Germline breast cancer susceptibility gene mutations and breast cancer outcomes

Characterization of the Germline Pathogenic Mutational Landscape and Oncologic Outcomes Among 877 Patients with Invasive Lobular Carcinoma

PURPOSE

There is a paucity of literature on germline pathogenic variants (gPVs) in patients with invasive lobular carcinoma (ILC). This study characterizes the landscape and compares clinicopathologic variables and treatment outcomes between those with and without gPVs.

METHODS

A prospectively maintained institutional database was used to identify all patients diagnosed with nonmetastatic ILC who had germline genetic testing. Clinicopathologic characteristics and time to recurrence, contralateral cancer, and death were compared for patients with and without gPVs. Conditional hazard ratios, computed by Cox proportional hazards models, described associations between clinicopathologic factors, including gPV status, and cancer events.

RESULTS

Of 4398 patients with nonmetastatic ILC seen between 1989 and 2024, 1170 patients were evaluated by genetic counselors; 877 underwent genetic testing. 10% (83/877) had gPVs, of whom 87% (72/83) had gPVs in known breast cancer predisposition genes; 13% had gPVs in preliminary evidence genes or genes not previously known to be breast cancer associated. Patients with gPVs were more likely to be younger than 40 years, be premenopausal, have high grade and triple-negative receptor status, and undergo mastectomy compared with those without gPV (p < 0.01). At median follow-up of 80 months (interquartile range, IQR 38-135 years), there was no significant difference in the time to contralateral breast cancer, distant or local-regional recurrence, and survival among patients with and without gPVs.

CONCLUSION

In this large single-institutional analysis, patients with ILC had a distinct landscape of gPVs in breast cancer and non-breast cancer predisposition genes. A significant proportion of patients with ILC have gPVs, and these findings have potentially actionable implications.

Treatment, toxicity, and mortality after subsequent breast cancer in female survivors of childhood cancer

Childhood cancer survivors, particularly those who received chest radiotherapy, are at high risk for developing subsequent breast cancer. Minimizing long-term toxicity risks associated with additional radiotherapy and chemotherapy is a priority, but therapeutic tradeoffs have not been comprehensively characterized and their impact on survival is unknown. In this study, 431 female childhood cancer survivors with subsequent breast cancer from a multicenter retrospective cohort study were evaluated. Compared with one-to-one matched females with first primary breast cancer, survivors are as likely to be prescribed guideline-concordant treatment (N = 344 pairs; survivors: 94%, controls: 93%), but more frequently undergo mastectomy (survivors: 81%, controls: 60%) and are less likely to be treated with anthracyclines (survivors: 47%, controls: 66%) or radiotherapy (survivors: 18%, controls: 61%). Despite this, survivors have nearly 3.5-fold (95% CI = 2.17-5.57) greater mortality risk. Here, we show survivors with subsequent breast cancer face excess mortality despite therapeutic tradeoffs and require specialized treatment guidelines.

Cross-Talk Between Cancer and Its Cellular Environment-A Role in Cancer Progression

The tumor microenvironment is a dynamic and complex three-dimensional network comprising the extracellular matrix and diverse non-cancerous cells, including fibroblasts, adipocytes, endothelial cells and various immune cells (lymphocytes T and B, NK cells, dendritic cells, monocytes/macrophages, myeloid-derived suppressor cells, and innate lymphoid cells). A constantly and rapidly growing number of studies highlight the critical role of these cells in shaping cancer survival, metastatic potential and therapy resistance. This review provides a synthesis of current knowledge on the modulating role of the cellular microenvironment in cancer progression and response to treatment.

Genomic hallmarks of endocrine therapy resistance in ER/PR+HER2- breast tumours

ER/PR+HER2- breast tumours are the most predominant subtype of breast cancer worldwide, including India. Unlike TNBCs, these tumours can be treated with anti-estrogens or aromatase inhibitors. Despite the success of endocrine therapy, a fraction of patients with ER/PR+ breast tumours do not respond to hormone-receptor-specific treatment and encounter disease recurrence contributing to their poor survival. The genomic underpinnings of therapy resistance in ER/PR+HER2- breast tumours are incompletely understood. We have performed whole genome sequencing (WGS) from tumour and normal tissue samples from endocrine-therapy resistant ER/PR+HER2- breast cancer patients who have relapsed on endocrine therapy and have conducted a comparative analysis of WGS data generated from tissues of endocrine therapy sensitive patients who remained free of disease during a minimum 5-year follow-up. Our analysis shows (a) a three-gene (PIK3CA-ESR1-TP53) resistance signature, and (b) impaired DNA double-strand break repair and homologous recombination pathways, were significantly associated with endocrine-therapy resistance and disease recurrence in ER/PR+HER2- tumours. Genome instability, contributing to high burden of copy-number, structural alterations and telomere-shortening identified as major markers of endocrine treatment resistance. Early prediction of endocrine-therapy resistance from the genomic landscape of breast tumours will aid therapeutics. Our finding also opens up the possibility of repurposing PARP inhibitors in treating endocrine therapy-resistant breast cancer patients.

Whole‑exome sequencing insights into synchronous bilateral breast cancer with discordant molecular subtypes

The incidence of synchronous bilateral breast cancer (SBBC) is very low, and SBBC with discordant molecular subtypes is even more uncommon. As such, little is known about the pathogenesis of SBBC with discordant molecular subtypes, and reports about this entity are scarce. In the present study, the case of a 72-year-old female patient who presented with SBBC with discordant molecular subtypes is reported, with a stage IA hormone receptor negative {human epidermal growth factor receptor-2 [HER2(+)]} tumor in the left breast and a stage IIIA hormone sensitive tumor [HER2(-)] in the right breast. Whole-exome sequencing was performed to identify the differential genetic variations in the BBC tissues. A total of 8 key mutated cancer susceptibility genes (ALK, BRCA1, FAT1, HNF1A, KDR, PTCH1, SDHA and SETBP1) were screened, and mutations were found in 10 vital cancer driver genes, including BRCA1, EBF1, MET, NF2, NUMA1 RALGAPA1, ROBO2, SMYD4, UBR5 and ZNF844. The high-frequency mutated genes mainly contained missense mutations, among which single nucleotide variants were the most common mutations, with C > T and C > A as the main forms. The pathways associated with the high frequency mutated genes were further elucidated by functional category and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. Heterogeneity in the hormone receptor and HER2 status of SBBC poses unique therapeutic challenges. Future studies should aim to identify the optimal management strategy for this disease.

Benign polymorphisms in the BRCA genes with linkage disequilibrium is associated with cancer characteristics

Germline pathogenic mutation of the BRCA gene increases the prevalence of breast cancer. Reports on the benign variants of BRCA genes are limited. However, the definition of these variants might be altered with the accumulation of clinical evidence. Therefore, in the present study, we focused on benign single nucleotide polymorphisms (SNPs) of BRCA genes. Linkage disequilibrium was calculated from whole genome sequencing of the BRCA genes obtained from 500 healthy controls and 49 breast cancer patients. Sanger sequencing was used to confirm the mutation. The linkage disequilibrium was noted for seven and three SNPs in the BRCA1 and BRCA2 genes, respectively. Breast cancer with BRCA1/2 linkage disequilibrium was not correlated with a personal history of benign diseases or family history of cancer. Nevertheless, breast cancer with BRCA1 linkage disequilibrium was correlated with high tumor-infiltrating lymphocytes and positive extensive intraductal components. The patients with BRCA1 linkage disequilibrium tended to have worse disease-specific survival. Cancers with BRCA2 linkage disequilibrium are associated with a lower ratio of grade III cancer. Moreover, patients with BRCA2 linkage disequilibrium tended to have better overall survival. In conclusion, linkage disequilibrium from benign SNPs of the BRCA genes potentially affects cancer characteristics.

A Pilot Study on BRCA1/2 and PI3K Mutations Across Subtypes of Triple Negative Breast Cancer in North Indian Population

BRCA1/2 are tumor suppressor genes which regulate the DNA repair mechanism. Mutations in BRCA1/2 may increase the risk of breast cancer in patients. In the present study frequency of BRCA1/2 mutations in triple negative breast cancer (TNBC) patients was assessed and correlated with molecular subtypes of TNBC. Blood samples from 65 confirmed cases of TNBC were collected. DNA was isolated from whole blood and libraries were prepared using a BRCA1/2 custom panel. Sequencing was done on Ion torrent S5 sequencer and ion reporter was used for data analysis. Further molecular subtyping of mutation positive TNBC cases was done using immunohistochemistry markers CK5/6; CK4/14; Vimentin and E-Cadherin and androgen receptor (AR) using tissue microarray. Twenty five of 65 patients had heterozygous pathogenic mutations, alterations with conflicting interpretation of pathogenicity, variants of uncertain significance and variants of unknown significance. Nine patients had pathogenic mutation in BRCA 1 gene only and 2 patients had pathogenic mutations in BRCA2 gene. Two patients were transheterozygous for BRCA mutations, that is, had pathogenic mutations in both BRCA1/2 genes simultaneously and 5 were compound heterozygous (involving BRCA2 gene in all the cases). Prevalent subtypes among BRCA positive cases were unclassified subtype (n=4, 33%), Basal like (n=5, 41%), and mesenchymal subtype (n=3, 25%). None of the LAR subtype showed BRCA1/2 mutations. The present study observed that the BRCA1 mutation is more frequent than BRCA2 mutation in TNBC. BRCA1/2 mutations do not correspond to BRCAness or basal phenotype. Considering high incidence of breast cancer and lack of correlation of basal morphology with BRCA1/2 mutation, the molecular methods should be used for screening for BRCA1/2 mutations. This will not only help in familial screening but also in deciding targeted therapy with PARP (poly-ADP ribose polymerase) inhibitors.

Nomograms predicting all-cause death and cancer-specific death in patients with bilateral primary breast cancer: a study based on Surveillance, Epidemiology, and End Results

Bilateral primary breast cancer (BPBC) patients have a worse prognosis. Tools for accurately predicting mortality risk in patients with BPBC are lacking in clinical practice. We aimed to develop a clinically useful prediction model for the death of BPBC patients. A total of 19,245 BPBC patients from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015 were randomly divided into the training set (n = 13,471) and test set (5,774). Models for predicting the 1-, 3- and 5-year death risk of BPBC patients were developed. Multivariate Cox regression analysis was used to develop the all-cause death prediction model, and competitive risk analysis was used to establish the cancer-specific death prediction model. The performance of the model was assessed by calculating the area under the receiver operating characteristic curve (AUC) with 95% confidence interval (CI), sensitivity, specificity and accuracy. Age, married status, interval time and first and second tumor's status were associated with both all-cause death and cancer-specific death (all P < 0.05). The AUC of Cox regression models predicted 1-, 3- and 5-year all-cause death was 0.854 (95% CI, 0.835-0.874), 0.838 (95% CI, 0.823-0.852) and 0.799 (95% CI, 0.785-0.812), respectively. The AUC of competitive risk models to predict 1-, 3- and 5-year cancer-specific death was 0.878 (95% CI, 0.859-0.897), 0.866 (95% CI, 0.852-0.879) and 0.854 (95% CI, 0.841-0.867), respectively. Nomograms were developed to predict all-cause death and cancer-specific death in BPBC patients, which may provide tools for clinicians to predict the death risk of BPBC patients.

Mutation Spectrum Comparison between Benign Breast Lesion Cohort, Unselected Cancer Cohort and High-Risk Breast Cancer Cohort

Mutation study for high-risk breast and ovarian cancer (HBOC) has been extensively studied in patients of different ethnicities. Here we compared the germline mutation rate and mutation spectrum of patients (n = 4341) with benign breast diseases or breast cancers, with and without other risk factors. Three cohorts of Chinese patients were recruited. The first cohort, high-risk cohort (HR, n = 3935) included high-risk breast cancer patients fulfilling high-risk HBOC criteria and who are recruited at our genetics clinic. The second cohort, unselected cancer cohort (CC, n = 307) was from general recruitment of patients with breast cancer at breast surgery clinics. The third cohort, benign breast lesion cohort (NC, n = 99) comprised 99 patients with benign breast diseases such as fibroadenoma, fibroadenomatoid hyperplasia, and intraductal papilloma. Thirty HBOC related genes were sequenced on the above-mentioned patient cohorts. The germline mutation rates of HR, CC, and NC cohort were 11.9%, 6.5%, and 8.1%, respectively. In the CC cohort, 29.3% (90/307) of patients fulfilled the National Comprehensive Cancer Network (NCCN) high-risk genetic test criteria 2022 v.2. The mutation rate for this group of patients was 11.1%, similar to that of the HR cohort, while the mutation rate for those not fulfilling testing criteria was 4.6%, like that of the NC cohort. High penetrance genes (BRCA1/2, CDH1, PALB2, PTEN, and TP53) mutations were only found in the HR (10.6%) and CC (3.3%) cohorts but were not found in the NC cohort. ATM, BRIP1, RAD51C, and RAD51D mutations were identified in all cohorts. RAD51C and RAD51D mutations showed conflicting penetrance. An unexpectedly high mutation rate of total 2% was found in the NC cohort but it was only 0.3% and 0.5% in the HR cohort and CC cohort, respectively. Our results show a clinical need to enhance genetic testing of unselected breast cancer patients to identify the high-risk patients.

Multigenic panels in breast cancer: Clinical utility and management of patients with pathogenic variants other than BRCA1/2

Multigene panels can analyze high and moderate/intermediate penetrance genes that predispose to breast cancer (BC), providing an opportunity to identify at-risk individuals within affected families. However, considering the complexity of different pathogenic variants and correlated clinical manifestations, a multidisciplinary team is needed to effectively manage BC. A classification of pathogenic variants included in multigene panels was presented in this narrative review to evaluate their clinical utility in BC. Clinical management was discussed for each category and focused on BC, including available evidence regarding the multidisciplinary and integrated management of patients with BC. The integration of both genetic testing and counseling is required for customized decisions in therapeutic strategies and preventative initiatives, as well as for a defined multidisciplinary approach, considering the continuous evolution of guidelines and research in the field.

Public neoantigens in breast cancer immunotherapy (Review)

Among women globally, breast cancer is the most prevalent cancer and the leading cause of cancer‑related death. Interestingly, though genetic mutations contribute to the disease, <15% of women diagnosed with breast cancer have a family history of the disease, suggesting a prevalence of sporadic genetic mutations in breast cancer development. In the rapidly rising field of cancer genomics, neoantigen‑based immunotherapy has come to the fore. The investigation of novel proteins arising from unique somatic mutations or neoantigens have opened a new pathway for both individualized and public cancer treatments. Because they are shared among individuals with similar genetic changes, public neoantigens provide an opportunity for 'off‑the‑shelf' anticancer therapies, potentially extending the benefits to a wider patient group. The present review aimed to highlight the role of shared or public neoantigens as therapeutic targets for patients with breast cancer, emphasizing common hotspot mutations of certain genes identified in breast cancer. The clinical utilization of public neoantigen‑based therapies for breast cancer treatment were also discussed.

Mismatch Repair (MMR) Gene Mutation Carriers Have Favorable Outcome in Colorectal and Endometrial Cancer: A Prospective Cohort Study

Germline (Lynch syndrome, LS) and somatic deficiencies of mismatch repair proteins (MMRd) are linked to colorectal and endometrial cancer; however, their prognostic impact in Asian populations remains unclear. This prospective cohort study aimed to determine the prevalence and outcome of germline and somatic MMRd in cancer patients suspected of LS. Patients with colorectal or endometrial cancer suspected of LS were enrolled and underwent gene sequencing for germline MMRd (gMMRd) and immunohistochemistry staining of MMR proteins in a subset of the pathological samples (pMMRd). Among the 451 enrolled patients, 36 patients were gMMRd (+). Compared with gMMRd (-) patients, the 10-year relapse-free survival in gMMRd (+) patients was significantly higher (100% vs. 77.9%; p = 0.006), whereas the 10-year overall survival was similar (100% vs. 90.9%; p = 0.12). Among the 102 gMMRd (-) patients with available pMMR status, 13.7% were pMMRd (+). The 5-year relapse-free survival was 62.9% in gMMRd (-) pMMRd (+) patients and 35.0% in gMMRd (-) pMMRd (-) patients, both lower than gMMRd (+) patients (100%; p < 0.001). This study showed that having LS confers a favorable outcome in colorectal and endometrial cancer patients and highlights the importance of germline genetic testing following the detection of somatic MMRd.

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.

Impact of breast surgical procedure on survival in BRCA mutated patients with invasive breast cancer: Mastectomy versus conservative treatment

INTRODUCTION

Patients with BRCA1/2 mutations have a higher risk of developing breast cancer compared to the wild-type population. For patients with a BRCA mutation, there are no specific recommendations for surgical management. The aim of this study was therefore to retrospectively investigate overall survival (OS) and recurrence-free survival (RFS) of BRCA mutated patients with localized invasive breast cancer, by comparing conservative surgery versus mastectomy.

METHODS

This study was based on data from the Côte d'Or breast and gynecological cancer registry. Data from patients with a constitutional BRCA1/2 mutation who presented with invasive breast cancer were collected retrospectively from 1998 to 2018. The Kaplan-Meier method was used to describe RFS and OS.

RESULTS

A total of 104 patients were included in the analysis, of whom 69 had conservative surgery and 35 underwent mastectomy. Regarding survival, there was no significant difference in OS (HR =1.49; 95 % confidence interval (CI) [0.76-2.93], p = 0.25). Similarly, there was no significant difference in RFS (HR =1.40; 95 % CI [0.81-2.40], p = 0.22), survival without homolateral recurrence (HR =0.88; 95 % CI [0.30-2.61], p = 0.89), without contralateral recurrence (HR =1.50; 95 % CI [0.55-4.09], p = 0.42), or without distant metastatic recurrence (HR =1.42, 95 % CI [0.69-2.90], p = 0.33).

CONCLUSION

In invasive breast cancer in a patient with a germline BRCA1/2 mutation, conservative surgery, when possible, appears to be a feasible option over total mastectomy, with no difference in overall survival. However, the patient should be informed of the aggressive nature of recurrence in this population requiring chemotherapy in most cases.

Untypical bilateral breast cancer with peritoneal fibrosis on 18F-FDG PET/CT: case report and literature review

Background

Retroperitoneal fibrosis, a condition of uncertain origin, is rarely linked to 8% of malignant cases, including breast, lung, gastrointestinal, genitourinary, thyroid, and carcinoid. The mechanism leading to peritoneal fibrosis induced by tumors is not well understood, possibly encompassing direct infiltration of neoplastic cells or the initiation of inflammatory responses prompted by cytokines released by tumor cells. We report a case of breast cancer with renal metastasis and retroperitoneal fibrosis detected using 18F-FDG PET/CT, providing help for clinical diagnosis and treatment.

Case report

A 49-year-old woman was referred to the hospital with elevated creatinine and oliguria for over a month. Abdominal computer tomography (CT) and magnetic resonance imaging (MRI) showed a retroperitoneal fibrosis-induced acute kidney injury (AKI) was suspected. However, a percutaneous biopsy of the kidney lesion confirmed metastasis from breast cancer. The physical examination revealed inverted nipples and an orange peel appearance on the skin of both breasts. Ultrasonography revealed bilateral hyperplasia (BIRADS 4a) of the mammary glands and bilateral neck and axillary lymphadenopathy. Subsequently, 18F-deoxyglucose positron emission tomography/computer tomography (18F-FDG PET/CT) detected abnormally high uptake (SUVmax) in the bilateral mammary glands and axillary lymph nodes, suggesting bilateral breast cancer. Furthermore, abnormal 18F-FDG uptake was detected in the kidney, suggesting renal metastasis. In addition, abnormal 18F-FDG uptake was observed in the vertebrae, accompanied by an elevation in inhomogeneous bone mineral density, raising suspicion of bone metastases. However, the possibility of myelodysplasia cannot be dismissed, and further investigations will be conducted during close follow-ups. There was significant 18F-FDG uptake in the retroperitoneal position indicating a potential association between retroperitoneal fibrosis and breast cancer. The final pathological diagnosis of the breast tissue confirmed bilateral invasive ductal carcinoma. The patient had been treated with 11 cycles of albumin-bound (nab)-paclitaxel (0.3 mg) and had no significant adverse reaction.

Conclusion

In this case, neither the bilateral breast cancer nor the kidney metastatic lesion showed typical nodules or masses, so breast ultrasound, abdominal CT, and MRI did not suggest malignant lesions. PET/CT played an important role in detecting occult metastases and primary lesions, thereby contributing to more accurate staging, monitoring treatment responses, and prediction of prognosis in breast cancer.

Germline RECQL gene mutations in Chinese patients with breast cancer

Introduction

Breast cancer is the most common malignant tumor in women, seriously threatening health and survival. TP-dependent DNA helicase Q1 (RECQL) is a breast cancer susceptibility gene with possible familial links. However, RECQL gene mutations among Chinese women with breast cancer have not been evaluated. Therefore, this study assessed RECQL mutations and their relationships with clinicopathological and epidemiological characteristics in Chinese women with breast cancer.

Method

Clinical information was also obtained via the hospital information system and a follow-up questionnaire. Peripheral venous blood (2 mL) was extracted from all patients and stored at -80°C for future use; the early venous blood samples were from our hospital's sample bank. RECQL gene sequencing were performed by the Shanghai Aishe Gene Company (China).

Results

We found that a RECQL mutation is a susceptibility factor for breast cancer. Moreover, patients with RECQL mutations were more likely to have a family history of breast cancer than those without. Also, patients with RECQL variants of uncertain significance (VUS) were less likely to develop invasive ductal carcinoma than those without. In addition, unexplained RECQL mutations occurred more often in patients with human epidermal growth factor receptor 2+ breast cancer than in those with other subtypes.

Discussion

These results provide a basis for creating screening criteria specific to Chinese women. However, the frequency of RECQL mutations was low, and the number of pathogenic mutations was too small and could not be analyzed. Thus, more extensive, long-term studies that include other functional experiments are needed to verify these results.

Prevalence of BRCA1, BRCA2, and PALB2 genomic alterations among 924 Taiwanese breast cancer assays with tumor-only targeted sequencing: extended data analysis from the VGH-TAYLOR study

BACKGROUND

The homologous recombination (HR) repair pathway for DNA damage, particularly the BRCA1 and BRCA2 genes, has become a target for cancer therapy, with poly ADP-ribose polymerase (PARP) inhibitors showing significant outcomes in treating germline BRCA1/2 (gBRCA1/2) mutated breast cancer. Recent studies suggest that some patients with somatic BRCA1/2 (sBRCA1/2) mutation or mutations in HR-related genes other than BRCA1/2 may benefit from PARP inhibitors as well, particularly those with PALB2 mutations. The current analysis aims to evaluate the prevalence of genetic alterations specific to BRCA1, BRCA2, and PALB2 in a large cohort of Taiwanese breast cancer patients through tumor-targeted sequencing.

METHODS

A total of 924 consecutive assays from 879 Taiwanese breast cancer patients underwent tumor-targeted sequencing (Thermo Fisher Oncomine Comprehensive Assay v3). We evaluated BRCA1, BRCA2, and PALB2 mutational profiles, with variants annotated and curated by the ClinVAR, the Oncomine™ Knowledgebase Reporter, and the OncoKB™. We also conducted reflex germline testing using either whole exome sequencing (WES) or whole genome sequencing (WGS), which is ongoing.

RESULTS

Among the 879 patients analyzed (924 assays), 130 had positive mutations in BRCA1 (3.1%), BRCA2 (8.6%), and PALB2 (5.2%), with a total of 14.8% having genetic alterations. Co-occurrence was noted between BRCA1/BRCA2, BRCA1/PALB2, and BRCA2/PALB2 mutations. In BRCA1-mutated samples, only p.K654fs was observed in three patients, while other variants were observed no more than twice. For BRCA2, p.N372H was the most common (26 patients), followed by p.S2186fs, p.V2466A, and p.X159_splice (5 times each). For PALB2, p.I887fs was the most common mutation (30 patients). This study identified 176 amino acid changes; 60.2% (106) were not documented in either ClinVAR or the Oncomine™ Knowledgebase Reporter. Using the OncoKB™ for annotation, 171 (97.2%) were found to have clinical implications. For the result of reflex germline testing, three variants (BRCA1 c.1969_1970del, BRCA1 c.3629_3630del, BRCA2 c.8755-1G > C) were annotated as Pathogenic/Likely pathogenic (P/LP) variants by ClinVar and as likely loss-of-function or likely oncogenic by OncoKB; while one variant (PALB2 c.448C > T) was not found in ClinVar but was annotated as likely loss-of-function or likely oncogenic by OncoKB.

CONCLUSION

Our study depicted the mutational patterns of BRCA1, BRCA2, and PALB2 in Taiwanese breast cancer patients through tumor-only sequencing. This highlights the growing importance of BRCA1/2 and PALB2 alterations in breast cancer susceptibility risk and the treatment of index patients. We also emphasized the need to meticulously annotate variants in cancer-driver genes as well as actionable mutations across multiple databases.

Exome Sequencing Reveals Novel Germline Variants in Breast Cancer Patients in the Southernmost Region of Thailand

Germline carriers of pathogenic variants in cancer susceptibility genes are at an increased risk of breast cancer (BC). We characterized germline variants in a cohort of 151 patients diagnosed with epithelial BC in the southernmost region of Thailand, where the predominant ethnicity differs from that of the rest of the country. Whole exome sequencing was used to identify and subsequently filter variants present in 26 genes known to be associated with cancer predisposition. Of the 151 individuals assessed, 23, corresponding to 15.2% of the sample, exhibited the presence of one or more pathogenic or likely pathogenic variants associated with BC susceptibility. We identified novel germline truncating variants in BRIP1, CHEK2, MSH6, PALB2, and PTEN and annotated variants of uncertain significance (VUSs), both novel and previously documented. Therefore, it is advisable to use genetic testing as an additional risk screening method for BC in this area.

A de Novo BRCA1 Pathogenic Variant in a 29-Year-Old Woman with Triple-Negative Breast Cancer

Introduction

Germline pathogenic variants in the BRCA1 and BRCA2 genes lead to a highly increased lifetime risk for breast and ovarian cancer. These variants are usually inherited and reports of de novo occurrences are a very rare phenomenon.

Case Presentation

We report on a breast cancer patient with a de novo BRCA1 variant c.121C>T (p.His41Tyr). The pathogenic variant was detected in leukocyte DNA of a patient with negative family history who had developed early onset, triple-negative breast cancer. The variant was not found in any of the maternal and paternal tissues tested, but it was detected in multiple samples representing all three germ layers of the affected carrier, which renders somatic mosaicism unlikely.

Conclusion

This case highlights the importance of including early onset of disease and triple negativity of the tumor as criteria for genetic testing, even in patients without family history. Considering the availability of effective breast cancer treatments in patients with pathogenic variants in the BRCA genes, this finding underscores the importance of genetic testing in breast cancer patients.

Comparison of Long-Term Oncological Results in Young Women with Breast Cancer between BRCA-Mutation Carriers Versus Non-Carriers: How Tumor and Genetic Risk Factors Influence the Clinical Prognosis

BACKGROUND

Breast cancer (BC) is very uncommon in young women (YW) and it is unclear whether a BRCA mutation has prognostic implications. Our aim was to evaluate the characteristics of YW with BC by comparing the long-term oncological results between BRCA-mutation carriers and non-carriers.

METHODS

We retrospectively reviewed all the consecutive YW (aged 18-40 years) diagnosed with BC. Endpoints were disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS).

RESULTS

63 YW with a BRCA mutation were compared with 339 YW without BRCA mutation. BRCA-mutation carriers were younger (60.3% versus 34.8% if age ≤ 35 years, p = 0.001) and presented with more aggressive tumors (66.7% versus 40.7% if G3, p = 0.001; 57.2% versus 12.4% if biological subtype triple-negative, p = 0.001; 73.0% versus 39.2% if Ki67 ≥ 25%, p = 0.001). Non-carriers presented significantly better DFS, DDFS, and OS compared with BRCA-mutation carriers. Neoadjuvant chemotherapy was found to be an independent protective factor for OS in BRCA-mutation carriers.

CONCLUSIONS

BC is more likely to present at a younger age (≤ 35 years) and with more aggressive characteristics (G3, triple-negative, Ki67 ≥ 25%) in YW with BRCA mutation compared with their non-mutated counterparts. Young BRCA-mutation carriers showed a poorer prognosis in terms of recurrence and survival compared with non-carriers. The implementation of neoadjuvant chemotherapy may improve survival in YW with BC and BRCA mutation.

Molecular characteristics of breast tumors in patients screened for germline predisposition from a population-based observational study

BACKGROUND

Pathogenic germline variants (PGVs) in certain genes are linked to higher lifetime risk of developing breast cancer and can influence preventive surgery decisions and therapy choices. Public health programs offer genetic screening based on criteria designed to assess personal risk and identify individuals more likely to carry PGVs, dividing patients into screened and non-screened groups. How tumor biology and clinicopathological characteristics differ between these groups is understudied and could guide refinement of screening criteria.

METHODS

Six thousand six hundred sixty breast cancer patients diagnosed in South Sweden during 2010-2018 were included with available clinicopathological and RNA sequencing data, 900 (13.5%) of which had genes screened for PGVs through routine clinical screening programs. We compared characteristics of screened patients and tumors to non-screened patients, as well as between screened patients with (n = 124) and without (n = 776) PGVs.

RESULTS

Broadly, breast tumors in screened patients showed features of a more aggressive disease. However, few differences related to tumor biology or patient outcome remained significant after stratification by clinical subgroups or PAM50 subtypes. Triple-negative breast cancer (TNBC), the subgroup most enriched for PGVs, showed the most differences between screening subpopulations (e.g., higher tumor proliferation in screened cases). Significant differences in PGV prevalence were found between clinical subgroups/molecular subtypes, e.g., TNBC cases were enriched for BRCA1 PGVs. In general, clinicopathological differences between screened and non-screened patients mimicked those between patients with and without PGVs, e.g., younger age at diagnosis for positive cases. However, differences in tumor biology/microenvironment such as immune cell composition were additionally seen within PGV carriers/non-carriers in ER + /HER2 - cases, but not between screening subpopulations in this subgroup.

CONCLUSIONS

Characterization of molecular tumor features in patients clinically screened and not screened for PGVs represents a relevant read-out of guideline criteria. The general lack of molecular differences between screened/non-screened patients after stratification by relevant breast cancer subsets questions the ability to improve the identification of screening candidates based on currently used patient and tumor characteristics, pointing us towards universal screening. Nevertheless, while that is not attained, molecular differences identified between PGV carriers/non-carriers suggest the possibility of further refining patient selection within certain patient subsets using RNA-seq through, e.g., gene signatures.

TRIAL REGISTRATION

The Sweden Cancerome Analysis Network - Breast (SCAN-B) was prospectively registered at ClinicalTrials.gov under the identifier NCT02306096.

The Firmicutes/Bacteroidetes Ratio as a Risk Factor of Breast Cancer

The gut microbiome can reflect the health condition of the entire body. Firmicutes and Bacteroidetes, the major phyla of the colon, can influence diseases related to obesity which are also risk factors for breast cancer. Therefore, the Firmicutes/Bacteroidetes (F/B) ratio was analyzed in patients with breast cancer. Bacterial extracellular vesicles were extracted from the serum of patients with breast cancer and healthy controls. Phyla Firmicutes and Bacteroidetes were analyzed using microbiome sequencing. Prognostic factors for breast cancer and serological test results were analyzed for correlations with the F/B ratio. The F/B ratio was three times lower in patients with breast cancer than in healthy controls. In addition, the risk factor for breast cancer, such as fasting serum glucose, was found to be related to the F/B ratio. The F/B ratio can be used as a risk factor of breast cancer and as a clue to explain underlying mechanisms affecting the development of breast cancer.

MR imaging phenotypes and features associated with pathogenic mutation to predict recurrence or metastasis in breast cancer

OBJECTIVES

Distant metastasis remains the main cause of death in breast cancer. Breast cancer risk is strongly influenced by pathogenic mutation.This study was designed to develop a multiple-feature model using clinicopathological and imaging characteristics adding pathogenic mutations associated signs to predict recurrence or metastasis in breast cancers in high familial risk women.

METHODS

Genetic testing for breast-related gene mutations was performed in 54 patients with breast cancers. Breast MRI findings were retrospectively evaluated in 64 tumors of the 54 patients. The relationship between pathogenic mutation, clinicopathological and radiologic features was examined. The disease recurrence or metastasis were estimated. Multiple logistic regression analyses were performed to identify independent factors of pathogenic mutation and disease recurrence or metastasis. Based on significant factors from the regression models, a multivariate logistic regression was adopted to establish two models for predicting disease recurrence or metastasis in breast cancer using R software.

RESULTS

Of the 64 tumors in 54 patients, 17 tumors had pathogenic mutations and 47 tumors had no pathogenic mutations. The clinicopathogenic and imaging features associated with pathogenic mutation included six signs: biologic features (p = 0.000), nuclear grade (p = 0.045), breast density (p = 0.005), MRI lesion type (p = 0.000), internal enhancement pattern (p = 0.004), and spiculated margin (p = 0.049). Necrosis within the tumors was the only feature associated with increased disease recurrence or metastasis (p = 0.006). The developed modelIincluding clinico-pathologic and imaging factors showed good discrimination in predicting disease recurrence or metastasis. Comprehensive model II, which included parts of modelIand pathogenic mutations significantly associated signs, showed significantly more sensitivity and specificity for predicting disease recurrence or metastasis compared to Model I.

CONCLUSIONS

The incorporation of pathogenic mutations associated imaging and clinicopathological parameters significantly improved the sensitivity and specificity in predicting disease recurrence or metastasis. The constructed multi-feature fusion model may guide the implementation of prophylactic treatment for breast cancers at high familial risk women.

Overview on population screening for carriers with germline BRCA mutation in China

Carriers with BRCA1/2 germline pathogenic variants are associated with a high risk of breast and ovarian cancers (also pancreatic and prostate cancers). While the spectrum on germline BRCA mutations among the Chinese population shows ethnic specificity, the identification of carriers with germline BRCA mutation before cancer onset is the most effective approach to protect them. This review focused on the current status of BRCA1/2 screening, the surveillance and prevention measures, and discussed the issues and potential impact of BRCA1/2 population screening in China. We conducted literature research on databases PubMed and Google Scholar, as well as Chinese databases CNKI and Wangfang Med Online database (up to 31 March 2022). Latest publications on germline BRCA1/2 prevalence, spectrum, genetic screening as well as carrier counseling, surveillance and prevention were captured where available. While overall 15,256 records were retrieved, 72 publications using germline BRCA1/2 testing were finally retained for further analyses. Germline BRCA1/2 mutations are common in Chinese patients with hereditary breast, ovarian, prostate and pancreatic cancers. Within previous studies, a unique BRCA mutation spectrum in China was revealed. Next-generation sequencing panel was considered as the most common method for BRCA1/2 screening. Regular surveillance and preventive surgeries were tailored to carriers with mutated-BRCA1/2. We recommend that all Chinese diagnosed with breast, ovarian, pancreatic or prostate cancers and also healthy family members, shall undergo BRCA1/2 gene test to provide risk assessment. Subsequently, timely preventive measures for mutation carriers are recommended after authentic genetic counseling.

Targeted Sequencing of Germline Breast Cancer Susceptibility Genes for Discovering Pathogenic/Likely Pathogenic Variants in the Jakarta Population

Germline predisposition plays an important role in breast cancer. Different ethnic populations need respective studies on cancer risks pertinent to germline variants. We aimed to discover the pathogenic and likely pathogenic variants (P/LP-Vs) of germline breast cancer susceptibility genes and to evaluate their correlation with the clinical characteristics in Jakarta populations. The pure DNA was extracted from the blood buffy coat, using reagents from the QIAamp DNA Mini Kit® (Qiagen, Hilden, Germany). The DNA libraries were prepared using the TargetRich™ Hereditary Cancer Panel (Kailos Genetics®, Huntsville, AL, USA). The barcoded DNA libraries were sequenced using the Illumina NextSeq 500 platform. In-house bioinformatics pipelines were used to analyze the gene variants. We identified 35 pathogenic and likely pathogenic (P/LP-Vs) variants (28 frameshift, 5 nonsense, and 2 splice-site variants). The P/LP-Vs group was statistically significantly different in luminal B status (p < 0.05) compared with the non-P/LP-Vs group. The P/LP-Vs found both in BRCA1/2 genes and non-BRCA genes may increase the risk of breast cancer and alter drug responses. The screening of multigene variants is suggested, rather than BRCA testing only. Prior knowledge of the germline variants status is important for optimal breast cancer diagnosis and optimal therapy.

Multi-gene panel testing increases germline predisposing mutations’ detection in a cohort of breast/ovarian cancer patients from Southern Italy

Breast cancer is the most common neoplasia in females worldwide, about 10% being hereditary/familial and due to DNA variants in cancer-predisposing genes, such as the highly penetrant BRCA1/BRCA2 genes. However, their variants explain up to 25% of the suspected hereditary/familial cases. The availability of NGS methodologies has prompted research in this field. With the aim to improve the diagnostic sensitivity of molecular testing, a custom designed panel of 44 genes, including also non-coding regions and 5’ and 3’ UTR regions, was set up. Here, are reported the results obtained in a cohort of 64 patients, including also few males, from Southern Italy. All patients had a positive personal and/or familial history for breast and other cancers, but tested negative to routine BRCA analysis. After obtaining their written informed consent, a genomic DNA sample/patient was used to obtain an enriched DNA library, then analyzed by NGS. Sequencing data analysis allowed the identification of pathogenic variants in 12 of tested patients (19%). Interestingly, MUTYH was the most frequently altered gene, followed by RNASEL, ATM, MSH6, MRE11A, and PALB2 genes. The reported resultsreinforce the need for enlarged molecular testing beyond BRCA genes, at least in patients with a personal and familial history, strongly suggestive for a hereditary/familial form. This gives also a hint to pursue more specific precision oncology therapy.

Stratified analysis of the association between periodontitis and female breast cancer based on age, comorbidities and level of urbanization: A population-based nested case-control study

PURPOSE

To conduct stratified analysis of the association between periodontitis exposure and the risk of female breast cancer based on age, comorbidities and level of urbanization.

METHODS

Using claims data taken from the 1997-2013 Taiwanese National Health Insurance Research Database (NHIRD), we identified 60,756 newly-diagnosed female breast cancer patients during the period 2003-2013 from all beneficiaries. We then randomly selected 243,024 women without breast cancer matching (1:4) for age and the year of the index date during 1997-2013 from a one million representative population acting as the control group. A conditional logistic regression analysis was used to examine the association between periodontitis (ICD-9-CM codes 523.3-4) and the risk of breast cancer, shown as an odds ratio (OR) with a 95% confidence interval (CI) after adjustments for the Charlson Comorbidity Index (CCI) and level of urbanization. Subgroup analyses were conducted based on age, CCI and level of urbanization.

RESULTS

The mean ± standard deviation age was 53 ± 14 years. After adjusting for potential confounders, the risk of female breast cancer was found to be associated with a history of periodontitis (OR, 1.12; 95% CI, 1.10-1.14). Such an association was significantly different between patients aged < 65 years (OR, 1.09; 95% CI, 1.06-1.11) and patients aged ≥ 65 years (OR, 1.23; 95% CI, 1.18-1.28; p for interaction <0.001), as well as between patients where the CCI = 0 (OR, 1.17; 95% CI, 1.15-1.20) and patients with CCI > 0 (OR, 0.99; 95% CI, 0.96-1.03; p for interaction <0.001). The highest level of urbanization was also associated with the risk of breast cancer.

CONCLUSIONS

This population-based nested case-control study demonstrated that periodontitis was significantly associated with the risk of female breast cancer and such an association was modified by both age and comorbidities.

Management Strategies of Breast Cancer Patients with BRCA1 and BRCA2 Pathogenic Germline Variants

Most of breast cancer cases are sporadic; however, 15–20% are associated with family history, and some are inherited. Among those, deleterious mutations in BRCA1 and BRCA2 tumor suppressor genes are the most commonly encountered pathogenic germline variants (PGVs). Given the availability and affordability of multi-gene panel sequencing technologies, testing for PGVs is commonly practiced. With our enhanced understanding of cancer genetics and specific molecular alterations, the better acceptance of risk-directed screening and prevention, and the recent introduction of novel targeted therapies, management of BRCA-positive breast cancers is taking a new direction, focusing more on risk-reducing interventions, including mastectomy and salpingo-oophorectomy, and incorporating special treatment regimens, including platinum-based chemotherapy, and the recently-introduced PARP (poly (ADP)-ribose polymerase) inhibitors. Given the recent advances in reproductive technology and molecular medicine, younger women with PGVs may have the option of embryo selection through preimplantation genetic testing and diagnosis, thus preventing the potential transmission of the implicated genes to the next generations. In this review, we cover the clinical implications of identifying a pathogenic germline mutation in BRCA1 and BRCA2 genes in breast cancer patients, and their relatives, across the continuum of care – from cancer prevention and early detection, through active treatment and up to survivorship issues.

Surveillance mammography after treatment for male breast cancer

PURPOSE

To identify the practice patterns related to use of surveillance mammography in male breast cancer (MaBC) survivors.

METHODS

Using administrative claims data from OptumLabs Data Warehouse, we identified men who underwent surgery for breast cancer during 2007-2017. We calculated the proportion of men who had at least one mammogram (a) within 13 months for all patients and (b) within 24 months amongst those who maintained their insurance coverage for at least that length of time after surgery. Multivariate logistic regression modeling was used to identify factors associated with mammography within each timeframe.

RESULTS

Out of 729 total MaBC survivors, 209 (29%) underwent mammography within 13 months after surgery. Among those who had lumpectomy, 41% underwent mammography, whereas among those who had mastectomy, 27% had mammography. Amongst 526 men who maintained consistent insurance coverage for 24 months after surgery, 215 (41%) underwent mammography at least once during that 24-month period. In this cohort, the proportion who had at least one mammogram during the 24-month period was 49% after lumpectomy and 40% after mastectomy. In a multivariate logistic regression model, more recent diagnosis (2015+) and older age at diagnosis were associated with lower odds of undergoing mammography, while receipt of radiation was associated with higher odds of undergoing mammography.

CONCLUSIONS

Although recent ASCO guidelines recommend surveillance mammography after lumpectomy, a minority of MaBC survivors undergo surveillance mammography, even after lumpectomy. This is likely due to the paucity of data regarding the true benefits and harms of surveillance/screening mammography for MaBC.

Epstein-Barr Virus Association with Breast Cancer: Evidence and Perspectives

Epstein-Barr virus (EBV) is an enveloped DNA virus that belongs to the gamma Herpesviridae family. The virus establishes a latent/lytic persistent infection, though it can be involved in cancer development in some subjects. Indeed, evidence supports an etiological role of EBV in undifferentiated nasopharyngeal carcinoma (NPC), a subset of gastric carcinomas and lymphomas. Additionally, EBV has been detected in breast carcinomas (BCs) although its role has not been established. In this review, we summarize epidemiological information regarding the presence of EBV in BC and we propose mechanistic models. However, additional epidemiological and experimental evidence is warranted to confirm these models.

Hereditary breast cancer and fertility preservation outcomes

PURPOSE

To determine the frequency of hereditary breast cancer associated with different mutated genes and to evaluate fertility preservation (FP) outcomes among young women with hereditary breast cancer when compared to non-hereditary breast cancer.

MATERIAL AND METHODS

A retrospective cohort study of women with breast cancer who underwent fertility preservation treatment at our academic fertility center between 2005 and 2019. We included all women with breast cancer aged < 40 years who had a genetic testing and underwent fertility preservation before starting gonadotoxic therapy (n = 132). Our objective was to evaluate the total number of oocytes retrieved, mature oocytes MII, embryos (where appropriate), cryopreserved oocytes, and/or embryos.

RESULTS

Of 132 women with breast cancer, 40 women were found to be genetically positive (31.4%), 31 women of 40 (77.5%) had a BRCA mutation, 3 (7.5%) had ATM, 2 (5%) had CHK2, and one (2.5%) for each of the following genes: PALP2, NF, MUTYH.c.536A, and TP53. There was no significant difference between the groups in the total number of eggs retrieved and the number of MII oocytes and cryopreserved oocytes. The numbers of fertilized oocytes and cryopreserved embryos in the hereditary (n = 40) and non-hereditary (n = 92) group were (5.15 ± 6.6 vs 2.90 ± 4.2, P = 0.054) and (3.35 ± 3.7 vs 1.9 ± 2.8, P = 0.046) respectively.

CONCLUSION

More than three quarters of positive mutated genes in women with breast cancer are BRCA mutations. Compared to those with non-hereditary breast cancer, women with hereditary breast cancer attained higher number of cryopreserved embryos.

Germline Variants in Cancer Genes from Young Breast Cancer Mexican Patients

Breast cancer (BC) is one of the most frequent cancer types in women worldwide. About 7% is diagnosed in young women (YBC) less than 40 years old. In Mexico, however, YBC reaches 15% suggesting a higher genetic susceptibility. There have been some reports of germline variants in YBC across the world. However, there is only one report from a Mexican population, which is not restricted by age and limited to a panel of 143 genes resulting in 15% of patients carrying putatively pathogenic variants. Nevertheless, expanding the analysis to whole exome involves using more complex tools to determine which genes and variants could be pathogenic. We used germline whole exome sequencing combined with the PeCanPie tool to analyze exome variants in 115 YBC patients. Our results showed that we were able to identify 49 high likely pathogenic variants involving 40 genes on 34% of patients. We noted many genes already reported in BC and YBC worldwide, such as BRCA1, BRCA2, ATM, CHEK2, PALB2, and POLQ, but also others not commonly reported in YBC in Latin America, such as CLTCL1, DDX3X, ERCC6, FANCE, and NFKBIE. We show further supporting and controversial evidence for some of these genes. We conclude that exome sequencing combined with robust annotation tools and further analysis, can identify more genes and more patients affected by germline mutations in cancer.

Patient-reported outcomes following bilateral prophylactic mastectomy and immediate breast reconstruction: comparing implant-based with autologous breast reconstruction

Background

Since the number of breast cancer genetic gene testing is increasing, more women opt for bilateral prophylactic mastectomy (BPM) followed by breast reconstruction. However, little is known about the differences in Quality of Life (QoL) after various reconstructive surgeries in this population. In this study, the long-term breast-related, body-related, and health-related QoL between immediate implant-based breast reconstruction (IBBR) and autologous breast reconstruction (ABR) were compared, in women who underwent BPM.

Methods

In this cross-sectional study, women who underwent postmastectomy breast reconstruction between January 2015 and December 2018 were invited for an online questionnaire, in which the BREAST-Q, the BODY-Q and the SF-36 were included. Women who underwent BPM and immediate breast reconstruction were included for analysis. Multivariable linear regression analysis was performed to adjust mean differences in patient-reported outcomes between IBBR and ABR for potential confounders.

Results

Of the included women (n = 47), 33 underwent ABR and 14 women underwent IBBR following BPM. BREAST-Q scores were in favor of the ABR group before and after adjustment, with statistically significance on Satisfaction with breasts (mean difference 15.8, p = 0.019) and Physical well-being (mean difference 13.5, p = 0.033). None of the mean differences in BODY-Q and SF-36 scores between groups, before and after adjustment, were statistically significant.

Conclusion

This study suggests that there is a higher satisfaction with breasts and better physical well-being in women who underwent immediate ABR compared to those who underwent immediate IBBR after BPM. However, these data should be interpreted carefully as a result of selection bias and a small sample size.

Level of Evidence: Level III, risk study.

Case Report and Literature Review: Diagnosis, Tailored Genetic Counseling and Cancer Prevention for a Locally Advanced dMMR/MSI-H/TMB-H Lung Cancer Patient With Concurrent Lynch Syndrome Mediated by a Rare PMS2 Splicing Variant (c.1144+1G>A)

Lynch syndrome (LS) is a cancer-predisposing genetic disease mediated by pathogenic mutations in DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. Accumulating evidence demonstrates that there is significant biological heterogeneity across MMR genes. Compared to MLH1 and MSH2, PMS2 variant carriers have a much lower risk for LS-related cancers. Tumors in MLH1 and MSH2 variant carriers often display MMR deficiency (dMMR) and/or high microsatellite instability (MSI-H), two predictive biomarkers for immunotherapy efficacy. However, tumors in PMS2 variant carriers are largely microsatellite stable (MSS) instead of MSI. Therefore, the optimal management of cancer patients with LS requires the integration of disease stage, MMR gene penetrance, dMMR/MSI status, and tumor mutational burden (TMB). In this work, we presented a locally advanced lung cancer patient with dMMR/MSI-H/TMB-H tumor and selective loss of PMS2 by immunohistochemistry. Germline testing revealed a rare PMS2 splicing variant (c.1144+1G>A) in the proband and his healthy daughter. The diagnosis of LS was made based on genetic analysis of this variant and literature review. Given the incomplete penetrance of PMS2, the proband and the carrier received tailored genetic counseling. To reduce cancer risk, the proband received four cycles of nivolumab plus chemotherapy and achieved a disease-free survival of sixteen months.

Clinical feature-related single-base substitution sequence signatures identified with an unsupervised machine learning approach

BACKGROUND

Mutation processes leave different signatures in genes. For single-base substitutions, previous studies have suggested that mutation signatures are not only reflected in mutation bases but also in neighboring bases. However, because of the lack of a method to identify features of long sequences next to mutation bases, the understanding of how flanking sequences influence mutation signatures is limited.

METHODS

We constructed a long short-term memory-self organizing map (LSTM-SOM) unsupervised neural network. By extracting mutated sequence features via LSTM and clustering similar features with the SOM, single-base substitutions in The Cancer Genome Atlas database were clustered according to both their mutation site and flanking sequences. The relationship between mutation sequence signatures and clinical features was then analyzed. Finally, we clustered patients into different classes according to the composition of the mutation sequence signatures by the K-means method and then studied the differences in clinical features and survival between classes.

RESULTS

Ten classes of mutant sequence signatures (mutation blots, MBs) were obtained from 2,141,527 single-base substitutions via LSTM-SOM machine learning approach. Different features in mutation bases and flanking sequences were revealed among MBs. MBs reflect both the site and pathological features of cancers. MBs were related to clinical features, including age, sex, and cancer stage. The class of an MB in a given gene was associated with survival. Finally, patients were clustered into 7 classes according to the MB composition. Significant differences in survival and clinical features were observed among different patient classes.

CONCLUSIONS

We provided a method for analyzing the characteristics of mutant sequences. Result of this study showed that flanking sequences, together with mutation bases, shape the signatures of SBSs. MBs were shown related to clinical features and survival of cancer patients. Composition of MBs is a feasible predictive factor of clinical prognosis. Further study of the mechanism of MBs related to cancer characteristics is suggested.

Germline breast cancer susceptibility genes, tumor characteristics, and survival

BACKGROUND

Mutations in certain genes are known to increase breast cancer risk. We study the relevance of rare protein-truncating variants (PTVs) that may result in loss-of-function in breast cancer susceptibility genes on tumor characteristics and survival in 8852 breast cancer patients of Asian descent.

METHODS

Gene panel sequencing was performed for 34 known or suspected breast cancer predisposition genes, of which nine genes (ATM, BRCA1, BRCA2, CHEK2, PALB2, BARD1, RAD51C, RAD51D, and TP53) were associated with breast cancer risk. Associations between PTV carriership in one or more genes and tumor characteristics were examined using multinomial logistic regression. Ten-year overall survival was estimated using Cox regression models in 6477 breast cancer patients after excluding older patients (≥75years) and stage 0 and IV disease.

RESULTS

PTV9genes carriership (n = 690) was significantly associated (p < 0.001) with more aggressive tumor characteristics including high grade (poorly vs well-differentiated, odds ratio [95% confidence interval] 3.48 [2.35-5.17], moderately vs well-differentiated 2.33 [1.56-3.49]), as well as luminal B [HER-] and triple-negative subtypes (vs luminal A 2.15 [1.58-2.92] and 2.85 [2.17-3.73], respectively), adjusted for age at diagnosis, study, and ethnicity. Associations with grade and luminal B [HER2-] subtype remained significant after excluding BRCA1/2 carriers. PTV25genes carriership (n = 289, excluding carriers of the nine genes associated with breast cancer) was not associated with tumor characteristics. However, PTV25genes carriership, but not PTV9genes carriership, was suggested to be associated with worse 10-year overall survival (hazard ratio [CI] 1.63 [1.16-2.28]).

CONCLUSIONS

PTV9genes carriership is associated with more aggressive tumors. Variants in other genes might be associated with the survival of breast cancer patients. The finding that PTV carriership is not just associated with higher breast cancer risk, but also more severe and fatal forms of the disease, suggests that genetic testing has the potential to provide additional health information and help healthy individuals make screening decisions.

Racial and Ethnic Differences in Multigene Hereditary Cancer Panel Test Results for Women With Breast Cancer

To evaluate the racial and ethnic differences in prevalence of germline pathogenic variants (PVs) and the effect of race and ethnicity on breast cancer (BC) risk among carriers, results of multigene testing of 77 900 women with BC (non-Hispanic White [NHW] = 57 003; Ashkenazi-Jewish = 4798; Black = 6722; Hispanic = 5194; and Asian = 4183) were analyzed, and the frequency of PVs in each gene were compared between BC patients (cases) and race- and ethnicity-matched gnomAD reference controls. Compared with NHWs, BRCA1 PVs were enriched in Ashkenazi-Jews and Hispanics, whereas CHEK2 PVs were statistically significantly lower in Blacks, Hispanics, and Asians (all 2-sided P < .05). In case-control studies, BARD1 PVs were associated with high risks (odds ratio > 4.00) of BC in Blacks, Hispanics, and Asians; ATM PVs were associated with increased risk of BC among all races and ethnicities except Asians, whereas CHEK2 and BRIP1 PVs were associated with increased risk of BC among NHWs and Hispanics only. These findings suggest a need for personalized management of BC risk in PV carriers based on race and ethnicity.

Hereditary Breast and Ovarian Cancer Screening Syndrome Profile in Women Diagnosed with Breast Cancer from Paraná State Southwest

OBJECTIVE

 This study evaluated the risk of the hereditary breast and ovarian cancer (HBOC) syndrome in patients with breast cancer by using the Family History Screening 7 (FHS-7) tool, a validated low-cost questionnaire with high sensitivity able to screen the HBOC risk in the population.

METHODS

 Women diagnosed with breast cancer (n = 101) assisted by the Unified Health System at the 8th Regional Health Municipal Office of the state of Paraná answered the FHS-7, and the results were analyzed using IBM SPSS Statistics for Windows, Version 25.0. software (IBM Corp., Armonk, NY, USA).

RESULTS

 The risk of HBOC was 19.80% (n = 20). Patients at risk exhibited aggressive tumor characteristics, such as high-grade tumors (30%), presence of angiolymphatic emboli (35%), and premenopausal at diagnosis (50%). Significant associations between the prevalence of high-grade tumors were observed in women younger than 50 years at diagnosis with HBOC (p = 0.003).

CONCLUSION

 Our findings suggest a possible family inheritance associated with worse clinical features in women with breast cancer in this population, indicating that HBOC investigation can be initially performed with low-cost instruments such as FHS-7.

Association of Genetic Testing Results with Mortality Among Women with Breast Cancer or Ovarian Cancer

BACKGROUND

Breast cancer and ovarian cancer patients increasingly undergo germline genetic testing. However, little is known about cancer-specific mortality among carriers of a pathogenic variant (PV) in BRCA1/2 or other genes in a population-based setting.

METHODS

Georgia and California Surveillance Epidemiology and End Results (SEER) registry records were linked to clinical genetic testing results. Women were included who had stages I-IV breast cancer or ovarian cancer diagnosed in 2013-2017; received chemotherapy; and linked to genetic testing results. Multivariable Cox proportional hazard models were used to examine the association of genetic results with cancer-specific mortality.

RESULTS

22,495 breast and 4,320 ovarian cancer patients were analyzed, with a median follow-up of 41 months. PVs were present in 12.7% of breast cancer patients with estrogen and/or progesterone receptor-positive, HER2-negative cancer, 9.8% with HER2-positive cancer, 16.8% with triple-negative breast cancer and 17.2% with ovarian cancer. Among triple-negative breast cancer patients, cancer-specific mortality was lower with BRCA1 (hazard ratio [HR] = 0.49, 95% confidence interval [CI] = 0.35-0.69) and BRCA2 PVs (HR = 0.60, 95% CI = 0.41-0.89), and equivalent with PVs in other genes (HR = 0.65, 95% CI = 0.37-1.13), versus non-carriers. Among ovarian cancer patients, cancer-specific mortality was lower with PVs in BRCA2 (HR = 0.35, 95% CI = 0.25-0.49) and genes other than BRCA1/2 (HR = 0.47, 95% CI = 0.32-0.69). No PV was associated with higher cancer-specific mortality.

CONCLUSIONS

Among breast cancer and ovarian cancer patients treated with chemotherapy in the community, BRCA1/2 and other gene PV carriers had equivalent or lower short-term cancer-specific mortality than non-carriers. These results may reassure newly diagnosed patients and longer follow-up is ongoing.

Clinical Features and Long-term Prognosis of Retinoblastoma according to Age at Diagnosis

PURPOSE

We aimed to study the clinical characteristics and long-term prognoses of retinoblastoma according to the age at diagnosis.

METHODS

A retrospective chart review of non-screened patients newly diagnosed with retinoblastoma between January 2007 and February 2018.

RESULTS

Among the 20 patients analyzed, 11 were diagnosed at an age younger than 1 year (group 1) and nine at 1 year or older (group 2). The mean lag times until diagnosis were 1.0 ± 0.4 and 5.0 ± 2.1 months for groups 1 and 2, respectively (p = 0.056). The mean follow-up durations were 49.4 ± 12.7 and 58.3 ± 8.8 months, respectively (p = 0.412). Group 1 had a significantly higher proportion of bilateral retinoblastoma than did group 2 (72.7% vs. 11.1%, p = 0.010). Four of five patients (80.0%) with germline RB1 mutations were diagnosed with retinoblastoma at age 3 months or younger. The eyes of patients in group 2 had significantly higher International Intraocular Retinoblastoma Classification stages than did those of patients in group 1 (p for trend = 0.010). The proportion of eyes with optic nerve invasion and those that had undergone enucleation were significantly higher in group 2 (p = 0.033 and 0.046, respectively). Survival did not differ according to the age at diagnosis.

CONCLUSIONS

Early onset retinoblastoma does not seem to indicate poor ocular or survival prognosis in Korean children with retinoblastoma.

Prognostic Impact of BRCA1 and BRCA2 Mutations on Long-Term Survival Outcomes in Egyptian Female Breast Cancer Patients

Evidence on the prognostic relevance of BRCA1/2 mutations on breast cancer survival is still debatable. To address this ambiguity, we sought to elucidate the impact of BRCA1/2 mutation carriership on long-term clinical outcomes for the first time in Egyptian female breast cancer patients. This study comprised 103 Egyptian female breast cancer patients previously tested for BRCA1/2 mutations. Clinicopathological characteristics and long-term follow-up data were retrieved from clinical records until death or loss to follow-up. Overall survival (OS), recurrence-free survival (RFS), disease-free survival (DFS), and metastasis-free survival (MFS) were compared in BRCA1/2 mutation carriers and non-carriers. Pathogenic variants (Class 5 according to ACMG/AMP guidelines) were observed in 29 cases. The profile of the detected variants was previously reported. After median follow-up time of 6.9 years (range, 4.2-24.4 years), BRCA1/2 carriers exhibited significantly worse RFS compared to non-carriers (p = 0.01; HR = 3.00 (95%CI 1.35-6.68)). However, we couldn't demonstrate statistically significant difference between carriers of pathogenic mutations and non-carriers regarding MFS (p = 0.24; HR = 1.38 (95%CI 0.8-2.4)), DFS (p = 0.11; HR = 1.23 (95%CI 0.74-2.06)), or OS (p = 0.36; HR = 1.23 (95%CI 0.58-2.61)). Though no significant impact was observed in OS, yet BRCA1/2 mutation carriers were at high risk of recurrence, highlighting the importance of adopting BRCA screening strategies and prophylactic measures.

BRCA1 and BRCA2 Variation in Taiwanese General Population and the Cancer Cohort

BRCA1 and BRCA2 (BRCA) play essential roles in maintaining genome stability. Rapidly evolving human BRCA generates oncogenic variants causing high cancer risk. BRCA variation is ethnic-specific in reflecting adaptation and/or effects of genetic drift. Taiwanese population of 23.8 million is an admixture of multiple ethnic origins; Taiwan's subtropical and tropical climate and geographically islandic location provide a unique natural environment. Therefore, Taiwanese population provides a unique model to study human BRCA variation. Through collecting, standardizing, annotating, and classifying publicly available BRCA variants derived from Taiwanese general population and the cancer cohort, we identified 335 BRCA variants, of which 164 were from 1,517 non-cancer individuals, 126 from 2,665 cancer individuals, and 45 from both types of individuals. We compared the variant data with those from other ethnic populations such as mainland Chinese, Macau Chinese, Japanese, Korean, Indian, and non-Asians. We observed that the sharing rates with other Asian ethnic populations were correlated with its genetic relationship. Over 60% of the 335 Taiwanese BRCA variants were VUS, unclassified variants, or novel variants, reflecting the ethnic-specific features of Taiwanese BRCA variation. While it remains challenging to classify these variants, our structural and in silico analyses predicted their enrichment of BRCA deleterious variants. We further determined the 3.8% prevalence of BRCA pathogenic variants in the Taiwanese breast cancer cohort, and determined 0.53% prevalence of the BRCA pathogenic variants in Taiwanese general population, with the estimated 126,140 BRCA pathogenic variant carriers. We identified BRCA2 c.5164_5165delAG at BRCA2 BRC6 motif as a potential founder mutation in Taiwanese population. Our study on BRCA variation in Taiwanese and other East Asian populations demonstrates that ethnic specificity is a common phenomenon for BRCA variation in East Asian population; the data generated from the study provide a reference for clinical applications in BRCA-related cancer in Taiwanese population.

Patterns and Prevalence of BRCA1 and BRCA2 Germline Mutations Among Patients with Triple-Negative Breast Cancer: Regional Perspectives

Background

Among all subtypes, patients with triple-negative (TN) breast cancer is known for their poor outcome and their higher risk of harboring BRCA1 or BRCA2 pathogenic mutations. Identification of such mutations has clinical impact on breast and ovarian cancer prevention and treatment decisions. We here report on patterns and prevalence of BRCA1 and BRCA2 mutations among Arab patients diagnosed with TN subtype.

Patients and Methods

Patients with TN-breast cancer (n=197) were enrolled regardless of their age or family history. Following a detailed genetic counseling, BRCA1/2 testing was performed at reference labs. BRCA1 and BRCA2 variants were classified as negative, pathogenic/likely pathogenic (positive) and variants of uncertain significance (VUS).

Results

Median age of enrolled patients was 42 (range, 19–74) years and 27 (13.7%) were non-Jordanian Arabs. Among the study group, 50 (25.4%) were tested positive for BRCA1 (n=36, 18.3%) or BRCA2 (n=14, 7.1%), while 14 (7.1%) others had VUS. Compared to older ones, mutation rates were higher among patients <40 years (32.9%, P= 0.034), those with close relatives with breast, ovarian, pancreatic or prostate cancer (37.8%, P=0.002) and those with two or more breast cancers (41.4%, P=0.032). Among eligible patients, 23 (63.9%) patients underwent prophylactic mastectomy, while 19 (52.8%) patients had risk-reducing salpingo-oophorectomy. None of the patients with VUS underwent any prophylactic surgery.

Conclusion

Arab patients with TN-breast cancer have relatively high BRCA1 or BRCA2 mutation rates. Young age at diagnosis and personal and family history of breast cancer further increase this risk.

DNA methylation variations in familial female and male breast cancer

In total, ~25% of familial breast cancer (BC) is attributed to germline mutations of the BRCA1 and BRCA2 genes, while the rest of the cases are included in the BRCAX group. BC is also known to affect men, with a worldwide incidence of 1%. Epigenetic alterations, including DNA methylation, have been rarely studied in male breast cancer (MBC) on a genome-wide level. The aim of the present study was to examine the global DNA methylation profiles of patients with BC to identify differences between familial female breast cancer (FBC) and MBC, and according to BRCA1, BRCA2 or BRCAX mutation status. The genomic DNA of formalin-fixed paraffin-embedded tissues from 17 women and 7 men with BC was subjected to methylated DNA immunoprecipitation and hybridized on human promoter microarrays. The comparison between FBC and MBC revealed 2,846 significant differentially methylated regions corresponding to 2,486 annotated genes. Gene Ontology enrichment analysis revealed molecular function terms, such as the GTPase superfamily genes (particularly the GTPase Rho GAP/GEF and GTPase RAB), and cellular component terms associated with cytoskeletal architecture, such as 'cytoskeletal part', 'keratin filament' and 'intermediate filament'. When only FBC was considered, several cancer-associated pathways were among the most enriched KEGG pathways of differentially methylated genes when the BRCA2 group was compared with the BRCAX or BRCA1+BRCAX groups. The comparison between the BRCA1 and BRCA2+BRCAX groups comprised the molecular function term 'cytoskeletal protein binding'. Finally, the functional annotation of differentially methylated genes between the BRCAX and BRCA1+BRCA2 groups indicated that the most enriched molecular function terms were associated with GTPase activity. In conclusion, to the best of our knowledge, the present study was the first to compare the global DNA methylation profile of familial FBC and MBC. The results may provide useful insights into the epigenomic subtyping of BC and shed light on a possible novel molecular mechanism underlying BC carcinogenesis.

Association between BRCA mutational status and survival in patients with breast cancer: a systematic review and meta-analysis

BACKGROUND

Studies evaluating role of BRCA mutations on the survival outcomes in breast cancer (BC) patients have given confounding results and hence, in this meta-analysis, we assessed the impact of BRCA mutations on survival in BC patients.

METHODS

Studies comparing survival outcomes of BC patients having BRCA mutations against wildtype BRCA phenotype were retrieved from PubMed, EMBASE, and Cochrane Library. Overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCCS) were the outcomes. Hazard ratio (HR) with 95% confidence interval (CI) was used for analysis. Subgroup analysis was performed for survival based on triple negative breast cancer (TNBC) and follow-up durations. The meta-analysis was performed as per PRISMA guidelines.

RESULTS

Altogether, 30 articles with 35,972 patients (mean age 45.6 years) were included. Patients with BRCA 1 mutation had significantly lower OS (HR [95% CI] 1.2 [1.08, 1.33]; P < 0.001), BRCA 2 mutation had significantly lower DFS (HR [95% CI] 1.35 [1.1, 1.67]; P = 0.0049) and BCSS (HR [95%CI] 1.46 [1.26, 1.7]; P < 0.0001), and TNBC patients with BRCA 1 mutation had significantly poor DFS (HR [95% CI] 1.65 [1.08, 2.54]; P = 0.0216). Based on follow-up duration, the OS in BRCA 1-mutated patients revealed significantly poorer outcomes in studies with ≤ 5 years (HR 1.48) and > 5 years (HR 1.14) of follow-up. In BRCA 2 -mutated patients, the OS was significantly poorer in studies with > 5 years of follow-up (HR 1.39, P < 0.05).

CONCLUSION

BC patients with BRCA 1 or BRCA 2 mutations had poor survival outcomes and hence screening patients with BC for BRCA mutations might help in strategizing their treatment and improving their survival.

Germline BRCA Mutation and Clinical Outcomes in Breast Cancer Patients Focusing on Survival and Failure Patterns: A Long-Term Follow-Up Study of Koreans

Background and Objectives: This study aimed to evaluate the effect of a BRCA mutation on survival and failure patterns, focusing on the risk of ipsilateral recurrence and contralateral breast cancer in patients. Materials and Methods: We retrospectively reviewed medical records of 300 patients with breast cancer who underwent genetic screening for BRCA1/2 genes and were treated at Samsung Medical Center between 1 January 2000 and 31 December 2010. Ultimately, clinical outcomes of 273 patients were analyzed. Results: The median follow-up duration was 102 months (range, 1 to 220 months). Patients with BRCA1/2-mutated tumors had a shorter 10-year disease-free survival (DFS) rate compared to those with non-mutated tumors (62.8% vs. 80.0%, p = 0.02). Regarding failure patterns, patients with BRCA1/2-mutated tumors showed a higher incidence of contralateral breast cancer than those with non-mutated tumors (BRCA1/2 non-mutated vs. mutated tumors: 4.9% vs. 26.0%, p < 0.001). BRCA mutation status remained a significant prognostic factor for contralateral breast recurrence-free survival (HR: 4.155; 95% CI: 1.789–9.652; p = 0.001). Korean patients with a BRCA mutation showed inferior DFS compared to those without a BRCA mutation. Conclusions: BRCA mutation status is a strong predictor of recurrence in contralateral breast cancer. Strategies such as prophylactic treatment and active surveillance should be discussed with breast cancer patients who have a BRCA mutation.

Mutation in Exon2 of BRCA1 Gene in Adult Bengali Bangladeshi Female Patients with Breast Cancer: An Experience from Two Tertiary-Care Hospitals

Background:

The occurrence rate of BRCA1 mutations is found to be high in South Asian countries where early onset of breast cancer is common. In Bangladesh, noticeable percentage of patients experience breast cancer in their reproductive ages. The objective of this study was to identify any mutation in exon2 of the BRCA1 gene in adult Bengali Bangladeshi female patients with breast cancer.

Methods:

In this cross-sectional descriptive study, the genomic DNA was extracted from the blood of adult fifty Bengali Bangladeshi female breast cancer patients. The whole region of exon2 of the BRCA1 gene was amplified and the amplified DNA products were sequenced using Sanger sequencing. The raw chromatogram data were analyzed using Chromas software, and analyzed sequences were compared with the NCBI RefSeq database by BLAST search. The resultant amino acid change was detected by MEGA X software.

Results:

We found the mean age at diagnosis 44.66 years, whereas 96% of patients were married, 90% were multiparous and 86% breastfed their children. All patients had unilateral breast cancer and among them 94% had invasive ductal carcinoma. Only 24.5% of the patients had associated omorbidity. The family history of breast cancer or other BRCA-associated cancer was positive only for 4% of patients. A total of five mutations were identified all of which caused by substitutions. Among them three were nonsynonymous and two were synonymous. Only 2.5% of the patients, within the age group of 18-50 years, were found to have mutations in their blood, whereas 26.66% of the patients above 50 years found to have mutations in this study.

Conclusions:

Among this small sample size, we found five mutations in exon2 of the BRCA1 gene and this indicates the necessity to find out the mutation spectra of the BRCA1 gene in the Bangladeshi population.

Enhance PARPi Application beyond BRCA-Mutant Breast Cancer (BC): Facts Are Facts

Breast cancer (BC) represents one of the three most common neoplasia and the principal worldwide leading cause of death among women [...].

Summary of BARD1 Mutations and Precise Estimation of Breast and Ovarian Cancer Risks Associated with the Mutations

Over the last two decades, numerous BARD1 mutations/pathogenic variants (PVs) have been found in patients with breast cancer (BC) and ovarian cancer (OC). However, their role in BC and OC susceptibility remains controversial, and strong evidence-based guidelines for carriers are not yet available. Herein, we present a comprehensive catalog of BARD1 PVs identified in large cumulative cohorts of ~48,700 BC and ~20,800 OC cases (retrieved from 123 studies examining the whole coding sequence of BARD1). Using these resources, we compared the frequency of BARD1 PVs in the cases and ~134,100 controls from the gnomAD database and estimated the effect of the BARD1 PVs on BC and OC risks. The analysis revealed that BARD1 is a BC moderate-risk gene (odds ratio (OR) = 2.90, 95% CIs:2.25–3.75, p < 0.0001) but not an OC risk gene (OR = 1.36, 95% CIs:0.87–2.11, p = 0.1733). In addition, the BARD1 mutational spectrum outlined in this study allowed us to determine recurrent PVs and evaluate the variant-specific risk for the most frequent PVs. In conclusion, these precise estimates improve the understanding of the role of BARD1 PVs in BC and OC predisposition and support the need for BARD1 diagnostic testing in BC patients.