse outcomes are mitigated.

Device quantization policy in variation-aware in-memory computing design.

Device quantization of in-memory computing (IMC) that considers the non-negligible variation and finite dynamic range of practical memory technology is investigated, aiming for quantitatively co-optimizing system performance on accuracy, power, and area. Architecture- and algorithm-level solutions are taken into consideration. Weight-separate mapping, VGG-like algorithm, multiple cells per weight, and fine-tuning of the classifier layer are effective for suppressing inference accuracy loss due to variation and allow for the lowest possible weight precision to improve area and energy efficiency. Higher priority should be given to developing low-conductance and low-variability memory devices that are essential for energy and area-efficiency IMC whereas low bit precision (< 3b) and memory window (< 10) are less concerned.

Spectrum of Germline Mutations Within Fanconi Anemia-Associated Genes Across Populations of Varying Ancestry.

BACKGROUND: Fanconi anemia (FA) is a rare genetic disorder associated with hematological disorders and solid tumor predisposition. Owing to phenotypic heterogeneity, some patients remain undetected until adulthood, usually following cancer diagnoses. The uneven prevalence of FA cases with different underlying FA gene mutations worldwide suggests variable genetic distribution across populations. Here, we aim to assess the genetic spectrum of FA-associated genes across populations of varying ancestries and explore potential genotype-phenotype associations in cancer. METHODS: Carrier frequency and variant spectrum of potentially pathogenic germline variants in 17 FA genes (excluding BRCA1/FANCS, BRCA2/FANCD1, BRIP1/FANCJ, PALB2/FANCN, RAD51C/FANCO) were evaluated in 3523 Singaporeans and 7 populations encompassing Asian, European, African, and admixed ancestries from the Genome Aggregation Database. Germline and somatic variants of 17 FA genes in 7 cancer cohorts from The Cancer Genome Atlas were assessed to explore genotype-phenotype associations. RESULTS: Germline variants in FANCA were consistently more frequent in all populations. Similar trends in carrier frequency and variant spectrum were detected in Singaporeans and East Asians, both distinct from other ancestry groups, particularly in the lack of recurrent variants. Our exploration of The Cancer Genome Atlas dataset suggested higher germline and somatic mutation burden between FANCA and FANCC with head and neck and lung squamous cell carcinomas as well as FANCI and SLX4/FANCP with uterine cancer, but the analysis was insufficiently powered to detect any statistical significance. CONCLUSION: Our findings highlight the diverse genetic spectrum of FA-associated genes across populations of varying ancestries, emphasizing the need to include all known FA-related genes for accurate molecular diagnosis of FA.

Impact of Variant Reclassification in Cancer Predisposition Genes on Clinical Care.

PURPOSE: Genetic testing has clinical utility in the management of patients with hereditary cancer syndromes. However, the increased likelihood of encountering a variant of uncertain significance in individuals of non-European descent such as Asians may be challenging to both clinicians and patients. This study aims to evaluate the impact of variant reclassification in an Asian country with variants of uncertain significance reported in cancer predisposition genes. METHODS: A retrospective analysis of patients seen at the Cancer Genetics Service at the National Cancer Centre Singapore between February 2014 and March 2020 was conducted. The frequency, direction, and time to variant reclassification were evaluated by comparing the reclassified report against the original report. RESULTS: A total of 1,412 variants of uncertain significance were reported in 49.9% (845 of 1,695) of patients. Over 6 years, 6.7% (94 of 1,412) of variants were reclassified. Most variants of uncertain significance (94.1%, 80 of 85) were downgraded to benign or likely benign variant, with a smaller proportion of variants of uncertain significance (5.9%, 5 of 85) upgraded to pathogenic or likely pathogenic variant. Actionable variants of uncertain significance upgrades and pathogenic or likely pathogenic variant downgrades, which resulted in management changes, happened in 31.0% (39 of 126) of patients. The median and mean time taken for reclassification were 1 and 1.62 year(s), respectively. CONCLUSION: We propose a clinical guideline to standardize management of patients reported to have variants of uncertain significance. Management should be based on the patient's personal history, family history, and variant interpretation. For clinically relevant or suspicious variants of uncertain significance, follow-up is recommended every 2 years, as actionable reclassifications may happen during this period.

Identifying ataxia-telangiectasia in cancer patients: Novel insights from an interesting case and review of literature.

Timely genetic testing leading to early diagnosis of A-T is crucial due to its plethora of implications on clinical management, particularly in those who develop malignancies. Thus, clinicians have to be astute in identifying diagnostic clues of A-T.

Factors shaping at-risk individuals' decisions to undergo genetic testing for cancer in Asia.

This study aims to enrich our understanding of factors influencing medically indicated at-risk individuals' decisions to take genetic tests (or not) in the context of cancer treatment and prevention. While previous studies have explored this topic in communities in Europe and the United States, we know relatively little about the situation in Asia. In this study, we conducted in-depth interviews with 24 women who underwent genetic testing for hereditary breast and ovarian cancer syndromes in Singapore. Grounded theory with thematic analysis was applied. Six encouraging and three discouraging factors are identified in the analysis. The six encouraging factors are: desire to create awareness for self and family; perceived benefits for self and family; strong family history of cancer; presence of family support; medical professional recommendation and adequate amount of time to consider undertaking the test. The three discouraging factors are: high costs of tests; perceived lack of ability to cope with test results; and insufficient information about genetic testing. Taken together, the findings in this study add to the current literature by providing empirical evidence regarding the importance of holding family included pre-test counselling and providing adequate time for patients to decide to undergo genetic testing for hereditary cancer syndromes.

Predictive Testing for Tumor Predisposition Syndromes in Pediatric Relatives: An Asian Experience.

Approximately 10% of pediatric cancer patients possess germline pathogenic/likely pathogenic variants (PV/LPV) in known tumor predisposition genes. Predictive testing is the optimal approach to identify asymptomatic at-risk relatives to guide gene-directed surveillance for early cancer detection and/or risk-reducing strategies. However, the uptake rate for predictive testing remains low in Asian countries. We aim to evaluate the uptake rate of predictive testing in a pediatric population (aged under 21-years-old) in a multi-ethnic Asian cancer center. Our retrospective analysis included families with PV/LPVs identified in genes associated with pediatric tumor predisposition. Of the 83 pediatric first-degree relatives (FDRs) from 49 unrelated families, 20 FDRs (24.1%) originating from 13 families (26.6%) underwent predictive testing. Genes tested in pediatric FDRs were APC, RB1, SBDS, SDHA, SDHB, SDHD, and TP53. All pediatric FDRs of probands with PV/LPVs in RB1 and biallelic PVs in SBDS underwent predictive testing, while <45% of pediatric FDRs had predictive testing for familial PV/LPVs identified in the APC, SDHA, SDHB, SDHD, and TP53 genes. Amongst the 13 families who underwent pre-test counseling, 80% of pediatric FDRs in these families proceeded with predictive testing. Malay pediatric FDRs and siblings of probands were more likely to undergo predictive testing. We conclude that the predictive testing rate in pediatric FDRs is higher than that of adult FDRs in Asia, but still below the global average. We postulate factors that may influence predictive testing uptake in pediatric FDRs includes a lack of genetics awareness, concerns regarding insurance, and genetic discrimination.

Early-onset breast cancer in a woman with a germline mobile element insertion resulting in BRCA2 disruption: a case report.

Mobile element insertions (MEIs) contribute to genomic diversity, but they can be responsible for human disease in some cases. Initial clinical testing (BRCA1, BRCA2 and PALB2) in a 40-year-old female with unilateral breast cancer did not detect any pathogenic variants. Subsequent reanalysis for MEIs detected a novel likely pathogenic insertion of the retrotransposon element (RE) c.7894_7895insSVA in BRCA2. This case highlights the importance of bioinformatic pipeline optimization for the detection of MEIs in genes associated with hereditary cancer, as early detection can significantly impact clinical management.

Biallelic NF1 inactivation in high grade serous ovarian cancers from patients with neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a multisystem disorder caused by germline heterozygous NF1 loss-of-function variants. The NF1 gene encodes neurofibromin, a RAS GTPase-activating protein, which functions by down-regulating RAS/RAF/MAPK-signalling pathways. Somatic NF1 aberrations frequently occur in sporadic ovarian cancer (OC), but the incidence of OC in NF1 patients is rare. Here we report the germline and somatic findings for two unrelated patients with NF1 and high-grade serous OC. Germline testing revealed a heterozygous NF1 pathogenic variant in each patient, c.7096_7101del (p.Asn2366_Phe2367del) and c.964delA (p.Ile322Leufs*54), respectively. No germline variants in well-established OC predisposition genes were detected, including BRCA1 and BRCA2. Tumor loss-of-heterozygosity analysis demonstrated loss of the wild type NF1 allele for both patients. Biallelic NF1 inactivation occurs as part of OC pathogenesis in NF1 patients. Although the penetrance of NF1-associated OC is insufficient to warrant risk-reducing interventions, our findings highlight the potential for therapies targeting the RAS/RAF/MAPK-signalling pathway for these cases.