Germline Mutations in Triple-Negative Breast Cancer

Poly (adenosine diphosphate-ribose) polymerase inhibitors in the treatment of triple-negative breast cancer with homologous repair deficiency

Breast cancer (BC) is a highly heterogeneous disease, and the presence of germline breast cancer gene mutation (gBRCAm) is associated with a poor prognosis. Triple-negative breast cancer (TNBC) is a BC subtype, characterized by the absence of hormone and growth factor receptor expression, making therapeutic decisions difficult. Defects in the DNA damage response pathway due to mutation in breast cancer genes (BRCA 1/2) lead to homologous recombination deficiency (HRD). However, in HRD conditions, poly (adenosine diphosphate-ribose) polymerase (PARP) proteins repair DNA damage and lead to tumor cell survival. Biological understanding of HRD leads to the development of PARP inhibitors (PARPi), which trap PARP proteins and cause genomic instability and tumor cell lysis. HRD assessment can be an important biomarker in identifying gBRCAm patients with BC who could benefit from PARPi therapy. HRD can be identified by homologous recombination repair (HRR) gene-based assays, genomic-scarring assays and mutational signatures, transcription and protein expression profiles, and functional assays. However, gold standard methodologies that are robust and reliable to assess HRD are not available currently. Hence, there is a pressing need to develop accurate biomarkers identifying HRD tumors to guide targeted therapies such as PARPi in patients with BC. HRD assessment has shown fruitful outcomes in chemotherapy studies and preliminary evidence on PARPi intervention as monotherapy and combination therapy in HRD-stratified patients. Furthermore, ongoing trials are exploring the potential of PARPi in BC and clinically complex TNBC settings, where HRD testing is used as an adjunct to stratify patients based on BRCA mutations.

[18F]F-Poly(ADP-Ribose) Polymerase Inhibitor Radiotracers for Imaging PARP Expression and Their Potential Clinical Applications in Oncology

Including poly(ADP-ribose) polymerase (PARP) inhibitors in managing patients with inoperable tumors has significantly improved outcomes. The PARP inhibitors hamper single-strand deoxyribonucleic acid (DNA) repair by trapping poly(ADP-ribose)polymerase (PARP) at sites of DNA damage, forming a non-functional "PARP enzyme-inhibitor complex" leading to cell cytotoxicity. The effect is more pronounced in the presence of PARP upregulation and homologous recombination (HR) deficiencies such as breast cancer-associated gene (BRCA1/2). Hence, identifying HR-deficiencies by genomic analysis-for instance, BRCA1/2 used in triple-negative breast cancer-should be a part of the selection process for PARP inhibitor therapy. Published data suggest BRCA1/2 germline mutations do not consistently predict favorable responses to PARP inhibitors, suggesting that other factors beyond tumor mutation status may be at play. A variety of factors, including tumor heterogeneity in PARP expression and intrinsic and/or acquired resistance to PARP inhibitors, may be contributing factors. This justifies the use of an additional tool for appropriate patient selection, which is noninvasive, and capable of assessing whole-body in vivo PARP expression and evaluating PARP inhibitor pharmacokinetics as complementary to the currently available BRCA1/2 analysis. In this review, we discuss [18F]Fluorine PARP inhibitor radiotracers and their potential in the imaging of PARP expression and PARP inhibitor pharmacokinetics. To provide context we also briefly discuss possible causes of PARP inhibitor resistance or ineffectiveness. The discussion focuses on TNBC, which is a tumor type where PARP inhibitors are used as part of the standard-of-care treatment strategy.

Germline pathogenic variants associated with triple-negative breast cancer in US Hispanic and Guatemalan women using hospital and community-based recruitment strategies

PURPOSE

Recruit and sequence breast cancer subjects in Guatemalan and US Hispanic populations. Identify optimum strategies to recruit Latin American and Hispanic women into genetic studies of breast cancer.

METHODS

We used targeted gene sequencing to identify pathogenic variants in 19 familial breast cancer susceptibility genes in DNA from unselected Hispanic breast cancer cases in the US and Guatemala. Recruitment across the US was achieved through community-based strategies. In addition, we obtained patients receiving cancer treatment at major hospitals in Texas and Guatemala.

RESULTS

We recruited 287 Hispanic US women, 38 (13%) from community-based and 249 (87%) from hospital-based strategies. In addition, we ascertained 801 Guatemalan women using hospital-based recruitment. In our experience, a hospital-based approach was more efficient than community-based recruitment. In this study, we sequenced 103 US and 137 Guatemalan women and found 11 and 10 pathogenic variants, respectively. The most frequently mutated genes were BRCA1, BRCA2, CHEK2, and ATM. In addition, an analysis of 287 US Hispanic patients with pathology reports showed a significantly higher percentage of triple-negative disease in patients with pathogenic variants (41% vs. 15%). Finally, an analysis of mammography usage in 801 Guatemalan patients found reduced screening in women with a lower socioeconomic status (p < 0.001).

CONCLUSION

Guatemalan and US Hispanic women have rates of hereditary breast cancer pathogenic variants similar to other populations and are more likely to have early age at diagnosis, a family history, and a more aggressive disease. Patient recruitment was higher using hospital-based versus community enrollment. This data supports genetic testing in breast cancer patients to reduce breast cancer mortality in Hispanic women.

Challenges in the management of operable triple-negative breast cancer in a survivor of the B-cell acute lymphoblastic leukemia: a case report

Background

Operable triple-negative breast cancer (TNBC) is an unfavorable subtype of breast cancer, which usually requires an aggressive perioperative systemic treatment. When TNBC presents as a second primary cancer after cured acute leukemia, its management might be challenging.

Case presentation

We present a case report of a young postmenopausal woman with an operable TNBC who had a history of the B-cell acute lymphoblastic leukemia (B-ALL) and graft versus host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT). A history of previous treatment with anthracyclines and radiotherapy and GVHD limited the use of doxorubicin for treatment of her TNBC. Due to the history of GVHD, perioperative treatment with pembrolizumab was omitted. Genetic testing was challenging due to the possible contamination of her tissues with the donor's cells after allo-SCT. In samples of our patient's buccal swab, peripheral blood, and tumor tissue, a pathogenic variant in the partner and localizer of BRCA2 (PALB2) gene was found. With neoadjuvant chemotherapy which included carboplatin, a pathologic complete response was achieved. Although our patient has a low risk for recurrence of TNBC, her risk for the development of new primary cancers remains substantial.

Conclusion

This case highlights challenges in the systemic treatment, genetic testing, and follow-up of patients with operable TNBC and other solid cancers who have a history of acute leukemia.

Facing the conundrum: which first-line therapy should be used for patients with metastatic triple-negative breast cancer carrying germline BRCA mutation?

Pembrolizumab combined with chemotherapy has been established as the preferred first-line therapy for treating metastatic triple-negative breast cancer (mTNBC) with programmed cell death ligand-1 (PD-L1)-positive disease since its approval for that indication. However, the optimal sequencing of therapy remains an unanswered question for a subset of mTNBC patients who harbor germline breast cancer gene 1/2 (BRCA1/2; gBRCA1/2) mutation. This article aims to offer insights into the optimal therapy sequencing for mTNBC patients with gBRCA1/2 mutations and its impact on clinical decision-making. The perspective offered is based on the best currently available data and propose a practical algorithm to guide the management of this subgroup in the frontline setting.

Selection bias as an explanation for the observed protective association of childhood adiposity with breast cancer

OBJECTIVES

Recalled childhood adiposity is inversely associated with breast cancer observationally, including in Mendelian randomization (MR) studies. Breast cancer studies recruited in adulthood only include survivors of childhood adiposity and breast cancer or a competing risk. We assessed recalled childhood adiposity on participant reported sibling and maternal breast cancer to ensure ascertainment of nonsurvivors.

STUDY DESIGN AND SETTING

We obtained independent strong genetic predictors of recalled childhood adiposity for women and their associations with participant reported own, sibling and maternal breast cancer from UK Biobank genome wide association studies.

RESULTS

Recalled childhood adiposity in women was inversely associated with own breast cancer using Mendelian randomization inverse variance weighting (odds ratio (OR) 0.66, 95% confidence interval (CI) 0.52-0.84) but less clearly related to participant reported sibling (OR 0.89, 95% CI 0.69-1.14) or maternal breast cancer (OR 0.84, 95% CI 0.67-1.05).

CONCLUSION

Weaker inverse associations of recalled childhood adiposity with breast cancer with more comprehensive ascertainment of cases before recruitment suggests the inverse association of recalled childhood adiposity with breast cancer could be partly selection bias from preferential selection of survivors. Greater consideration of survival bias in public health relevant causal inferences would be helpful.

Primary Prevention and Early Detection of Hereditary Breast Cancer

Background

Primary prevention and early detection of hereditary breast cancer has been one of the main topics of breast cancer research in recent decades. The knowledge of risk factors for breast cancer has been increasing continuously just like the recommendations for risk management. Pathogenic germline variants (mutations, class 4/5) of risk genes are significant susceptibility factors in healthy individuals. At the same time, germline mutations serve as biomarkers for targeted therapy in breast cancer treatment. Therefore, management of healthy mutation carriers to enable primary prevention is in the focus as much as the consideration of pathogenic germline variants for therapeutic decisions. Since 1996, the German Consortium has provided quality-assured care for counselees and patients with familial burden of breast and ovarian cancer.

Summary

Currently, there are 23 university centers with over 100 cooperating DKG-certified breast and gynecological cancer centers. These centers provide standardized, evidence-based, and knowledge-generating care, which includes aspects of primary as well as secondary and tertiary prevention. An important aspect of quality assurance and development was the inclusion of the HBOC centers in the certification system of the German Cancer Society (GCS). Since 2020, the centers have been regularly audited and their quality standards continuously reviewed according to quality indicators adapted to the current state of research. The standard of care at GC-HBOC' centers involves the evaluation as well as evolution of various aspects of care like inclusion criteria, identification of new risk genes, management of variants of unknown significance (class 3), evaluation of risk-reducing options, intensified surveillance, and communication of risks. Among these, the possibility of intensified surveillance in the GC-HBOC for early detection of breast cancer is an important component of individual risk management for many counselees. As has been shown in recent years, in carriers of pathogenic variants in high-risk genes, this approach enables the detection of breast cancer at very early, more favorable stages although no reduction of mortality has been demonstrated yet. The key component of the intensified surveillance is annual contrast-enhanced breast MRI, supplemented by up to biannual breast ultrasound and mammography usually starting at age 40.

Key Messages

Apart from early detection, the central goal of care is the prevention of cancer. By utilizing individualized risk calculation, the optimal timeframe for risk-reducing surgery can be estimated, and counselees can be supported in reaching preference-sensitive decisions.

Contribution of constitutional BRCA1 promoter methylation to early-onset and familial breast cancer patients from Pakistan

PURPOSE

Constitutional BRCA1 promoter methylation has been identified as a potential risk factor for breast cancer (BC) in the Caucasian population. However, this data is lacking for BC patients of Asian origin. Therefore, we assessed the contribution of constitutional BRCA1 promoter methylation in Pakistani BC patients.

METHODS

A total of 385 BRCA1/2-negative index BC patients (197 early-onset BC (≤ 30 years), 152 familial BC, 17 familial BC and ovarian cancer, 19 male BC) and 107 healthy controls were screened for the constitutional BRCA1 promoter methylation by methylation-sensitive high-resolution melting assay. Overall, 131 patients displayed triple-negative BC (TNBC) and 254 non-TNBC phenotypes. The prevalence of BRCA1 promoter methylation was calculated based on clinicopathological characteristics using univariable and multivariable logistic regression models.

RESULTS

Constitutional BRCA1 promoter methylation was identified in 19.5% (75/385) of BC patients and 13.1% (14/107) of controls. The frequency of methylation was higher in early-onset BC (23.4% vs. 13.1%, P = 0.035) and TNBC patients (29.0% vs. 13.1%, P = 0.004) compared to controls. Methylation was also more prevalent in patients with high-grade than low-grade tumors (21.7% vs. 12.2%, P = 0.034) and progesterone receptor (PR)-negative than PR-positive tumors (26.0% vs. 13.9%, P = 0.004). Constitutional BRCA1 promoter methylation remained independently associated with TNBC phenotype (odds ratio 1.99; 95% CI 1.12-3.54; P = 0.02) after adjusting for BC diagnosis age, tumor grade, ER, and PR status.

CONCLUSION

Constitutional BRCA1 promoter methylation is associated with TNBC and can serve as a non-invasive blood-based biomarker for Pakistani TNBC patients.

Germline pathogenic variants in metaplastic breast cancer patients and the emerging role of the BRCA1 gene

Metaplastic breast cancer (MpBC) is a rare, aggressive breast cancer (BC) histotype. Scarce information is available about MpBC genetic predisposition. Previous studies, mainly consisting of case reports, retrospective reviews and others on target therapies, pointed to a possible involvement of the BRCA1 gene in increasing MpBC risk, without ever confirming it. In this study, we retrospectively reviewed all BC patients counseled at our Institute for genetic testing of at least BRCA1 or BRCA2 (BRCA) genes and we found that 23 (23/5226 = 0.4%) were affected by MpBC. About 65% (15/23) of MpBC patients harbored a germline pathogenic variant (PV): 13 in BRCA1 (86.7%), including two patients who received genetic testing for known familial PV, one in TP53 (6.7%), and one in MLH1 (6.7%). We observed a statistically different frequency of MpBC in patients who carried a PV in the BRCA genes (13/1114 = 1.2%) vs. all other BC patients (10/4112 = 0.2%) (p = 0.0002). BRCA carriers proved to have an increased risk of developing MpBC compared to all other BC patients who were tested for BRCA genes (OR = 4.47; 95% CI: 1.95-10.23). Notably, MpBCs were diagnosed in 2.1% (13/610) of BRCA1 carriers. No MpBCs were observed in BRCA2 carriers (0/498 = 0%), revealing a statistically significant difference between the prevalence of MpBCs in BRCA1 and BRCA2 carriers (p = 0.0015). Our results confirmed that BRCA1 is involved in MpBC predisposition. Further studies on unselected patients are needed to elucidate the authentic role of BRCA1 and to explore the possible implication of other genes in MpBC predisposition.

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.

Metaplastic breast cancer: an all-round multidisciplinary consensus

Metaplastic breast cancer (MpBC) is a rare and aggressive histologic subtype of breast cancer (BC) characterized by the presence of at least two cellular types, commonly epithelial and mesenchymal components. Despite growing evidence that MpBC is a unique entity, it has long been treated as a variant of nonspecial type (NST) BC. MpBC typically shows the phenotype of triple-negative breast cancer (TNBC), but compared to NST-TNBC, it is a relatively chemorefractory tumor associated with worse outcomes. Therefore, there is an urgent need to develop management guidelines specifically for MpBC to improve the prognosis of patients with early MpBC. This expert consensus aims to guide diagnosis and standardize clinical management of early MpBC among treating physicians. We provide guidance on the challenging radiological and pathological diagnosis of MpBC. Evidence on the involvement of genetic predisposition in the development of MpBC is also explored. We emphasize the importance of a multidisciplinary approach for the treatment of patients with early MpBC. The optimal surgery and radiotherapy approach is presented, as well as the opportunity offered by novel therapeutic approaches to increase treatment response in this chemoresistant subtype. Appropriate management of patients with MpBC is critical to reduce the high risk of local and distant recurrence that characterizes this disease.

Endorsement of TNBC Biomarkers in Precision Therapy by Nanotechnology

Breast cancer is a heterogeneous disease which accounts globally for approximately 1 million new cases annually, wherein more than 200,000 of these cases turn out to be cases of triple-negative breast cancer (TNBC). TNBC is an aggressive and rare breast cancer subtype that accounts for 10-15% of all breast cancer cases. Chemotherapy remains the only therapy regimen against TNBC. However, the emergence of innate or acquired chemoresistance has hindered the chemotherapy used to treat TNBC. The data obtained from molecular technologies have recognized TNBC with various gene profiling and mutation settings that have helped establish and develop targeted therapies. New therapeutic strategies based on the targeted delivery of therapeutics have relied on the application of biomarkers derived from the molecular profiling of TNBC patients. Several biomarkers have been found that are targets for the precision therapy in TNBC, such as EGFR, VGFR, TP53, interleukins, insulin-like growth factor binding proteins, c-MET, androgen receptor, BRCA1, glucocorticoid, PTEN, ALDH1, etc. This review discusses the various candidate biomarkers identified in the treatment of TNBC along with the evidence supporting their use. It was established that nanoparticles had been considered a multifunctional system for delivering therapeutics to target sites with increased precision. Here, we also discuss the role of biomarkers in nanotechnology translation in TNBC therapy and management.

Triple-negative breast cancer: epidemiology, molecular mechanisms, and modern vaccine-based treatment strategies

Long-standing scarcity of efficacious treatments and tumor heterogeneity have contributed to triple-negative breast cancer (TNBC), a subtype with a poor prognosis and aggressive behavior that accounts for 10-15% of all new cases of breast cancer. TNBC is characterized by the absence of progesterone and estrogen receptor expression and lacks gene amplification or overexpression of HER2. Genomic sequencing has detected that the unique mutational profile of both the somatic and germline modifications in TNBC is staggeringly dissimilar from other breast tumor subtypes. The clinical utility of sequencing germline BRCA1/2 genes has been well established in TNBC. Nevertheless, reports regarding the penetrance and risk of other susceptibility genes are relatively scarce. Recurring mutations (e.g., TP53 and PI3KCA mutations) occur together with rare mutations in TNBC, and the shared effects of genomic modifications drive its progression. Given the heterogeneity and complexity of this disease, a clinical understanding of the genomic modifications in TNBC can pave an innovative way toward its therapy. In this review, we summarized the most recent discoveries associated with the underlying biology of developmental signaling pathways in TNBC. We also summarize the recent advancements in genetics and epidemiology and discuss state-of-the-art vaccine-based therapeutic strategies for TNBC that will enable tailored therapeutics.

Targeted treatment of triple-negative-breast cancer through pH-triggered tumour associated macrophages using smart theranostic nanoformulations

Triple-negative breast cancer (TNBC) represents 15-25 % of the new breast cancer cases diagnosed worldwide every year. TNBC is among the most aggressive and worst prognosis breast cancer, mainly because targeted therapies are not available. Herein, we developed a magnetic theranostic hybrid nanovehicle for targeted treatment of TNBC through pH-triggered tumour associated macrophages (TAMs) targeting. The lipid core of the nanovehicle was composed of a Carnaúba wax matrix that simultaneously incorporated iron oxide nanoparticles and doxorubicin (DOX) - a chemotherapeutic drug. These drug-loaded wax nanovehicles were modified with a combination of two functional and complementary molecules: (i) a mannose ligand (macrophage targeting) and (ii) an acid-sensitive sheddable polyethylene glycol (PEG) moiety (specificity). The TAMs targeting strategy relied on the mannose - mannose receptor recognition exclusively after acid-sensitive "shedding" of the PEG in the relatively low tumour microenvironment pH. The pH-induced targeting capability towards TAMs was confirmed in vitro in a J774A.1 macrophage cell line at different pH (7.4 and 6.5). Biocompatibility and efficacy of the final targeted formulations were demonstrated in vitro in the TNBC MDA-MB-231 cell line and in vivo in an M-Wnt tumour-bearing (TNBC) mouse model. A preferential accumulation of the DOX-loaded lipid nanovehicles in the tumours of M-Wnt-tumour bearing mice was observed, which resulted both on an efficient tumour growth inhibition and a significantly reduced off-target toxicity compared to free DOX. Additionally, the developed magnetic hybrid nanovehicles showed outstanding performances as T₂-contrast agents in magnetic resonance imaging (r₂ ≈ 400-600 mM^-1·s^-1) and as heat generating sources in magnetic hyperthermia (specific absorption rate, SAR ≈ 178 W·g^-1_Fe). These targeted magnetic hybrid nanovehicles emerge as a suitable theranostic option that responds to the urgent demand for more precise and personalized treatments, not only because they are able to offer localized imaging and therapeutic potential, but also because they allow to efficiently control the balance between safety and efficacy.

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.

Triple negative breast cancer: approved treatment options and their mechanisms of action

PURPOSE

Breast cancer, the most prevalent cancer worldwide, consists of 4 main subtypes, namely, Luminal A, Luminal B, HER2-positive, and Triple-negative breast cancer (TNBC). Triple-negative breast tumors, which do not express estrogen, progesterone, and HER2 receptors, account for approximately 15-20% of breast cancer cases. The lack of traditional receptor targets contributes to the heterogenous, aggressive, and refractory nature of these tumors, resulting in limited therapeutic strategies.

METHODS

Chemotherapeutics such as taxanes and anthracyclines have been the traditional go to treatment regimens for TNBC patients. Paclitaxel, docetaxel, doxorubicin, and epirubicin have been longstanding, Food and Drug Administration (FDA)-approved therapies against TNBC. Additionally, the FDA approved PARP inhibitors such as olaparib and atezolizumab to be used in combination with chemotherapies, primarily to improve their efficiency and reduce adverse patient outcomes. The immunotherapeutic Keytruda was the latest addition to the FDA-approved list of drugs used to treat TNBC.

RESULTS

The following review aims to elucidate current FDA-approved therapeutics and their mechanisms of action, shedding a light on the various strategies currently used to circumvent the treatment-resistant nature of TNBC cases.

CONCLUSION

The recent approval and use of therapies such as Trodelvy, olaparib and Keytruda has its roots in the development of an understanding of signaling pathways that drive tumour growth. In the future, the emergence of novel drug delivery methods may help increase the efficiency of these therapies whiel also reducing adverse side effects.

A randomized phase 3 trial of Gemcitabine or Nab-paclitaxel combined with cisPlatin as first-line treatment in patients with metastatic triple-negative breast cancer

Platinum is recommended in combination with gemcitabine in the treatment of metastatic triple-negative breast cancer (mTNBC). We conduct a randomized phase 3, controlled, open-label trial to compare nab-paclitaxel/cisplatin (AP) with gemcitabine/cisplatin (GP) in mTNBC patients (ClinicalTrials.gov NCT02546934). 254 patients with untreated mTNBC randomly receive AP (nab-paclitaxel 125 mg/m² on day 1, 8 and cisplatin 75 mg/m² on day 1) or GP (gemcitabine 1250 mg/m² on day 1, 8 and cisplatin 75 mg/m² on day 1) intravenously every 3 weeks until progression disease, intolerable toxicity or withdrawal of consent. The primary endpoint is progression-free survival (PFS); secondary endpoints are objective response rate (ORR), safety and overall survival (OS). The trial has met pre-specified endpoints. The median PFS is 9.8 months with AP as compared to 7.4 months with GP (stratified HR, 0.67; 95% CI, 0.50–0.88; P = 0.004). AP significantly increases ORR (81.1% vs. 56.3%, P < 0.001) and prolongs OS (stratified HR, 0.62; 95% CI, 0.44–0.90; P = 0.010) to GP. Of grade 3 or 4 adverse events, a significantly higher incidence of neuropathy in AP and thrombocytopenia in GP is noted. These findings warrant further assessment of adding novel agents to the nab-paclitaxel/platinum backbone due to its high potency for patients with mTNBC.

Platinum agents, such as carboplatin and cisplatin, have been recommended in combination with gemcitabine for the treatment of metastatic triple negative breast cancer (TNBC). Here the authors report the results of a randomized phase 3 trial to compare the efficacy of first-line nab-paclitaxel/cisplatin to gemcitabine/cisplatin in patients with TNBC.

Germline Mutational Landscape in Chinese Patients With Advanced Breast Cancer

Background

Genetic testing for breast cancer (BC) patients may shift the paradigm towards more personalized management and treatment strategies. While gene alterations may be ethnic-specific in breast cancer, our understanding of genetic epidemiology of BC remains mainly driven by data from Caucasian populations and further limited to selected handful of genes.

Methods

We collected whole blood samples from 356 BC patients at metastatic first line BC and primary stage IV disease at Beijing Cancer Hospital between Jan. 2013 to Dec. 2019. A comprehensive 600-gene cancer panel was used to detect germline variants in the covered genes with a median 300x sequencing depth. Variants were classified into pathogenic, likely pathogenic, variant of uncertain significance, likely benign and benign groups according to the ACMG/AMP Standards and Guidelines. Pathogenic and likely pathogenic variants were considered as deleterious mutations.

Results

The median age of 356 BC patients was 49 years (range, 21-87 years) at the first diagnosis of BC. Deleterious germline mutations across 48 cancer-related genes were identified in 21.6% (77/356) of the patients. The most prevalent mutations were BRCA1/2 mutations (7.0%), followed by ATM and RAD50 mutations (1.4% each). In addition, patients with family history were more likely to carry BRCA1 mutations (P=0.04). Moreover, patients with triple-negative breast cancer (TNBC) were more likely to harbor BRCA1 mutations than those with HR+ or HER2+ breast cancer (P=0.006). While there was no significant survival difference observed in BRCA1/2 carriers relative to non-carriers, patients with DNA damage repair (DDR) gene mutations (mostly frequently BRCA, ATM, RAD50) had worse disease-free survival (P=0.02).

Conclusions

The most prevalent germline mutations in a large cohort of Chinese patients with advanced BC were BRCA1/2 mutations, followed by ATM and RAD50 mutations. In total, approximately 16.0% (57/356) of patients carry deleterious mutations in DDR pathway. Patients with breast or ovarian cancer family history were more likely to carry BRCA1/2 mutations, and ones with DDR mutations had worse survival. These findings suggest that DDR mutations are prevalent in Chinese BC patients who may potentially benefit from treatment with Poly (ADP-ribose) polymerase inhibitors.

Comparative analysis of protein-protein interaction networks in metastatic breast cancer

Metastatic lesions leading causes of the majority of deaths in patients with the breast cancer. The present study aimed to provide a comprehensive analysis of the differentially expressed genes (DEGs) in the brain (MDA-MB-231 BrM2) and lung (MDA-MB-231 LM2) metastatic cell lines obtained from breast cancer patients compared with those who have primary breast cancer. We identified 981 and 662 DEGs for brain and lung metastasis, respectively. Protein-protein interaction (PPI) analysis revealed seven shared (PLCB1, FPR1, FPR2, CX3CL1, GABBR2, GPR37, and CXCR4) hub genes between brain and lung metastasis in breast cancer. Moreover, GNG2 and CXCL8, C3, and PTPN6 in the brain and SAA1 and CCR5 in lung metastasis were found as unique hub genes. Besides, five co-regulation of clusters via seven important co-expression genes (COL1A2, LUM, SPARC, THBS2, IL1B, CXCL8, THY1) were identified in the brain PPI network. Clusters screening followed by biological process (BP) function and pathway enrichment analysis for both metastatic cell lines showed that complement receptor signalling, acetylcholine receptor signalling, and gastric acid secretion pathways were common between these metastases, whereas other pathways were site-specific. According to our findings, there are a set of genes and functional pathways that mark and mediate breast cancer metastasis to the brain and lungs, which may enable us understand the molecular basis of breast cancer development in a deeper levele to the brain and lungs, which may help us gain a more complete understanding of the molecular underpinnings of breast cancer development.

Clonal Hematopoiesis-Associated Gene Mutations in a Clinical Cohort of 448 Patients With Ovarian Cancer

BACKGROUND

Cancer patients are at risk of secondary therapy-related myeloid neoplasms (t-MNs). Acquired blood-specific mutations in clonal hematopoiesis (CH)-associated genes are t-MN risk factors, and their occurrence associated with cancer therapy and age. Patients with ovarian cancer (OC) showed a particularly high prevalence of CH-associated gene mutations, which may additionally be explained by the high proportion of a hereditary disease cause in this cancer entity.

METHODS

We performed a retrospective analysis of 448 OC patients enrolled in the AGO-TR1 study; 249 were enrolled at primary diagnosis and 199 at platinum-sensitive recurrence. Analyses included the most frequently altered CH-associated genes (ASXL1, DNMT3A, GNAS, JAK2, PPM1D, SF3B1, SH2B3, SRSF2, TET2, TP53). Results were analyzed according to the BRCA1/2 germline (gBRCA1/2) mutation status. All statistical tests were 2-sided.

RESULTS

Advanced age at blood draw and a high number of prior platinum-based chemotherapy lines were risk factors to acquire CH-associated gene mutations, with gene-specific effects observed. Binomial logistic regression suggested increased probabilities for gBRCA1/2 mutation carriers to acquire CH-associated PPM1D and TP53 gene mutations (PPM1D: odds ratio = 4.30, 95% confidence interval = 1.48 to 12.46, P = .007; TP53: odds ratio = 6.20, 95% confidence interval = 0.98 to 53.9, P = .06). This observation was due to a statistically significantly increased number of platinum-based chemotherapy lines in gBRCA1/2 mutation carriers vs noncarriers (PPM1D: mean [SD] = 2.04 [1.27] vs 1.04 [0.99], P < .001; TP53: mean [SD] = 2.83 [1.33] vs 1.07 [1.01], P < .001). No interaction between platinum-based chemotherapy and gBRCA1/2 mutation status with the occurrence of CH-associated gene mutations was observed.

CONCLUSIONS

A positive gBRCA1/2 mutation status is not a risk factor to acquire CH-associated gene mutations. OC patients may benefit from monitoring CH-associated gene mutations, especially following carboplatin exposure. Future clinical studies are required to assess whether treatment regimen should be adapted according to individual t-MN risks.

Somatic Mutational Profile of High-Grade Serous Ovarian Carcinoma and Triple-Negative Breast Carcinoma in Young and Elderly Patients: Similarities and Divergences

Background: Triple-negative breast cancer (TNBC) and High-Grade Serous Ovarian Cancer (HGSOC) are aggressive malignancies that share similarities; however, different ages of onset may reflect distinct tumor behaviors. Thus, our aim was to compare somatic mutations in potential driver genes in 109 TNBC and 81 HGSOC from young (Y ≤ 40 years) and elderly (E ≥ 75 years) patients. Methods: Open access mutational data (WGS or WES) were collected for TNBC and HGSOC patients. Potential driver genes were those that were present in the Cancer Gene Census—CGC, the Candidate Cancer Gene Database—CCGD, or OncoKB and those that were considered pathogenic in variant effect prediction tools. Results: Mutational signature 3 (homologous repair defects) was the only gene that was represented in all four subgroups. The median number of mutated CGCs per sample was similar in HGSOC (Y:3 vs. E:4), but it was higher in elderly TNBC than it was in young TNBC (Y:3 vs. E:6). At least 90% of the samples from TNBC and HGSOC from Y and E patients presented at least one known affected TSG. Besides TP53, which was mutated in 67–83% of the samples, the affected TSG in TP53 wild-type samples were NF1 (yHGSOC and yTNBC), PHF6 (eHGSOC and yTNBC), PTEN, PIK3R1 and ZHFX3 (yTNBC), KMT2C, ARID1B, TBX3, and ATM (eTNBC). A few samples only presented one affected oncogene (but no TSG): KRAS and TSHR in eHGSOC and RAC1 and PREX2 (a regulator of RAC1) in yTNBC. At least ⅔ of the tumors presented mutated oncogenes associated with tumor suppressor genes; the Ras and/or PIK3CA signaling pathways were altered in 15% HGSOC and 20–35% TNBC (Y vs. E); DNA repair genes were mutated in 19–33% of the HGSOC tumors but were more frequently mutated in E-TNBC (56%). However, in HGSOC, 9.5% and 3.3% of the young and elderly patients, respectively, did not present any tumors with an affected CGC nor did 4.65% and none of the young and elderly TNBC patients. Conclusion: Most HGSOC and TNBC from young and elderly patients present an affected TSG, mainly TP53, as well as mutational signature 3; however, a few tumors only present an affected oncogene or no affected cancer-causing genes.

Association of Germline Variant Status With Therapy Response in High-risk Early-Stage Breast Cancer: A Secondary Analysis of the GeparOcto Randomized Clinical Trial

Importance

The GeparOcto randomized clinical trial compared the efficacy of 2 neoadjuvant breast cancer (BC) treatment regimens: sequential intense dose-dense epirubicin, paclitaxel, and cyclophosphamide (iddEPC) vs weekly paclitaxel and nonpegylated liposomal doxorubicin (PM) in patients with different biological BC subtypes. Patients with triple-negative BC (TNBC) randomized to the PM arm received additional carboplatin (PMCb). Overall, no difference in pathologic complete response (pCR) rates was observed between study arms. It remained elusive whether the germline variant status of BRCA1/2 and further BC predisposition genes are associated with treatment outcome.

Objective

To determine treatment outcome for BC according to germline variant status.

Design, Setting, and Participants

This retrospective biomarker study is a secondary analysis of the GeparOcto multicenter prospective randomized clinical trial conducted between December 2014 and June 2016. Genetic analyses assessing for variants in BRCA1/2 and 16 other BC predisposition genes in 914 of 945 women were performed at the Center for Familial Breast and Ovarian Cancer, Cologne, Germany, from August 2017 through December 2018.

Main Outcomes and Measures

Proportion of patients who achieved pCR (ypT0/is ypN0 definition) after neoadjuvant treatment according to germline variant status.

Results

In the study sample of 914 women with different BC subtypes with a mean (range) age at BC diagnosis of 48 (21-76) years, overall higher pCR rates were observed in patients with BRCA1/2 variants than in patients without (60.4% vs 46.7%; odds ratio [OR], 1.74; 95% CI, 1.13-2.68; P = .01); variants in non-BRCA1/2 BC predisposition genes were not associated with therapy response. Patients with TNBC with BRCA1/2 variants achieved highest pCR rates. In the TNBC subgroup, a positive BRCA1/2 variant status was associated with therapy response in both the PMCb arm (74.3% vs 47.0% without BRCA1/2 variant; OR, 3.26; 95% CI, 1.44-7.39; P = .005) and the iddEPC arm (64.7% vs 45.0%; OR, 2.24; 95% CI, 1.04-4.84; P = .04). A positive BRCA1/2 variant status was also associated with elevated pCR rates in patients with ERBB2-negative, hormone receptor-positive BC (31.8% vs 11.9%; OR, 3.44; 95% CI, 1.22-9.72; P = .02).

Conclusions and Relevance

Effective chemotherapy for BRCA1/2-mutated TNBC is commonly suggested to be platinum based. With a pCR rate of 64.7%, iddEPC may also be effective in these patients, though further prospective studies are needed. The elevated pCR rate in BRCA1/2-mutated ERBB2-negative, hormone receptor-positive BC suggests that germline BRCA1/2 testing should be considered prior to treatment start.

Trial Registration

ClinicalTrials.gov Identifier: NCT02125344.

BRCA1/2 pathogenic variants in triple-negative versus luminal-like breast cancers: genotype-phenotype correlation in a cohort of 531 patients

BACKGROUND

Several available data suggest the association between specific molecular subtypes and BRCA1/2 mutational status. Previous investigations showed the association between BRCA1/2 pathogenic variants (PVs) in specific genomic regions and phenotypic variations of cancer relative risk, while the role of PV type and location in determining the breast cancer (BC) phenotypic features remains still unclear. The aim of this research was to describe the germline BRCA1/2 PVs in triple-negative breast cancer (TNBC) versus luminal-like BC and their potential leverage on BC phenotype.

PATIENTS & METHODS

We retrospectively collected and analyzed all clinical information of 531 patients with BC genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis at University Hospital Policlinico "P. Giaccone" of Palermo (Sicily) from January 2016 to February 2020.

RESULTS

Our results corroborate the evidence that BRCA1-related tumors often have a profile which resembles the TNBC subtype, whereas BRCA2-associated tumors have a profile that resembles luminal-like BC, especially the Luminal B subtype. Interestingly, our findings suggest that the PVs identified in TNBC were not largely overlapping with those in luminal-like tumors. Differences in the frequency of two PVs potentially associated with different molecular tumor subtypes were observed. BRCA1-633delC was detected with relatively higher prevalence in patients with TNBC, whereas BRCA2-1466delT was found mainly in Luminal B tumors, but in no TNBC patient.

CONCLUSION

Future studies examining the type and location of BRCA1/2 PVs within different molecular subtypes are required to verify our hypothesis and could provide an interesting insight into the complex topic of genotype-phenotype correlations. Additionally, a more in-depth understanding of the potential correlations between BRCA PVs and clinical and phenotypic features of hereditary BC syndrome patients could be the key to develop better strategies of prevention and surveillance in BRCA-positive carriers without disease.

Breast cancer associated pathogenic variants among women 61 years and older with triple negative breast cancer

Women with triple negative breast cancer (TNBC) have a high prevalence of BRCA1 mutations, and current clinical guidelines recommend genetic testing for patients with TNBC aged ≤60 years. However, studies supporting this recommendation have included few older women with TNBC.

METHODS

Genetic testing results from women aged >60 years with TNBC enrolled in the Clinical Cancer Genomics Community Research Network (CCGCRN) registry were included in this analysis. Prevalence of breast cancer-associated pathogenic variants (PVs) was compared across age groups.

RESULTS

We identified 151 women with TNBC aged >60 years (median 65 years; SD 5.3). Of these, 130 (86%) underwent genetic testing, and a breast cancer-associated PV was identified in 16 (12.3%; 95% CI 7-19): BRCA1 (n = 6), BRCA2 (n = 5), PALB2 (n = 2), ATM (n = 1) and RAD51C (n = 2). We found no differences in the proportion of patients with close blood relatives with breast (≤50 years) or ovarian cancer (any age) between PV carriers (37.5%) and non-carriers (34.2%) (p = 0.79). Among PV's carriers, the proportion of older women with a BRCA1 PV was lower when compared to younger women (37.5% vs 77.2%; p < 0.01).

CONCLUSION

Breast cancer-associated PVs were found in an important proportion of women aged >60 years with TNBC undergoing genetic testing, including greater representation of BRCA2. These results suggest that older women with TNBC should be offered genetic testing, and that their exclusion based on chronologic age alone may not be appropriate.

Triple-Negative Breast Cancer Comparison With Canine Mammary Tumors From Light Microscopy to Molecular Pathology

Many similar characteristics in human and dog cancers including, spontaneous development, clinical presentation, tumor heterogeneity, disease progression, and response to standard therapies have promoted the approval of this comparative model as an alternative to mice. Breast cancer represents the second most frequent neoplasm in humans after lung cancer. Triple-negative breast cancers (TNBC) constitute around 15% of all cases of breast cancer and do not express estrogen receptor (ER), progesterone receptor (PR), and do not overexpress human epidermal growth factor receptor 2 (HER2). As a result, they do not benefit from hormonal or trastuzumab-based therapy. Patients with TNBC have worse overall survival than patients with non-TNBC. Lehmann and collaborators described six different molecular subtypes of TNBC which further demonstrated its transcriptional heterogeneity. This six TNBC subtype classification has therapeutic implications. Breast cancer is the second most frequent neoplasm in sexually intact female dogs after skin cancer. Canine mammary tumors are a naturally occurring heterogeneous group of cancers that have several features in common with human breast cancer (HBC). These similarities include etiology, signaling pathway activation, and histological classification. Molecularly CMTs are more like TNBCs, and therefore dogs are powerful spontaneous models of cancer to test new therapeutic approaches, particularly for human TNBCs. More malignant tumors of the breast are more often ER and PR negative in both humans and dogs. Promising breast cancer biomarkers in both humans and canines are cancer-associated stroma (CAS), circulating tumor cells and tumor DNA (ctDNA), exosomes and miRNAs, and metabolites.

Kinase-substrate Edge Biomarkers Provide a More Accurate Prognostic Prediction in ER-negative Breast Cancer

The estrogen receptor (ER)-negative breast cancer subtype is aggressive with few treatment options available. To identify specific prognostic factors for ER-negative breast cancer, this study included 705,729 and 1034 breast invasive cancer patients from the Surveillance, Epidemiology, and End Results (SEER) and The Cancer Genome Atlas (TCGA) databases, respectively. To identify key differential kinase-substrate node and edge biomarkers between ER-negative and ER-positive breast cancer patients, we adopted a network-based method using correlation coefficients between molecular pairs in the kinase regulatory network. Integrated analysis of the clinical and molecular data revealed the significant prognostic power of kinase-substrate node and edge features for both subtypes of breast cancer. Two promising kinase-substrate edge features, CSNK1A1-NFATC3 and SRC-OCLN, were identified for more accurate prognostic prediction in ER-negative breast cancer patients.

Efficacy of platinum in advanced triple-negative breast cancer with germline BRCA mutation determined by next generation sequencing

Objective

To compare the efficacy of platinum- and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer (TNBC) and analyze the relationship between their efficacy and BRCA gene status.

Methods

Retrospectively analyze clinical data of 220 patients diagnosed pathologically with advanced TNBC and treated at the Department of Breast Oncology, Peking University Cancer Hospital from 2013 to 2018 and evaluate the efficacy of chemotherapy. A total of 114 patients had BRCA1/2 gene tested by next generation sequencing (NGS) using peripheral blood, and we analyzed the correlation between their efficacy and BRCA1/2 gene status.

Results

Non-platinum-based chemotherapy (NPCT) was administered to 129 and platinum-based chemotherapy (PBCT) to 91 study patients. The clinical benefit rate (CBR) and median progression-free survival (PFS) were not statistically different between NPCT and PBCT groups. The median overall survival (OS) was 30.0 and 22.5 months for PBCT and NPCT group, respectively [P=0.090, hazard ratios (HR)=0.703]. BRCA status was assessed in 114 patients, 14 of whom had deleterious germline BRCA1/2 (gBRCA) mutations (seven in each group). In PBCT group, the CBR was 85.7% and 35.1% for patients with and without deleterious gBRCA mutations, respectively (P=0.039). The median PFS were 14.9 and 5.3 months and median OS were 26.5 and 15.5 months for patients with and without deleterious gBRCA mutations, respectively (P=0.001, P=0.161, respectively). Patients in PBCT group had significantly greater rates of grade 3−4 anemia (5.5%vs. 0%) and thrombocytopenia (8.8% vs. 0%), whereas palmar-plantar erythrodysesthesia (12.4% vs. 0%) and peripheral neuropathy (8.6% vs. 1.1%) occurred more frequently in NPCT group.

Conclusions

Platinum-based regimens are more effective in patients with deleterious gBRCA mutations, but no difference in patients without BRCA gene mutations, so non-platinum is an option in patients without BRCA gene mutations considering the toxicity and side effect. And we recommend that patients with advanced TNBC should have BRCA gene test.

Nonsurgical Prevention Strategies in BRCA1 and BRCA2 Mutation Carriers

Background

Female carriers of a BRCA1 or 2 germline mutation face a high lifetime risk to develop breast and ovarian cancer. Risk-reducing surgery, such as prophylactic bilateral mastectomy and prophylactic bilateral salpingo-oophorectomy, are proven strategies to prevent breast and ovarian cancer. These procedures are, however, associated with considerable side effects, and the uptake of these highly effective interventions is therefore low in many countries. This highlights the need for alternative and noninvasive strategies for risk reduction in mutation carriers.

Summary

While endocrine treatments with tamoxifen and aromatase inhibitors (AI) have been shown to be effective in secondary prevention, their benefit in primary prevention has never been prospectively evaluated. Moreover, their side effect profile makes them inappropriate candidates for chemoprevention in healthy premenopausal women. Recently, denosumab, a well-tolerated osteoprotective drug, has been shown to have an antitumoral effect on RANK+, BRCA1-deficient luminal progenitor cells in vitro, and has been demonstrated to abrogate tumors in BRCA1-deficient mouse models.

Key Message

The prospectively randomized, double-blind BRCA-P trial is currently investigating the preventative effect of denosumab in healthy BRCA1 germline mutation carriers.

Non-surgical prevention strategies in women with hereditary breast and ovarian cancer syndromes

Objectives To review non-surgical prevention strategies in women with hereditary breast and ovarian cancer syndromes. Content Women with a gBRCA1 or 2 mutations face a high cumulative breast and ovarian cancer risk. While bilateral mastectomy (PBM) and bilateral salpingo-oophrectomy (PBSO) profoundly reduce the respective cancer risks, they are also associated with considerable side effects. There is therefore an urgent need for alternative and non-surgical risk reduction options. Tamoxifen and aromatase inhibitors have both been evaluated in secondary prevention, but their benefit in primary prevention is currently unknown in BRCA mutation carriers. In addition, their use is compromised by their side effect profile which makes them less appealing for a use in chemoprevention. Summary and outlook Denosumab is a well-tolerated osteoprotective drug, which has been demonstrated to have a potential preventive effect particularly in BRCA1-deficient models in vitro. The prospectively randomized double-blind BRCA-P trial is currently investigating the preventative effect of denosumab in healthy BRCA1 germ line mutation carriers.

Genomic Alteration in Metastatic Breast Cancer and Its Treatment

Metastatic breast cancer (mBC) remains responsible for the majority of breast cancer deaths. Whereas clinical outcomes have improved with the development of novel therapies, resistance almost inevitably develops, indicating the need for novel therapeutic approaches for the treatment of mBC. Recent investigations into mBC genomic alterations have revealed novel and potential therapeutic targets. Most notably, therapies against PIK3CA mutation and germline BRCA1/2 mutations have solidified the role of targeted therapy in mBC, with treatments against these alterations now approved by the U.S. Food and Drug Administration (FDA) on the basis of clinical benefit for patients with mBC. Familiarity with relevant genomic alterations in mBC, technologies for mutation detection, methods of interpreting genomic alterations, and an understanding of their clinical impact will aid practicing clinicians in the treatment of mBC as the field of breast oncology moves toward the era of precision medicine.

Deconvolution of the Genomic and Epigenomic Interaction Landscape of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer. Emerging evidenced suggests that both genetics and epigenetic factors play a role in the pathogenesis of TNBC. However, oncogenic interactions and cooperation between genomic and epigenomic variation have not been characterized. The objective of this study was to deconvolute the genomic and epigenomic interaction landscape in TNBC using an integrative genomics approach, which integrates information on germline, somatic, epigenomic and gene expression variation. We hypothesized that TNBC originates from a complex interplay between genomic (both germline and somatic variation) and epigenomic variation. We further hypothesized that these complex arrays of interacting genomic and epigenomic factors affect entire molecular networks and signaling pathways which, in turn, drive TNBC. We addressed these hypotheses using germline variation from genome-wide association studies and somatic, epigenomic and gene expression variation from The Cancer Genome Atlas (TCGA). The investigation revealed signatures of functionally related genes containing germline, somatic and epigenetic variations. DNA methylation had an effect on gene expression. Network and pathway analysis revealed molecule networks and signaling pathways enriched for germline, somatic and epigenomic variation, among them: Role of BRCA1 in DNA Damage Response, Hereditary Breast Cancer Signaling, Molecular Mechanisms of Cancer, Estrogen-Dependent Breast Cancer, p53, MYC Mediated Apoptosis, and PTEN Signaling pathways. The investigation revealed that integrative genomics is a powerful approach for deconvoluting the genomic-epigenomic interaction landscape in TNBC. Further studies are needed to understand the biological mechanisms underlying oncogenic interactions between genomic and epigenomic factors in TNBC.

Interval breast cancer is associated with other types of tumors

Breast cancer (BC) patients diagnosed between two screenings (interval cancers) are more likely than screen-detected patients to carry rare deleterious mutations in cancer genes potentially leading to increased risk for other non-breast cancer (non-BC) tumors. In this study, we include 14,846 women diagnosed with BC of which 1,772 are interval and 13,074 screen-detected. Compared to women with screen-detected cancers, interval breast cancer patients are more likely to have a non-BC tumor before (Odds ratio (OR): 1.43 [1.19–1.70], P = 9.4 x 10⁻⁵) and after (OR: 1.28 [1.14–1.44], P = 4.70 x 10⁻⁵) breast cancer diagnosis, are more likely to report a family history of non-BC tumors and have a lower genetic risk score based on common variants for non-BC tumors. In conclusion, interval breast cancer is associated with other tumors and common cancer variants are unlikely to be responsible for this association. These findings could have implications for future screening and prevention programs.

Interval cancer patients are more likely to carry rare gene mutations than screen-detected breast cancer patients. Here, the authors report that interval cancer patients are more likely cancer survivors and are at a greater risk of developing other non-breast tumors.

BRCA1 promoter methylation in peripheral blood is associated with the risk of triple-negative breast cancer

Methylation of the promoter of the BRCA1 gene in DNA derived from peripheral blood cells is a possible risk factor for breast cancer. It is not clear if this association is restricted to certain types of breast cancer or is a general phenomenon. We evaluated BRCA1 methylation status in peripheral blood cells from 942 breast cancer patients and from 500 controls. We also assessed methylation status in 262 paraffin-embedded breast cancer tissues. Methylation status was assessed using methylation-sensitive high-resolution melting and was categorized as positive or negative. BRCA1 methylation in peripheral blood cells was strongly associated with the risk of triple-negative breast cancer (TNBC) (odds ratio [OR] 4.70; 95% confidence interval [CI]: 3.13-7.07; p < 0.001), but not of estrogen-receptor positive breast cancer (OR 0.80; 95% CI: 0.46-1.42; p = 0.46). Methylation was also overrepresented among patients with high-grade cancers (OR 4.53; 95% CI: 2.91-7.05; p < 0.001) and medullary cancers (OR 3.08; 95% CI: 1.38-6.88; p = 0.006). Moreover, we detected a significant concordance of BRCA1 promoter methylation in peripheral blood and paired tumor tissue (p < 0.001). We found that BRCA1 promoter methylation in peripheral blood cells is associated with approximately five times greater risk of TNBC. We propose that BRCA1 methylation in blood-derived DNA could be a novel biomarker of increased breast cancer susceptibility, in particular for triple-negative tumors.

BRCA1 and BRCA2 Germline Mutation Analysis in Hereditary Breast/Ovarian Cancer Families from the Aures Region (Eastern Algeria): First Report

Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. In this study, we aimed to investigate the mutation spectrum of BRCA1 and BRCA2 genes in hereditary breast/ovarian cancer (HBOC) families from the Aures region (eastern Algeria). High risk breast/ovarian cancer families were selected from overall 1162 consecutive patients collected from cancer registry of anticancer center of Batna. Breast cancers were diagnosed between 2011 and 2015. Recurrent mutations on BRCA1 and BRCA2 previously found in Algerian patients were screened using PCR-direct sequencing in 113 HBOC families. In addition, for the first time in Algeria, HBOC patients were analyzed by NGS using a cancer panel of 30 hereditary cancer genes or BRCA1/2 genetic test. Six distinct deleterious mutations in BRCA1 and BRCA2 and a new VUS in PALB2 were detected in ten patients. Two distinct BRCA2 pathogenic variants c.1813dupA and c.8485C > T detected in two young female triple negative breast cancer (TNBC) patients, respectively, with a family history of male breast cancer, are reported here for the first time in Algerian population. Interestingly, we also detected a BRCA exon 15 deletion in two unrelated young female TNBC patients with strong family history of breast/ovarian cancer. Our study showed differences in the distribution of the mutation spectrum of BRCA genes between the Aures region and the north central region of Algeria. Our results will contribute in the implementation of genetic counseling and testing for patients and families at risk of hereditary breast and ovarian cancer.

Germline TP53 and MSH6 mutations implicated in sporadic triple-negative breast cancer (TNBC): a preliminary study

Background

Germline BRCA1/2 prevalence is relatively low in sporadic triple-negative breast cancer (TNBC). We hypothesized that non-BRCA genes may also have significant germline contribution to Chinese sporadic TNBC, and the somatic mutational landscape of TNBC may vary between ethnic groups. We therefore conducted this study to investigate germline and somatic mutations in 43 cancer susceptibility genes in Chinese sporadic TNBC.

Patients and methods

Sixty-six Chinese sporadic TNBC patients were enrolled in this study. Germline and tumor DNA of each patient were subjected to capture-based next-generation sequencing using a 43-gene panel. Standard bioinformatic analysis and variant classification were performed to identify deleterious/likely deleterious germline mutations and somatic mutations. Mutational analysis was conducted to identify significantly mutated genes.

Results

Deleterious/likely deleterious germline mutations were identified in 27 (27/66, 40.9%) patients. Among the 27 patients, 9 (9/66, 13.6%) were TP53 carriers, 5 (5/66, 7.6%) were MSH6 carriers, and 5 (5/66, 7.6%) were BRCA1 carriers. Somatic mutations were identified in 64 (64/66, 97.0%) patients. TP53 somatic mutations occurred in most of the patients (45/66, 68.2%) and with highest mean allele frequency (28.1%), while NF1 and POLE were detected to have the highest mutation counts.

Conclusions

Our results supported our hypotheses and suggested great potentials of TP53 and MSH6 as novel candidates for TNBC predisposition genes. The high frequency of somatic NF1 and POLE mutations in this study showed possibilities for clinical benefits from androgen-blockade therapies and immunotherapies in Chinese TNBC patients. Our study indicated necessity of multi-gene testing for TNBC prevention and treatment.

Electronic supplementary material

The online version of this article (10.1186/s40246-018-0186-y) contains supplementary material, which is available to authorized users.

Uterine cancer in Jewish Israeli BRCA1/2 mutation carriers

BACKGROUND

BRCA1/2 mutation carriers have an increased risk of developing ovarian cancer, leading to the recommendation of risk-reducing salpingo-oophorectomy (RRSO) at 35-40 years of age. The role, if any, that BRCA mutations play in conferring uterine cancer risk, is unresolved.

METHOD

Jewish Israeli women, carriers of one of the predominant Jewish mutations in BRCA1/2 from 1998 to 2016, were recruited. Cancer diagnoses were determined through the Israeli National Cancer Registry. Uterine cancer risk was assessed by computing the standardized incidence ratio of observed-to-expected number of cases, using the exact 2-sided P value of Poisson count.

RESULTS

Overall, 2627 eligible mutation carriers were recruited from 1998 to 2016, 2312 (88%) of whom were Ashkenazi Jews (1463 BRCA1, 1154 BRCA2 mutation carriers, 10 double mutation carriers). Among these participants, 1310 underwent RRSO without hysterectomy at a mean (± standard deviation) age of 43.6 years (± 4.4 years). During 32,774 women-years of follow up, 14 women developed uterine cancer, and the observed-to-expected rate of all histological subtypes was 3.98 (95% confidence interval [CI], 2.17-6.67; P < .001). For serous papillary (n = 5), the observed-to-expected ratio was 14.29 (95% CI, 4.64-33.34; P < .001), and for sarcoma (n = 4) it was 37.74 (95% CI, 10.28-96.62). These rates were also higher than those detected in a group of 1844 age- and ethnicity-matched women (53% with breast cancer).

CONCLUSION

Israeli BRCA1 or BRCA2 mutation carriers are at an increased risk for developing uterine cancer, especially serous papillary and sarcoma. These elevated risks of uterine cancer should be discussed with BRCA carriers.

Prevalence and oncologic outcomes of BRCA 1/2 mutations in unselected triple-negative breast cancer patients in Korea

PURPOSE

Triple-negative breast cancer (TNBC) accounts for 10-20% of all diagnosed BCs and it is enriched in BRCA1 mutation. Guidelines for Western countries suggest that BRCA 1/2 genetic testing should be done for patients with TNBC diagnosed less than 60 years, but there is lack of evidence supporting genetic testing in Asian populations. We determined the prevalence of germline BRCA 1/2 mutations among unselected Korean patients with TNBC and analyzed oncologic outcomes.

METHODS

From among 1628 women with TNBC who underwent surgery at Samsung Medical Center (SMC) between Jul 2008 and Jan 2016, 999 samples were available in the SMC biobank for testing germline BRCA 1/2 mutations using next-generation DNA sequencing.

RESULTS

Overall, 131 Korean patients (13.1%) had BRCA 1/2 mutations: 97 (9.7%) were in BRCA 1, and 35 (3.5%) were in BRCA 2. One patient had both BRCA 1 and BRCA 2 mutations. Overall, 68 distinct pathologic or likely pathogenic variants (43 BRCA1 and 25 BRCA2) were found. Among those diagnosed at ≤ 60 years, the prevalence of BRCA 1/2 mutation was 14.5%. The mean age of diagnosis of BRCA1/2 mutation carriers was significantly younger than that of non-carriers (45.6 vs. 50.1 years, p < 0.0001). The median follow-up duration was 53.6 months. There were no significant differences in disease-free survival, overall survival, or breast cancer-specific survival (p = 0.799, 0.092, and 0.124, respectively) between BRCA 1/2 carriers and non-carriers, although BRCA 1/2 carriers showed significantly worse contralateral breast cancer-free survival (p < 0.0001) than non-carriers.

CONCLUSION

In unselected TNBC patients, we found BRCA 1/2 mutations in 13.1% of overall patients and 14.5% of patients ≤ 60 years. We suggest that Korean women with TNBC diagnosed at ≤ 60 years should be tested for BRCA1/2 mutation.

Gene panel testing of 5589 BRCA1/2-negative index patients with breast cancer in a routine diagnostic setting: results of the German Consortium for Hereditary Breast and Ovarian Cancer

The prevalence of germ line mutations in non-BRCA1/2 genes associated with hereditary breast cancer (BC) is low, and the role of some of these genes in BC predisposition and pathogenesis is conflicting. In this study, 5589 consecutive BC index patients negative for pathogenic BRCA1/2 mutations and 2189 female controls were screened for germ line mutations in eight cancer predisposition genes (ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D, and TP53). All patients met the inclusion criteria of the German Consortium for Hereditary Breast and Ovarian Cancer for germ line testing. The highest mutation prevalence was observed in the CHEK2 gene (2.5%), followed by ATM (1.5%) and PALB2 (1.2%). The mutation prevalence in each of the remaining genes was 0.3% or lower. Using Exome Aggregation Consortium control data, we confirm significant associations of heterozygous germ line mutations with BC for ATM (OR: 3.63, 95%CI: 2.67-4.94), CDH1 (OR: 17.04, 95%CI: 3.54-82), CHEK2 (OR: 2.93, 95%CI: 2.29-3.75), PALB2 (OR: 9.53, 95%CI: 6.25-14.51), and TP53 (OR: 7.30, 95%CI: 1.22-43.68). NBN germ line mutations were not significantly associated with BC risk (OR:1.39, 95%CI: 0.73-2.64). Due to their low mutation prevalence, the RAD51C and RAD51D genes require further investigation. Compared with control datasets, predicted damaging rare missense variants were significantly more prevalent in CHEK2 and TP53 in BC index patients. Compared with the overall sample, only TP53 mutation carriers show a significantly younger age at first BC diagnosis. We demonstrate a significant association of deleterious variants in the CHEK2, PALB2, and TP53 genes with bilateral BC. Both, ATM and CHEK2, were negatively associated with triple-negative breast cancer (TNBC) and estrogen receptor (ER)-negative tumor phenotypes. A particularly high CHEK2 mutation prevalence (5.2%) was observed in patients with human epidermal growth factor receptor 2 (HER2)-positive tumors.

Fanconi Anemia Signaling and Cancer

The extremely high cancer incidence associated with patients suffering from a rare human genetic disease, Fanconi anemia (FA), demonstrates the importance of FA genes. Over the course of human tumor development, FA genes perform critical tumor-suppression roles. In doing so, FA provides researchers with a unique genetic model system to study cancer etiology. Here, we review how aberrant function of the 22 FA genes and their signaling network contributes to malignancy. From this perspective, we will also discuss how the knowledge discovered from FA research serves basic and translational cancer research.

Improvement of Bone Physiology and Life Quality Due to Association of Risedronate and Anastrozole

The endocrine therapy is the new frontiers of many breast cancers hormone sensitive. Hormone therapy for treating women with hormone receptor-positive cancer suppresses breast cancer growth either by reducing estrogen synthesis or by interfering with the action of estrogen within tumor cells. In this prospective randomized observational study we investigate the effect of adjuvant anastrozole in monotherapy or associated with risedronate on bone physiology and quality of life in postmenopausal, hormone-sensitive early breast cancer women at mild to moderate risk of fragility fractures.

Methods : 84 women were randomly assigned to receive anastrozole alone (group A) or anastrozole plus oral risedronate (group A+R). At baseline and after 24 months lumbar spine (LS) and femoral neck (FN) BMD were evaluated with dual-energy x-ray absorptiometry and health-related quality of life (HRQoL) was examined using the short-form healthy survey.

Results : After 24 months, the group A+R has showed a significant increase in T-score for LS (p < 0.05) and for FN (p < 0.05) whereas women of group A had a statistically significant rate of bone loss both in LS T-score (p < 0.05) and in FN (p < 0.05). A significant change in T-score BMD was seen for group A+R compared with group A at the LS (p = 0.04) and at FN (p = 0.04). Finally, group A+R showed an overall significant improvement of health profile (SF-36) in group A (p = 0.03).

Conclusion : Postmenopausal breast cancer women with osteopenia during treatment with anastrozole have considerable risk of developing osteoporosis during the first 2 years; preventive measures such as healthy lifestyle and daily supplements of calcium and vitamin D alone seem to be insufficient in holding their bones healthy. Our findings suggest the usefulness of addition of risedronate in order to prevent aromatase inhibitors-related bone loss, not only in case of high-risk of fractures, but also for women at mild-moderate risk. This determines a significant improvement in bone health and a positive impact on HRQoL.

Breast cancer in Africa: prevalence, treatment options, herbal medicines, and socioeconomic determinants

Breast cancer is the leading cause of cancer-related deaths in women worldwide. GLOBOCAN estimated about 1.7 million new cases of breast cancer diagnoses worldwide and about 522,000 deaths in 2012. The burden of breast cancer mortality lies in the developing low-income and middle-income countries, where about 70% of such deaths occur. The incidence of breast cancer is also rising in low-income and middle-income countries in Africa as trend towards urbanization, and adoption of Western lifestyles increases. In general, the triple-negative breast cancer (TNBC) subtype tends to be frequent in women of African ancestry. What are the factors contributing to this prevalence? Are there genetic predispositions to TNBC in African women? This review addresses these questions and provides an update on the incidence, survival, and mortality of breast cancer in Africans, with a focus on sub-Saharan Africans. We have also addressed factors that could account for ethical disparities in incidence and mortality. Further, we have highlighted challenges associated with access to essential drug and to healthcare treatment in some African countries and outlined alternative/herbal treatment methods that are increasingly implemented in Africa and other developing nations.