A systematic review of the international prevalence of BRCA mutation in breast cancer

Talazoparib in Patients With Solid Tumors With BRCA1/2 Mutation: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a phase II basket trial evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancer and genomic alterations known to be drug targets. Results of a cohort of patients with various solid tumors with germline or somatic BRCA1/2 mutations treated with talazoparib are reported.

METHODS

Eligible patients had advanced solid tumors, measurable disease (RECIST), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. Patients with germline BRCA-mutated human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer were not eligible for this study. Primary end point was disease control (DC) determined by investigator assessment of objective response (OR) or stable disease (SD) of at least 16 weeks duration (SD16+). The results were evaluated on the basis of a one-sided exact binomial test with a null DC rate of 15% versus 35% (power = 0.82; α = .10). Secondary end points were OR, progression-free survival, overall survival, duration of response, duration of SD, and safety.

RESULTS

Twenty-eight patients (20 cancer types) with BRCA1/2 mutations were enrolled from December 2019 to September 2021 and collapsed into a single histology pooled cohort for analysis. All patients were evaluable for efficacy. One complete response, nine partial response, and six SD16+ were observed for DC and OR rates of 57% (one-sided 90% CI, 43 to 100) and 36% (95% CI, 19 to 56), respectively. The null hypothesis of a 15% DC rate was rejected (P < .001). Patients with OR had the following tumor types: breast (2), nonmelanoma skin, mesothelioma, stomach, uterus, non-small cell lung cancer, ovary, hepatocellular carcinoma, and pancreas. Thirteen patients had at least one grade 3-5 adverse event (AE) or serious AE at least possibly related to talazoparib. All were consistent with the drug label except bilirubin increase and hyponatremia (both grade 3 AEs).

CONCLUSION

Talazoparib demonstrated antitumor activity in patients with advanced solid tumors and BRCA1/2 mutations, including cancer types for which poly ADP-ribose polymerase inhibitors are not yet US Food and Drug Administration-approved.

Incidental pathogenic germline alterations detected through liquid biopsy in patients with solid tumors: prevalence, clinical utility and implications

Liquid biopsy, a minimally invasive approach for detecting tumor biomarkers in blood, has emerged as a leading-edge technique in cancer precision medicine. New evidence has shown that liquid biopsies can incidentally detect pathogenic germline variants (PGVs) associated with cancer predisposition, including in patients with a cancer for which genetic testing is not recommended. The ability to detect these incidental PGV in cancer patients through liquid biopsy raises important questions regarding the management of this information and its clinical implications. This incidental identification of PGVs raises concerns about cancer predisposition and the potential impact on patient management, not only in terms of providing access to treatment based on the tumor molecular profiling, but also the management of revealing genetic predisposition in patients and families. Understanding how to interpret this information is essential to ensure proper decision-making and to optimize cancer treatment and prevention strategies. In this review we provide a comprehensive summary of current evidence of incidental PGVs in cancer predisposition genes identified by liquid biopsy in patients with cancer. We critically review the methodological considerations of liquid biopsy as a tool for germline diagnosis, clinical utility and potential implications for cancer prevention, treatment, and research.

Concordance between an FDA-approved companion diagnostic and an alternative assay kit for assessing homologous recombination deficiency in ovarian cancer

OBJECTIVE

Authors evaluated the performance of a commercially available next-generation sequencing assay kit; this was based on genomic content from Illumina's TruSight™ Oncology 500 research assay that identifies BRCA variants and proprietary algorithms licensed from Myriad and, with additional genomic content, measures the homologous recombination deficiency (HRD) genomic instability score (GIS) in tumor tissue (TSO 500 HRD assay).

METHODS

Data from the TSO 500 HRD assay were compared with data from the Myriad MyChoice®CDx PLUS assay (Myriad assay). Prevalence rates for overall HRD status and BRCA mutations (a deleterious or suspected deleterious BRCA1 or BRCA2 mutation or both) and assay agreement rates for HRD GIS and BRCA analysis were assessed in ovarian tumor samples. Pearson correlations of the continuous HRD GIS and analytic sensitivity and specificity were evaluated.

RESULTS

The prevalence of overall HRD positivity was 51.2% (TSO 500 HRD assay) versus 49.2% (Myriad assay) and the prevalence of BRCA mutations was 27.6% (TSO 500 HRD assay) versus 25.5% (Myriad assay). After post-processing optimization, concordance of the HRD GIS was 0.980 in all samples and 0.976 in the non-BRCA mutation cohort; the area under the receiver operating characteristic curve was 0.995 and 0.992, respectively.

CONCLUSIONS

Comparison between the Illumina and Myriad assays showed that overall HRD status, the individual components of BRCA analysis, and HRD GIS detection results were highly concordant (>93%), suggesting the TSO 500 HRD assay will approach the analytical accuracy of the FDA-approved Myriad assay.

Real-world overall survival and characteristics of patients with ER-zero and ER-low HER2-negative breast cancer treated as triple-negative breast cancer: a Swedish population-based cohort study

Background

Estrogen receptor-low (ER-low) HER2-negative breast cancer has similar pathological and molecular characteristics as triple-negative breast cancer (TNBC), and it is questionable whether it should be considered a separate entity. When the international guidelines lowered the cutoff for ER positivity to ≥1% in 2010, the ≥10% threshold was kept in Sweden. ER-low breast cancer (ER 1-9%) is thus in Sweden treated as TNBC. We aimed to describe patient and tumor characteristics, treatment patterns and overall survival in a Swedish population-based cohort of patients with ER-zero and ER-low HER2-negative breast cancer treated as TNBC.

Methods

All TNBC cases diagnosed in Sweden 2008-2020 were included in a population-based cohort study. Patient, tumor and treatment characteristics were analyzed by ER-status (ER 0% vs 1-9%), and associations between subgroups compared using χ2 test. Survival endpoint was overall survival (OS), and Kaplan-Meier curves were estimated. Cox proportional hazards models were used to estimate adjusted hazard ratios comparing ER-low to ER-zero.

Findings

Of the 5655 tumors, 90.1% had an ER expression of 0%, while 9.9% were ER-low. ER-low tumors were grade III in 69.4% (80.8% in ER-zero tumors, p-value = 0.001), with a median Ki67 of 60% (63% in ER-zero tumors, p-value = 0.005). There were no significant differences in given chemotherapy (p = 0.546). A pathological complete response (pCR) was achieved in 28.1% of ER-low tumors (25.1% in ER-zero tumors). In the unadjusted analysis of OS, women with ER-low disease had a borderline but not significantly better OS than those with ER-zero disease (HR 0.84 (95% CI 0.71-1.00), p = 0.052). ER-status 1-9% vs 0% was not associated with OS in the multivariable analysis (HR 1.11 (0.90-1.36)). Distant disease-free survival did not differ by ER-status 0% vs 1-9% (HR 0.97 for ER-zero vs ER-low (0.62-1.53), p = 0.905). After preoperative treatment, the impact of pCR for OS did not significantly differ between ER-zero or ER-low disease.

Interpretation

ER-low HER2-negative breast cancer has characteristics and prognosis similar to TNBC, when treated in the same way. Therefore, it seems reasonable to use a ≥10% threshold for ER positivity. This would provide patients with ER-low tumors the same treatment opportunities as patients with TNBC, within studies and within clinical routine.

Funding

This work was financially supported by Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, in accordance with terms and conditions of a Master Collaboration Agreement between the company and Karolinska Institutet.

Macronutrient composition of plant-based diets and breast cancer risk: the E3N prospective cohort study

PURPOSE

Recent evidence suggests that plant-based diets may reduce the risk of breast cancer (BC). However, the macronutrient composition of plant-based diets and its potential impact on BC risk has not been well explored. This analysis investigated the association of macronutrient composition with BC risk across a spectrum of plant-based diet indexes using a multidimensional approach.

DESIGN

This study followed 64,655 participants from the Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (E3N) cohort from 1993 to 2014. Diets were evaluated using validated 208-item diet history questionnaires at baseline (1993) and follow-up (2005), to calculate adherence to the overall plant-based diet (PDI), healthful plant-based diet (hPDI), and unhealthful plant-based diet (uPDI). The association of macronutrient composition with BC risk was assessed via generalized additive time-dependent Cox models across different levels of these indexes. Response surfaces were generated to visualize compositional associations at the 25th, 50th, and 75th percentile of each index (low, moderate, and high).

RESULTS

A total of 3,932 incident BC cases were identified during the 21-year follow-up. There was a significant association between macronutrient composition and BC risk for hPDI, uPDI, and PDI (all P < 0.001). Akaike information criterion favored the hPDI model for characterizing the association between macronutrients and BC. BC risk was highest for individuals with a lower hPDI score who also consumed a diet containing lower protein (10%), lower carbohydrate (35%), and higher fat (55%). The lowest risk of BC was observed in those with higher hPDI scores with the lowest intake of protein (10%). At higher PDI and uPDI, diets containing higher protein (30%) and fat (45%) had the highest BC risk.

CONCLUSION

These results demonstrate a complex relationship between macronutrient composition, plant-based diet quality, and BC risk. Further research is needed to examine specific foods that may be driving these associations.

REGISTRY

The protocol is registered at clinicaltrials.gov as NCT03285230.

Comprehensive germline profiling of patients with breast cancer: initial experience from a Familial Cancer Clinic

Introduction

Breast cancer is the most common cancer among Indian females. There is limited data on germline profiling of breast cancer patients from India.

Objective

The objective of the current study was to analyse the frequency and spectrum of germline variant profiles and clinicopathological characteristics of breast cancer patients referred to our Familial Cancer Clinic (FCC).

Materials and methods

It is a single-centre audit of patients with a confirmed diagnosis of breast carcinoma referred to our FCC from January 2017 to 2020. All patients underwent pretest counselling. Genetic testing was done by multigene panel testing by next-generation sequencing along with reflex multiplication ligation-dependent probe amplification for BRCA1 and 2. The variants were classified based on American College of Medical Genetics guidelines. Demographic and clinicopathological details were extracted from the case record files.

Results

One hundred and fifty-five patients were referred to the FCC and underwent pretest counselling. A total of 99 (63.9%) patients underwent genetic testing. Among them, 62 patients (62/99 = 62.6%) had a germline variant. A pathogenic/likely pathogenic (P/LP) germline variant was identified in 41 (41.4%) of the patients who underwent testing. Additional variants of unknown significance (VUS) were identified in seven patients who also carried a P/LP variant. VUS alone was detected in 21 patients (21/99 = 21.2%). Among the P/LP pathogenic variants (PV), BRCA 1 PV were seen in 27 patients (65.8%), BRCA 2 variants in 7 patients (17.1%), ATM variants in 3 patients (7.3%) and RAD51, TP53, CHEK2 and HMMR in 1 patient each. Variants were significantly more common in patients with a family history (FH) of malignancy than those without FH (58.5% versus 29.5%; p = 0.013). Age and triple-negative histology were not found to be significantly associated with the occurrence of P/LP PVs.

Conclusion

We report a 41% P/LP variant rate in our selected cohort of breast cancer patients, with variants in BRCA constituting 83% and non-BRCA gene variants constituting 17%.

A nomogram model combining ultrasound-based radiomics features and clinicopathological factors to identify germline BRCA1/2 mutation in invasive breast cancer patients

Objective

BRCA1/2 status is a key to personalized therapy for invasive breast cancer patients. This study aimed to explore the association between ultrasound radiomics features and germline BRCA1/2 mutation in patients with invasive breast cancer.

Materials and methods

In this retrospective study, 100 lesions in 92 BRCA1/2-mutated patients and 390 lesions in 357 non-BRCA1/2-mutated patients were included and randomly assigned as training and validation datasets in a ratio of 7:3. Gray-scale ultrasound images of the largest plane of the lesions were used for feature extraction. Maximum relevance minimum redundancy (mRMR) algorithm and multivariate logistic least absolute shrinkage and selection operator (LASSO) regression were used to select features. The multivariate logistic regression method was used to construct predictive models based on clinicopathological factors, radiomics features, or a combination of them.

Results

In the clinical model, age at first diagnosis, family history of BRCA1/2-related malignancies, HER2 status, and Ki-67 level were found to be independent predictors for BRCA1/2 mutation. In the radiomics model, 10 significant features were selected from the 1032 radiomics features extracted from US images. The AUCs of the radiomics model were not inferior to those of the clinical model in both training dataset [0.712 (95% CI, 0.647-0.776) vs 0.768 (95% CI, 0.704-0.835); p = 0.429] and validation dataset [0.705 (95% CI, 0.597-0.808) vs 0.723 (95% CI, 0.625-0.828); p = 0.820]. The AUCs of the nomogram model combining clinical and radiomics features were 0.804 (95% CI, 0.748-0.861) in the training dataset and 0.811 (95% CI, 0.724-0.894) in the validation dataset, which were proved significantly higher than those of the clinical model alone by DeLong's test (p = 0.041; p = 0.007). To be noted, the negative predictive values (NPVs) of the nomogram model reached a favorable 0.93 in both datasets.

Conclusion

This machine nomogram model combining ultrasound-based radiomics and clinical features exhibited a promising performance in identifying germline BRCA1/2 mutation in patients with invasive breast cancer and may help avoid unnecessary gene tests in clinical practice.

Primary Peritoneal Carcinosarcoma in a Breast Cancer Patient Harboring a Germline BRCA2 Pathogenic Variant: Case Report

Malignant mixed müllerian tumor (MMMT) is a rare neoplasm, consisting of carcinomatous (epithelial) and sarcomatous (mesenchymal) components that most commonly arise in the endometrium and more infrequently in the ovaries, fallopian tube, cervix, and vagina. Primary peritoneal carcinosarcoma (PPCS) is an extremely rare extragenital presentation of MMMT. Although the occurrence of breast cancer and epithelial ovarian carcinoma in association with BRCA pathogenic variants is firmly established, the etiologic role of these genes in the development of other tumor types is less well known. Here, we present a rare case of PPCS in a 42-year-old Brazilian woman with a BRCA2 pathogenic variant, c.2808_2811del (NM_000059.3). The patient developed metastatic breast cancer at the age of 37 and underwent a risk-reducing bilateral salpingo-oophorectomy 2 years later. She was then diagnosed with PPCS 3 years after the risk-reducing surgery. She underwent treatment with surgery, chemotherapy, and targeted therapy but passed away almost 5 years after the second primary tumor diagnosis. To our knowledge, this is the first case of peritoneal carcinosarcoma described in a BRCA2 pathogenic variant carrier, and its report leads to a better understanding of the disease's molecular features and possible therapeutic approaches.

Recent trends in hereditary breast cancer incidence by race and age in KwaZulu-Natal, South Africa: An 11-year single-centre retrospective study (2011-2021)

Breast cancer incidence has increased globally in the last decade, especially in low- and middle-income countries. In Sub-Saharan Africa, breast cancer trends have been described only in a few populations owing to the scarcity of population-specific data. Using data collected between 2011 and 2021 at Inkosi Albert Luthuli Central Hospital, this retrospective study describes demographic and genetic trends for hereditary breast cancer patients in the KwaZulu-Natal province, South Africa. Six hundred and forty-five patients were included, of whom 44.3% were Black, 36.8% Indian, 15.6% White and 3.2% Coloured. The number of annual new cases increased from eight in 2011 to 145 in 2021, with a notable increase among Blacks. The mean onset age was 46 years, and Black patients were diagnosed ~10 years earlier than White and Indian patients. Triple-negative breast cancers accounted for 20.3% of hereditary cases, and 51.1% of them were Black. Bilateral and recurrent breast cancers constituted 7.4%, while pathogenic sequence variants in BRCA1/2 were reported in 10.4% of all patients, and the majority were Blacks and Indians. Overall, the KwaZulu-Natal province has seen an increase in hereditary breast cancer incidence in the past decade. Despite testing negative for pathogenic sequence variants, Black women frequently presented with breast cancers that are BRCA1-like, while Indians presented with extensive family history. This suggests that South African patients may require unique approaches to interventions, such as early detection and awareness programs among Blacks and increased genetic screening among Indians.

Emerging evidence on the role of breast microbiota on the development of breast cancer in high-risk patients

Cancer is a multi-factorial disease, and the etiology of breast cancer (BC) is due to a combination of both genetic and environmental factors. Breast tissue shows a unique microbiota, Proteobacteria and Firmicutes are the most abundant bacteria in breast tissue, and several studies have shown that the microbiota of healthy breast differs from that of BC. Breast microbiota appears to be correlated with different characteristics of the tumor, and prognostic clinicopathologic features. It also appears that there are subtle differences between the microbial profiles of the healthy control and high-risk patients. Genetic predisposition is an extremely important risk factor for BC. BRCA1/2 germline mutations and Li-Fraumeni syndrome are DNA repair deficiency syndromes inherited as autosomal dominant characters that substantially increase the risk of BC. These syndromes exhibit incomplete penetrance of BC expression in carrier subjects. The action of breast microbiota on carcinogenesis might explain why women with a mutation develop cancer and others do not. Among the potential biological pathways through which the breast microbiota may affect tumorigenesis, the most relevant appear to be DNA damage caused by colibactin and other bacterial-derived genotoxins, β-glucuronidase-mediated estrogen deconjugation and reactivation, and HPV-mediated cancer susceptibility. In conclusion, in patients with a genetic predisposition, an unfavorable breast microbiota may be co-responsible for the onset of BC. Prospectively, the ability to modulate the microbiota may have an impact on disease onset and progression in patients at high risk for BC.

Cross-Cultural Adaptation and Psychometric Validation of the Interview Satisfaction Questionnaire (ISQ) to Assess Unmet Health Communication Needs of Iranian Breast Cancer Patients

Autonomous and patient-centered health communication (PCHC) between a healthcare provider (HCP) and a client (HCC) is a critical fundament for successful healthcare outcomes. A standard and validated data collection tool for studying the satisfaction of Iranian breast cancer patients (BCPs) with various aspects of their health communication with HCPs does not exist. The current study assessed the application, feasibility, and cultural appropriateness of the Persian-translated version of the interview satisfaction questionnaire (ISQ) in the Iranian context. A standard translation/back-translation procedure was used to prepare a preliminary Persian version of the ISQ (ISQ-P) which was then evaluated for content and face validity by a panel of experts. The study data were collected from 200 breast cancer patients and used to estimate the internal consistency measure of Cronbach's alpha and intra-class correlation coefficient. Confirmatory factor analysis (CFA) was performed to verify the compatibility of the instrument's identified dimensions with the original ISQ's factor structure. The calculated content validity index (CVI = 0.89), content validity ratio (CVR = 0.49), and Cronbach's alpha coefficient (0.79) indicated the appropriateness of the ISQ-P for its intended purpose. The CFA's outputs (root mean square error of approximation (RMSEA) = 0.09, comparative fit index (CFI) = 0.954, Tucker-Lewis index (TLI) = 0.931, standardized root mean square residual (SRMR) = 0.04) affirmed the fitness of the study data to the original 4-factor conceptual model. The study findings supported the suitability of ISQ-P for assessing health communication episodes by Persian-speaking BCPs. However, due to cultural variation, cross-border diversity of health systems, and organizational circumstances, further validity and reliability appraisal of the ISQ-P in distinct sub-samples is recommended.

PSPC1 Inhibition Synergizes with Poly(ADP-ribose) Polymerase Inhibitors in a Preclinical Model of BRCA-Mutated Breast/Ovarian Cancer

Poly (ADP-ribose) polymerase (PARP) inhibitors are effective against BRCA1/2-mutated cancers through synthetic lethality. Unfortunately, most cases ultimately develop acquired resistance. Therefore, enhancing PARP inhibitor sensitivity and preventing resistance in those cells are an unmet clinical need. Here, we investigated the ability of paraspeckle component 1 (PSPC1), as an additional synthetic lethal partner with BRCA1/2, to enhance olaparib sensitivity in preclinical models of BRCA1/2-mutated breast and ovarian cancers. In vitro, the combined olaparib and PSPC1 small interfering RNA (siRNA) exhibited synergistic anti-proliferative activity in BRCA1/2-mutated breast and ovarian cancer cells. The combination therapy also demonstrated synergistic tumor inhibition in a xenograft mouse model. Mechanistically, olaparib monotherapy increased the expressions of p-ATM and DNA-PKcs, suggesting the activation of a DNA repair pathway, whereas combining PSPC1 siRNA with olaparib decreased the expressions of p-ATM and DNA-PKcs again. As such, the combination increased the formation of γH2AX foci, indicating stronger DNA double-strand breaks. Subsequently, these DNA-damaged cells escaped G2/M checkpoint activation, as indicated by the suppression of p-cdc25C (Ser216) and p-cdc2 (Tyr15) after combination treatment. Finally, these cells entered mitosis, which induced increased apoptosis. Thus, this proves that PSPC1 inhibition enhances olaparib sensitivity by targeting DNA damage response in our preclinical model. The combination of olaparib and PSPC1 inhibition merits further clinical investigation to enhance PARP inhibitor efficacy.

The Landscape of BRCA Mutations among Egyptian Women with Breast Cancer

BACKGROUND

Deleterious germline mutations in BRCA1 and BRCA2 genes are associated with a high risk of breast and ovarian cancer. In many developing countries, including Egypt, the prevalence of BRCA1/2 mutations among women with breast cancer (BC) is unknown.

AIM

We aimed to determine the prevalence of deleterious germline BRCA mutations in Egyptian patients with breast cancer.

METHODS

We report the results of a cohort study of 81 Egyptian patients with breast cancer who were tested for germline BRCA1/2 mutations during routine clinical practice, mostly for their young age of presentation, BC subtype, or presence of family history. In addition, we searched five databases to retrieve studies that reported the prevalence of BRCA1/2 mutation status in Egyptian women with BC. A systematic review of the literature was performed, including prospective and retrospective studies.

RESULTS

In our patient cohort study, 12 patients (14.8%) were positive for either BRCA1/2 deleterious mutations. Moreover, 13 (16.1%) patients had a variant of unknown significance (VUS) of BRCA1/2 genes. Twelve studies were eligible for the systematic review, including 610 patients. A total of 19 deleterious germline mutations in BRCA1/2 were identified. The pooled prevalence of BRCA1/2 mutations was 40% (95% confidence interval 1-80%).

CONCLUSION

The reported prevalence was highly variable among the small-sized published studies that adopted adequate techniques. In our patient cohort, there was a high incidence of VUS in BRCA1/2 genes. Accordingly, there is an actual demand to conduct a prospective well-designed national study to accurately estimate the prevalence of BRCA1/2 mutations among patients with BC in Egypt.

Performance of a RAD51-based functional HRD test on paraffin-embedded breast cancer tissue

PURPOSE

BRCA-deficient breast cancers (BC) are highly sensitive to platinum-based chemotherapy and PARP inhibitors due to their deficiency in the homologous recombination (HR) pathway. However, HR deficiency (HRD) extends beyond BRCA-associated BC, highlighting the need for a sensitive method to enrich for HRD tumors in an alternative way. A promising approach is the use of functional HRD tests which evaluate the HR capability of tumor cells by measuring RAD51 protein accumulation at DNA damage sites. This study aims to evaluate the performance of a functional RAD51-based HRD test for the identification of HRD BC.

METHODS

The functional HR status of 63 diagnostic formalin-fixed paraffin-embedded (FFPE) BC samples was determined by applying the RAD51-FFPE test. Samples were screened for the presence of (epi)genetic defects in HR and matching tumor samples were analyzed with the RECAP test, which requires ex vivo irradiated fresh tumor tissue on the premise that the HRD status as determined by the RECAP test faithfully represented the functional HR status.

RESULTS

The RAD51-FFPE test identified 23 (37%) of the tumors as HRD, including three tumors with pathogenic variants in BRCA1/2. The RAD51-FFPE test showed a sensitivity of 88% and a specificity of 76% in determining the HR-class as defined by the RECAP test.

CONCLUSION

Given its high sensitivity and compatibility with FFPE samples, the RAD51-FFPE test holds great potential to enrich for HRD tumors, including those associated with BRCA-deficiency. This potential extends to situations where DNA-based testing may be challenging or not easily accessible in routine clinical practice. This is particularly important considering the potential implications for treatment decisions and patient stratification.

Molecularly Targeted Therapies for Triple Negative Breast Cancer: History, Advances, and Future Directions

Triple negative breast cancer (TNBC) remains the subtype with poorest prognosis. Despite the subtype's heterogeneity, there is still a paucity in effective targeted therapeutics that offer both good efficacy and tolerability, and chemotherapy remains the backbone of modern TNBC therapy. In the past few years, immunotherapy as well as novel therapeutic modalities like antibody-drug conjugates (ADCs) have shown clinical benefit and have been FDA approved in various clinical stages of unselected TNBC. However, there has not been similar advancement in molecularly targeted therapies, especially when compared to advancements seen in hormone receptor (HR)-positive or HER2-positive breast cancer. PARP inhibitors have been approved for BRCA-mutated TNBC, but responses are short-lived, and resistance remains a barrier for current treatment. PI3K pathway inhibitors approved in HR+ breast cancer has not worked for TNBC and continue to have significant dose-limiting adverse effects. EGFR inhibition has been thoroughly explored in TNBC, but all trials so far have shown minimal efficacy. Nevertheless, despite these setbacks, current research in targeted therapy for TNBC holds great promise in overcoming the barriers of the past and developing novel therapeutic approaches for the future. In this review, we describe molecular targets both identified and validated in the treatment of TNBC, discuss the historical efforts towards development of targeted agents and current areas of improvement, and address promising advances that have the potential to improve outcomes in this heterogenous and aggressive breast cancer subtype. Immunotherapy, ADCs, and AR targeting will be discussed in separate reviews of this edition.

Evaluation of European-based polygenic risk score for breast cancer in Ashkenazi Jewish women in Israel

BACKGROUND

Polygenic risk score (PRS), calculated based on genome-wide association studies (GWASs), can improve breast cancer (BC) risk assessment. To date, most BC GWASs have been performed in individuals of European (EUR) ancestry, and the generalisation of EUR-based PRS to other populations is a major challenge. In this study, we examined the performance of EUR-based BC PRS models in Ashkenazi Jewish (AJ) women.

METHODS

We generated PRSs based on data on EUR women from the Breast Cancer Association Consortium (BCAC). We tested the performance of the PRSs in a cohort of 2161 AJ women from Israel (1437 cases and 724 controls) from BCAC (BCAC cohort from Israel (BCAC-IL)). In addition, we tested the performance of these EUR-based BC PRSs, as well as the established 313-SNP EUR BC PRS, in an independent cohort of 181 AJ women from Hadassah Medical Center (HMC) in Israel.

RESULTS

In the BCAC-IL cohort, the highest OR per 1 SD was 1.56 (±0.09). The OR for AJ women at the top 10% of the PRS distribution compared with the middle quintile was 2.10 (±0.24). In the HMC cohort, the OR per 1 SD of the EUR-based PRS that performed best in the BCAC-IL cohort was 1.58±0.27. The OR per 1 SD of the commonly used 313-SNP BC PRS was 1.64 (±0.28).

CONCLUSIONS

Extant EUR GWAS data can be used for generating PRSs that identify AJ women with markedly elevated risk of BC and therefore hold promise for improving BC risk assessment in AJ women.

Implications of a Supernumerary Nipple Breast Cancer in a BReast CAncer Sequence Variation Carrier: A Case Report

Supernumerary nipples develop on the chest and abdominopelvic regions along the embryonic milk line. Their anatomy varies from isolated accessory nipples to complete supernumerary nipples (accessory nipple, areola, and underlying glandular breast tissue). Patients with a pathogenic BReast CAncer (BRCA) sequence variation are at an increased cumulative risk of developing breast cancer, and it is the standard of care for them to be offered medical or surgical risk reduction. Given the relatively low prevalence of breast cancer within supernumerary nipples and ectopic glandular breast tissue, no current recommendations exist to guide multidisciplinary management of patients with BRCA sequence variations and ectopic breast tissue. Our case is of a 62-year-old female BRCA-1 carrier with a previous history of right breast cancer who developed a new primary breast cancer within a supernumerary nipple after undergoing surgical risk reduction. With no current consensus on the surgical management of supernumerary nipples in BRCA-1 carriers, our recommendation is to perform a thorough physical examination before risk-reducing operation. If supernumerary nipples or ectopic glandular breast tissue are present, wide-local excision of the tissue should be offered for more complete surgical risk reduction.

Management of breast cancer patients with BRCA gene mutations in Jordan: perspectives and challenges

BACKGROUND

This paper explores and discusses local challenges oncologists face for diagnosing and managing breast cancer patients with BRCA gene mutations in Jordan.

METHODS

A task force involving key opinion leaders, experts in the management of breast cancer, and stakeholders in healthcare systems where genetic testing is available in Jordan discussed current evidence and local real-life practice. The task force then formulated recommendations to achieve better patient outcomes and satisfaction based on evidence-based medicine and their clinical experience in BRCA-mutated breast cancer management.

RESULTS AND CONCLUSION

Eligibility of patients for genetic testing, physician acceptance and willingness to integrate genetic testing into routine practice is encouraging but remains restricted by testing availability and financial coverage. Until more data is available, genetic testing should be targeted for breast cancer patients based on tumor subtypes, as well as family and personal history of cancer, as per international guidelines. Whenever possible, genetic testing should aim to detect all actionable genes through a multigene panel including BRCA1/2. Major challenges faced in clinical practice in Jordan include fear of genetic discrimination and social stigmatization, as well as hesitancy toward risk-reducing surgery. Pre-testing counseling is therefore critical to promote acceptance of genetic testing. Since geneticists are in short supply in Jordan, genetic counseling can be offered through a specially trained genetic counselor or through a hybrid system that includes oncologist-based counselling. In addition to cancer prevention, germline genetic testing may assist in the selection of specific anti-cancer therapy, such as PARP inhibitors, in patients with BRCA1/2 mutation. Nationwide initiatives are also needed to ensure access to PARP inhibition therapy and provide financial coverage for genetic screening, mastectomies and reconstructive surgery across Jordan.

Investigation of germline variants in Bahraini women with breast cancer using next-generation sequencing based-multigene panel

Germline variants in BRCA1 and BRCA2 (BRCA1/2) genes are the most common cause of hereditary breast cancer. However, a significant number of cases are not linked to these two genes and additional high-, moderate- and low-penetrance genes have been identified in breast cancer. The advent of next-generation sequencing (NGS) allowed simultaneous sequencing of multiple cancer-susceptibility genes and prompted research in this field. So far, cancer-predisposition genes other than BRCA1/2 have not been studied in the population of Bahrain. We performed a targeted NGS using a multi-panel covering 180 genes associated with cancer predisposition to investigate the spectrum and frequency of germline variants in 54 women with a positive personal and/or family history of breast cancer. Sequencing analysis revealed germline variants in 29 (53.7%) patients. Five pathogenic/likely pathogenic variants in four DNA repair pathway-related genes were identified in five unrelated patients (9.3%). Two BRCA1 variants, namely the missense variant c.287A>G (p.Asp96Gly) and the truncating variant c.1066C>T (p.Gln356Ter), were detected in two patients (3.7%). Three variants in non-BRCA1/2 genes were detected in three patients (1.85% each) with a strong family history of breast cancer. These included a monoallelic missense variant c.1187G>A (p.Gly396Asp) in MUTYH gene, and two truncating variants namely c.3343C>T (p.Arg1115Ter) in MLH3 gene and c.1826G>A (p.Trp609Ter) in PMS1 gene. Other variants of uncertain significance (VUS) were also detected, and some of them were found together with the deleterious variants. In this first application of NGS-based multigene testing in Bahraini women with breast cancer, we show that multigene testing can yield additional genomic information on low-penetrance genes, although the clinical significance of these genes has not been fully appreciated yet. Our findings also provide valuable epidemiological information for future studies and highlight the importance of genetic testing, and an NGS-based multigene analysis may be applied supplementary to traditional genetic counseling.

Ex Vivo Chromosomal Radiosensitivity Testing in Patients with Pathological Germline Variants in Breast Cancer High-Susceptibility Genes BReast CAncer 1 and BReast CAncer 2

BACKGROUND

Individual radiosensitivity is an important factor in the occurrence of undesirable consequences of radiotherapy. The potential for increased radiosensitivity has been linked to highly penetrant heterozygous mutations in DNA repair genes such as BRCA1 and BRCA2. By studying the chromosomal radiosensitivity of BRCA1/2 mutation carriers compared to the general population, we study whether increased chromosomal radiation sensitivity is observed in patients with BRCA1/2 variants.

METHODS

Three-color-fluorescence in situ hybridization was performed on ex vivo-irradiated peripheral blood lymphocytes from 64 female patients with a heterozygous germline BRCA1 or BRCA2 mutation. Aberrations in chromosomes #1, #2 and #4 were analyzed. Mean breaks per metaphase (B/M) served as the parameter for chromosomal radiosensitivity. The results were compared with chromosomal radiosensitivity in a cohort of generally healthy individuals and patients with rectal cancer or breast cancer.

RESULTS

Patients with BRCA1/2 mutations (n = 64; B/M 0.47) overall showed a significantly higher chromosomal radiosensitivity than general healthy individuals (n = 211; B/M 0.41) and patients with rectal cancer (n = 379; B/M 0.44) and breast cancer (n = 147; B/M 0.45) without proven germline mutations. Chromosomal radiosensitivity varied depending on the locus of the BRCA1/2 mutation.

CONCLUSIONS

BRCA1/2 mutations result in slightly increased chromosomal sensitivity to radiation. A few individual patients have a marked increase in radiation sensitivity. Therefore, these patients are at a higher risk for adverse therapeutic consequences.

Which Patients Do We Need to Test for BRCA1/2 Mutation? Feasibility of Adjuvant Olaparib Treatment in Early Breast Cancer-Real-World Data from Two Large German Breast Centers

BACKGROUND

Approximately 6% of women with breast cancer carry pathogenic germline variants in predisposition genes such as BRCA1 and BRCA2. Depending on personal and family cancer history, it is therefore recommended to test for hereditary breast cancer. Moreover, as shown by the phase III OlympiA trial, olaparib significantly improves overall survival in patients with HER2 negative (HER2-) early breast cancer who (1) carry a BRCA1 or BRCA2 germline mutation (gBRCA1/2-positive), (2) have received (neo)adjuvant chemotherapy and (3) are at high clinical risk. The objective of the current analysis was to determine the number of patients with early HER2- breast cancer who are at high clinical risk, according to the inclusion criteria of OlympiA, and to estimate how many of these patients would meet the criteria for hereditary cancer testing in a real-world analysis.

METHODS

All patients included in this retrospective analysis were treated for early breast cancer (eBC) at the Department of Gynecology and Obstetrics, Ulm University Hospital, Germany, and the Department of Women's Health at Tuebingen University Hospital, Germany, between January 2018 and December 2020. Patients were identified as high risk, in line with the clinicopathological determiners used in the OlympiA trial. The criteria of the German Consortium for Hereditary Breast and Ovarian Cancer were used to identify patients who qualify for hereditary cancer testing.

RESULTS

Of 2384 eligible patients, 1738 patients (72.9%) showed a hormone receptor positive (HR+)/HER2- tumor biology, 345 patients (14.5%) displayed HER2+ breast cancer and 301 patients (12.6%) suffered from HR-/HER2- breast cancer (TNBC). Of 2039 HER2- breast cancer patients, 271 patients (13.3%) were at high clinical risk. This cohort encompassed 130 of the 1738 patients with HR+/HER2- breast cancer (7.5%) and 141 of 301 patients with TNBC (46.8%). A total of 121 of 271 patients (44.6%) with high clinical risk met the criteria for hereditary cancer testing (34 of 130 (26.2%) HR+/HER2- patients and 87 of 141 (61.7%) patients with TNBC).

CONCLUSION

Approximately one in ten patients with HR+/HER2-, and half of the patients with TNBC, meet the high-risk criteria according to OlympiA. Half of these patients do not meet the criteria for hereditary cancer testing and should therefore be tested for the presence of gBRCA1/2 mutations, irrespective of their own or family cancer history. The overall number of patients with early breast cancer benefiting from olaparib needs to be investigated in future studies.

An overview of the research progress of BRCA gene mutations in breast cancer

The breast cancer susceptibility gene (BRCA) is an important tumor suppressor gene, including BRCA1 and BRCA2, a biomarker that assesses the risk of breast cancer and influences a patient's individualized treatment options. BRCA1/2 mutation (BRCAm) increases the risk of breast cancer. However, breast-conserving surgery is still an option for BRCAm, and prophylactic mastectomy and nipple-sparing mastectomy may also reduce the risk of breast cancer. BRCAm is sensitive to Poly (ADP-ribose) polymerase inhibitor (PARPi) therapy due to specific types of DNA repair defects, and its combination with other DNA damage pathway inhibitors and endocrine therapy and immunotherapy are also used for the treatment of BRCAm breast cancer. The current treatment and research progress of BRCA1/2 mutant breast cancer in this review provides a basis for the individualized treatment of patients with this type of breast cancer.

Metabolomics unravels subtype-specific characteristics related to neoadjuvant therapy response in breast cancer patients

INTRODUCTION

Breast cancer is the most diagnosed tumor and the leading cause of cancer death in women worldwide. Metabolomics allows the quantification of the entire set of metabolites in blood samples, making it possible to study differential metabolomics patterns related to neoadjuvant treatment in the breast cancer neoadjuvant setting.

OBJECTIVES

Characterizing metabolic differences in breast cancer blood samples according to their response to neoadjuvant treatment.

METHODS

One hundred and three plasma samples of breast cancer patients, before receiving neoadjuvant treatment, were analyzed through UPLC-MS/MS metabolomics. Then, metabolomics data were analyzed using probabilistic graphical models and biostatistics methods.

RESULTS

Metabolomics data allowed the identification of differences between groups according to response to neoadjuvant treatment. These differences were specific to each breast cancer subtype. Patients with HER2+ tumors showed differences in metabolites related to amino acids and carbohydrates pathways between the two pathological response groups. However, patients with triple-negative tumors showed differences in metabolites related to the long-chain fatty acids pathway. Patients with Luminal B tumors showed differences in metabolites related to acylcarnitine pathways.

CONCLUSIONS

It is possible to identify differential metabolomics patterns between complete and partial responses to neoadjuvant therapy, being this metabolomic profile specific for each breast cancer subtype.

Current advances in microbial-based cancer therapies

Microbes have an immense metabolic capability and can adapt to a wide variety of environments; as a result, they share complicated relationships with cancer. The goal of microbial-based cancer therapy is to treat patients with cancers that are not easily treatable, by using tumor-specific infectious microorganisms. Nevertheless, a number of difficulties have been encountered as a result of the harmful effects of chemotherapy, radiotherapy, and alternative cancer therapies, such as the toxicity to non-cancerous cells, the inability of medicines to penetrate deep tumor tissue, and the ongoing problem of rising drug resistance in tumor cells. Due to these difficulties, there is now a larger need for designing alternative strategies that are more effective and selective when targeting tumor cells. The fight against cancer has advanced significantly owing to cancer immunotherapy. The researchers have greatly benefited from their understanding of tumor-invading immune cells as well as the immune responses that are specifically targeted against cancer. Application of bacterial and viral cancer therapeutics offers promising potential to be employed as cancer treatments among immunotherapies. As a novel therapeutic strategy, microbial targeting of tumors has been created to address the persisting hurdles of cancer treatment. This review outlines the mechanisms by which both bacteria and viruses target and inhibit the proliferation of tumor cells. Their ongoing clinical trials and possible modifications that can be made in the future have also been addressed in the following sections. These microbial-based cancer medicines have the ability to suppress cancer that builds up and multiplies in the tumor microenvironment and triggers antitumor immune responses, in contrast to other cancer medications.

Impact of Beta Blockers on Breast Cancer Incidence and Prognosis

Several studies have investigated the link between beta blockers (BB) and breast cancer outcomes but have reported mixed results. Our aim was to investigate the relationship between BB and breast cancer outcomes. Literatures investigating the relationship between BB and breast cancer outcomes were searched through PubMed and Embase. A total 43 articles were included by meta-analysis. We found BB increased breast cancer risk (n = 22, RR: 1.169, 95% CI: 1.063-1.285). We also found BB were associated with a lower overall survival (OS, n = 19, RR: 1.125, 95% CI: 1.078-1.173) and a higher recurrence risk (n = 8, RR: 1.130, 95% CI: 1.040-1.227) for breast cancer. Interestingly, subgroup analyses found only selective BB increased breast cancer risk (n = 5, RR: 1.766, 95% CI: 1.148-2.718) and recurrence risk (n = 2, RR: 1.168 -, 95% CI: 1.026-1.328) while only nonselective BB were associated with a lower OS (n = 4, RR: 1.135, 95% CI: 1.073-1.202) for breast cancer. Moreover, we found BB were associated with a significantly lower OS (n = 3, RR: 2.751, 95% CI: 1.213-6.238) and higher recurrence (n = 2, RR: 1.284, 95% CI: 1.102-1.497) only in luminal breast cancer while with a higher PFS (n = 2, RR: 0.585, 95% CI: 0.343-0.997) in Her2+ breast cancer. No significant differences in terms of CSM (n = 19, RR: 1.009, 95% CI: 0.947-1.077), PFS (n = 4, RR: 0.932, 95% CI: 0.616-1.305), and DFS (n = 2, RR: 0.776, 95% CI: 0.512-1.176) were observed. Our results provide evidence of the relationship between BB and breast cancer incidence and prognosis.

PARP inhibition synergizes with CD47 blockade to promote phagocytosis by tumor-associated macrophages in homologous recombination-proficient tumors

AIMS

PARP inhibitors (PARPi) are known to exert anti-tumor effects in patients with BRCA-mutated (BRCAmut) or homologous recombination (HR)-deficient cancer, but recent clinical investigations have suggested that this treatment may also be beneficial in patients with HR-proficient tumors. In this study, we aimed to investigate how PARPi exerts anti-tumor effects in non-BRCAmut tumors.

MAIN METHODS

BRCA wild-type, HR-deficient-negative ID8 and E0771 murine tumor cells were treated in vitro and in vivo with olaparib, a clinically approved PARPi. The effects on tumor growth in vivo were determined in immune-proficient and -deficient mice and alterations of immune cell infiltrations were analyzed with flow cytometry. Tumor-associated macrophages (TAMs) were further investigated with RNA-seq and flow cytometry. In addition, we confirmed olaparib's effect on human TAMs.

KEY FINDINGS

Olaparib did not affect HR-proficient tumor cell proliferation and survival in vitro. However, olaparib significantly decreased tumor growth in C57BL/6 and SCID-beige mice (defective in lymphoid development and NK cell activity). Olaparib increased macrophage numbers in the tumor microenvironment, and their depletion diminished the anti-tumor effects of olaparib in vivo. Further analysis revealed that olaparib improved TAM-associated phagocytosis of cancer cells. Notably, this enhancement was not solely reliant on the "Don't Eat Me" CD47/SIRPα signal. In addition, compared to monotherapy, the concomitant administration of αCD47 antibodies with olaparib improved tumor control.

SIGNIFICANCE

Our work provides evidence for broadening the application of PARPi in HR-proficient cancer patients and paves the way for developing novel combined immunotherapy to upgrade the anti-tumor effects of macrophages.

Prevalence of Pathogenic Germline Variants in Women with Non-Familial Unilateral Triple-Negative Breast Cancer

INTRODUCTION

International guidelines recommend genetic testing for women with familial breast cancer at an expected prevalence of pathogenic germline variants (PVs) of at least 10%. In a study sample of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), we have previously shown that women with TNBC diagnosed before the age of 50 years but without a family history of breast or ovarian cancer (sTNBC) meet this criterion. The present study investigates the PV prevalence in BRCA1, BRCA2, and nine additional cancer predisposition genes in an extended sTNBC study sample including a cohort of women with a later age at sTNBC diagnosis.

PATIENTS AND METHODS

In 1,600 women with sTNBC (median age at diagnosis: 41 years, range 19-78 years), we investigated the association between age at diagnosis and PV occurrence in cancer predisposition genes using logistic regression.

RESULTS

260 sTNBC patients (16.2%) were found to have a PV in cancer predisposition genes (BRCA1: n = 170 [10.6%]; BRCA2: n = 46 [2.9%], other: n = 44 [2.8%]). The PV prevalence in women diagnosed between 50 and 59 years (n = 194) was 11.3% (22/194). Logistic regression showed a significant increase in PV prevalence with decreasing age at diagnosis (OR 1.41 per 10 years younger age at diagnosis; 95% confidence interval: 1.21-1.65; p < 0.001). The PV prevalence predicted by the model was above 10% for diagnoses before the age of 56.8 years.

CONCLUSION

Based on the data presented, we recommend genetic testing by gene panel analysis for sTNBC patients diagnosed before the age of 60 years. Due to the still uncertain estimate for women with sTNBC diagnosed above the age of 60 years, further studies are needed.

Germline BRCA-Mutated HER2-Negative Advanced Breast Cancer: Overcoming Challenges in Genetic Testing and Clinical Considerations When Using Talazoparib

Genetic testing is essential to the diagnosis and management of patients with breast cancer. For example, women who carry mutations in BRCA1/2 genes have an increased lifetime risk of breast cancer and the presence of these mutations may sensitize the patient to treatment with poly(ADP-ribose) polymerase (PARP) inhibitors. Two PARP inhibitors are approved by the US Food and Drug Administration for patients with germline BRCA-mutated advanced breast cancer (olaparib and talazoparib). The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer (Version 2.2023) recommend that all patients with recurrent or metastatic breast cancer (mBC) be assessed for the presence of germline BRCA1/2 mutations. However, many women eligible for genetic testing do not receive it. Here, we provide our perspectives on both the importance of genetic testing and the challenges patients and community clinicians may face when trying to access genetic testing. We also present a hypothetical case study involving a female patient with germline BRCA-mutated human epidermal growth factor receptor 2 (HER2)-negative mBC to highlight potential clinical considerations on the use of talazoparib, including the decision to initiate therapy, dosing considerations, potential drug-drug interactions, and managing side effects. This case illustrates the benefits of a multidisciplinary approach to managing patients with mBC and involving the patient in the decision-making process. This patient case is fictional and does not represent events or a response from an actual patient; this fictional case is for educational purposes only.

A phase II study of pembrolizumab plus carboplatin in BRCA-related metastatic breast cancer (PEMBRACA)

BACKGROUND

BRCA1/2-related metastatic breast cancers (mBC) are sensitive to DNA-damage agents and show high tumor-infiltrated lymphocytes. We hypothesized that the association between pembrolizumab and carboplatin could be active in BRCA-related mBC.

PATIENTS AND METHODS

In this phase II Simon's design multicenter single-arm study, BRCA1/2-related mBC patients received carboplatin at area under the curve 6 every 3 weeks for six courses associated with 200 mg pembrolizumab every 3 weeks until disease progression or unacceptable toxicity. The primary aim at first stage was overall response rate (ORR) ≥70%. Disease control rate (DCR), time to progression (TTP), duration of response (DOR), and overall survival (OS) were the secondary aims.

RESULTS

Among 22 patients enrolled at the first stage, 5 BRCA1 and 17 BRCA2, 16 (76%) were luminal tumors and 6 (24%) triple-negative BC (TNBC). In 21 patients, ORR and DCR were 43% and 76% (47% and 87% in luminal, 33% and 50% in TNBC), respectively. TTP was 7.1 months, DOR was 6.3 months, and median OS was not reached. Grade ≥3 adverse events (AEs) or serious AEs occurred in 5/22 patients (22.7%). Since the primary aim was not met, the study was terminated at the first stage.

CONCLUSIONS

Although the primary aim was not reached, data on efficacy and safety of pembrolizumab plus carboplatin in first-line visceral disease BRCA-related luminal mBC were provided and they need to be further investigated.

BRCA1-methylated triple negative breast cancers previously exposed to neoadjuvant chemotherapy form RAD51 foci and respond poorly to olaparib

Background

About 15% of Triple-Negative-Breast-Cancer (TNBC) present silencing of the BRCA1 promoter methylation and are assumed to be Homologous Recombination Deficient (HRD). BRCA1-methylated (BRCA1-Me) TNBC could, thus, be eligible to treatment based on PARP-inhibitors or Platinum salts. However, their actual HRD status is discussed, as these tumors are suspected to develop resistance after chemotherapy exposure.

Methods

We interrogated the sensitivity to olaparib vs. carboplatin of 8 TNBC Patient-Derived Xenografts (PDX) models. Four PDX corresponded to BRCA1-Me, of which 3 were previously exposed to NeoAdjuvant-Chemotherapy (NACT). The remaining PDX models corresponded to two BRCA1-mutated (BRCA1-Mut) and two BRCA1-wild type PDX that were respectively included as positive and negative controls. The HRD status of our PDX models was assessed using both genomic signatures and the functional BRCA1 and RAD51 nuclear foci formation assay. To assess HR restoration associated with olaparib resistance, we studied pairs of BRCA1 deficient cell lines and their resistant subclones.

Results

The 3 BRCA1-Me PDX that had been exposed to NACT responded poorly to olaparib, likewise BRCA1-WT PDX. Contrastingly, 3 treatment-naïve BRCA1-deficient PDX (1 BRCA1-Me and 2 BRCA1-mutated) responded to olaparib. Noticeably, the three olaparib-responsive PDX scored negative for BRCA1- and RAD51-foci, whereas all non-responsive PDX models, including the 3 NACT-exposed BRCA1-Me PDX, scored positive for RAD51-foci. This suggested HRD in olaparib responsive PDX, while non-responsive models were HR proficient. These results were consistent with observations in cell lines showing a significant increase of RAD51-foci in olaparib-resistant subclones compared with sensitive parental cells, suggesting HR restoration in these models.

Conclusion

Our results thus support the notion that the actual HRD status of BRCA1-Me TNBC, especially if previously exposed to chemotherapy, may be questioned and should be verified using the BRCA1- and RAD51-foci assay.

Temporality of body mass index, blood tests, comorbidities and medication use as early markers for pancreatic ductal adenocarcinoma (PDAC): a nested case-control study

OBJECTIVE

Prior studies identified clinical factors associated with increased risk of pancreatic ductal adenocarcinoma (PDAC). However, little is known regarding their time-varying nature, which could inform earlier diagnosis. This study assessed temporality of body mass index (BMI), blood-based markers, comorbidities and medication use with PDAC risk .

DESIGN

We performed a population-based nested case-control study of 28 137 PDAC cases and 261 219 matched-controls in England. We described the associations of biomarkers with risk of PDAC using fractional polynomials and 5-year time trends using joinpoint regression. Associations with comorbidities and medication use were evaluated using conditional logistic regression.

RESULTS

Risk of PDAC increased with raised HbA1c, liver markers, white blood cell and platelets, while following a U-shaped relationship for BMI and haemoglobin. Five-year trends showed biphasic BMI decrease and HbA1c increase prior to PDAC; early-gradual changes 2-3 years prior, followed by late-rapid changes 1-2 years prior. Liver markers and blood counts (white blood cell, platelets) showed monophasic rapid-increase approximately 1 year prior. Recent diagnosis of pancreatic cyst, pancreatitis, type 2 diabetes and initiation of certain glucose-lowering and acid-regulating therapies were associated with highest risk of PDAC.

CONCLUSION

Risk of PDAC increased with raised HbA1c, liver markers, white blood cell and platelets, while followed a U-shaped relationship for BMI and haemoglobin. BMI and HbA1c derange biphasically approximately 3 years prior while liver markers and blood counts (white blood cell, platelets) derange monophasically approximately 1 year prior to PDAC. Profiling these in combination with their temporality could inform earlier PDAC diagnosis.

DNA Damage and Its Role in Cancer Therapeutics

DNA damage is a double-edged sword in cancer cells. On the one hand, DNA damage exacerbates gene mutation frequency and cancer risk. Mutations in key DNA repair genes, such as breast cancer 1 (BRCA1) and/or breast cancer 2 (BRCA2), induce genomic instability and promote tumorigenesis. On the other hand, the induction of DNA damage using chemical reagents or radiation kills cancer cells effectively. Cancer-burdening mutations in key DNA repair-related genes imply relatively high sensitivity to chemotherapy or radiotherapy because of reduced DNA repair efficiency. Therefore, designing specific inhibitors targeting key enzymes in the DNA repair pathway is an effective way to induce synthetic lethality with chemotherapy or radiotherapy in cancer therapeutics. This study reviews the general pathways involved in DNA repair in cancer cells and the potential proteins that could be targeted for cancer therapeutics.

The economic value of knowing BRCA status: universal BRCA testing for breast cancer prevention

BACKGROUND

This study aimed to estimate the incremental lifetime effects, costs, and net monetary benefit (NMB) of knowing BRCA information by universal genetic testing of all US women without breast cancer turning 40 in a given year, and the cumulative savings or losses of yearly cohort testing over 16 years. We compared two strategies: (1) 'with BRCA information' and (2) 'without BRCA information.'

METHODS

Incremental NMB (INMB) was calculated as the monetized benefit per person of knowing BRCA status. The net monetized value (cumulated INMB) of knowing BRCA information was estimated by multiplying the INMB with the eligible population or the year 2020 cohort of US women age 40 and extended for a total of 16 yearly cohorts.

RESULTS

Universal testing of the female population at the age of 40 in a given year provided aan INMB of $663/person (payer) and $1,006/person (society).Escalated to the U.S. population of women age 40 , knowing BRCA status resulted in lifetime cumulated INMB of $1.3 billion (payer) and $2.0 billion (society) for the 2020 cohort; and yielded accumulated monetized value of $18.3 billion (payer) and $27.6 billion (society) over 16 yearly cohorts of 40-year-old women.

CONCLUSIONS

The universal testing for BRCA status of all US women at age 40 provides compelling short-term and long-term economic value.

Long-term adherence to healthful and unhealthful plant-based diets and breast cancer risk overall and by hormone receptor and histologic subtypes among postmenopausal females

BACKGROUND

Epidemiological studies assessing the influence of vegetarian diets on breast cancer (BC) risk have produced inconsistent results. Few studies have assessed how the incremental decrease in animal foods and the quality of plant foods are linked with BC.

OBJECTIVES

Disentangle the influence of plant-based diet quality on BC risk between postmenopausal females.

METHODS

Total of 65,574 participants from the E3N (Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale) cohort were followed from 1993-2014. Incident BC cases were confirmed through pathological reports and classified into subtypes. Cumulative average scores for healthful (hPDI) and unhealthful (uPDI) plant-based diet indices were developed using self-reported dietary intakes at baseline (1993) and follow-up (2005) and divided into quintiles. Cox proportional hazards models were used to estimate adjusted HR and 95% CI.

RESULTS

During a mean follow-up of 21 y, 3968 incident postmenopausal BC cases were identified. There was a nonlinear association between adherence to hPDI and BC risk (Pnonlinear < 0.01). Compared to participants with low adherence to hPDI, those with high adherence had a lower BC risk [HRQ3 compared withQ1 (95% CI): 0.79 (0.71, 0.87) and HRQ4 compared with Q1 (95% CI): 0.78 (0.70, 0.86)]. In contrast, higher adherence to unhealthful was associated with a linear increase in BC risk [Pnonlinear = 0.18; HRQ5 compared with Q1 (95% CI): 1.20 (1.08, 1.33); Ptrend < 0.01]. Associations were similar according to BC subtypes (Pheterogeneity > 0.05 for all).

CONCLUSIONS

Long-term adherence to healthful plant foods with some intake of unhealthy plant and animal foods may reduce BC risk with an optimal risk reduction in the moderate intake range. Adherence to an unhealthful plant-based diet may increase BC risk. These results emphasize the importance of the quality of plant foods for cancer prevention. This trial was registered at clinicaltrials.gov (NCT03285230).

Survival outcomes of metastatic breast cancer patients by germline BRCA1/2 status in a large multicenter real-world database

The outcomes and best treatment strategies for germline BRCA1/2 mutation (gBRCAm) carriers with metastatic breast cancer (MBC) remain uncertain. We compared the overall survival and the first line progression free survival (PFS1) of patients with a gBRCAm identified at initiation of first-line treatment with those of BRCA wild-type (WT) and not-tested (NT) individuals in the ESME real-world database of MBC patients between 2008 and 2016 (NCT03275311). Among the 20 624 eligible patients, 325 had a gBRCAm, 1138 were WT and 19 161 NT. Compared with WT, gBRCAm carriers were younger, and had more aggressive diseases. At a median follow-up of 50.5 months, median OS was 30.6 (95%CI: 21.9-34.3), 35.8 (95%CI: 32.2-37.8) and 39.3 months (95% CI: 38.3-40.3) in the gBRCAm, WT and NT subgroups, respectively. Median PFS1 was 7.9 (95%CI: 6.6-9.3), 7.8 (95%CI: 7.3-8.5) and 9.7 months (95%CI, 9.5-10.0). In the multivariable analysis conducted in the whole cohort, gBRCAm status had however no independent prognostic impact on OS and PFS1. Though, in the triple-negative subgroup, gBRCAm patients had better OS and PFS1 (HR vs WT = 0.76; 95%CI: 0.60-0.97; P = .027 and 0.69; 95% CI: 0.55-0.86; P = .001, respectively). In contrast, in patients with HR+/HER2 negative cancers, PFS1 appeared significantly and OS non significantly lower for gBRCAm carriers (PFS1: HR vs WT = 1.23; 95%CI: 1.03-1.46; P = .024; OS:HR = 1.22, 95% CI: 0.97-1.52, P = .089). In conclusion, gBRCA1/2 status appears to have divergent survival effects in MBC according to IHC subtype.

Secondary findings in a large Pakistani cohort tested with whole genome sequencing

Studies on genomic secondary findings (SFs) are diverse in participants' characteristics, sequencing methods, and versions of the ACMG SF list. Based on whole genome sequencing and the version 3.1 of the ACMG SF list, we studied SFs in 863 individuals from five different regions in Pakistan. We identified 24 ACMG SFs in 23 (2.7%) of 863 individuals: 18 of 24 were related to cardiovascular disease and four to cancer syndromes. In addition to ACMG SFs, we identified 16 (1.9%) participants with pathogenic and likely pathogenic variants in genes that were not related to the participants' clinical conditions but with clear medical actionability (non-ACMG SFs): 4 of 16 were related to eye diseases, two to metabolic disorders, and two to urinary system disorders. By testing a large Pakistani cohort with whole genome sequencing, we concluded that in countries such as Pakistan, the ACMG SF list could be expanded, and our non-ACMG SF list is one example.

Risk-Reducing Breast and Gynecological Surgery for BRCA Mutation Carriers: A Narrative Review

This narrative review aims to clarify the role of breast and gynecological risk-reduction surgery in BRCA mutation carriers. We examine the indications, contraindications, complications, technical aspects, timing, economic impact, ethical issues, and prognostic benefits of the most common prophylactic surgical options from the perspectives of a breast surgeon and a gynecologist. A comprehensive literature review was conducted using the PubMed/Medline, Scopus, and EMBASE databases. The databases were explored from their inceptions to August 2022. Three independent reviewers screened the items and selected those most relevant to this review's scope. BRCA1/2 mutation carriers are significantly more likely to develop breast, ovarian, and serous endometrial cancer. Because of the Angelina effect, there has been a significant increase in bilateral risk-reducing mastectomy (BRRM) since 2013. BRRM and risk-reducing salpingo-oophorectomy (RRSO) significantly reduce the risk of developing breast and ovarian cancer. RRSO has significant side effects, including an impact on fertility and early menopause (i.e., vasomotor symptoms, cardiovascular disease, osteoporosis, cognitive impairment, and sexual dysfunction). Hormonal therapy can help with these symptoms. Because of the lower risk of developing breast cancer in the residual mammary gland tissue after BRRM, estrogen-only treatments have an advantage over an estrogen/progesterone combined treatment. Risk-reducing hysterectomy allows for estrogen-only treatments and lowers the risk of endometrial cancer. Although prophylactic surgery reduces the cancer risk, it has disadvantages associated with early menopause. A multidisciplinary team must carefully inform the woman who chooses this path of the broad spectrum of implications, from cancer risk reduction to hormonal therapies.

All HER2-negative breast cancer patients need gBRCA testing: cost-effectiveness and clinical benefits

BACKGROUND

The OlympiA trial demonstrated the benefits of adjuvant usage of olaparib for high-risk patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) and germline BRCA (gBRCA) mutation. This provoked thoughts on the clinical criteria of gBRCA testing. This study aims to estimate the costs and benefits of gBRCA testing and adjuvant olaparib therapy for patients with triple-negative breast cancer (TNBC) and hormone-receptor (HR)-positive and HER2-negative BC in China and the United States of America (USA).

METHODS

We used a Markov chain decision tree analytic model to compare three gBRCA screening policies in China and the USA: (1) no gBRCA testing; (2) selected gBRCA testing and (3) universal gBRCA testing for nonmetastatic TNBC and HR-positive HER2-negative BC patients. We modelled the benefit of systemic therapy and risk-reducing surgeries among patients identified with pathogenic or likely pathogenic variants (PVs) in BRCA1 and BRCA2.

RESULTS

Changing from the selected gBRCA testing to the universal gBRCA testing in TNBC patients is cost-effective, with the incremental cost-effectiveness ratios (ICERs) being 10991.1 and 56518.2 USD/QALY in China and the USA, respectively. Expanding universal gBRCA testing to HR-positive HER2-negative BC and TNBC patients has ICERs of 2023.3 and 16611.1 USD/QALY in China and the USA, respectively.

DISCUSSION

By performing gBRCA testing on all HER2-negative BC patients, adjuvant olaparib can be offered to high-risk patients with a PV in BRCA1 or BRCA2. These patients are also candidates for risk-reducing surgeries, an important aspect of their survivorship care, and these interventions can improve survival outcomes. With the willingness-to-pay thresholds being 31,500.0 and 100,000.0 USD per QALY gained in China and the USA, respectively, universal gBRCA testing is likely cost-effective for all HER2-negative BC patients. This simplified criterion of gBRCA testing for BC is recommended for adoption by current guidelines in China and the USA.

Development of Homologous Recombination Functional Assays for Targeting the DDR

Identification of tumours that have homologous recombination deficiency (HRD) has become of increasing interest following the licensing of PARP inhibitors. Potential methods to assess HRD status include; clinical selection for platinum sensitive disease, mutational/methylation status, genomic scars/signature and functional RAD51 assays. Homologous recombination (HR) is a dynamic process with the potential to evolve over a disease course, particularly in relation to previous treatment. This is one of the major drawbacks of genomic scars/signatures, as they only demonstrate historic HR status. Functional HR assays have the benefit of giving a real time HR status readout and therefore have the potential for clearer identification of patients who may benefit from PARP inhibitors at that specific time point. However, the development of RAD51 foci assays ready for clinical practice has been challenging. Pre-clinical considerations have included; controlling for variation in tumour proliferation, tissue type and whether DNA damage induction is required. Furthermore, the assays require correlation with clinical outcomes, an understanding of how they complement current testing modalities and validation of test performance in large cohorts. Despite these challenges, given the profound benefit from PARP inhibitors seen in those with an HRD phenotype to date, the ongoing development and validation of these functional HR assays remains of high clinical importance.

Genomic analysis of breast cancer patients from Kerala: A novel BRCA1 mutation detected

BACKGROUND

Breast cancer is the most common cancer among females, with an incidence of 6,41,000 cases annually. The genetic makeup of the individuals, ethnicity, geographical location, lifestyle, and BMI are some well-described factors associated with breast cancer. It is well known that pathogenic variants in BRCA1 and BRCA2 are associated with a majority of hereditary breast cancer. Genome-wide association studies (GWAS) have identified more than 80 germline susceptibility loci responsible for hereditary breast cancer.

METHODS

In the present study, analysis of 94 genes associated with hereditary cancer was performed using next generation sequencing (NGS) in twelve patients having breast cancer and suspected with hereditary association.

RESULTS

Four out of twelve (33%) patients harbored pathogenic mutation of the BRCA1 gene. Two patients was identified p. E23Vfs*17 mutation in BRCA1, one patient had p.Glu1580Gln in BRCA1, and a novel frameshift variant p.T1456Ifs*9(c.4367Cdel) in one patient.

CONCLUSION

In the present study, out of four detected mutations in the BRCA1 gene, three were known and one was a novel BRCA1 mutation. It is advised to perform NGS-based genome sequencing to identify the genetic predisposition in breast cancer patients.

Pathogenic variant profile in DNA damage response genes correlates with metastatic breast cancer progression-free survival in a Mexican-mestizo population

Introduction

Metastatic breast cancer causes the most breast cancer-related deaths around the world, especially in countries where breast cancer is detected late into its development. Genetic testing for cancer susceptibility started with the BRCA 1 and 2 genes. Still, recent research has shown that variations in other members of the DNA damage response (DDR) are also associated with elevated cancer risk, opening new opportunities for enhanced genetic testing strategies.

Methods

We sequenced BRCA1/2 and twelve other DDR genes from a Mexican-mestizo population of 40 metastatic breast cancer patients through semiconductor sequencing.

Results

Overall, we found 22 variants -9 of them reported for the first time- and a strikingly high proportion of variations in ARID1A. The presence of at least one variant in the ARID1A, BRCA1, BRCA2, or FANCA genes was associated with worse progression-free survival and overall survival in our patient cohort.

Discussion

Our results reflected the unique characteristics of the Mexican-mestizo population as the proportion of variants we found differed from that of other global populations. Based on these findings, we suggest routine screening for variants in ARID1A along with BRCA1/2 in breast cancer patients from the Mexican-mestizo population.

Testing for homologous recombination repair or homologous recombination deficiency for poly (ADP-ribose) polymerase inhibitors: A current perspective

Poly (ADP-ribose) polymerase inhibitors (PARPis) have demonstrated clinical activity in patients with BRCA1 and/or BRCA2 mutated breast, ovarian, prostate, and pancreatic cancers. Notably, BRCA mutations are associated with defects in the homologous recombination repair (HRR) pathway. This homologous recombination deficiency (HRD) phenotype can also be observed as genomic instability in tumour cells. Accordingly, PARPi sensitivity has been observed in various tumours with HRD, independent of BRCA mutations. Currently, four PARPis are approved by regulatory agencies for the treatment of cancer across multiple tumour types. Most indications are specific to tumours with a confirmed BRCA mutation, mutations in other HRR-related genes, HRD evidenced by genomic instability, or evidence of platinum sensitivity. Regulatory agencies have also approved companion and complementary diagnostics to facilitate patient selection for each PARPi indication. This review aims to summarise the biological basis, clinical validation, and clinical relevance of the available diagnostic methods and assays to assess HRD.

Frequency of Pathogenic Germline Mutations in Early and Late Onset Familial Breast Cancer Patients Using Multi-Gene Panel Sequencing: An Egyptian Study

BACKGROUND

Precision oncology has been increasingly used in clinical practice and rapidly evolving in the oncology field. Thus, this study was performed to assess the frequency of germline mutations in early and late onset familial breast cancer (BC) Egyptian patients using multi-gene panel sequencing to better understand the contribution of the inherited germline mutations in BC predisposition. Moreover, to determine the actionable deleterious mutations associated with familial BC that might be used as biomarker for early cancer detection.

METHODS

Whole blood samples were collected from 101 Egyptian patients selected for BC family history, in addition to 50 age-matched healthy controls. A QIAseq targeted DNA panel (human BC panel) was used to assess the frequency of germline mutations.

RESULTS

A total of 58 patients (57.4%) out of 101 were found to have 27 deleterious germline mutations in 11 cancer susceptibility genes. Of them, 32 (31.6%) patients carried more than one pathogenic mutation and each one carried at least one pathogenic mutation. The major genes harboring the pathogenic mutations were: ATM, BRCA2, BRCA1, VHL, MSH6, APC, CHEK2, MSH2, MEN1, PALB2, and MUTYH. Thirty-one patients (30.6%) had BRCA2 mutations and twenty (19.8%) had BRCA1 mutations. Our results showed that exon 10 and exon 11 harbored 3 and 5 mutations, respectively, in BRCA1 and BRCA2 genes. Our analysis also revealed that the VHL gene significantly co-occurred with each of the BRCA2 gene (p = 0.003, event ratio 11/21), the MSH2 gene (p = 0.01, 4/10), the CHEK2 gene (p = 0.02, 4/11), and the MSH6 gene (p = 0.04, 4/12). In addition, the APC gene significantly co-occurred with the MSH2 gene (p = 0.01, 3/7). Furthermore, there was a significant mutually exclusive event between the APC gene and the ATM gene (p = 0.04, 1/36). Interestingly, we identified population specific germline mutations in genes showing potentials for targeted therapy to meet the need for incorporating precision oncology into clinical practice. For example, the mutations identified in the ATM, APC, and MSH2 genes.

CONCLUSIONS

Multi-gene panel sequencing was used to detect the deleterious mutations associated with familial BC, which in turns mitigate the essential need for implementing next generation sequencing technologies in precision oncology to identify cancer predisposing genes. Moreover, identifying DNA repair gene mutations, with focus on non-BRCA genes, might serve as candidates for targeted therapy and will be increasingly used in precision oncology.

Immune Checkpoint Inhibitors and Novel Immunotherapy Approaches for Breast Cancer

PURPOSE OF REVIEW

To critically review the existing evidence on immune checkpoint inhibitors (ICIs) in early-stage and metastatic breast cancer and discuss emerging strategies in the different breast cancer subtypes.

RECENT FINDINGS

Immunotherapy has become one of the major milestones in contemporary oncology, revolutionizing the treatment of multiple solid tumors. ICI agents combined with chemotherapy have demonstrated significant efficacy in both early-stage and metastatic triple-negative breast cancer. However, only a subgroup of patients responds to those agents and some associated toxicities, although infrequent, can be life-disabling. Emerging data from immunotherapy studies in advanced hormone receptor-positive (HR +) breast cancer as well as HER2-positive disease are arising with mixed results. Although breast cancer has not classically been considered a hot tumor, ICIs have proven to be effective in a subset of breast cancer patients. However, much remains to be learned, and the identification of new biomarkers beyond PD-L1 expression is essential not only to improve the efficacy of ICI but also to identify patients who can avoid them, together with their toxicities and costs.

Disparities in Breast Cancer Mortality Rates in Israel among Urban and Rural Women

Breast cancer is a leading cause of death. There are a number of risk factors for breast cancer mortality including parity, age, ethnicity, genetic history, and place of residence. This study examined the disparities in breast cancer-related mortality rates among women from urban areas compared to rural areas in Israel. This was a retrospective, follow-up study on mortality from breast cancer among 894,608 Israeli women born between the years of 1940 and 1960. Data was collected from the Israeli Central Bureau of Statistics, the Population Authority, the Education Ministry, and the Health Ministry. Over 80% of women lived in urban areas. A higher incidence of mortality from breast cancer in Israel was found among urban women compared to rural women (1047.8/100,000 compared to 837/100,000, respectively). Even after adjusting for sociodemographic variables, higher mortality rates were found among women from urban areas in Israel compared to women from rural areas in Israel. It is believed that environmental factors can partially explain the geographic variation of breast cancer incidence, and that breast cancer incidence is likely a complex interaction between genetic, environmental, and health factors.

PARP1 proximity proteomics reveals interaction partners at stressed replication forks

PARP1 mediates poly-ADP-ribosylation of proteins on chromatin in response to different types of DNA lesions. PARP inhibitors are used for the treatment of BRCA1/2-deficient breast, ovarian, and prostate cancer. Loss of DNA replication fork protection is proposed as one mechanism that contributes to the vulnerability of BRCA1/2-deficient cells to PARP inhibitors. However, the mechanisms that regulate PARP1 activity at stressed replication forks remain poorly understood. Here, we performed proximity proteomics of PARP1 and isolation of proteins on stressed replication forks to map putative PARP1 regulators. We identified TPX2 as a direct PARP1-binding protein that regulates the auto-ADP-ribosylation activity of PARP1. TPX2 interacts with DNA damage response proteins and promotes homology-directed repair of DNA double-strand breaks. Moreover, TPX2 mRNA levels are increased in BRCA1/2-mutated breast and prostate cancers, and high TPX2 expression levels correlate with the sensitivity of cancer cells to PARP-trapping inhibitors. We propose that TPX2 confers a mitosis-independent function in the cellular response to replication stress by interacting with PARP1.

Interdisciplinary risk counseling for hereditary breast and ovarian cancer: real-world data from a specialized center

Purpose

Hereditary breast and ovarian cancer has long been established to affect a considerable number of patients and their families. By identifying those at risk ideally before they have been diagnosed with breast and/or ovarian cancer, access to preventive measures, intensified screening and special therapeutic options can be obtained, and thus, prognosis can be altered beneficially. Therefore, a standardized screening and counseling process has been established in Germany under the aegis of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC). As one of these specialized clinics, the HBOC-Center at Charité offers genetic counseling as well as genetic analysis based on the GC-HBOC standards. This analysis aims first at depicting this process from screening through counseling to genetic analysis as well as the patient collective and second at correlating the results of genetic analysis performed. Thus, real-world data from an HBOC-Center with a substantial patient collective and a high frequency of pathogenic variants in various genes shall be presented.

Methods

The data of 2531 people having been counseled at the HBOC-Center at Charité in 2016 and 2017 were analyzed in terms of patient and family history as well as pathogenic variants detected during genetic analysis with the TruRisk® gene panel when genetic analysis was conducted. This standardized analysis is compiled and regularly adjusted by the GC-HBOC. The following genes were included at time of research: BRCA1, BRCA2, ATM, CDH1, CHEK2, PALB2, RAD51C, RAD51D, NBN, and TP53.

Results

Genetic analysis was conducted in 59.8% of all cases meeting the criteria for genetic analysis and 286 pathogenic variants were detected among 278 (30.3%) counselees tested using the TruRisk® gene panel. These were primarily found in the genes BRCA1 (44.8%) and BRCA2 (28.3%) but also in CHEK2 (12.2%), ATM (5.6%) and PALB2 (3.5%). The highest prevalence of pathogenic variants was seen among the families with both ovarian and breast cancer (50.5%), followed by families with ovarian cancer only (43.2%) and families with breast cancer only (35.6%)—these differences are statistically significant (p < 0.001). Considering breast cancer subtypes, the highest rate of pathogenic variants was detected among patients with triple-negative breast cancer (40.7%) and among patients who had had been diagnosed with triple-negative breast cancer before the age of 40 (53.4%)—both observations proved to be statistically significant (p = 0.003 and p = 0.001).

Conclusion

Genetic counseling and analysis provide the foundation in the prevention and therapy of hereditary breast and ovarian cancer. The rate of pathogenic variants detected is associated with family history as well as breast cancer subtype and age at diagnosis, and can reach considerable dimensions. Therefore, a standardized process of identification, genetic counseling and genetic analysis deems mandatory.

Relatives from Hereditary Breast and Ovarian Cancer and Lynch Syndrome Families Forgoing Genetic Testing: Findings from the Swiss CASCADE Cohort

Cascade genetic testing of relatives from families with pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS) has important implications for cancer prevention. We compared the characteristics of relatives from HBOC or LS families who did not have genetic testing (GT (−) group) with those who had genetic testing (GT (+) group), regardless of the outcome. Self-administered surveys collected cross-sectional data between September 2017 and December 2021 from relatives participating in the CASCADE cohort. We used multivariable logistic regression with LASSO variable selection. Among n = 115 relatives who completed the baseline survey, 38% (n = 44) were in the GT (−) group. Being male (OR: 2.79, 95% CI: 1.10–7.10) and without a previous cancer diagnosis (OR: 4.47, 95% CI: 1.03–19.42) increased the odds of being untested by almost three times. Individuals from families with fewer tested relatives had 29% higher odds of being untested (OR: 0.71, 95% CI: 0.55–0.92). Reasons for forgoing cascade testing were: lack of provider recommendation, lack of time and interest in testing, being afraid of discrimination, and high out-of-pocket costs. Multilevel interventions designed to increase awareness about clinical implications of HBOC and LS in males, referrals from non-specialists, and support for testing multiple family members could improve the uptake of cascade testing.

Human WDR5 promotes breast cancer growth and metastasis via KMT2-independent translation regulation

Metastatic breast cancer remains a major cause of cancer-related deaths in women, and there are few effective therapies against this advanced disease. Emerging evidence suggests that key steps of tumor progression and metastasis are controlled by reversible epigenetic mechanisms. Using an in vivo genetic screen, we identified WDR5 as an actionable epigenetic regulator that is required for metastatic progression in models of triple-negative breast cancer. We found that knockdown of WDR5 in breast cancer cells independently impaired their tumorigenic as well as metastatic capabilities. Mechanistically, WDR5 promotes cell growth by increasing ribosomal gene expression and translation efficiency in a KMT2-independent manner. Consistently, pharmacological inhibition or degradation of WDR5 impedes cellular translation rate and the clonogenic ability of breast cancer cells. Furthermore, a combination of WDR5 targeting with mTOR inhibitors leads to potent suppression of translation and proliferation of breast cancer cells. These results reveal novel therapeutic strategies to treat metastatic breast cancer.