The landscape of BRCA1 and BRCA2 large rearrangements in an international cohort of over 20 000 ovarian tumors identified using next-generation sequencing.

BACKGROUND: Approximately half of ovarian tumors have defects within the homologous recombination repair pathway. Tumors carrying pathogenic variants (PVs) in BRCA1/BRCA2 are more likely to respond to poly-ADP ribose polymerase (PARP) inhibitor treatment. Large rearrangements (LRs) are a challenging class of variants to identify and characterize in tumor specimens and may therefore be underreported. This study describes the prevalence of pathogenic BRCA1/BRCA2 LRs in ovarian tumors and discusses the importance of their identification using a comprehensive testing strategy. METHODS: Sequencing and LR analyses of BRCA1/BRCA2 were conducted in 20 692 ovarian tumors received between March 18, 2016 and February 14, 2023 for MyChoice CDx testing. MyChoice CDx uses NGS dosage analysis to detect LRs in BRCA1/BRCA2 genes using dense tiling throughout the coding regions and limited flanking regions. RESULTS: Of the 2217 PVs detected, 6.3% (N = 140) were LRs. Overall, 0.67% of tumors analyzed carried a pathogenic LR. The majority of detected LRs were deletions (89.3%), followed by complex LRs (5.7%), duplications (4.3%), and retroelement insertions (0.7%). Notably, 25% of detected LRs encompassed a single or partial single exon. This study identified 84 unique LRs, 2 samples each carried 2 unique LRs in the same gene. We identified 17 LRs that occurred in multiple samples, some of which were specific to certain ancestries. Several cases presented here illustrate the intricacies involved in characterizing LRs, particularly when multiple events occur within the same gene. CONCLUSIONS: Over 6% of PVs detected in the ovarian tumors analyzed were LRs. It is imperative for laboratories to utilize testing methodologies that will accurately detect LRs at a single exon resolution to optimize the identification of patients who may benefit from PARP inhibitor treatment.

Psychological predictors of advanced cancer patients' preferences for return of results from comprehensive tumor genomic profiling.

This study assessed the psychological predictors of preferences for return of comprehensive tumor genomic profiling (CTGP) results in patients with advanced cancers, enrolled in the Molecular Screening and Therapeutics Program. Patients completed a questionnaire prior to undergoing CTGP. Of the 1434 who completed a questionnaire, 96% would like to receive results that can guide treatment for their cancer, and preference for receiving this type of result was associated with lower tolerance of uncertainty. Sixty-four percent would like to receive results that cannot guide treatment, and lower tolerance of uncertainty, self-efficacy, and perceived importance were associated with this preference. Fifty-nine percent would like to receive variants of unknown significance, which was associated with lower tolerance of uncertainty, higher self-efficacy, and perceived importance. Eighty-six percent wanted to receive germline results that could inform family risk. This was associated with higher self-efficacy, perceived importance, and perceived susceptibility. Although most patients wanted to receive all types of results, given the differing patient preferences regarding the return of results depending on the utility of the different types of results, it appears critical to safeguard patient understanding of result utility to achieve informed patient choices. This should be accompanied by appropriate consent processes.

Routine informed consent for mismatch repair testing in endometrial cancers: Review and ethical analysis.

OBJECTIVE: To review available data regarding consent for tumor testing for mismatch repair (MMR), and to make recommendation for ethical best practices based on synthesis of contemporary data and ethical principles. METHODS: PubMed and CINAHL databases were searched through September 2021; articles reporting on consent for MMR tumor testing for patients at risk for Lynch Syndrome were abstracted. Additional articles were identified through review of references. Key data and ethical principles were extracted, summarized, and analyzed in the context of contemporary clinical practice. RESULTS: 16 articles met inclusion criteria for this review, none of which specifically related to MMR testing for endometrial cancers. All but two studies were published prior to the approval of pembrolizumab for treatment of MMR-deficient tumors. Scant available data suggest that routine consent prior to tumor testing is uncommon; however, several decision aids improved patient knowledge and satisfaction prior to deciding whether to proceed with tumor testing. Previous ethical analyses invoke clinical utility, potential germline implications, and logistical factors in making recommendations regarding consent practices. These analyses varied in their final recommendations; however, all had significant deficits in their arguments related to contemporary clinical care for patients with endometrial cancer. CONCLUSION: Current data are needed to assess the impact of potential consent strategies for tumor testing. Based on available data, and consistent with contemporary ethical best practices, we recommend that planned MMR testing of endometrial cancers be discussed routinely with patients verbally or in surgical consent documents.

Performance characteristics of screening strategies to identify Lynch syndrome in women with ovarian cancer.

BACKGROUND: For women with ovarian cancer (OC), the optimal screening strategy to identify Lynch syndrome (LS) has not been determined. In the current study, the authors compared the performance characteristics of various strategies combining mismatch repair (MMR) immunohistochemistry (IHC), microsatellite instability testing (MSI), and family history for the detection of LS. METHODS: Women with nonserous and/or nonmucinous ovarian cancer were recruited prospectively from 3 cancer centers in Ontario, Canada. All underwent germline testing for LS and completed a family history assessment. Tumors were assessed using MMR IHC and MSI. The sensitivity, specificity, and positive and negative predictive values of screening strategies were compared with the gold standard of a germline result. RESULTS: Of 215 women, germline data were available for 189 (88%); 13 women (7%) had pathogenic germline variants with 7 women with mutS homolog 6 (MSH6); 3 women with mutL homolog 1 (MLH1); 2 women with PMS1 homolog 2, mismatch repair system component (PMS2); and 1 woman with mutS homolog 2 (MSH2). A total of 28 women had MMR-deficient tumors (13%); of these, 11 had pathogenic variants (39%). Sequential IHC (with MLH1 promoter methylation analysis on MLH1-deficient tumors) followed by MSI for nonmethylated and/or MMR-intact patients was the most sensitive (92.3%; 95% confidence interval, 64%-99.8%) and specific (97.7%; 95% confidence interval, 94.2%-99.4%) approach, missing 1 case of LS. IHC with MLH1 promoter methylation analysis missed 2 patients of LS. Family history was found to have the lowest sensitivity at 55%. CONCLUSIONS: Sequential IHC (with MLH1 promoter methylation analysis) followed by MSI was found to be most sensitive. However, IHC with MLH1 promoter methylation analysis also performed well and is likely more cost-effective and efficient in the clinical setting. The pretest probability of LS is high in patients with MMR deficiency and warrants universal screening for LS.

Tumor analysis of MMR genes in Lynch-like syndrome: Challenges associated with results interpretation.

BACKGROUND: Up to 70% of suspected Lynch syndrome patients harboring MMR deficient tumors lack identifiable germline pathogenic variants in MMR genes, being referred to as Lynch-like syndrome (LLS). Previous studies have reported biallelic somatic MMR inactivation in a variable range of LLS-associated tumors. Moreover, translating tumor testing results into patient management remains controversial. Our aim is to assess the challenges associated with the implementation of tumoral MMR gene testing in routine workflows. METHODS: Here, we present the clinical characterization of 229 LLS patients. MMR gene testing was performed in 39 available tumors, and results were analyzed using two variant allele frequency (VAF) thresholds (≥5% and ≥10%). RESULTS AND DISCUSSION: More biallelic somatic events were identified at VAF ≥ 5% than ≥10% (35.9% vs. 25.6%), although the rate of nonconcordant results regarding immunohistochemical pattern increased (30.8% vs. 20.5%). Interpretation difficulties question the current utility of the identification of MMR somatic hits in the diagnostic algorithm of suspected LS cases.

Implementation of Nurse Navigation Improves Rate of Molecular Tumor Testing for Ovarian Cancer in a Gynecologic Oncology Practice.

PURPOSE: The purpose of this study was to assess the impact of implementing a Nurse Navigator (NN) to improve the rate and timeliness of molecular tumor testing. METHODS: This is an evaluation of the impact of education sessions, consensus building, and NN implementation for molecular tumor testing in patients with epithelial ovarian cancer. The NNs' responsibilities included attending tumor boards and ensuring Next Generation Sequencing (NGS) is ordered, reviewed, and coordinated for appropriate patients. RESULTS: NNs significantly improved NGS testing rates from 35.29% to 77.27%, p = 0.002. Ordering a targeted panel test (TPT) was the most common reason for not ordering NGS in the pre-NN cohort (13/22, 59%). The total turnaround time for testing was reduced after the introduction of NNs from 145.2 days to 42.8 days, p < 0.0001. The post-NN group had a significantly higher rate of actionable mutations identified for the recurrent setting [67.6% versus 20.8% (p = 0.0005)] and a trend towards a higher rate of actionable mutations identified in the frontline setting [41.2% versus 33.3% (p = 0.41)]. CONCLUSION: NNs significantly improved somatic tumor testing rates and timeliness for patients with ovarian cancer. Discontinuing TPT in favor of NGS revealed a higher rate of actionable tumor mutations that would have been missed with TPT alone.

Healthcare professionals' perspectives on implementation of universal tumor DNA testing in ovarian cancer patients: multidisciplinary focus groups.

Universal tumor DNA testing in epithelial ovarian cancer patients can function not only as an efficient prescreen for hereditary cancer testing, but may also guide treatment choices. This innovation, introduced as Tumor-First workflow, offers great opportunities, but ensuring optimal multidisciplinary collaboration is a challenge. We investigated factors that were relevant and important for large-scale implementation. In three multidisciplinary online focus groups, healthcare professionals (gynecologic oncologists, pathologists, clinical geneticists, and clinical laboratory specialists) were interviewed on factors critical for the implementation of the Tumor-First workflow. Recordings were transcribed for analysis in Atlas.ti according to the framework of Flottorp that categorizes seven implementation domains. Healthcare professionals from all disciplines endorse implementation of the Tumor-First workflow, but more detailed standardization and advice regarding the logistics of the workflow were needed. Healthcare professionals explored ways to stay informed about the different phases of the workflow and the results. They emphasized the importance of including all epithelial ovarian cancer patients in the workflow and monitoring this inclusion. Overall, healthcare professionals would appreciate supporting material for the implementation of the Tumor-First workflow in the daily work routine. Focus group discussions have revealed factors for developing a tailored implementation strategy for the Tumor-First workflow in order to optimize care for epithelial ovarian cancer patients. Future innovations affecting multidisciplinary oncology teams including clinical geneticists can benefit from the lessons learned.

Implementing HRD Testing in Routine Clinical Practice on Patients with Primary High-Grade Advanced Ovarian Cancer.

The chemotherapy backbone for patients with high-grade advanced epithelial ovarian cancer (HG-AOC) is carboplatin and paclitaxel followed by a maintenance therapy either with bevacizumab, with a PARP inhibitor, or with a combination of both, which is defined by the presence of a homologous recombination deficiency (HRD) and by the BRCA1/2 status. This study included patients with a primary diagnosis of HG-AOC treated between December 2019 and December 2021. The HRD status was measured using the Myriad myChoice® test on all the patients with an indication for tumor HRD testing. Germline testing was conducted on all the patients using the TruRisk® panel as recommended by the national guidelines. HRD testing was requested for 190 patients, and, for 163 patients (85.8%), an HRD test result was available. An HRD test result could not be reported in 27 patients due to an insufficient tumor yield. The median time that it took to receive the HRD test results was 37 days (range of 8-97). In total, an HRD was present in 44.7% (73/163) of the patients based on a GIS ≥ 42 in 42.9% of the patients and based on a tumor BRCA1/2 mutation in 3 cases (all with a GIS < 42). The germline testing results were available for 148 patients, and, in 18 patients (12.2%), a deleterious germline mutation was detected. Of the 27 patients without sufficient HRD testing, BRCA1/2 germline testing results were available for 19 patients (70.4%), and a deleterious germline mutation was detected in 2 patients (7.4%). The implementation of HRD testing is feasible, and the results become available for treatment decisions in a timely manner for most patients. The prerequisite for HRD testing with the Myriad myChoice® test is a sufficient amount of tumor tissue. The cotesting of HRD and BRCA1/2 germline testing should be aimed for in order to enable optimal and timely treatment decisions on maintenance therapy as well as to test patients on whom the HRD test will not be evaluable.

Reliability of Tumor Testing Compared to Germline Testing for Detecting BRCA1 and BRCA2 Mutations in Patients with Epithelial Ovarian Cancer.

BACKGROUND: BRCA 1/2 mutation status has become one of the most important parameters for treatment decision in patients with epithelial ovarian cancer (EOC). The aim of this study was to compare tumor DNA with blood DNA sequencing to evaluate the reliability of BRCA tumor testing results. METHODS: Patients who were treated for EOC between 2003 and 2019 at the Medical University of Vienna and underwent both germline (gBRCA) and tumor (tBRCA) testing for BRCA mutations were identified. We calculated the concordance rate and further analyzed discordant cases. RESULTS: Out of 140 patients with EOC, gBRCA mutation was found in 47 (33.6%) and tBRCA mutation in 53 (37.9%) patients. Tumor testing identified an additional 9/140 (6.4%) patients with somatic BRCA mutation and negative germline testing. The comparison of germline testing with tumor testing revealed a concordance rate of 93.5% and a negative predictive value of tumor testing of 96.0%. After BRCA variants of uncertain significance were included in the analysis, concordance rate decreased to 90.9%. CONCLUSION: Tumor testing identified the majority of pathogenic germline BRCA mutations but missed three (2.1%) patients. In contrast, nine (6.4%) patients harboring a somatic BRCA mutation would have been missed by gBRCA testing only.

Differences in cancer patients' and clinicians' preferences for disclosure of uncertain genomic tumor testing results.

OBJECTIVE: To compare clinicians' and patients' preferences for disclosure of genomic tumor testing (GTT) results; to determine the sensitivity of these disclosure preferences to uncertainty about the actionability of results; and to explore factors associated with disclosure preferences. METHODS: Community-based oncology clinicians (n = 94) and patients (n = 1121) were surveyed about their preferences for disclosing GTT results with varying levels of uncertainty (Tiers 1, 2, 3). Descriptive and multivariable regression analyses were used to compare clinicians' and patients' disclosure preferences and their sensitivity to uncertainty, and to explore associations between disclosure preferences and sociodemographic, clinical, and psychological factors. RESULTS: Relatively more patients than clinicians preferred disclosure, and their preferences were less sensitive to the uncertainty of GTT results. For patients and clinicians, lower uncertainty sensitivity was associated with positive GTT attitudes; for patients it was also associated with greater uncertainty tolerance and knowledge of uncertainty in GTT. CONCLUSION: Relatively more cancer patients than clinicians prefer disclosure of GTT results, and their preferences are less sensitive to result uncertainty. Uncertainty sensitivity in disclosure preferences is associated with GTT-related attitudes and uncertainty tolerance. PRACTICE IMPLICATIONS: Differences in cancer patients' and clinicians' preferences for disclosure of uncertain GTT results warrant greater attention in cancer care.

Modern Approaches to Testing Drug Sensitivity of Patients' Tumors (Review).

Drug therapy is still one of the basic techniques used to treat cancers of different etiology. However, tumor resistance to drugs is a pressing problem limiting drug treatment efficacy. It is obvious for both modern fundamental and clinical oncology that there is the need for an individual approach to treating cancer taking into account the biological properties of a tumor when prescribing chemo- and targeted therapy. One of the promising strategies is to increase the antitumor therapy efficacy by developing predictive tests, which enable to evaluate the sensitivity of a particular tumor to a specific drug or a drug combination before the treatment initiation and, thus, make individual therapy selection possible. The present review considers the main approaches to drug sensitivity assessment of patients' tumors: molecular genetic profiling of tumor cells, and direct efficiency testing of the drugs on tumor cells isolated from surgical or biopsy material. There were analyzed the key directions in research and clinical studies such as: the search for predictive molecular markers, the development of methods to maintain tumor cells or tissue sections viable, i.e. in a condition maximum close to their physiological state, the development of high throughput systems to assess therapy efficiency. Special attention was given to a patient-centered approach to drug therapy in colorectal cancer.

Tumor and germline next generation sequencing in high grade serous cancer: experience from a large population-based testing program.

The aim of this study was to determine the prevalence of somatic and germline pathogenic variants (PVs) in high-grade serous cancer (HGSC) and to demonstrate the technical feasibility and effectiveness of a large-scale, population-based tumor testing program. It involved a retrospective review of genetic test results in 600 consecutive HGSC tumor samples and a subsequent comparison of germline and tumor results in a subset of 200 individuals. Tumor testing was successful in 95% of samples (570/600) with at least one BRCA1/2 PV identified in 16% (93/570) of cases. Among the 200 paired cases, BRCA1/2 PVs were detected in 38 tumors (19%); 58% were somatic (22/38); and 42% were germline (16/38). There was 100% concordance between germline and tumor test results. This is the largest series of BRCA1/2 testing in HGSC (tumor-only and paired cohorts), reported to date, and our data show that an effectively designed and validated population-based tumor testing program can be used to determine both treatment eligibility and hereditary cancer risk.

Tumor Testing for Somatic and Germline BRCA1/BRCA2 Variants in Ovarian Cancer Patients in the Context of Strong Founder Effects.

Deleterious variants in the BRCA1/BRCA2 genes and homologous recombination deficiency (HRD) status are considered strong predictors of response to poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi). The introduction of PARPi in clinical practice for the treatment of patients with advanced ovarian cancer imposed changes in the molecular diagnosis of BRCA1/BRCA2 variants. BRCA1/BRCA2 tumor testing by next-generation sequencing (NGS) can detect simultaneously both somatic and germline variants, allowing the identification of more patients with higher likelihood of benefiting from PARPi. Our main goal was to determine the frequency of somatic and germline BRCA1/BRCA2 variants in a series of non-mucinous OC, and to define the best strategy to be implemented in a routine diagnostic setting for the screening of germline/somatic variants in these genes, including the BRCA2 c.156_157insAlu Portuguese founder variant. We observed a frequency of 19.3% of deleterious variants, 13.3% germline, and 5.9% somatic. A higher prevalence of pathogenic variants was observed in patients diagnosed with high-grade serous ovarian cancer (23.2%). Considering the frequencies of the c.3331_3334del and the c.2037delinsCC BRCA1 variants observed in this study (73% of all BRCA1 pathogenic germline variants identified) and the limitations of NGS to detect the BRCA2 c.156_157insAlu variant, it might be cost-effective to test for these founder variants with a specific test prior to tumor screening of the entire coding regions of BRCA1 and BRCA2 by NGS in patients of Portuguese ancestry.

Gene Panel Tumor Testing in Ovarian Cancer Patients Significantly Increases the Yield of Clinically Actionable Germline Variants beyond BRCA1/BRCA2.

Since the approval of PARP inhibitors for the treatment of high-grade serous ovarian cancer, in addition to cancer risk assessment, BRCA1 and BRCA2 genetic testing also has therapeutic implications (germline and somatic variants) and should be offered to these patients at diagnosis, irrespective of family history. However, variants in other genes besides BRCA1 and BRCA2 are associated with ovarian cancer predisposition, which would be missed by a genetic testing aimed only at indication for PARP inhibitor treatment. In this study, we aimed to evaluate the yield of clinically actionable germline variants using next-generation sequencing of a customized panel of 10 genes for the analysis of formalin-fixed paraffin-embedded samples from 96 ovarian carcinomas, a strategy that allows the detection of both somatic and germline variants in a single test. In addition to 13.7% of deleterious germline BRCA1/BRCA2 carriers, we identified 7.4% additional patients with pathogenic germline variants in other genes predisposing for ovarian cancer, namely RAD51C, RAD51D, and MSH6, representing 35% of all pathogenic germline variants. We conclude that the strategy of reflex gene-panel tumor testing enables the identification of clinically actionable germline variants in a significantly higher proportion of ovarian cancer patients, which may be valuable information in patients with advanced disease that have run out of approved therapeutic options. Furthermore, this approach increases the chance to make available genetic counseling, presymptomatic genetic testing, and gynecological cancer prophylaxis to female relatives who turn out to be healthy carriers of deleterious germline variants.

Is tumor testing efficiency for Lynch syndrome different in rectal and colon cancer?

BACKGROUND: Tumor testing utility in Lynch syndrome (LS) diagnosis is established. AIMS: Analyze the differences between tumor testing efficiency in rectal (RC) and colon cancer (CC). METHODS: We performed immunohistochemistry (IHC) for MisMatch Repair (MMR) proteins (IHC-MMR) and MicroSatellite Instability analysis (MSI) on 482 unselected primary tumors: 320 CCs and 162 RCs. Samples had proficient-IHC, deficient-IHC or borderline-IHC ("patchy" expression). MSI-H borderline-IHC tumors were considered as likely MMR-deficient. Germline testing was offered to MMR-deficient patients without BRAF mutation or MLH1 promoter hypermetilation (MLH1-Hy). RESULTS: We identified 51/482 (10.6%) MMR-defective tumors. Multivariable analysis demonstrated a significant correlation between tumor testing results with histotype, lymph-node involvement and tumor location. In particular, RC showed a lower MMR-deficiency rate than CC (p<0.0001). Interestingly, MLH1 loss was detected in 0% RCs and 76.1% CCs, with 80% of them showing BRAF mutation/MLH1-Hy. A germline variant was detected in 12 out of 18 patients (mutation detection rate of 66.7%). CONCLUSION: Tumor testing results showed molecular differences between CCs and RCs, in terms of MMR proteins expression, and presence of BRAF mutation/MLH1-Hy. MSH6 variants were the most frequent ones (50%). Although young age at diagnosis was associated with mutation detection (p = 0.045), 33.3% of LS patients were >50 years.

Germline and Somatic Tumor Testing in Gynecologic Cancer Care.

New technologies have advanced the science of tumor biology and genomics. Commercially available germline and somatic testing modalities have the downstream benefits of enabling prevention strategies in women with hereditary cancers and their family members in addition to identifying women who benefit most from novel targeted therapeutics. The matrix of available testing is complex and evolving. Women's health providers need to be versed in benefits and limitations of available testing. Genetic counselors play a pivotal role in interpretation of relevant mutations, and in avoiding common pitfalls, but their skill set is not sufficient to optimally integrate cancer genomics into clinical practice.

Afatinib use in recurrent epithelial ovarian carcinoma.

•Genomic tumor testing is an important tool in guiding treatment for gynecologic malignancies.•Targetable mutations may lead to new therapies in gynecologic cancer treatment.•Her2/neu mutations in serous ovarian carcinomas can be targeted with ERBB2 inhibitors.•Afatinib shows promising response rates in lung cancers carrying Her2/neu mutations.•Afatinib may be effective in serous ovarian tumors exhibiting Her2/neu or ERBB2 mutations.

An update on genetic risk assessment and prevention: the role of genetic testing panels in breast cancer.

Introduction: In the past 5 years, multi-gene panels have replaced the practice of BRCA1 and BRCA2 genetic testing in cases of suspected inherited breast cancer susceptibility. A variety of genes have been included on these panels without certainty of their clinical utility. Pertinent current and historical literature was reviewed to provide an up-to-date snapshot of the changing landscape of the use of gene panel tests in the context of breast cancer. Areas covered: Following a recent review of the evidence, 10 genes have been found to have definitive evidence of increased breast cancer risk with variable penetrance. Here, we review the recent changes to the practice of multi-gene panel use in breast cancer diagnoses, including an update on next generation sequencing, alternative models of genetic testing, considerations when ordering these panel tests, and recommendations for management in identified carriers for a variety of genes. A comparison of screening recommendations and carrier frequencies from recent studies is also explored. Lastly, we consider what the future of hereditary oncologic genetic testing holds. Expert opinion: The transition to multi-gene panels in breast cancer patients has improved the likelihood of capturing a rare variant in a well-established gene associated with hereditary breast cancer (e.g. BRCA1 and BRCA2, TP53). There is also an increase in the likelihood of uncovering an uncertain result. This could be in the form of a variant of uncertain significance, or a pathogenic variant in a gene with questionable breast cancer risk-association. Concurrently, a changing landscape of who orders genetic tests will improve access to genetic testing. This pervasiveness of genetic testing must be accompanied with increased genetic literacy in all health-care providers, and access to support from genetics professionals for management of patients and at-risk family members.

Regarding the Yin and Yang of Precision Cancer- Screening and Treatment: Are We Creating a Neglected Majority?

In this commentary, we submit that the current emphasis of precision cancer screening and treatment (PCST) has been to provide and interpret the implications of "positive" screening results for those deemed to be at greatest risk for cancer or most likely to benefit from targeted treatments. This is an important, but proportionately small target group, regardless of the cancer context. Overlooked by this focus is the larger majority of those screened who receive "negative" results. We contend that for optimal dissemination of PCST, the complement of positive and negative results be viewed as an inseparable yin-yang duality with the needs of those who receive negative screening results viewed as important as those deemed to be at highest risk or derive targeted treatment benefit. We describe three areas where communication of negative PCST results warrant particular attention and research consideration: population-based family history screening, germline testing for hereditary cancer syndromes, and tumor testing for targeted cancer treatment decision-making. Without thoughtful consideration of the potential for negative results to have psychological and behavioral influences, there is a potential to create a "neglected majority". This majority may be inclined to misinterpret results, disseminate inaccurate information to family, dismiss the credibility of results, or become disillusioned with existing medical treatments.