Current guidelines for BRCA testing of breast cancer patients are insufficient to detect all mutation carriers

Management and Clinical Outcomes of Breast Cancer in Women Diagnosed with Hereditary Cancer Syndromes in a Clinic-Based Sample from Colombia

This study aimed to investigate prognosis and survival differences in 82 breast cancer patients with germline pathogenic/likely pathogenic variants (PVs) treated and followed at the Breast Unit of the Instituto Nacional de Cancerología, Colombia (INC-C) between 2018 and 2021. Median age at diagnosis was 46 years, with 62.2% presenting locally advanced tumors, 47.6% histological grade 3, and 35.4% with triple-negative breast cancer (TNBC) subtype. Most carriers, 74.4% (61/82), had PVs in known breast cancer susceptibility genes (i.e., "associated gene carriers" group, considered inherited breast cancer cases): BRCA2 (30), BRCA1 (14), BARD1 (4), RAD51D (3), TP53 (2), PALB2 (2), ATM (2), CHEK2 (1), RAD51C (1), NF1 (1), and PTEN (1). BRCA1-2 represented 53.7%, and homologous recombination DNA damage repair (HR-DDR) genes associated with breast cancer risk accounted for 15.9%. Patients with PVs in non-breast-cancer risk genes were combined in a different category (21/82; 25.6%) (i.e., "non-associated gene carriers" group, considered other breast cancer cases). Median follow-up was 38.1 months, and 24% experienced recurrence, with 90% being distant. The 5-year Disease-Free Survival (DFS) for inherited breast cancer cases was 66.5%, and for other breast cancer cases it was 88.2%. In particular, for carriers of PVs in the BRCA2 gene, it was 37.6%. The 5-year Overall Survival (OS) rates ranged from 68.8% for those with PVs in BRCA2 to 100% for those with PVs in other HR-DDR genes. Further studies are crucial for understanding tumor behavior and therapy response differences among Colombian breast cancer patients with germline PVs.

BRCA testing and management of BRCA-mutated early-stage breast cancer: a comprehensive statement by expert group from GCC region

BReast CAncer (BRCA)1 and BRCA2 gene pathogenic variants account for most hereditary breast cancers (BC). Identification of BRCA mutations can significantly influence both prognosis and treatment outcomes. Furthermore, it enables the identification of individuals who are at heightened risk of developing BC due to inherited genetic mutations. Many developing countries rely on western guidelines for BRCA testing and BC management; however, there exist wide disparities in the prevalence of risk factors, availability of medical resources, and practice patterns. Guidelines tailored to specific regions can help mitigate healthcare variations, promote consistency in treatment, and aid healthcare providers in identifying effective therapies for improving patient outcomes. Hence, oncologists from the Gulf Cooperation Council (GCC) congregated virtually in March 2023 and reviewed existing data on the epidemiology of BC, BRCA mutations, practices and challenges associated with BRCA testing and management of BRCA mutated early-stage BC in the GCC region. They also provided insights on the real-world diagnostic and treatment practices and challenges in the GCC region in the BRCA-mutated early-stage BC domain and suggested some variations to international guidelines to aid their uptake in this region.

Implications of Highly Penetrant Genetic Variants on Breast Surgery

It seems the most probable beneficiaries from the molecular era are those harboring hereditary genetic variants, which are responsible for 5% to 10% of all breast cancer diagnoses. There are several key implications of such variants on clinical practice, from expedited anticipation of primary cancer diagnoses, which can have their risk mitigated by risk reduction surgery, to pragmatism surrounding the management of male breast cancer patients. This communication discusses the implications of highly penetrant (or pathogenic) hereditary variants in contemporary breast surgery practice.

Barriers and facilitators to the implementation of family cancer history collection tools in oncology clinical practices

INTRODUCTION

This study aimed to identify barriers and facilitators to the implementation of family cancer history (FCH) collection tools in clinical practices and community settings by assessing clinicians' perceptions of implementing a chatbot interface to collect FCH information and provide personalized results to patients and providers.

OBJECTIVES

By identifying design and implementation features that facilitate tool adoption and integration into clinical workflows, this study can inform future FCH tool development and adoption in healthcare settings.

MATERIALS AND METHODS

Quantitative data were collected using survey to evaluate the implementation outcomes of acceptability, adoption, appropriateness, feasibility, and sustainability of the chatbot tool for collecting FCH. Semistructured interviews were conducted to gather qualitative data on respondents' experiences using the tool and recommendations for enhancements.

RESULTS

We completed data collection with 19 providers (n = 9, 47%), clinical staff (n = 5, 26%), administrators (n = 4, 21%), and other staff (n = 1, 5%) affiliated with the NCI Community Oncology Research Program. FCH was systematically collected using a wide range of tools at sites, with information being inserted into the patient's medical record. Participants found the chatbot tool to be highly acceptable, with the tool aligning with existing workflows, and were open to adopting the tool into their practice.

DISCUSSION AND CONCLUSIONS

We further the evidence base about the appropriateness of scripted chatbots to support FCH collection. Although the tool had strong support, the varying clinical workflows across clinic sites necessitate that future FCH tool development accommodates customizable implementation strategies. Implementation support is necessary to overcome technical and logistical barriers to enhance the uptake of FCH tools in clinical practices and community settings.

Increased prevalence of the founder BRCA1 c.5309G>T and recurrent BRCA2 c.1310_1313delAAGA mutations in breast cancer families from Northerstern region of Morocco: evidence of geographical specificity and high relevance for genetic counseling

BACKGROUND

Inherited mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 (BRCA1/2) confer high risks of breast and ovarian cancer. Because the contribution of BRCA1/2 germline mutations to BC in the Northeastern population of Morocco remains largely unknown, we conducted this first study to evaluate the prevalence and the phenotypic spectrum of two BRCA1/2 pathogenic mutations (the founder BRCA1 c.5309G>T and BRCA2 c.1310_1313delAAGA). This choice was also argued by the presence of an apparent specific geographical connection of these mutations and the Northeastern region of Morocco.

METHODS

Screening for the germline mutations c.5309G>T and BRCA2 c.1310_1313delAAGA was performed by sequencing on a total of 184 breast cancer (BC) patients originated from the Northeastern region of Morocco. The likelihood of identifying a BRCA mutation is calculated using the Eisinger scoring model. The clinical and pathologic features were compared between the BRCA-positive and BRCA-negative groups of patients. Difference in survival outcomes was compared between mutation carriers and non-carriers.

RESULTS

BRCA1 c.5309G>T and BRCA2 c.1310_1313delAAGA are responsible for a significant proportion of all BC cases (12.5%) and at least 20% of familial BC. The screening of BRCA1/2 genes by NGS sequencing confirmed that there are no additional mutations detected among positive patients. The clinicopathological features in positive patients were in accordance with typical characteristics of BRCA pathogenic mutations. The mean features in the carriers were the early onset of the disease, familial history, triple negative status (for BRCA1 c.5309G>T) and worse prognosis in terms of overall surviving. Our study indicates that the Eisinger scoring model could be recommended to identify patients for referral to BRCA1/2 oncogenetic counseling.

CONCLUSION

Our findings suggest that BRCA1 c.5309G>T and BRCA2 c.1310_1313delAAGA mutations may have a strong founder and/or recurrent effect on breast cancer among the Northeastern Moroccan population. There contribution to breast cancer incidence is certainly substantial in this subgroup. Therefore, we believe that BRCA1 c.5309G>T and BRCA2 c.1310_1313delAAGA mutations have to be included in the array of tests aimed at revealing cancer syndrome carriers among subjects of Moroccan origin.

Genetic testing in privately insured women with surgically treated breast cancer

PURPOSE

Rates of BRCA1 and BRCA2 prevalence among women with breast cancer vary by age, hormone receptor status, and family history. Recommendations for genetic testing have varied between overlapping guidelines, payor coverage policies, and have evolved over time, resulting in unclear implications for adoption into routine breast cancer care.

METHODS

Using a large, private insurer database, we examined rates of BRCA1/BRCA2 genetic testing in women with newly diagnosed invasive breast cancer undergoing surgery from 2015 through 2019.

RESULTS

Testing increased among women 50 years or older from 26 to 38%, remained stable at 66% in both 2015 and 2019 in the under 50 population, and was slightly decreased in women under age 45 years.

CONCLUSION

Among privately insured patients with breast cancer, rates are increasing in older women, but appear persistently underused in younger women.

The genetics of hereditary cancer risk syndromes in Brazil: a comprehensive analysis of 1682 patients

Hereditary cancer risk syndromes are caused by germline variants, commonly in tumor suppressor genes. Most studies on hereditary cancer have been conducted in white populations. We report the largest study in Brazilian individuals with multiple ethnicities. We genotyped 1682 individuals from all country regions with Next-generation sequencing (NGS) panels. Most were women with a personal/family history of cancer, mostly breast and ovarian. We identified 321 pathogenic/likely pathogenic (P/LP) variants in 305 people (18.1%) distributed among 32 genes. Most were on BRCA1 and BRCA2 (129 patients, 26.2% and 14.3% of all P/LP, respectively), MUTYH (42 monoallelic patients, 13.1%), PALB2 (25, 7.8%), Lynch syndrome genes (17, 5.3%), and TP53 (17, 5.3%). Transheterozygosity prevalence in our sample was 0.89% (15/1682). BRCA1/BRCA2 double heterozygosity rate was 0.78% (1/129) for BRCA variants carriers and 0.06% (1/1682) overall. We evaluated the performance of the genetic testing criteria by NCCN and the Brazilian National Health Agency (ANS). The inclusion criteria currently used in Brazil fail to identify 17%-25% of carriers of P/LP variants in hereditary cancer genes. Our results add knowledge on the Brazilian spectrum of cancer risk germline variants, demonstrate that large multigene panels have high positivity rates, and indicate that Brazilian inclusion criteria for genetic testing should be improved.

BRCA1/2 variants of unknown significance in hereditary breast and ovarian cancer (HBOC) syndrome: looking for the hidden meaning

Hereditary breast and ovarian cancer syndrome is caused by germline mutations in BRCA1/2 genes. These genes are very large and their mutations are heterogeneous and scattered throughout the coding sequence. In addition to the above-mentioned mutations, variants of uncertain/unknown significance (VUSs) have been identified in BRCA genes, which make more difficult the clinical management of the patient and risk assessment. In the last decades, several laboratories have developed different databases that contain more than 2000 variants for the two genes and integrated strategies which include multifactorial prediction models based on direct and indirect genetic evidence, to classify the VUS and attribute them a clinical significance associated with a deleterious, high-low or neutral risk. This review provides a comprehensive overview of literature studies concerning the VUSs, in order to assess their impact on the population and provide new insight for the appropriate patient management in clinical practice.

Prediction of BRCA Gene Mutation in Breast Cancer Based on Deep Learning and Histopathology Images

BACKGROUND

Breast cancer is one of the most common cancers and the leading cause of death from cancer among women worldwide. The genetic predisposition to breast cancer may be associated with a mutation in particular genes such as gene BRCA1/2. Patients who carry a germline pathogenic mutation in BRCA1/2 genes have a significantly increased risk of developing breast cancer and might benefit from targeted therapy. However, genetic testing is time consuming and costly. This study aims to predict the risk of gBRCA mutation by using the whole-slide pathology features of breast cancer H&E stains and the patients' gBRCA mutation status.

METHODS

In this study, we trained a deep convolutional neural network (CNN) of ResNet on whole-slide images (WSIs) to predict the gBRCA mutation in breast cancer. Since the dimensions are too large for slide-based training, we divided WSI into smaller tiles with the original resolution. The tile-based classification was then combined by adding the positive classification result to generate the combined slide-based accuracy. Models were trained based on the annotated tumor location and gBRCA mutation status labeled by a designated breast cancer pathologist. Four models were trained on tiles cropped at 5×, 10×, 20×, and 40× magnification, assuming that low magnification and high magnification may provide different levels of information for classification.

RESULTS

A trained model was validated through an external dataset that contains 17 mutants and 47 wilds. In the external validation dataset, AUCs (95% CI) of DL models that used 40×, 20×, 10×, and 5× magnification tiles among all cases were 0.766 (0.763-0.769), 0.763 (0.758-0.769), 0.750 (0.738-0.761), and 0.551 (0.526-0.575), respectively, while the corresponding magnification slides among all cases were 0.774 (0.642-0.905), 0.804 (0.676-0.931), 0.828 (0.691-0.966), and 0.635 (0.471-0.798), respectively. The study also identified the influence of histological grade to the accuracy of the prediction.

CONCLUSION

In this paper, the combination of pathology and molecular omics was used to establish the gBRCA mutation risk prediction model, revealing the correlation between the whole-slide histopathological images and gRCA mutation risk. The results indicated that the prediction accuracy is likely to improve as the training data expand. The findings demonstrated that deep CNNs could be used to assist pathologists in the detection of gene mutation in breast cancer.

Identification of women at risk for hereditary breast and ovarian cancer in a sample of 1000 Slovenian women: a comparison of guidelines

Background

An important number of breast and ovarian cancer cases is due to a strong genetic predisposition. The main tool for identifying individuals at risk is recognizing a suggestive family history of cancer. We present a prospective study on applying three selected clinical guidelines to a cohort of 1000 Slovenian women to determine the prevalence of at-risk women according to each of the guidelines and analyze the differences amongst the guidelines.

Methods

Personal and family history of cancer was collected for 1000 Slovenian women. Guidelines by three organizations: National Comprehensive Cancer Network (NCCN), American College of Medical Genetics in cooperation with National Society of Genetic Counselors (ACMG/NSGC), and Society of Gynecologic Oncology (SGO) were applied to the cohort. The number of women identified, the characteristics of the high-risk population, and the agreement between the guidelines were explored.

Results

NCCN guidelines identify 13.2% of women, ACMG/NSGC guidelines identify 7.1% of women, and SGO guidelines identify 7.0% of women from the Slovenian population, while 6.2% of women are identified by all three guidelines as having high-risk for hereditary breast and ovarian cancer.

Conclusions

We identified 13.7% of women from the Slovenian population as being at an increased risk for breast and ovarian cancer based on their personal and family history of cancer using all of the guidelines. There are important differences between the guidelines. NCCN guidelines are the most inclusive, identifying nearly twice the amount of women as high-risk for hereditary breast and ovarian cancer as compared to the AGMG/NSCG and SGO guidelines in the Slovenian population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08400-8.

Comparing models of delivery for cancer genetics services among patients receiving primary care who meet criteria for genetic evaluation in two healthcare systems: BRIDGE randomized controlled trial

BACKGROUND

Advances in genetics and sequencing technologies are enabling the identification of more individuals with inherited cancer susceptibility who could benefit from tailored screening and prevention recommendations. While cancer family history information is used in primary care settings to identify unaffected patients who could benefit from a cancer genetics evaluation, this information is underutilized. System-level population health management strategies are needed to assist health care systems in identifying patients who may benefit from genetic services. In addition, because of the limited number of trained genetics specialists and increasing patient volume, the development of innovative and sustainable approaches to delivering cancer genetic services is essential.

METHODS

We are conducting a randomized controlled trial, entitled Broadening the Reach, Impact, and Delivery of Genetic Services (BRIDGE), to address these needs. The trial is comparing uptake of genetic counseling, uptake of genetic testing, and patient adherence to management recommendations for automated, patient-directed versus enhanced standard of care cancer genetics services delivery models. An algorithm-based system that utilizes structured cancer family history data available in the electronic health record (EHR) is used to identify unaffected patients who receive primary care at the study sites and meet current guidelines for cancer genetic testing. We are enrolling eligible patients at two healthcare systems (University of Utah Health and New York University Langone Health) through outreach to a randomly selected sample of 2780 eligible patients in the two sites, with 1:1 randomization to the genetic services delivery arms within sites. Study outcomes are assessed through genetics clinic records, EHR, and two follow-up questionnaires at 4 weeks and 12 months after last genetic counseling contactpre-test genetic counseling.

DISCUSSION

BRIDGE is being conducted in two healthcare systems with different clinical structures and patient populations. Innovative aspects of the trial include a randomized comparison of a chatbot-based genetic services delivery model to standard of care, as well as identification of at-risk individuals through a sustainable EHR-based system. The findings from the BRIDGE trial will advance the state of the science in identification of unaffected patients with inherited cancer susceptibility and delivery of genetic services to those patients.

TRIAL REGISTRATION

BRIDGE is registered as NCT03985852 . The trial was registered on June 6, 2019 at clinicaltrials.gov .

An Overview of PARP Inhibitors for the Treatment of Breast Cancer

Loss-of-function mutations in BRCA1 and BRCA2 are detected in at least 5% of unselected patients with breast cancer (BC). These BC susceptibility genes encode proteins critical for DNA homologous recombination repair (HRR). This review provides an update on oral poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of BC. Olaparib and talazoparib are PARP inhibitors approved as monotherapies for deleterious/suspected deleterious germline BRCA-mutated, HER2-negative BC. Olaparib is approved in the USA for metastatic BC and in Europe for locally advanced/metastatic BC. Talazoparib is approved for locally advanced/metastatic BC in the USA and Europe. In phase 3 trials, olaparib and talazoparib monotherapies demonstrated significant progression-free survival benefits compared with chemotherapy. Common toxicities were effectively managed by supportive treatment and dose interruptions/reductions. Veliparib combined with platinum-based chemotherapy has also shown promise for locally advanced/metastatic BC in a phase 3 trial. Differences in efficacy and safety across PARP inhibitors (olaparib, talazoparib, veliparib, niraparib, rucaparib) may relate to differences in potency of PARP trapping on DNA and cytotoxic specificity. PARP inhibitors are being investigated in early BC, in novel combinations, and in patients without germline BRCA mutations, including those with somatic BRCA mutations and other HRR gene mutations. Ongoing phase 2/3 studies include PARP inhibitors combined with immune checkpoint inhibitors for the treatment of triple-negative BC. Wider access to testing for BRCA and other mutations, and to genetic counseling, are required to identify patients who could benefit from PARP inhibitor therapy. The advent of PARP inhibitors has potential benefits for BC treatment beyond the locally advanced/metastatic setting.

Analysis of BRCA1/2 variants of unknown significance in the prospective Korean Hereditary Breast Cancer study

Genetic testing for BRCA1 and BRCA2 is crucial in diagnosing hereditary breast and ovarian cancer syndromes and has increased with the development of multigene panel tests. However, results classified as variants of uncertain significance (VUS) present challenges to clinicians in attempting to choose an appropriate management plans. We reviewed a total of 676 breast cancer patients included in the Korean Hereditary Breast Cancer (KOHBRA) study with a VUS on BRCA mutation tests between November 2007 and April 2013. These results were compared to the ClinVar database. We calculated the incidence and odds ratios for these variants using the Korean Reference Genome Database. A total of 58 and 91 distinct VUS in BRCA1 and BRCA2 were identified in the KOHBRA study (comprising 278 and 453 patients, respectively). A total of 27 variants in the KOHBRA study were not registered in the Single Nucleotide Polymorphism database. Among BRCA1 VUSs, 20 were reclassified as benign or likely benign, four were reclassified as pathogenic or likely pathogenic, and eight remained as VUSs according to the ClinVar database. Of the BRCA2 VUSs, 25 were reclassified as benign or likely benign, two were reclassified as pathogenic or likely pathogenic, and 33 remained as VUS according to the ClinVar database. There were 12 variants with conflicting interpretations of pathogenicity for BRCA1 and 18 for BRCA2. Among them, p.Leu1780Pro showed a particularly high odds ratio. Six pathogenic variants and one conflicting variant identified using ClinVar could be reclassified as pathogenic variants in this study. Using updated ClinVar information and calculating odds ratios can be helpful when reclassifying VUSs in BRCA1/2.

Management of patients with BRCA mutation from the point of view of a breast surgeon

Germ-line mutation in BRCA (BReast CAncer gene) 1 or BRCA2 are found in 3–4% of all women with breast cancer. These patients have a significant increased risk of breast and ovarian cancer. They are often younger when diagnosed with the mutation, and the possible breast cancer they get is often aggressive with inferior outcome. There are risk reducing strategies, and the most powerful strategy is risk reducing surgery, both risk reducing bilateral mastectomy (RRM) and risk reducing bilateral salpino-oophorectomy (PBSO). This review is meant to address breast surgery in patients with germline BRCA mutation. The guidelines and techniques applied is under continuous change and it is important for the clinicians to be well informed to provide the patient with the information needed for them to make an informed decision on what risk strategy to choose.

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Patients with germ-line mutation in BRCA1 or BRCA2 have a significant increased risk of breast and ovarian cancer.

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There are different risk reducing strategies and the most powerful strategy is risk-reducing surgery, both risk reducing bilateral mastectomy and risk reducing bilateral salpingo-oophorectomy.

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Guidelines and techniques for the risk reducing surgery of the breast are under continuous change and improvement.

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Breast conserving therapy is not associated with worse survival and is a good option for a BRCA mutation carrier diagnosed with breast cancer. Risk-reducing mastectomy can be performed in a later setting.

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The management of BRCA mutation carriers, both affected and unaffected, should be performed in a multidisciplinary team. Physicians need to be systematically educated and updated on the most recent literature.

Biologic behavior of resected BRCA-mutated pancreatic cancer: Comparison with sporadic pancreatic cancer and other BRCA-related cancers

BACKGROUND

Since margin-negative resection is essential for the cure of pancreatic cancer (PC), early detection of PC is important. Although PC is the third most common cancer associated with BRCA1/2 mutations, clinical research regarding BRCA mutations in resected PC are rare. In this study, we investigated the oncologic characteristics of resected PC with BRCA mutation to suggest management strategies.

METHODS

We retrospectively reviewed data from 493 patients who were confirmed to be pathogenic BRCA1/2 mutation carriers between January 2007 and December 2019. We investigated the oncologic characteristics of PC patients by comparing them with resected sporadic PC and other BRCA-related cancer groups (breast cancer, ovarian cancer, and others).

RESULTS

Ten BRCA mutation carriers (2.0%) experienced PC, and PC onset was significantly later than that of BRCA-related breast cancer (age: breast vs. pancreas, 45.0 vs. 53.5 years, p = 0.050). Six patients underwent pancreatectomy and their long-term survival outcomes did not differ from those of sporadic PC patients (disease free survival: BRCA1/2 vs. sporadic, 10.0 months vs. 9.0 months, p = 0.504; overall survival: BRCA1/2 vs. sporadic, 29.0 months vs. 35.0 months, p = 0.520).

CONCLUSION

BRCA-mutated PC occurs later than BRCA-mutated breast cancer. Active genetic testing to identify BRCA1/2 mutation carriers at the onset of breast cancer and continuous long-term surveillance of these patients can provide opportunities to detect BRCA-mutated PC at a resectable stage.

Mainstreamed genetic testing of breast cancer patients in two hospitals in South Eastern Norway

Studies have shown that a significant number of eligible breast cancer patients are not offered genetic testing or referral to genetic counseling. To increase access to genetic testing in South Eastern Norway, testing has since 2014 been offered directly to breast cancer patients by surgeons and oncologists. This practice is termed “mainstreamed genetic testing”. The aim of this study was to investigate to what extent patients in South Eastern Norway are offered testing. Three hundred and sixty one patients diagnosed in 2016 and 2017 at one regional and one university hospital in South Eastern Norway were included. Data on whether the patients fulfilled the criteria, whether they had been offered testing and if they were tested were collected. In total, 26.6% (96/361) fulfilled the criteria for testing. Seventy five percent (69/92) of these were offered testing, and 71.7% (66/92) were tested. At the university hospital, 90.2% (37/41) of eligible patients were offered testing, and at the regional hospital 62.7% (32/51). Fifty two percent (12/23) of eligible patient not offered testing were younger than 50 years at time of diagnosis. As many as 95.4% (125/131) of all patients who were offered testing, wanted to be tested. The majority of patients who fulfilled the criteria were offered testing, supporting the practice of mainstreamed genetic testing. There were nevertheless differences in rates of testing between the hospitals that affected all groups of patients, indicating that genetic testing may not be equally accessible to all patients. We suggest that efforts should be made to increase awareness and improve routines for genetic testing of breast cancer patients in Norway.

BRCA testing and outcomes in women with breast cancer

MAIN PURPOSE

Germline BRCA mutations (BRCAm) strongly influence the risk of developing breast cancer. This study aimed to understand the role of BRCAm testing in affected individuals and to assess its impact on the outcome of BRCAm carriers compared to non-carriers (BRCAwt) with breast cancer.

RESEARCH QUESTION

The research question is "Does standard of care testing for BRCAm improve survival outcomes of breast cancer patients?"

METHODS

In a single institution observational cohort study, demographic and clinical characteristics were compared between breast cancer patients with and without BRCAm. Frequency of BRCA testing was assessed. Survival outcomes were assessed by initial treatment setting stratified by BRCA status.

RESULTS

Of 5712 identified women with breast cancer, 14.6% (n = 835) were tested for a BRCA mutation and had a documented result. The total number and proportion of women tested for a BRCAm increased between 2000 and 2014, resulting in an increased number of BRCAm carriers identified. However, the proportion of women who underwent testing and had a BRCAm decreased during the study period from 27.5% in 2000-2004 to 13.3% in 2010-2014. Disease-free survival was similar in the adjuvant and neoadjuvant treatment settings between BRCAm and BRCAwt patients. Progression-free survival on first line treatment and overall survival for patients with metastatic disease was also similar between BRCAm and BRCAwt patients.

CONCLUSIONS

The proportion of women tested and the number of BRCAm identified increased during the study period despite a decreasing proportion of positive results among women tested.

Integrating fundamental cause theory and Bourdieu to explain pathways between socioeconomic status and health: the case of health insurance denials for genetic testing

Fundamental cause theory (FCT) is among the most widely recognised and accepted social science frameworks used to examine the processes driving health inequalities. Despite the wide influence of the theory, it remains largely underutilised in practical and applied research on health disparities. This paper proposes that Pierre Bourdieu's theories of capital and symbolic power can be integrated with FCT to address limitations in the latter theory, making it more useful in health disparities research. Using a case study of U.S. health insurance claim denials for genetic testing among women with a breast cancer diagnosis, this work illustrates how the theoretical constructs of FCT and Bourdieu's work articulate, and consequently deepens our appreciation for the durable relationship between socioeconomic status and health. Study results reveal the multiple and complex mechanisms that play a role in access to healthcare services, which has significant implications for how we think about the role of health policy in addressing health disparities.

Pathology of Hereditary Breast and Ovarian Cancer

Hereditary breast and ovarian cancer (HBOC) syndrome is most commonly characterized by deleterious germline mutations in BRCA1 and BRCA2. HBOC patients are prone to the development of malignant neoplasms in multiple organs including the breast, ovary, and fallopian tube. From a pathological perspective, a number of morphological features have been described in BRCA-associated breast and tubo-ovarian cancers. For example, breast cancers diagnosed in BRCA1-mutation carriers are frequently of a high Nottingham grade and display medullary morphology and a triple-negative and/or a basal-like immunophenotype. In contrast, breast cancers in BRCA2-mutation carriers are similar to sporadic luminal-type tumors that are positive for hormone receptors and lack expression of human epidermal growth factor receptor 2. Cancers arising in the fallopian tube and ovary are almost exclusively of a high-grade serous histotype with frequent Solid, pseudo-Endometrioid, and Transitional cell carcinoma-like morphology (“SET features”), marked nuclear atypia, high mitotic index, abundant tumor infiltrating lymphocytes, and necrosis. In addition, pushing or infiltrative micropapillary patterns of invasion have been described in BRCA-associated metastases of tubo-ovarian high-grade serous carcinomas. Besides BRCA1 and BRCA2 mutations, alterations in a number of other homologous recombination genes with moderate penetrance, including PALB2, RAD51C, RAD51D, BRIP1, and others, have also been described in HBOC patients with varying frequency; however, distinct morphological characteristics of these tumors have not been well characterized to date. In this review, the above pathological features are discussed in detail and a focus is placed on how accurate pathologic interpretation plays an important role in allowing HBOC patients to receive the best possible management.

Changing practice: moving to a specialist nurse-led service for BRCA gene testing

Some 5–10% of all breast cancers are associated with a pathogenic variant in a breast cancer-associated gene (BRCA1/BRCA2). Historically, with referral to the Nottingham University Hospitals NHS Trust's clinical genetics department for genetic testing, waiting times were on average 12–14 weeks for an initial appointment and 4–6 months to obtain results from the date of testing. A specialist, nurse-led mainstreaming cancer genetics (MCG) service was set up in the trust's Nottingham Breast Institute (NBI) to: reduce waiting times for the initial consultation, counselling, consent and obtaining results for BRCA1/BRCA2 gene testing; and to ensure appropriate patients with breast cancer were offered genetic testing. Two breast clinical nurse specialists were trained so they could counsel, consent and give results for the BRCA1/BRCA2 gene testing directly to patients. Average waiting times for results from the time of testing were reduced to 35.8 days under the nurse-led service, which enabled oncologists and patients to consider individual treatment options at an earlier time. The MCG service reduced waiting times, resulting in an improved, more streamlined service for patients undergoing genetic testing. The MCG service extended the scope of practice of the breast nurse clinical specialists, embedded an expert advanced nursing role in the breast multidisciplinary team and developed nurse mentoring opportunities.

How and when to refer patients for oncogenetic counseling in the era of PARP inhibitors

Poly(ADP-ribose)polymerase (PARP) inhibitors are targeted therapy for cancers with homologous repair deficiency (HRD). They were first approved for ovarian cancer and have changed current treatment strategies. They have also demonstrated efficacy in HER2-negative metastatic breast cancer and advanced prostate cancer with BRCA1/2 or ATM mutations. Patients with somatic and/or germline BRCA1/2 mutations benefit more from these treatments than other patients. Nowadays, the diagnosis of HRD is largely based on germline genetic testing, which is performed after an in-person genetic counseling session, even for patients without any family history of cancer. However, with the increasing number of PARP inhibitor indications across different tumor types, rapid access to oncogenetic consultations will become a challenge. To meet this demand, tumor genomic testing could be offered at initial diagnosis. Telephone counseling and other referral systems could replace in-person consultations for certain subgroups of patients deemed to have a low risk of harboring a germline mutation. This article reviews international guidelines for genetic counseling testing. We herein propose new care pathways for breast, prostate and ovarian cancers, including tumor genomic testing at initial diagnosis in order to help triage genetic counseling referrals.

Should Genetic Testing for Cancer Predisposition Be Standard-of-Care for Women with Invasive Breast Cancer? The Murtha Cancer Center Experience

Currently, genetic testing is offered only to women diagnosed with breast cancer who meet a defined set of criteria and is not included as standard-of-care treatment at the time of diagnosis. Thus, a significant number of women diagnosed with breast cancer may miss the opportunity for precision medical treatment and risk management. The effects of eligibility, timing, and uptake of genetic testing were evaluated in a cohort of women with invasive breast cancer diagnosed between 2001-2018. Risk status was estimated using NCCN BRCA1/2 testing criteria and panel testing was performed for all women who had genomic DNA available. Of the 1231 women, 57.8% were eligible for genetic testing. Uptake of testing within high-risk women was 42.7% of which 6.6% pursued clinical testing only after a second tumor event. Mutation frequencies were 15.8%, 5.5%, and 4.0% in high-risk women with clinical testing, high-risk women without clinical testing, and low-risk women, respectively. More than 4% of all patients harbored pathogenic or likely pathogenic mutations detected only in the research setting. Inclusion of panel testing at the time of diagnosis would allow for appropriate surveillance and treatment strategies to be employed to reduce the risk of secondary tumors and improve patient outcome.

Updates in Genetic Testing Guidelines for Breast Cancer Susceptibility Genes: a Change in the Paradigm

Purpose of Review

Up to 10% of all breast cancers are associated with inherited germline mutations. Genetic testing guidelines for hereditary breast cancer susceptibility have changed significantly since their inception in the late 1990s. The purpose of this review is to discuss the changes in technology that have improved our ability to efficiently detect germline mutations, introduce the recent paradigm change towards population-based testing currently supported by the American Society of Breast Surgeons, and highlight the challenges that expansion of testing parameters presents.

Recent Findings

Next-generation sequencing with multi-gene panels has replaced the traditional Sanger method of genetic testing and has quickly become the standard of care for germline mutation analysis. Benefits of this technology include increased efficiency and cost reduction. While National Comprehensive Cancer Network and US Preventive Task Force guidelines maintain family history as the basis for testing in both unaffected and affected women, new evidence supports testing of all newly diagnosed breast cancer patients and thereby cascade testing to increase rate of mutation detection prior to the diagnosis of breast cancer. Furthermore, recent studies of population-based testing in high-risk groups suggest that population-based screening in the general population is feasible and cost effective.

Summary

Recent developments in technology and germline mutation testing studies support the expansion of genetic testing criteria for hereditary breast cancer. Consensus guidelines are starting to reflect these changes at a national level. The next great challenge will be determining the effectiveness of population-based testing for all women in an effort to increase breast cancer prevention for all.

Knowledge and opinions regarding BRCA1 and BRCA2 genetic testing among primary care physicians

BRCA1 and BRCA2 (BRCA1/2) testing is standard for individuals with personal and/or family history suggestive of hereditary breast and ovarian cancer syndrome. The indications for testing have been expanding. To accommodate the need, incorporation of cancer genetic services into the practice of non-genetic healthcare providers should be considered. We carried out a survey to evaluate the knowledge and opinions regarding BRCA1/2 testing among primary care providers. The survey was sent to 245 Obstetrics/Gynecology and 97 Family Medicine physicians in the UPMC network. Eighty-six completed the survey between July 2015 and September 2015. The average correct responses to knowledge questions was 73%. A few respondents reported being completely confident, and ~50% reported being somewhat confident, in providing BRCA1/2-related information. Respondents selected genetic specialists and oncologists as the most qualified to provide cancer genetic services. Several perceived barriers and motivating factors to the implementation of BRCA1/2 testing in primary care were identified. The findings from this study suggested that primary care providers were not uniformly ready to provide BRCA1/2 genetic testing. Availability of professional society guidelines and evidence of testing's usefulness might motivate the incorporation of BRCA1/2 genetic testing into primary care practices. These findings would help guide future educational efforts to promote provision of cancer genetic services by non-genetic professionals.

Genetic Testing for Breast Cancer Susceptibility Should Be Offered before Unilateral Abdominally Based Free Flap Breast Reconstruction

BACKGROUND

Pathogenic mutations have been identified in approximately 10 percent of patients who present with breast cancer. Notably, failure to identify deleterious genetic mutations has particular implications for patients undergoing abdominally based breast reconstruction, as the donor site can be used only once. The authors sought to determine: (1) how many patients underwent genetic testing before unilateral abdominally based free flap breast reconstruction; (2) how often deleterious mutations were detected after abdominally based free flap breast reconstruction; and (3) the cost-effectiveness of expanding genetic testing in this patient population.

METHODS

The authors retrospectively identified all patients who underwent unilateral abdominally based free flap breast reconstruction at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2007 and 2016. Chart review was performed to collect relevant demographic and clinical data. Relevant hospital financial data were obtained.

RESULTS

Of the 713 who underwent free flap breast reconstruction, 160 patients met inclusion criteria, and mean follow-up was 5.8 years. Three patients (1.9 percent of 160) underwent contralateral surgery after completing reconstruction, two of whom had BRCA2 and one with ATM mutation. One hundred eleven patients met National Comprehensive Cancer Network guidelines for genetic testing, but of those only 55.9 percent (62 patients) were tested. Financial data revealed that testing every patient in the cohort would result in a net savings of $262,000.

CONCLUSIONS

During a relatively short follow-up period, a small percentage of patients were diagnosed with pathogenic mutations and underwent contralateral mastectomy and reconstruction. However, because of the costliness of surgery and the decreased cost of genetic testing, it is cost-effective to test every patient before unilateral abdominally based free flap breast reconstruction.

Multi-Gene Panel Testing of 23,179 Individuals for Hereditary Cancer Risk Identifies Pathogenic Variant Carriers Missed by Current Genetic Testing Guidelines

Recent advancements in next-generation sequencing have greatly expanded the use of multi-gene panel testing for hereditary cancer risk. Although genetic testing helps guide clinical diagnosis and management, testing recommendations are based on personal and family history of cancer and ethnicity, and many carriers are being missed. Herein, we report the results from 23,179 individuals who were referred for 30-gene next-generation sequencing panel testing for hereditary cancer risk, independent of current testing guidelines-38.7% of individuals would not have met National Comprehensive Cancer Network criteria for genetic testing. We identified a total of 2811 pathogenic variants in 2698 individuals for an overall pathogenic frequency of 11.6% (9.1%, excluding common low-penetrance alleles). Among individuals of Ashkenazi Jewish descent, three-quarters of pathogenic variants were outside of the three common BRCA1 and BRCA2 founder alleles. Across all ethnic groups, pathogenic variants in BRCA1 and BRCA2 occurred most frequently, but the contribution of pathogenic variants in other genes on the panel varied. Finally, we found that 21.7% of individuals with pathogenic variants in genes with well-established genetic testing recommendations did not meet corresponding National Comprehensive Cancer Network criteria. Taken together, the results indicate that more individuals are at genetic risk for hereditary cancer than are identified by current testing guidelines and/or use of single-gene or single-site testing.

Prevalence of BRCA1 and BRCA2 pathogenic variants in a large, unselected breast cancer cohort

Breast cancer patients with BRCA1/2-driven tumors may benefit from targeted therapy. It is not clear whether current BRCA screening guidelines are effective at identifying these patients. The purpose of our study was to evaluate the prevalence of inherited BRCA1/2 pathogenic variants in a large, clinically representative breast cancer cohort and to estimate the proportion of BRCA1/2 carriers not detected by selectively screening individuals with the highest probability of being carriers according to current clinical guidelines. The study included 5,122 unselected Swedish breast cancer patients diagnosed from 2001 to 2008. Target sequence enrichment (48.48 Fluidigm Access Arrays) and sequencing were performed (Illumina Hi-Seq 2,500 instrument, v4 chemistry). Differences in patient and tumor characteristics of BRCA1/2 carriers who were already identified as part of clinical BRCA1/2 testing routines and additional BRCA1/2 carriers found by sequencing the entire study population were compared using logistic regression models. Ninety-two of 5,099 patients with valid variant calls were identified as BRCA1/2 carriers by screening all study participants (1.8%). Only 416 study participants (8.2%) were screened as part of clinical practice, but this identified 35 out of 92 carriers (38.0%). Clinically identified carriers were younger, less likely postmenopausal and more likely to be associated with familiar ovarian cancer compared to the additional carriers identified by screening all patients. More BRCA2 (34/42, 81.0%) than BRCA1 carriers (23/50, 46%) were missed by clinical screening. In conclusion, BRCA1/2 mutation prevalence in unselected breast cancer patients was 1.8%. Six in ten BRCA carriers were not detected by selective clinical screening of individuals.

Hereditary Pancreatic Cancer: A Retrospective Single-Center Study of 5143 Italian Families with History of BRCA-Related Malignancies

The identification of BRCA mutations plays a crucial role in the management of hereditary cancer prevention and treatment. Nonetheless, BRCA-testing in pancreatic cancer (PC) patients is not universally introduced in clinical practice. A retrospective analysis was conducted, firstly, to evaluate the rate of BRCA-positive families among those presenting a family history of PC besides breast and/or ovarian cancer. Secondly, the relationship between BRCA pathogenic variants and PC risk was evaluated. Finally, the characteristics of PC developed in BRCA families were described. Among 5143 family trees reporting breast and/or ovarian cancer cases, 392 showed a family history of PC. A total of 35 families (24.5% selected by the Modena Criteria and 21.3% by the NCCN Criteria) were positive to BRCA testing. Among the BRCA1 mutations, 36.8% were found within a region defined by c.3239–c.3917, whilst 43.7% of BRCA2 mutations were located within c.7180–c.8248. This study confirmed that an increase in the rate of positive tests in families with PC when associated to breast and/or ovarian tumors. Moreover, this analysis indicated two possible Pancreatic Cancer Cluster Regions that should be verified in future research. Finally, PC in families with breast and/or ovarian cancer history, particularly in BRCA families, were diagnosed at younger age and showed better one-year overall survival.

Cancer-related distress in unselected women with newly diagnosed breast or ovarian cancer undergoing BRCA1/2 testing without pretest genetic counseling

BACKGROUND

Genetic testing is increasing in patients newly diagnosed with cancer. This study investigated the levels, course and predictors of cancer-related distress, defined as intrusion and avoidance, in women undergoing BRCA1/2 testing without pretest genetic counseling shortly after a diagnosis of breast or ovarian cancer.

MATERIAL AND METHODS

Unselected for family history or age, 259 women with breast cancer and 50 women with ovarian cancer, underwent BRCA1/2 testing shortly after diagnosis. Cancer-related distress was measured with the Impact of Event Scale before and after genetic testing. In order to identify predictors of distress, the subscale scores were regressed on baseline predictor variables including sociodemographic and medical variables, perceived social support, and decisional conflict regarding genetic testing.

RESULTS

The mean levels of intrusion and avoidance were in the moderate range both before and after genetic testing with a statistically significant decline during follow-up. Younger age, shorter time since diagnosis, lower levels of social support, and a diagnosis of ovarian cancer predicted higher levels of both intrusion and avoidance. In addition, higher levels of decisional conflict and living with a partner predicted higher levels of intrusion.

CONCLUSIONS

Women having genetic testing shortly after a diagnosis of breast or ovarian cancer had a moderate mean level of cancer-related distress, which decreased with time. Health personnel offering genetic testing to newly diagnosed women with breast or ovarian cancer should be aware of the potential predictors for increased cancer-related distress identified in this study: younger age, less perceived social support, higher levels of decisional conflict regarding genetic testing, and living with a partner.

Whole genome sequencing of breast cancer

Breast cancer was the first to take advantage of targeted therapy using endocrine therapy, and for up to 20% of all breast cancer patients a further significant improvement has been obtained by HER2‐targeted therapy. Greater insight in precision medicine is to some extent driven by technical and computational progress, with the first wave of a true technical advancement being the application of transcriptomic analysis. Molecular subtyping further improved our understanding of breast cancer biology and has through a new tumor classification enabled allocation of personalized treatment regimens. The next wave in technical progression must be next‐generation‐sequencing which is currently providing new and exciting results. Large‐scale sequencing data unravel novel somatic and potential targetable mutations as well as allowing the identification of new candidate genes predisposing for familial breast cancer. So far, around 15% of all breast cancer patients are genetically predisposed with most genes being factors in pathways implicated in genome maintenance. This review focuses on whole‐genome sequencing and the new possibilities that this technique, together with other high‐throughput analytic approaches, provides for a more individualized treatment course of breast cancer patients.

Genetic counselling and testing of susceptibility genes for therapeutic decision-making in breast cancer-an European consensus statement and expert recommendations

An international panel of experts representing 17 European countries and Israel convened to discuss current needs and future developments in BRCA testing and counselling and to issue consensus recommendations. The experts agreed that, with the increasing availability of high-throughput testing platforms and the registration of poly-ADP-ribose-polymerase inhibitors, the need for genetic counselling and testing will rapidly increase in the near future. Consequently, the already existing shortage of genetic counsellors is expected to worsen and to compromise the quality of care particularly in individuals and families with suspected or proven hereditary breast or ovarian cancer. Increasing educational efforts within the breast cancer caregiver community may alleviate this limitation by enabling all involved specialities to perform genetic counselling. In the therapeutic setting, for patients with a clinical suspicion of genetic susceptibility and if the results may have an immediate impact on the therapeutic strategy, the majority voted that BRCA1/2 testing should be performed after histological diagnosis of breast cancer, regardless of oestrogen receptor and human epidermal growth factor receptor 2 (HER2) status. Experts also agreed that, in the predictive and therapeutic setting, genetic testing should be limited to individuals with a personal or family history suggestive of a BRCA1/2 pathogenic variant and should also include high-risk actionable genes beyond BRCA1/2. Of high-risk actionable genes, all pathological variants (i.e. class IV and V) should be reported; class III variants of unknown significance, should be reported provided that the current lack of clinical utility of the variant is expressly stated. Genetic counselling should always address the possibility that already tested individuals might be re-contacted in case new information on a particular variant results in a re-classification.

Underdiagnosis of Hereditary Breast and Ovarian Cancer in Medicare Patients: Genetic Testing Criteria Miss the Mark

BACKGROUND

An estimated 5-10% of breast and ovarian cancers are due to hereditary causes such as hereditary breast and ovarian cancer (HBOC) syndrome. Medicare, the third-party payer that covers 44 million patients in the United States, has implemented a set of clinical criteria to determine coverage for the testing of the BRCA1 and BRCA2 genes. These criteria, developed to identify carriers of BRCA1/2 variants, have not been evaluated in the panel testing era. This study investigated a series of Medicare patients undergoing genetic testing for HBOC to determine the efficacy of genetic testing criteria in identifying patients with hereditary risk.

METHODS

This study retrospectively examined de-identified data from a consecutive series of Medicare patients undergoing genetic testing based on personal and family history of breast and gynecologic cancer. Ordering clinicians indicated whether patients did or did not meet established criteria for BRCA1/2 genetic testing. The genetic test results were compared between the group that met the criteria and the group that did not. Patients in families with known pathogenic (P) or likely pathogenic (LP) variants were excluded from the primary analysis.

RESULTS

Among 4196 unique Medicare patients, the rate of P/LP variants for the patients who met the criteria for genetic testing was 10.5%, and for those who did not, the rate was 9% (p = 0.26).

CONCLUSIONS

The results of this study indicate that a substantial number of Medicare patients with clinically actionable genetic variants are being missed by current testing criteria and suggest the need for significant expansion and simplification of the testing criteria for HBOC.

Validation of CZECANCA (CZEch CAncer paNel for Clinical Application) for targeted NGS-based analysis of hereditary cancer syndromes

Background

Carriers of mutations in hereditary cancer predisposition genes represent a small but clinically important subgroup of oncology patients. The identification of causal germline mutations determines follow-up management, treatment options and genetic counselling in patients’ families. Targeted next-generation sequencing-based analyses using cancer-specific panels in high-risk individuals have been rapidly adopted by diagnostic laboratories. While the use of diagnosis-specific panels is straightforward in typical cases, individuals with unusual phenotypes from families with overlapping criteria require multiple panel testing. Moreover, narrow gene panels are limited by our currently incomplete knowledge about possible genetic dispositions.

Methods

We have designed a multi-gene panel called CZECANCA (CZEch CAncer paNel for Clinical Application) for a sequencing analysis of 219 cancer-susceptibility and candidate predisposition genes associated with frequent hereditary cancers.

Results

The bioanalytical and bioinformatics pipeline was validated on a set of internal and commercially available DNA controls showing high coverage uniformity, sensitivity, specificity and accuracy. The panel demonstrates a reliable detection of both single nucleotide and copy number variants. Inter-laboratory, intra- and inter-run replicates confirmed the robustness of our approach.

Conclusion

The objective of CZECANCA is a nationwide consolidation of cancer-predisposition genetic testing across various clinical indications with savings in costs, human labor and turnaround time. Moreover, the unified diagnostics will enable the integration and analysis of genotypes with associated phenotypes in a national database improving the clinical interpretation of variants.

Affinity-purified DNA-based mutation profiles of endometriosis-related ovarian neoplasms in Japanese patients

Aim

Endometriosis-related ovarian neoplasms (ERONs) have recently attracted considerable attention; however, the prevalence and patterns of ARID1A and POLE mutations in ERONs have not been studied in detail. The aim of this study was to investigate not only the carcinogenesis of ERONs, but also the prognostic significance of several gene mutations in this cohort. We used DNA purified from only tumor epithelial cells, from which fibroblasts were removed, using a specific method we called "liquid microdissection".

Methods

Tissue samples from 22 ovarian carcinomas (13 endometrioid, and nine clear cell) were used. Tumor cells were isolated using a cell sorting system and DNA was purified from tumor epithelial cells. Nucleotide sequencing was conducted to analyze the mutational status of ARID1A, p53, PTEN, POLE, PIK3CA, and KRAS.

Results

In ERONs, the frequencies of somatic mutations in ARID1A, p53, POLE, PTEN, PIK3CA, and KRAS were 19/20 (95.0%), 7/19 (36.8%), 9/22 (40.9%), 13/19 (68.4%), 3/19 (15.8%), and 1/9 (11.1%). The frequency of ARID1A mutations was significantly higher than that reported previously. Kaplan-Meier survival analysis revealed that mutations in all genes, including POLE, were not associated with patient prognosis in our Japanese cohort.

Conclusions

Our results suggest that the frequency of ARID1A mutations in ERONs may be higher than that previously reported. In addition, the "liquid microdissection" method that we chose for DNA purification could be used to obtain high-quality sequencing results. The findings suggest that ARID1A mutations represent the basis of ERON carcinogenesis; other subsequent gene mutations may result in the progression of carcinogenesis.

Inherited mutations in BRCA1 and BRCA2 in an unselected multiethnic cohort of Asian patients with breast cancer and healthy controls from Malaysia

BACKGROUND

Genetic testing for BRCA1 and BRCA2 is offered typically to selected women based on age of onset and family history of cancer. However, current internationally accepted genetic testing referral guidelines are built mostly on data from cancer genetics clinics in women of European descent. To evaluate the appropriateness of such guidelines in Asians, we have determined the prevalence of germ line variants in an unselected cohort of Asian patients with breast cancer and healthy controls.

METHODS

Germ line DNA from a hospital-based study of 2575 unselected patients with breast cancer and 2809 healthy controls were subjected to amplicon-based targeted sequencing of exonic and proximal splice site junction regions of BRCA1 and BRCA2 using the Fluidigm Access Array system, with sequencing conducted on a Illumina HiSeq2500 platform. Variant calling was performed with GATK UnifiedGenotyper and were validated by Sanger sequencing.

RESULTS

Fifty-five (2.1%) BRCA1 and 66 (2.6%) BRCA2 deleterious mutations were identified among patients with breast cancer and five (0.18%) BRCA1 and six (0.21%) BRCA2 mutations among controls. One thousand one hundred and eighty-six (46%) patients and 97 (80%) carriers fulfilled the National Comprehensive Cancer Network guidelines for genetic testing.

CONCLUSION

Five per cent of unselected Asian patients with breast cancer carry deleterious variants in BRCA1 or BRCA2. While current referral guidelines identified the majority of carriers, one in two patients would be referred for genetic services. Given that such services are largely unavailable in majority of low-resource settings in Asia, our study highlights the need for more efficient guidelines to identify at-risk individuals in Asia.

BRCA1 and BRCA2 mutation spectrum - an update on mutation distribution in a large cancer genetics clinic in Norway

Background

Founder mutations in the two breast cancer genes, BRCA1 and BRCA2, have been described in many populations, among these are Ashkenazi-Jewish, Polish, Norwegian and Icelandic. Founder mutation testing in patients with relevant ancestry has been a cost-efficient approach in such populations. Four Norwegian BRCA1 founder mutations were defined by haplotyping in 2001, and accounted for 68% of BRCA1 mutation carriers at the time. After 15 more years of genetic testing, updated knowledge on the mutation spectrum of both BRCA1 and BRCA2 in Norway is needed. In this study, we aim at describing the mutation spectrum and frequencies in the BRCA1/2 carrier population of the largest clinic of hereditary cancer in Norway.

Methods

A total of 2430 BRCA1 carriers from 669 different families, and 1092 BRCA2 carriers from 312 different families were included in a quality of care study. All variants were evaluated regarding pathogenicity following ACMG/ENIGMA criteria. The variants were assessed in AlaMut and supplementary databases to determine whether they were known to be founder mutations in other populations.

Results

There were 120 different BRCA1 and 87 different BRCA2 variants among the mutation carriers. Forty-six per cent of the registered BRCA1/2 families (454/981) had a previously reported Norwegian founder mutation. The majority of BRCA1/2 mutations (71%) were rare, each found in only one or two families. Fifteen per cent of BRCA1 families and 25% of BRCA2 families had one of these rare variants. The four well-known Norwegian BRCA1 founder mutations previously confirmed through haplotyping were still the four most frequent mutations in BRCA1 carriers, but the proportion of BRCA1 mutation carriers accounted for by these mutations had fallen from 68 to 52%, and hence the founder effect was weaker than previously described.

Conclusions

The spectrum of BRCA1 and BRCA2 mutations in the carrier population at Norway’s largest cancer genetics clinic is diverse, and with a weaker founder effect than previously described. As a consequence, retesting the families that previously have been tested with specific tests/founder mutation tests should be a prioritised strategy to find more mutation positive families and possibly prevent cancer in healthy relatives.