Familial invasive breast cancers: worse outcome related to BRCA1 mutations

Radiation therapy for triple-negative breast cancer: from molecular insights to clinical perspectives

INTRODUCTION

Triple-negative breast cancer (TNBC) lacks three common receptors, making traditional treatments less effective. This review highlights the importance of radiotherapy and emerging therapeutic strategies to enhance treatment outcomes in TNBC.

AREAS COVERED

We conducted a literature search on PubMed for publications from 2000 to 2023 to discuss the critical role of radiotherapy in managing TNBC, emphasizing its applications from locoregional control to improving survival rates. The review explores molecular mechanisms underlying TNBC's radiotherapy response, including DNA damage repair and apoptosis, with a focus on BRCA1/2 mutations and Poly (ADP-ribose) polymerase (PARP) inhibition. We summarize preclinical and clinical research on radiosensitization strategies, from gene-targeted therapies to immunotherapy combinations, and the impact of post-mastectomy radiation therapy on locoregional control. The potential of personalized treatment approaches, integrating molecular profiling, targeted radiosensitizers, and the synergistic effects of radiotherapy with immunotherapy, is also discussed.

EXPERT OPINION

Future TNBC treatment strategies should focus on precision medicine, integrating immunotherapy, developing novel radiosensitizers, and targeting biological pathways to overcome radioresistance. The integration of radiomics and artificial intelligence offers promising avenues for enhancing treatment personalization and efficacy, aiming to improve patient outcomes in TNBC.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

BRCA1 deficiency in triple-negative breast cancer: Protein stability as a basis for therapy

Mutations in breast cancer-associated 1 (BRCA1) increase the lifetime risk of developing breast cancer by up to 51% over the risk of the general population. Many aspects of this multifunctional protein have been revealed, including its essential role in homologous recombination repair, E3 ubiquitin ligase activity, transcriptional regulation, and apoptosis. Although most studies have focused on BRCA1 deficiency due to mutations, only a minority of patients carry BRCA1 mutations. A recent study has suggested an expanded definition of BRCA1 deficiency with reduced BRCA1 levels, which accounts for almost half of all triple-negative breast cancer (TNBC) patients. Reduced BRCA1 levels can result from epigenetic modifications or increased proteasomal degradation. In this review, we discuss how this knowledge of BRCA1 function and regulation of BRCA1 protein stability can help overcome the challenges encountered in the clinic and advance current treatment strategies for BRCA1-related breast cancer patients, especially focusing on TNBC.

Clinical outcomes and Oncotype DX Breast Recurrence Score® in early-stage BRCA-associated hormone receptor-positive breast cancer

Background

BRCA‐associated breast cancers tend to have distinctive features compared to sporadic breast cancers; further characterization can aid in optimizing treatment.

Methods

The study evaluated a patient cohort with early‐stage estrogen receptor positive, HER2 negative invasive breast cancer who had Oncotype DX Breast Recurrence Score® analysis and genetic testing for hereditary breast and ovarian cancer syndrome. Data on patients and their breast cancers with outcomes were collected and analyzed.

Results

745 patients were included, of whom 33 had pathogenic BRCA mutations (8 BRCA1, 25 BRCA2). Patients with BRCA mutations were younger and received more adjuvant chemotherapy, but less endocrine therapy and radiation therapy. BRCA‐associated breast cancers had less progesterone receptor expression, higher nuclear grade, and higher Oncotype DX Breast Recurrence Scores® with median Recurrence Score® 29, compared to 16 in cancers without mutations (p < 0.0001). Breast cancer recurrence developed in 18% of patients with BRCA mutations and 9% of patient without mutations, although multivariate analysis of relapse‐free survival was not significant, HR 1.519 (95% confidence interval [CI] 0.64–3.58; p = 0.3401). After adjusting for Recurrence Score®, overall survival by BRCA status was improved HR 0.448 (95% CI 0.06–3.34; p = 0.4333).

Conclusions

BRCA‐associated early‐stage hormone receptor‐positive breast cancers have higher Oncotype DX Breast Recurrence Score® compared to those without mutations. BRCA status did not significantly impact relapse‐free survival and overall survival. Larger clinical trials are needed to further assess the findings, and if confirmed, could impact clinical management of BRCA‐associated breast cancers.

Surgical Management of Hereditary Breast Cancer

The identification that breast cancer is hereditary was first described in the nineteenth century. With the identification of the BRCA1 and BRCA 2 breast/ovarian cancer susceptibility genes in the mid-1990s and the introduction of genetic testing, significant advancements have been made in tailoring surveillance, guiding decisions on medical or surgical risk reduction and cancer treatments for genetic variant carriers. This review discusses various medical and surgical management options for hereditary breast cancers.

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

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

Mutations in BRCA1/2 and Other Panel Genes in Patients With Metastatic Breast Cancer -Association With Patient and Disease Characteristics and Effect on Prognosis

PURPOSE

Among patients with metastatic breast cancer (mBC), the frequency of germline mutations in cancer susceptibility genes and the clinical relevance of these mutations are unclear. In this study, a prospective cohort of patients with mBC was used to determine mutation rates for breast cancer (BC) predisposition genes, to evaluate the clinical characteristics of patients with mutations, and to assess the influence of mutations on patient outcome.

PATIENTS AND METHODS

Germline DNA from 2,595 patients with mBC enrolled in the prospective PRAEGNANT registry was evaluated for mutations in cancer predisposition genes. The frequencies of mutations in known BC predisposition genes were compared with results from a prospective registry of patients with nonmetastatic BC sequenced using the same QIAseq method and with public reference controls. Associations between mutation status and tumor characteristics, progression-free survival, and overall survival were assessed.

RESULTS

Germline mutations in 12 established BC predisposition genes (including BRCA1 and BRCA2) were detected in 271 (10.4%) patients. A mutation in BRCA1 or BRCA2 was seen in 129 patients (5.0%). BRCA1 mutation carriers had a higher proportion of brain metastasis (27.1%) compared with nonmutation carriers (12.8%). Mutations were significantly enriched in PRAEGNANT patients with mBC compared with patients with nonmetastatic BC (10.4% v 6.6%, P < .01). Mutations did not significantly modify progression-free survival or overall survival for patients with mBC.

CONCLUSION

Multigene panel testing may be considered in all patients with mBC because of the high frequency of germline mutations in BRCA1/2 and other BC predisposition genes. Although the prognosis of mutation carriers and nonmutation carriers with mBC was similar, differences observed in tumor characteristics have implications for treatment and for future studies of targeted therapies.

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

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

Clinicopathological characteristics of BRCA-associated breast cancer in Asian patients

BRCA1/2 germline mutations account for the majority of hereditary breast cancers. Since the identification of the BRCA genes, several attempts have been made to define the clinicopathological characteristics of BRCA-associated breast cancer in comparison with sporadic breast cancer. Asians constitute 60% of the world population, and although the incidence of breast cancer in Asia remains low compared to the West, breast cancer is the most prevalent female cancer in the region. The epidemiological aspects of breast cancer are different between Asians and Caucasians. Asian patients present with breast cancer at a younger age than Western patients. The contributions of BRCA1/2 mutations to breast cancer incidence are expected to differ between Asians and Caucasians, and the different genetic backgrounds among races are likely to influence the breast cancer phenotypes. However, most large-scale studies on the clinicopathological characteristics of BRCA-associated breast cancer have been on Western patients, while studies on Asian populations were small and sporadic. In this review, we provide an overview of the clinical and pathological characteristics of BRCA-associated breast cancer, incorporating findings on Asian patients.

BRCA1/BRCA2 Pathogenic Variant Breast Cancer: Treatment and Prevention Strategies

Hereditary breast cancer is known for its strong tendency of inheritance. Most hereditary breast cancers are related to BRCA1/BRCA2 pathogenic variants. The lifelong risk of breast cancer in pathogenic BRCA1 and BRCA2 variant carriers is approximately 65% and 45%, respectively, whereas that of ovarian cancer is estimated to be 39% and 11%, respectively. Therefore, understanding these variants and clinical knowledge on their occurrence in breast cancers and carriers are important. BRCA1 pathogenic variant breast cancer shows more aggressive clinicopathological features than the BRCA2 pathogenic variant breast cancer. Compared with sporadic breast cancer, their prognosis is still debated. Treatments of BRCA1/BRCA2 pathogenic variant breast cancer are similar to those for BRCA-negative breast cancer, mainly including surgery, radiotherapy, and chemotherapy. Recently, various clinical trials have investigated poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor treatment for advanced-stage BRCA1/BRCA2 pathogenic variant breast cancer. Among the various PARP inhibitors, olaparib and talazoparib, which reached phase III clinical trials, showed improvement of median progression-free survival around three months. Preventive and surveillance strategies for BRCA pathogenic variant breast cancer to reduce cancer recurrence and improve treatment outcomes have recently received increasing attention. In this review, we provide an information on the clinical features of BRCA1/BRCA2 pathogenic variant breast cancer and clinical recommendations for BRCA pathogenic variant carriers, with a focus on treatment and prevention strategies. With this knowledge, clinicians could manage the BRCA1/BRCA2 pathogenic variant breast cancer patients more effectively.

Effects of BRCA Germline Mutations on Triple-Negative Breast Cancer Prognosis

Germline BRCA1 and BRCA2 mutations confer an increased lifetime risk for breast cancer and ovarian cancer. Several studies have investigated prognosis among BRCA1/2 mutation carriers and noncarriers, but the prognostic impact on outcomes of breast cancer patients has not been determined. The aim of this study was to determine the prognosis of TNBC patients with and without BRCA1/2 germline mutation. Among 502 patients diagnosed with TNBC between 2005 and 2008, 124 patients with a strong family history of breast cancer or ovarian cancer as well as TNBC patients diagnosed under 45 years were referred to the Genetic Counseling Unit for genetic counselling and genetic tests. In 30 (24%) of them, the BRCA1/2 mutation was detected (the most common 5382insC in 18 (60%) patients). The median follow-up of the entire group was 60 months. BRCA1/2 mutation carriers were statistically significantly younger at TNBC diagnosis compared with nonmutation patients (41 vs 47 years, respectively). Patients with the BRCA1/2 mutation had smaller tumors (stage I: 47% vs 24.5% in noncarriers), but there was no significant difference in the regional nodal status (58.5–63% with cN0). Contralateral breast cancer developed in 26.5% of BRCA1/2 mutation carriers and in 14% of noncarriers. Other primary cancers were also slightly more common in BRCA1/2 mutation carriers (16.5% vs 9.5%). The performed analysis did not show any significant differences between the groups in recurrence-free survival (p=0.312). There was no significant difference between patients with or without BRCA1/2 mutation as regards overall survival (p=0.649) and the risk of TNBC death (p=0.333). The survival from detection of metastases was similar in two groups (p=0.865). Our study demonstrated that the BRCA1 mutation does not affect TNBC patients' outcomes.

Bimodal age distribution at diagnosis in breast cancer persists across molecular and genomic classifications

PURPOSE

Female breast cancer demonstrates bimodal age frequency distribution patterns at diagnosis, interpretable as two main etiologic subtypes or groupings of tumors with shared risk factors. While RNA-based methods including PAM50 have identified well-established clinical subtypes, age distribution patterns at diagnosis as a proxy for etiologic subtype are not established for molecular and genomic tumor classifications.

METHODS

We evaluated smoothed age frequency distributions at diagnosis for Carolina Breast Cancer Study cases within immunohistochemistry-based and RNA-based expression categories. Akaike information criterion (AIC) values compared the fit of single density versus two-component mixture models. Two-component mixture models estimated the proportion of early-onset and late-onset categories by immunohistochemistry-based ER (n = 2860), and by RNA-based ESR1 and PAM50 subtype (n = 1965). PAM50 findings were validated using pooled publicly available data (n = 8103).

RESULTS

Breast cancers were best characterized by bimodal age distribution at diagnosis with incidence peaks near 45 and 65 years, regardless of molecular characteristics. However, proportional composition of early-onset and late-onset age distributions varied by molecular and genomic characteristics. Higher ER-protein and ESR1-RNA categories showed a greater proportion of late age-at-onset. Similarly, PAM50 subtypes showed a shifting age-at-onset distribution, with most pronounced early-onset and late-onset peaks found in Basal-like and Luminal A, respectively.

CONCLUSIONS

Bimodal age distribution at diagnosis was detected in the Carolina Breast Cancer Study, similar to national cancer registry data. Our data support two fundamental age-defined etiologic breast cancer subtypes that persist across molecular and genomic characteristics. Better criteria to distinguish etiologic subtypes could improve understanding of breast cancer etiology and contribute to prevention efforts.

Genistein Inhibits Proliferation of BRCA1 Mutated Breast Cancer Cells: The GPR30-Akt Axis as a Potential Target

Background

BRCA1 mutated breast cancer cells exhibit the elevated cell proliferation and the higher metastatic potential. G protein-coupled receptor 30 (GPR30) has been shown to regulate growth of hormonally responsive cancers, such as ovarian and breast cancers, and high expression of GPR30 is found in estrogen receptor (ER)-negative breast cancer cells. ER-negative breast cancer patients often have a mutation in the tumor suppressor gene, BRCA1. This study explored antiproliferative effects of genistein, a chemopreventive isoflavone present in legumes, and underlying molecular mechanisms in triple negative breast cancer cells with or without functionally active BRCA1.

Methods

Expression of BRCA1, GPR30 and Nrf2 was measured by Western blot analysis. Reactive oxygen species (ROS) accumulation was monitored by using the fluorescence-generating probe, 2’,7’-dichlorofluorescein diacetate. The effects of genistein on breast cancer cell viability and proliferation were assessed by the MTT, migration and clonogenic assays.

Results

The expression of GPR30 was dramatically elevated at both transcriptional and translational levels in BRCA1 mutated breast cancer cells compared to cells with wild-type BRCA1. Notably, there was diminished Akt phosporylation in GPR30 silenced cells. Treatment of BRCA1 silenced breast cancer cells with genistein resulted in the down-regulation of GPR30 expression and the inhibition of Akt phosphorylation as well as the reduced cell viability, migration and colony formation. Genistein caused cell cycle arrest at the G2/M phase in BRCA1-mutant cells through down-regulation of cyclin B1 expression. Furthermore, BRCA1-mutant breast cancer cells exhibited higher levels of intracellular ROS than those in the wild-type cells. Genistein treatment lowered the ROS levels through up-regulation of Nrf2 expression.

Conclusions

Lack of functional BRCA1 activates GPR30 signaling, thereby stimulating Akt phosphorylation and cell proliferation. Genistein induces G2/M phase arrest by down-regulating cyclin B1 expression, which is attributable to its suppression of GPR30 activation and Akt phosphorylation in BRCA1 impaired breast cancer cells.

Patterns of recurrence and metastasis in BRCA1/BRCA2-associated breast cancers

Background

Breast cancer subtypes are associated with distinct metastatic patterns. Whether germline BRCA1/BRCA2 mutation status is independently associated with central nervous system (CNS) relapse, controlling for tumor subtype, is unknown.

Methods

Patients who were treated at Dana‐Farber Cancer Institute and diagnosed with a first locoregional recurrence (LRR) or metastasis between 1981 and 2014 were identified using 2 institutional registries: 1) patients treated for recurrent breast cancer and 2) patients who underwent BRCA testing. The frequencies of LRR, sites of metastasis, and breast cancer‐specific survival from LRR or metastasis were calculated, and the factors associated with CNS recurrence were evaluated using multivariable logistic regression models.

Results

The final study cohort included 30 BRCA1 mutation carriers, 32 BRCA2 mutation carriers, and 270 noncarriers. Most BRCA1 carriers (73%) had triple‐negative breast cancer; whereas most BRCA2 carriers (72%) had hormone receptor‐positive tumors. BRCA1 carriers frequently experienced lung and distant lymph node metastasis, whereas BRCA2 carriers and noncarriers most often experienced bone metastasis. Although CNS disease occurred frequently in both BRCA1 and BRCA2 carriers (53% BRCA1, 50% BRCA2, 25% noncarriers; P < .001), only BRCA2 mutation (P = .006) was significantly associated with CNS metastasis in multivariable analysis controlling for tumor subtype. BRCA2 mutation (P = .01), triple‐negative subtype (P < .001), and the involvement of CNS (P < .001) and other non‐CNS distant sites (relative to locoregional recurrence or contralateral disease; P < .001) at presentation of recurrent breast cancer were associated with risk for mortality.

Conclusions

CNS involvement is frequent in women with germline BRCA1/BRCA2 mutations who have metastatic breast cancer. BRCA2 mutation carriers had a significantly higher frequency of CNS metastasis than noncarriers when controlling for breast cancer subtype.

Germline BRCA1 or BRCA2 alterations are associated with a high frequency (≥50%) of brain metastases in patients with locoregionally recurrent or metastatic breast cancer. In multivariable analysis, only BRCA2 mutation (P = .006) was significantly associated with central nervous system metastasis when controlling for breast cancer subtype.

Preventing BRCA1/ZBRK1 repressor complex binding to the GOT2 promoter results in accelerated aspartate biosynthesis and promotion of cell proliferation

Breast cancer susceptibility gene 1 (BRCA1) has been implicated in modulating metabolism via transcriptional regulation. However, direct metabolic targets of BRCA1 and the underlying regulatory mechanisms are still unknown. Here, we identified several metabolic genes, including the gene which encodes glutamate‐oxaloacetate transaminase 2 (GOT2), a key enzyme for aspartate biosynthesis, which are repressed by BRCA1. We report that BRCA1 forms a co‐repressor complex with ZBRK1 that coordinately represses GOT2 expression via a ZBRK1 recognition element in the promoter of GOT2. Impairment of this complex results in upregulation of GOT2, which in turn increases aspartate and alpha ketoglutarate production, leading to rapid cell proliferation of breast cancer cells. Importantly, we found that GOT2 can serve as an independent prognostic factor for overall survival and disease‐free survival of patients with breast cancer, especially triple‐negative breast cancer. Interestingly, we also demonstrated that GOT2 overexpression sensitized breast cancer cells to methotrexate, suggesting a promising precision therapeutic strategy for breast cancer treatment. In summary, our findings reveal that BRCA1 modulates aspartate biosynthesis through transcriptional repression of GOT2, and provides a biological basis for treatment choices in breast cancer.

BRCA1 mutation in breast cancer patients: Analysis of prognostic factors and survival

The presence of BRCA1 mutations is associated with an increased risk of breast and ovarian cancer. The present study compared clinicopathological characteristics and overall survival (OS) of hereditary and sporadic breast cancer. Using data collected from a previous study conducted between 2007-2016 at the Maria Skłodowska Curie Cancer Center and Institute of Oncology (Gliwice, Poland), the prognostic factors and survival in 60 breast cancer mutation carriers were analyzed. A control group was selected from the breast cancer patients without BRCA mutations (n=386). BRCA mutation carriers had significantly worse survival when compared with non-carriers (P=0.017). The 10-year OS rate was 78.0% for all analyzed groups: 65.9% for BRCA mutation carriers and 81.1% for non-carriers. In the univariate analyses, BRCA mutation carriers had a significantly higher risk of mortality in comparison to non-carriers [hazard ratio (HR)=1.87; 95% confidence interval (CI) 1.08-3.25]. Increased tumor size (HR=3.64), lymph node metastases (HR=2.45) and higher histological grade (HR=2.84) were significant factors for worse OS. Positive estrogen receptor status was associated with a better OS (HR=0.49, P=0.022). Age ≤40 years (HR=0.48, P=0.081) was an insignificantly favorable factor. The 10-year survival rate was significantly decreased in patients with BRCA1 mutation. Therefore, negative factors for OS in mutation carriers included lymph nodes metastases, negative steroid receptor status and increased tumor size.

Precision medicine based on tumorigenic signaling pathways for triple-negative breast cancer

As a clinically heterogeneous subtype of breast cancer, triple-negative breast cancer (TNBC) is associated with a poor clinical outcome and a high relapse rate. Conventional chemotherapy and radiotherapy are effective treatments for patients with TNBC. However, the prognosis of TNBC remains unsatisfactory. Therefore, a large volume of research has explored the molecular markers and oncogenic signaling pathways associated with TNBC, including the cell cycle, DNA damage response and androgen receptor (AR) signaling pathways, to identify more efficient targeted therapies. However, whether these predicted pathways are effective targets has yet to be confirmed. In the present review, potentially carcinogenic signaling pathways in TNBCs from previous reports were considered, and ultimately five tumorigenic signaling pathways were selected, specifically receptor tyrosine kinases and downstream signaling pathways, the epithelial-to-mesenchymal transition and associated pathways, the immunoregulatory tumor microenvironment, DNA damage repair pathways, and AR and coordinating pathways. The conclusions of the preclinical and clinical trials of each pathway were then consolidated. Although a number of signaling pathways in TNBC have been considered in preclinical and clinical trials, the aforementioned pathways account for the majority of the malignant behaviors of TNBC. Identifying the alterations to different carcinogenic signaling pathways and their association with the heterogeneity of TNBC may facilitate the development of optimal precision medical approaches for patients with TNBC, potentially improving the efficiency of anticancer therapy.

BRCA mutation in breast cancer patients: Prognostic impact and implications on clinical management

BRCA1/2 mutations are involved in breast cancer (BC) susceptibility but their influence on outcome is unclear. We reviewed BC patients tested for BRCA to determine biological features and influence on outcome. BRCA-1 was correlated to younger age (P = 0.035), nodal involvement (P = 0.030), higher tumor grade (P = 0.0022) and Ki-67 (P = 0.014), ER/PgR negative status (P = 0.00042 and 0.0091, respectively), and use of adjuvant chemotherapy (P = 0.000038); BRCA was neither predictive for chemotherapy administration nor resulted in impaired outcome or occurrence of secondary BC. BRCA status did not influence outcome despite higher biological aggressiveness and younger age at presentation.

BRCA mutations and survival in breast cancer: an updated systematic review and meta-analysis

BRCA mutations occur frequently in breast cancer (BC), but their prognostic impact on outcomes of BC has not been determined. We conducted an updated meta-analysis on the association between BRCA mutations and survival in patients with BC. Electronic databases were searched. The primary outcome measure was overall survival (OS), and the secondary outcome measures included breast cancer-specific survival (BCSS) and event-free survival (EFS). Hazard ratios (HR) and 95% confidence interval (CI) were abstracted and pooled with random-effect modeling. Data from 297, 402 patients with BC were pooled from 34 studies. The median prevalence rates of BRCA1 and BRCA2 mutations were 14.5% and 8.3%, respectively. BRCA mutations were associated with worse OS (BRCA1: HR = 1.69, 95% CI, 1.35 to 2.12, p < 0.001; BRCA2: HR = 1.50, 95% CI 1.03 to 2.19, p = 0.034). However, this did not translate into poor BCSS (BRCA1: HR = 1.14, 95% CI, 0.81 to 1.16, p = 0.448; BRCA2: HR = 1.16; 95% CI 0.82 to 1.66, p = 0.401) or EFS (BRCA1: HR = 1.10, 95% CI, 0.86 to 1.41, p = 0.438; BRCA2: HR= 1.09; 95% CI 0.81 to 1.47, p = 0.558). Several studies analyzed BRCA1 and BRCA2 mutations together and found no impact on OS (HR = 1.21; 95% CI, 0.73 to 2.00, p = 0.454) or EFS (HR = 0.94; 95% CI, 0.60 to 1.48, p = 0.787). BRCA1 and BRCA2 mutations were associated with poor OS in patients with BC, but had no significant impact on BCSS or EFS. An improved survival was observed in BC patients who had BRCA1 mutation and treated with endocrinotherapy. The results may have therapeutic and prognostic implications important for BRCA mutation carriers with BC.

Germline BRCA mutation and outcome in young-onset breast cancer (POSH): a prospective cohort study

BACKGROUND

Retrospective studies provide conflicting interpretations of the effect of inherited genetic factors on the prognosis of patients with breast cancer. The primary aim of this study was to determine the effect of a germline BRCA1 or BRCA2 mutation on breast cancer outcomes in patients with young-onset breast cancer.

METHODS

We did a prospective cohort study of female patients recruited from 127 hospitals in the UK aged 40 years or younger at first diagnosis (by histological confirmation) of invasive breast cancer. Patients with a previous invasive malignancy (except non-melanomatous skin cancer) were excluded. Patients were identified within 12 months of initial diagnosis. BRCA1 and BRCA2 mutations were identified using blood DNA collected at recruitment. Clinicopathological data, and data regarding treatment and long-term outcomes, including date and site of disease recurrence, were collected from routine medical records at 6 months, 12 months, and then annually until death or loss to follow-up. The primary outcome was overall survival for all BRCA1 or BRCA2 mutation carriers (BRCA-positive) versus all non-carriers (BRCA-negative) at 2 years, 5 years, and 10 years after diagnosis. A prespecified subgroup analysis of overall survival was done in patients with triple-negative breast cancer. Recruitment was completed in 2008, and long-term follow-up is continuing.

FINDINGS

Between Jan 24, 2000, and Jan 24, 2008, we recruited 2733 women. Genotyping detected a pathogenic BRCA mutation in 338 (12%) patients (201 with BRCA1, 137 with BRCA2). After a median follow-up of 8·2 years (IQR 6·0-9·9), 651 (96%) of 678 deaths were due to breast cancer. There was no significant difference in overall survival between BRCA-positive and BRCA-negative patients in multivariable analyses at any timepoint (at 2 years: 97·0% [95% CI 94·5-98·4] vs 96·6% [95·8-97·3]; at 5 years: 83·8% [79·3-87·5] vs 85·0% [83·5-86·4]; at 10 years: 73·4% [67·4-78·5] vs 70·1% [67·7-72·3]; hazard ratio [HR] 0·96 [95% CI 0·76-1·22]; p=0·76). Of 558 patients with triple-negative breast cancer, BRCA mutation carriers had better overall survival than non-carriers at 2 years (95% [95% CI 89-97] vs 91% [88-94]; HR 0·59 [95% CI 0·35-0·99]; p=0·047) but not 5 years (81% [73-87] vs 74% [70-78]; HR 1·13 [0·70-1·84]; p=0·62) or 10 years (72% [62-80] vs 69% [63-74]; HR 2·12 [0·82-5·49]; p= 0·12).

INTERPRETATION

Patients with young-onset breast cancer who carry a BRCA mutation have similar survival as non-carriers. However, BRCA mutation carriers with triple-negative breast cancer might have a survival advantage during the first few years after diagnosis compared with non-carriers. Decisions about timing of additional surgery aimed at reducing future second primary-cancer risks should take into account patient prognosis associated with the first malignancy and patient preferences.

FUNDING

Cancer Research UK, the UK National Cancer Research Network, the Wessex Cancer Trust, Breast Cancer Now, and the PPP Healthcare Medical Trust Grant.

Proteomic Analysis of the Downstream Signaling Network of PARP1

Poly-ADP-ribosylation (PARylation) is a protein posttranslational modification (PTM) that is critically involved in many biological processes that are linked to cell stress responses. It is catalyzed by a class of enzymes known as poly-ADP-ribose polymerases (PARPs). In particular, PARP1 is a nuclear protein that is activated upon sensing nicked DNA. Once activated, PARP1 is responsible for the synthesis of a large number of PARylated proteins and initiation of the DNA damage response mechanisms. This observation provided the rationale for developing PARP1 inhibitors for the treatment of human malignancies. Indeed, three PARP1 inhibitors (Olaparib, Rucaparib, and Niraparib) have recently been approved by the Food and Drug Administration for the treatment of ovarian cancer. Moreover, in 2017, both Olaparib and Niraparib have also been approved for the treatment of fallopian tube cancer and primary peritoneal cancer. Despite this very exciting progress in the clinic, the basic signaling mechanism that connects PARP1 to a diverse array of biological processes is still poorly understood. This is, in large part, due to the inherent technical difficulty associated with the analysis of protein PARylation, which is a low-abundance, labile, and heterogeneous PTM. The study of PARylation has been greatly facilitated by the recent advances in mass spectrometry-based proteomic technologies tailored to the analysis of this modification. In this Perspective, we discuss these breakthroughs, including their technical development, and applications that provide a global view of the many biological processes regulated by this important protein modification.

The expression of APE1 in triple-negative breast cancer and its effect on drug sensitivity of olaparib

Triple-negative breast cancer is a kind of breast cancer with poor prognosis and special biological behavior, which lacked endocrine therapy and targeted therapy. We investigate the effect of human APE1 (apurinic/apyrimidyl endonuclease 1), a rate-limiting enzyme of base excision repair, on the prognosis in triple-negative breast cancer and drug sensitivity of olaparib. The expression of APE1 was detected by immunohistochemistry in the triple-negative breast cancer tissues and its effect on survival of triple-negative breast cancer patients was followed. To find whether APE1 effect the drug sensitivity in triple-negative breast cancer cells, the APE1-knockout HCC1937 cell line (triple-negative breast cancer cell line) was established by CRISPR/Cas9 system. Then, we use the wild-type and knockout one to test the drug sensitivity of olaparib. The expression of APE1 in triple-negative breast cancer tissues was significantly higher than that in the adjacent tissues (85.6% vs 14.4%) and its expression was related to tumor size (p < 0.05). We also found that it is an independent prognostic factor in patients with triple-negative breast cancer (overall survival, p = 0.01). In vitro assay, the half maximal inhibitory concentration of olaparib in HCC1937-APE1-KO was significantly increased (17.22 vs 91.85 μM) compared to the wild type. The growth curve showed that olaparib had a stronger lethality on HCC1937 compared to HCC1937- APE1-KO (p < 0.05 on day 3). HCC1937 resulted in more mitotic G2/M arrest and increased apoptosis rate after treatment with 40 μM of olaparib, while HCC1937-APE1-KO did not change significantly. When HCC1937 was treated with different concentrations of olaparib, it was found that APE1 expression decreased more significantly at 15 μM of olaparib was. In HCC1937-APE1-KO, the expression of endogenous poly (ADP-ribose) polymerase 1 was also less than that of HCC1937. These results suggested that the expression of APE1 was an important basis for the maintenance of poly (ADP-ribose) polymerase 1, and the deletion of APE1 may be related to the resistance of olaparib.

Germline Mutations in Cancer Susceptibility Genes in a Large Series of Unselected Breast Cancer Patients

Purpose: The prevalence of mutations in cancer susceptibility genes such as BRCA1 and BRCA2 and other cancer susceptibility genes and their clinical relevance are largely unknown among a large series of unselected breast cancer patients in the Chinese population.Experimental Design: A total of 8,085 consecutive unselected Chinese breast cancer patients were enrolled. Germline mutations in 46 cancer susceptibility genes were detected using a 62-gene panel.Results: Pathogenic mutations were identified in 9.2% of patients among the 8,085 unselected breast cancer patients. Of these, 5.3% of patients carried a BRCA1 or BRCA2 mutation (1.8% in BRCA1 and 3.5% in BRCA2), 2.9% carried other breast cancer susceptibility genes (BOCG) and 1.0% carried another cancer susceptibility genes. Triple-negative breast cancers had the highest prevalence of BRCA1/2 mutations (11.2%) and other BOCG mutations (3.8%) among the four molecular subgroups, whereas ER^-/PR^-HER2⁺ breast cancers had the lowest mutations in BRCA1/2 (1.8%) and BOCG (1.6%). In addition, BRCA1 mutation carriers had a significant worse disease-free survival [unadjusted hazard ratio (HR) 1.60; 95% confidence interval (CI) 1.10-2.34; P = 0.014] and disease-specific survival (unadjusted HR 1.96; 95% CI, 1.03-3.65; P = 0.040) than did non-carriers, whereas no significant difference in survival was found between BRCA2 mutation carriers and non-carriers.Conclusions: 9.2% of breast cancer patients carry a pathogenic mutation in cancer susceptibility genes in this large unselected series. Triple-negative breast cancers have the highest prevalence of mutations in BRCA1 /2 and other breast cancer susceptibility genes among the four molecular subgroups, whereas ER^-/PR^-HER2⁺ breast cancers had the lowest mutations in these genes. Clin Cancer Res; 23(20); 6113-9. ©2017 AACR.

BRCA1-hapoinsufficiency: Unraveling the molecular and cellular basis for tissue-specific cancer

Over the past 20 years tremendous progress has been made in understanding the function of BRCA1 gene products. Yet one question still remains: why is mutation of BRCA1 typically associated with preferential development of breast and ovarian cancers and not tumors in other tissues? Here we discuss recent evidence documenting the effect of BRCA1-haploinsufficiency in different cells and tissues and synthesize a model for how mutations in a single BRCA1 allele in human cells might preferentially confer increased cancer risk in breast epithelial cells.

Tumor characteristics and prognosis in familial breast cancer

BACKGROUND

Approximately 5-10% of breast cancers are hereditary and their biology and prognosis appear to differ from those of sporadic breast cancers. In this study we compared the biological features and clinical characteristics of non metastatic breast cancer in patients with BRCA mutations versus patients with a family history suggesting hereditary breast cancer but without BRCA mutations (BRCA wild type) versus patients with sporadic disease, and correlated these findings with clinical outcome.

METHODS

We retrieved the clinical and biological data of 33 BRCA-positive, 66 BRCA-wild type and 1826 sporadic breast cancer patients contained in a single institution clinical database between 1980 and 2012. Specifically, we recorded age, tumor size, nodal status, treatment type, pattern of relapse, second primary incidence, outcome (disease-free survival and overall survival), and biological features (estrogen receptor [ER], progesterone receptor [PgR], tumor grade, proliferation and c-erbB2 status). Median follow-up was 70 months.

RESULTS

BRCA-positive patients were significantly younger than sporadic breast cancer patients, and less likely to be ER-, PgR- or c-erbB2-positive than women with BRCA-wild type or sporadic breast cancer. Tumor size and grade, nodal status and proliferation did not differ among the three groups. Rates of radical mastectomy were 58, 42 and 37%, and those of conservative surgery were 42, 58 and 63% in women with BRCA-positive, BRCA-wild type and sporadic breast cancer (p = 0.03), respectively. The incidence of contralateral breast cancer was 12, 14 and 0% (p <0.0001) and the incidence of second primary tumors (non breast) was 9, 1 and 2% (p <0.0001) in BRCA-positive, BRCA-wild type and sporadic breast cancer, respectively. Median disease-free survival in years was 29 in BRCA-wild type, 19 in BRCA-positive and 14 in sporadic breast cancer patients (log-rank = 0.007). Median overall survival in years was not reached for BRCA-wild type, 19 for BRCA-positive and 13 for sporadic breast cancer patients (log-rank <0.0001). At multivariate analyses only BRCA-wild type status was related to a significant improvement in overall survival versus the sporadic breast cancer group (HR = 0,51; 95% CI (0,28-0,93) p = 0.028).

CONCLUSIONS

The biology and outcome of breast cancer differ between patients with BRCA mutations, patients with a family history but no BRCA mutations and patients with sporadic breast cancer.

Early onset breast cancer in Ashkenazi women carriers of founder BRCA1/2 mutations: beyond 10 years of follow-up

This study uncovers disease characteristics by long-term follow-up in Ashkenazi early onset breast cancer (EOBC) patients, carriers of founder BRCA1/2 mutations compared to non-carriers of such mutations. An archives-retrospective design was conducted to study the pathological and clinical characteristics of 149 Ashkenazi Jewish EOBC patients (<42 years) who were referred consecutively to the oncogenetic clinic by the oncology centre at Rambam HealthCare Campus, as from 1995, with a mean follow-up of 13.61 years. Of 149 patients, 33 (22.1%) and 15 (10.1%) carried the founder BRCA1 (185delAG; 5382insC) and BRCA2 (6174delT) mutations, respectively; and 101 (67.8%) were non-carriers of these mutations. Contralateral breast-cancer was predominant among BRCA1/2 carriers compared to non-carriers (14, 58.3%; 6, 60%; 7, 8.1%; respectively, p < .001). Ovarian cancer was diagnosed in two BRCA1 carriers and one non-carrier. Oestrogen and/or progesterone receptor negative tumours were majorly detected in BRCA1 carriers (n = 16, 57.1%) compared to BRCA2 carriers (n = 4, 30.8%) and non-carriers (n = 23, 25.3%) (p = .007). BRCA1 carriers and non-carriers developed contralateral breast cancer at an earlier age than BRCA2 carriers. BRCA2 carriers portrayed similar tumour characteristics to non-carriers. EOBC BRCA1/2 carriers are at risk to develop bilateral disease; however, they are similarly susceptible for local recurrence, distant metastases and mortality.

Interaction between Hormonal Receptor Status, Age and Survival in Patients with BRCA1/2 Germline Mutations: A Systematic Review and Meta-Regression

Background

Germline mutations in the BRCA1 and BRCA2 genes are the most frequent known hereditary causes of familial breast cancer. Little is known about the interaction of age at diagnosis, estrogen receptor (ER) and progesterone receptor (PgR) expression and outcomes in patients with BRCA1 or BRCA2 mutations.

Methods

A PubMed search identified publications exploring the association between BRCA mutations and clinical outcome. Hazard ratios (HR) for overall survival were extracted from multivariable analyses. Hazard ratios were weighted and pooled using generic inverse-variance and random-effect modeling. Meta-regression weighted by total study sample size was conducted to explore the influence of age, ER and PgR expression on the association between BRCA mutations and overall survival.

Results

A total of 16 studies comprising 10,180 patients were included in the analyses. BRCA mutations were not associated with worse overall survival (HR 1.06, 95% CI 0.84–1.34, p = 0.61). A similar finding was observed when evaluating the influence of BRCA1 and BRCA2 mutations on overall survival independently (BRCA1: HR 1.20, 95% CI 0.89–1.61, p = 0.24; BRCA2: HR 1.01, 95% CI 0.80–1.27, p = 0.95). Meta-regression identified an inverse association between ER expression and overall survival (β = -0.75, p = 0.02) in BRCA1 mutation carriers but no association with age or PgR expression (β = -0.45, p = 0.23 and β = 0.02, p = 0.97, respectively). No association was found for BRCA2 mutation status and age, ER, or PgR expression.

Conclusion

ER-expression appears to be an effect modifier in patients with BRCA1 mutations, but not among those with BRCA2 mutations.

Comparison of Clinicopathological Features and Prognosis in Triple-Negative and Non-Triple Negative Breast Cancer

Purpose: Triple-negative breast cancer (TNBC) has attracted more attention both clinically and experimentally because of its high-risk biological characteristics and lacking of effective treatment method. The purpose of this retrospective study was to find out the incidence of triple-negative breast cancer (TNBC) in all kinds of breast cancers and to compare and analyze the clinicopathological features, recurrence, metastasis and prognosis of patients with TNBC and non-triple negative breast cancer (non-TNBC).

Methods: A total of 1578 female patients with primary breast cancer were diagnosed and treated at the department of General Surgery, the Chinese PLA General Hospital, China, from Jan. 2004 to Jun. 2009. The 1578 breast cancer patients were divided into two groups: the TNBC group and the non-TNBC group. The clinical features and prognosis of the two groups were compared.

Results: The incidence of TNBC was 20.41%. Compared with the non-TNBC, the TNBC were characterized as younger age, higher histological grade, higher rate of positive lymph node, bigger tumor size, higher clinical stage at diagnosis, higher histological grade, quicker and easier recurrence and metastasis and lower 5-year DFS rate and 5-year OS rate. The metastasis of TNBC had obvious organic tendency. The lungs, liver and brain were the first three most common sites of metastases. The information of age, the tumor size, lymph node status, clinical stage, histological grade, pathological types and operation method, especially the age and lymph node status play the important roles in judging the prognosis of TNBC.

Conclusions: According to this study we found that TNBC was a distinct subgroup of breast cancer with particular clinicopathologic behavior. Compared with the non-TNBC, TNBC was characterized by more aggressive behavior, and lower DFS and OS rate. The metastasis of TNBC had obvious organic tendency. The information of age, the maximum diameter of the tumor, lymph node status, clinical stage, histological grade, pathological types and operation method, especially the age and lymph node status played the important roles in judging the prognosis of TNBC patients.

What common biomarkers characterize a triple-negative profile in breast cancer?

Triple-negative breast cancers are not a homogeneous subgroup. There is substantial intra-subgroup diversity in tumor biology, prognosis and treatment sensitivity. Then, these triple-negative phenotype (TNP) groups, having specific features, can be again divided into subclasses based on an added immunohistochemical markers. The challenge in treating TNP breast cancers is that they are not responsive to antiestrogens or trastuzumab secondary to negative receptor status, and as a result have a poor prognosis. Therefore, the presence or absence of supplementary markers could help predict which therapies are best suited for patients based on the pattern that their disease markers show. In this review, we will recapitulate the major supplementary biomarkers related to triple-negative breast cancer, which could give new therapeutic options.

Association between cytosolic expression of BRCA1 and metastatic risk in breast cancer

Background:

Although BRCA1 has been extensively studied for its role as a tumour-suppressor protein, the role of BRCA1 subcellular localisation in oncogenesis and tumour progression has remained unclear. This study explores the impact of BRCA1 mislocalisation on clinical outcomes in breast cancer.

Methods:

Tissue microarrays assembled from a cohort of patients with all stages of breast cancer were analysed for BRCA1 localisation and correlated with patient survival. Tissue microarrays of patients who had breast cancer that had metastasised to the lung were assembled from an independent cohort of patients. These were analysed for BRCA1 subcellular expression. In vitro studies using cultured human breast cancer cells were conducted to examine the effect of cytosolic BRCA1 on cell migration and efficiency of invasion.

Results:

An inverse association was found between cytosolic BRCA1 expression and metastasis-free survival in patients aged >40 years. Further analysis of BRCA1 subcellular expression in a cohort of breast cancer patients with metastatic disease revealed that the cytosolic BRCA1 content of breast tumours that had metastasised to the lung was 36.0% (95% CI=(31.7%, 40.3%), which was markedly higher than what is reported in the literature (8.2–14.8%). Intriguingly, these lung metastases and their corresponding primary breast tumours demonstrated similarly high cytosolic BRCA1 distributions in both paired and unpaired analyses. Finally, in vitro studies using human breast cancer cells demonstrated that genetically induced BRCA1 cytosolic sequestration (achieved using the cytosol-sequestering BRCA1 5382insC mutation) increased cell invasion efficiency.

Conclusions:

Results from this study suggest a model where BRCA1 cytosolic mislocalisation promotes breast cancer metastasis, making it a potential biomarker of metastatic disease.

Worse breast cancer prognosis of BRCA1/BRCA2 mutation carriers: what's the evidence? A systematic review with meta-analysis

Objective

Conflicting conclusions have been published regarding breast cancer survival of BRCA1/2 mutation carriers. Here we provide an evidence-based systematic literature review.

Methods

Eligible publications were observational studies assessing the survival of breast cancer patients carrying a BRCA1/2 mutation compared to non-carriers or the general breast cancer population. We performed meta-analyses and best-evidence syntheses for survival outcomes taking into account study quality assessed by selection bias, misclassification bias and confounding.

Results

Sixty-six relevant studies were identified. Moderate evidence for a worse unadjusted recurrence-free survival for BRCA1 mutation carriers was found. For BRCA1 and BRCA2 there was a tendency towards a worse breast cancer-specific and overall survival, however, results were heterogeneous and the evidence was judged to be indecisive. Surprisingly, only 8 studies considered adjuvant treatment as a confounder or effect modifier while only two studies took prophylactic surgery into account. Adjustment for tumour characteristics tended to shift the observed risk estimates towards a relatively more favourable survival.

Conclusions

In contrast to currently held beliefs of some oncologists, current evidence does not support worse breast cancer survival of BRCA1/2 mutation carriers in the adjuvant setting; differences if any are likely to be small. More well-designed studies are awaited.

BRCA1 mutation site may be linked with nuclear DNA ploidy in BRCA1-mutated ovarian carcinomas

AIMS

BRCA1 has a role in maintaining normal nuclear DNA content during cell division and its inactivation may result in DNA aneuploidy and cancer progression. BRCA1-linked breast cancers are more aneuploid and have a worse prognosis, but this has not been elucidated in ovarian cancers. This study explores the potential difference in ploidy status between BRCA1-mutated and sporadic ovarian carcinomas. It also explores the potential association between BRCA1 mutation site and DNA ploidy status.

METHODS

This study compared DNA ploidy status of tumor blocks from 23 BRCA1-mutated ovarian carcinomas with that of 23 sporadic ovarian carcinomas matched for histologic subtype, patient age, stage and grade. DNA content of the nuclei was measured by Feulgen-Schiff staining followed by image cytometry and compared.

RESULTS

BRCA1-linked tumors with a stop codon closer to the N-terminal (between 1 and 500 aa; 6/6, 100%) had a significantly higher frequency of nondiploidy compared with those with stop codon above 500 aa (7/12, 58%) (P = 0.033). A diploid peak was detected in 28% of BRCA1-mutated ovarian cancers and in 33% of sporadic ovarian cancers.

CONCLUSIONS

The present study concluded that ovarian tumors with mutations closer to the N-terminal of BRCA1 may have a higher risk of DNA aneuploidy. There is no significant difference between BRCA1-mutated and sporadic ovarian carcinomas with respect to the DNA content.

Cumulative risk of second primary contralateral breast cancer in BRCA1/BRCA2 mutation carriers with a first breast cancer: A systematic review and meta-analysis

BRCA1/2 mutation carriers are at a higher risk of breast cancer and of subsequent contralateral breast cancer (CBC). This study aims to evaluate the evidence of the effect of the BRCA1/2-carriership on CBC cumulative risk in female breast cancer patients. The literature was searched in Pubmed and Embase up to June 2013 for studies on CBC risk after a first primary invasive breast cancer in female BRCA1/2 mutation carriers. A qualitative synthesis was carried out and the methodological quality of the studies evaluated. Cumulative risks of CBC after 5, 10 and 15 years since the first breast cancer diagnosis were pooled by BRCA1/2 mutation status. A total number of 20 articles, out of 1324 retrieved through the search, met the inclusion criteria: 18 retrospective and 2 prospective cohort studies. Cumulative risks of up to five studies were pooled. The cumulative 5-years risk of CBC for BRCA1 and BRCA2 mutation carriers was 15% (95% CI: 9.5%-20%) and 9% (95% CI: 5%-14%), respectively. This risk increases with time since diagnosis of the first breast cancer; the 10-years risk increased up to 27% and 19%, respectively. The 5-years cumulative risk was remarkably lower in non-BRCA carriers (3%; 95% CI: 2%-5%) and remained so over subsequent years (5%; 95% CI: 3%-7%). In conclusion, risk of CBC increases with length of time after the first breast cancer diagnosis in BRCA1/2 mutation carriers. Studies addressing the impact of treatment-related factors and clinical characteristics of the first breast cancer on this risk are warranted.

Effects of BRCA1- and BRCA2-related mutations on ovarian and breast cancer survival: a meta-analysis

PURPOSE

To estimate the effects of BRCA1 and BRCA2 mutations on ovarian cancer and breast cancer survival.

EXPERIMENTAL DESIGN

We searched PubMed and EMBASE for studies that evaluated the associations between BRCA mutations and ovarian or breast cancer survival. Meta-analysis was conducted to generate combined HRs with 95% confidence intervals (CI) for overall survival (OS) and progression-free survival (PFS).

RESULTS

From 1,201 unique citations, we identified 27 articles that compared prognosis between BRCA mutation carriers and noncarriers in patients with ovarian or breast cancer. Fourteen studies examined ovarian cancer survival and 13 studies examined breast cancer survival. For ovarian cancer, meta-analysis demonstrated that both BRCA1 and BRCA2 mutation carriers had better OS (HR, 0.76; 95% CI, 0.70-0.83 for BRCA1 mutation carriers; HR, 0.58; 95% CI, 0.50-0.66 for BRCA2 mutation carriers) and PFS (HR, 0.65; 95% CI, 0.52-0.81 for BRCA1 mutation carriers; HR, 0.61; 95% CI, 0.47-0.80 for BRCA2 mutation carriers) than noncarriers, regardless of tumor stage, grade, or histologic subtype. Among patients with breast cancer, BRCA1 mutation carriers had worse OS (HR, 1.50; 95% CI, 1.11-2.04) than noncarriers but were not significantly different from noncarriers in PFS. BRCA2 mutation was not associated with breast cancer prognosis.

CONCLUSIONS

Our analyses suggest that BRCA mutations are robust predictors of outcomes in both ovarian and breast cancers and these mutations should be taken into account when devising appropriate therapeutic strategies.

Properties of cellular and serum forms of thymidine kinase 1 (TK1) in dogs with acute lymphocytic leukemia (ALL) and canine mammary tumors (CMTs): implications for TK1 as a proliferation biomarker

BACKGROUND

Thymidine kinase 1 (TK1) is a deoxyribonucleic acid (DNA) precursor enzyme and a proliferation biomarker used for prognosis and treatment monitoring of breast cancer in humans. The aim was to determine if serum thymidine kinase 1 (sTK1) activity and sTK1 protein levels in dogs with mammary tumors could be useful in veterinary medicine.

RESULTS

Serum samples from 20 healthy dogs and 27 dogs with mammary tumors were analyzed for sTK1 activity, using an [(3)H]-deoxythymidine (dThd) phosphorylation assay, and for sTK1 protein levels by immune affinity/Western blot assay. The molecular forms of sTK1 in acute lymphocytic leukemia (ALL), canine mammary tumor (CMT), and healthy sera were determined by size exclusion chromatography. Mean sTK1 activities in CMT were 1.0 ± 0.36 pmol/min/mL, differing significantly from healthy dogs (mean ± SD = 0.73 ± 0.26 pmol/min/mL). Serum TK1 protein (26 kDa polypeptide) levels were also significantly higher in CMTs compared to healthy dogs (mean ± SD = 28.5 ± 11.4, and 8.5 ± 4 ng/mL, respectively). Cellular TK1 isolated from ALL tumor cells was predominantly a dimer, while the serum TK1 activity eluted as a high molecular weight (MW) oligomer. In analyses of CMT tissue extracts, TK1 activity eluted in two peaks, a minor peak with a high MW oligomer and a major tetramer peak. Western blot analysis of chromatographic fractions showed that cellular TK1 protein in both ALL and CMT dogs, and to some extent serum TK1 from ALL dogs, correlated with activity profiles, but a large fraction of inactive TK1 protein was detected in CMT.

CONCLUSIONS

Serum TK1 protein and activity levels were significantly higher in CMT than in healthy dogs. Size exclusion chromatography demonstrated major differences in the molecular forms of sTK1 in ALL, healthy, and CMT dogs, with a large fraction of inactive TK1 protein in CMT. Our results showed that the sTK1 protein assay can differentiate benign tumors (early stage tumors) from healthy more efficiently than sTK1 activity assay. This preliminary data supports that sTK1 protein assay is clinically useful. Further studies are needed to evaluate the diagnostic or prognostic role of serum TK1 protein in CMTs.

Surgical management of breast cancer in BRCA-mutation carriers: a systematic review and meta-analysis

This meta-analysis investigates the oncological safety of breast-conserving therapy BCT in BRCA-mutation carriers and the risk for contralateral breast cancer (CBC) compared with non-carriers, potential risk factors for ipsilateral breast recurrence (IBR) or CBC and grades these factors based on the level of evidence. A PubMed search was conducted through April 2013 to identify studies that described the risk for IBR and CBC after BCT in BRCA-mutation carriers versus non-carriers as well as studies that investigated risk factors for IBR and CBC in BRCA-mutation carriers. Results were summarized using meta-analysis when sufficient studies were available. Ten studies investigated the oncological safety of BCT in BRCA-mutation carriers versus non-carriers. There was no significant difference in IBR between carriers and controls (RR 1.45, 95 % CI 0.98-2.14). However, a significant higher risk for IBR in BRCA-mutation carriers was observed in studies with a median follow-up ≥7 years (RR 1.51, 95 % CI 1.15-1.98). CBCs were significantly greater in carriers versus controls (RR 3.56, 95 % CI 2.50-5.08). Use of adjuvant chemotherapy and oophorectomy were associated with a significantly lower risk for IBR in BRCA-mutation carriers. Three factors were associated with a lower risk for CBC in BRCA-mutation carriers: oophorectomy, use of tamoxifen, and age at first breast cancer. Based on current evidence, the use of BCT in BRCA-mutation carriers can be considered a reasonable option since it does not seem to increase the risk for IBR. However, several aspects should be taken into account before the final decision-making.

Clinicopathological and prognostic characteristics of triple- negative breast cancer (TNBC) in Chinese patients: a retrospective study

AIMS

To determine the clinical, pathological and prognostic features associated with triple-negative breast cancer (TNBC).

METHODS

Clinical and histologic data of 21,749 breast cancer patients who were treated at Tianjin Medical University Cancer Institute and Hospital between July 2002 and December 2011 were collected. Patients were divided into two groups: those with TNBC and those with other types of breast cancer. Patients and tumor characteristics were compared between the two groups using the Chi-square test. The prognostic results of 9,823 patients in the study population were also analyzed to determine long-term survival rates in the two groups of breast cancer patients.

RESULTS

Among the breast cancer patients treated in our hospital between 2003 and 2011, 10.4%-13.5% of them had triple-negative breast cancers. Data analyses revealed significant differences in disease onset age, family history of breast cancer, tumor size, tumor histologic grade, lymph note positivity and metastatic status between TNBC and non-TNBC patients. There were also significant differences in 5-year, 7-year and 9-year disease-free and 7-year and 9-year overall survival probability between the groups.

CONCLUSIONS

TNBC are associated with younger disease onset age, larger tumor size, higher rate of axillary lymph node positivity, and higher tumor histologic grade. TNBC is also related to family history of breast cancer, increased metastatic risk and poor prognosis.

The korean hereditary breast cancer study: review and future perspectives

Most studies related to BRCA mutations have been performed in Western populations, and only a few small studies have been conducted in Korean populations. In 2007, the Korean Hereditary Breast Cancer (KOHBRA) Study was established to obtain evidence for the accurate risk assessment and management of hereditary breast and ovarian cancer (HBOC) in Korea. Between May 2007 and May 2010, the first phase of the KOHBRA Study was performed to estimate the prevalence of BRCA1/2 mutations among patients and their families at risk for HBOC. Between June 2010 and May 2013, the second phase of the KOHBRA Study was performed to identify the clinical characteristics and prognostic indicators of BRCA-related breast cancer and environmental and genetic modifiers of BRCA mutations and to develop a Korean BRCA risk calculator and nationwide genetic counseling network for HBOC. Herein, we review the results of the KOHBRA Study and describe the future perspectives of the study.

Identifying and exploiting defects in the Fanconi anemia/BRCA pathway in oncology

Defects in components of DNA repair pathways are responsible for numerous hereditary cancer syndromes and are also common in many sporadic malignancies. Inherited mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 or components of the Fanconi anemia (FA) complex incite genomic instability and predispose to malignancy. The products of the BRCA and FA genes participate in a conserved DNA damage repair pathway that is responsible for repairing interstrand crosslinks and double-strand DNA breaks by homologous recombination. While the genetic instability resulting from FA/BRCA dysfunction contributes to cancer pathogenesis, deficiency of these genes also lends to therapeutic exploitation. Crosslinking agents and ionizing radiation induce damage in cancer cells that requires the FA/BRCA pathway to be resolved; thus cancers that are deficient in BRCA1, BRCA2, or any other component of the FA/BRCA pathway are hypersensitive to these agents. Moreover, emerging synthetic lethal strategies offer opportunities to selectively target cancer cells with defects in homologous recombination. Conversely, enhanced activity of the FA/BRCA pathway is responsible for acquired resistance to specific therapeutic agents, suggesting that both dysfunction and hyperfunction of the FA/BRCA repair machinery are rational targets for cancer therapy. Selection of specific cytotoxic agents based on repair capacity may improve responses and enable personalized cytotoxic chemotherapy. This article reviews the FA/BRCA pathway and current approaches to identify deficiencies within it, discusses synthetic lethality and enhanced repair capacity as causes of therapeutic hypersensitivity and resistance, respectively, and highlights recent studies that have linked FA/BRCA pathway function with therapeutic efficacy.

Breast cancer prognosis in BRCA1 and BRCA2 mutation carriers: an International Prospective Breast Cancer Family Registry population-based cohort study

PURPOSE

To compare breast cancer prognosis in BRCA1 and BRCA2 mutation carriers with that in patients with sporadic disease.

PATIENTS AND METHODS

An international population-based cohort study was conducted in Canada, the United States, and Australia of 3,220 women with incident breast cancer diagnosed between 1995 and 2000 and observed prospectively. Ninety-three had BRCA1 mutations; 71, BRCA2 mutations; one, both mutations; 1,550, sporadic breast cancer; and 1,505, familial breast cancer (without known BRCA1 or BRCA2 mutation). Distant recurrence and death were analyzed.

RESULTS

Mean age at diagnosis was 45.3 years; mean follow-up was 7.9 years. Risks of distant recurrence and death did not differ significantly between BRCA1 mutation carriers and those with sporadic disease in univariable and multivariable analyses. Risk of distant recurrence was higher for BRCA2 mutation carriers compared with those with sporadic disease in univariable analysis (hazard ratio [HR], 1.63; 95% CI, 1.02 to 2.60; P = .04). Risk of death was also higher in BRCA2 carriers in univariable analysis (HR, 1.81; 95% CI, 1.15 to 2.86; P = .01). After adjustment for age, tumor stage and grade, nodal status, hormone receptors, and year of diagnosis, no differences were observed for distant recurrence (HR, 1.00; 95% CI, 0.62 to 1.61; P = 1.00) or death (HR, 1.12; 95% CI, 0.70 to 1.79; P = .64).

CONCLUSION

Outcomes of BRCA1 mutation carriers were similar to those of patients with sporadic breast cancer. Worse outcomes in BRCA2 mutation carriers in univariable analysis seem to reflect the presence of more adverse tumor characteristics in these carriers. Similar outcomes were identified in BRCA2 carriers and those with sporadic disease in multivariable analyses.

Triple-negative breast cancers: an updated review on treatment options

Morphologic features of tumour cells have long been validated for the clinical classification of breast cancers and are regularly used as a "gold standard" to ascertain prognostic outcome in patients. Identification of molecular markers such as expression of the receptors for estrogen (er) and progesterone (pgr) and the human epidermal growth factor receptor 2 (her2) has played an important role in determining targets for the development of efficacious drugs for treatment and has also offered additional predictive value for the therapeutic assessment of patients with breast cancer. More recent technical advancements in identifying several cancer-related genes have provided further opportunities to identify specific subtypes of breast cancer. Among the subtypes, tumours with triple-negative cells are identified using specific staining procedures for basal markers such as cytokeratin 5 and 6 and the absence of er, pgr, and her2 expression. Patients with triple-negative breast cancers therefore have the disadvantage of not benefiting from currently available receptor-targeted systemic therapy. Optimal conditions for the therapeutic assessment of women with triple-negative breast tumours and for the management of their disease have yet to be validated in prospective investigations. The present review discusses the differences between triple-negative breast tumours and basal-like breast tumours and also the role of mutations in the BRCA genes. Attention is also paid to treatment options available to patients with triple-negative breast tumours.

Response to neoadjuvant systemic therapy for breast cancer in BRCA mutation carriers and noncarriers: a single-institution experience

PURPOSE

To compare the pathologic complete response (pCR) rate and relapse-free survival (RFS) and overall survival (OS) after neoadjuvant systemic chemotherapy (NST) in patients with breast cancer with and without deleterious BRCA1 and BRCA2 mutations.

PATIENTS AND METHODS

A total of 317 women who underwent BRCA genetic testing and were treated with NST for breast cancer between 1997 and 2009 were included in the study. The Kaplan-Meier product-limit method was used to estimate RFS and OS rates. Logistic regression models were fit to determine the associations between BRCA status, pCR, and survival.

RESULTS

Fifty-seven (18%) and 23 (7%) patients had BRCA1 and BRCA2 mutations, respectively. Twenty-six (46%) of 57 BRCA1 carriers achieved a pCR, compared with three (13%) of 23 BRCA2 carriers and 53 (22%) of 237 BRCA noncarriers (P < .001). In the multivariate logistic model, BRCA1 status (odds ratio [OR] = 3.16; 95% CI, 1.55 to 6.42; P = .002), estrogen receptor (ER) negativity (OR = 1.96; 95% CI:1.05 to 3.65; P = .03) and concurrent trastuzumab use (OR = 4.18; 95% CI, 2.04 to 8.57; P < .001) remained as independent significant predictors for a pCR. At a median follow-up of 3.2 years, 69 patients (22%) experienced a disease recurrence or death. No significant differences were noted in survival outcomes with respect to BRCA status and type of NST received. However, among BRCA1 carriers, patients who achieved a pCR had better 5-year RFS (P = .001) and OS (P = .01) rates than patients who did not.

CONCLUSION

BRCA1 status and ER negativity are independently associated with higher pCR rates in patients with breast cancer. Overall prognosis of breast cancer in BRCA carriers is similar to sporadic breast cancers.

Family history of breast cancer in relation to tumor characteristics and mortality in a population-based study of young women with invasive breast cancer

BACKGROUND

Inherited predisposition may be associated with distinctive breast cancer phenotypes and/or mortality. Past studies have had inconsistent results and little is known about the contributions of screening and treatment.

METHODS

Within a population-based cohort of 1,260 women diagnosed with invasive breast cancer before age 46, we assessed how family history of breast cancer relates to mortality and tumor characteristics. Analyses were repeated excluding BRCA1/BRCA2 carriers. Medical records were reviewed for treatment history and tumors were centrally reviewed and tested. Cox proportional hazard modeling was used to assess the risk of dying in relation to family history; logistic regression was used to assess the association of family history to tumor characteristics.

RESULTS

Compared with women with no family history, women with first-degree family history of breast cancer had a 40% reduction (95% CI: 0.5-0.8) in the risk of dying. Mortality in women with only a second-degree family history was similar to those with no family history. The risk of dying was further reduced in those with a greater number of affected relatives. These relationships did not seem to be attributable to differences in screening, detection method, or treatment. Tumors in women with a first-degree family history had generally more favorable prognostic profiles.

CONCLUSION

Our findings suggest that breast cancer patients with a first-degree family history, compared with their counterparts without such a profile, may have a better prognosis.

IMPACT

These findings support the need for future research directed at replicating these results and identifying factors underlying this possible relationship.

Outcome of triple-negative breast cancer in patients with or without deleterious BRCA mutations

More than 75% of breast cancers that develop in BRCA1 mutation carriers are triple-negative breast cancers (TNBC). The aim of this study was to compare the recurrence-free survival (RFS) and overall survival (OS) in high-risk patients with TNBC with and without deleterious BRCA1/2 mutations. A total of 227 women with TNBC who were referred for genetic counseling and underwent BRCA genetic testing between 1997 and 2010 were included in the study. The relationships between clinical variables and outcomes were evaluated using univariate and multivariate Cox proportional hazard regression models. Of 227 high-risk women with TNBC, 50% (n = 114) tested positive for BRCA1/2 mutations. Age, race, and tumor characteristics did not differ between BRCA non-carriers and carriers. At a median follow-up of 3.4 years, the 5-year RFS rates were 74 and 81% (P = 0.21), and 5-year OS rates were 85 and 93% in BRCA non-carriers and BRCA carriers, respectively (P = 0.11). In a multivariate model, after adjusting for age and disease stage, BRCA carriers tended to have a decreased risk of recurrence (HR = 0.67; 95% CI: 0.38-1.19; P = 0.17) or death (HR = 0.51; 95% CI:0.23-1.17; P = 0.11) compared to non-carriers. Our data indicate a 50% prevalence of deleterious BRCA1/2 mutations in high-risk women diagnosed with TNBC. Overall prognosis of TNBC in BRCA carriers and non-carriers is not significantly different within the first 5 years following an initial diagnosis. Further studies need to evaluate whether different therapies will change the outcome in these subgroups of TNBC.

Enhanced sensitivity to cisplatin and gemcitabine in Brca1-deficient murine mammary epithelial cells

Background

Breast cancers due to germline mutations or altered expression of the BRCA1 gene associate with an aggressive clinical course and frequently exhibit a "triple-negative" phenotype, i.e. lack of expression of the estrogen and progesterone hormone receptors and lack of overexpression of the HER2/NEU oncogene, thereby rendering them relatively insensitive to hormonal manipulation and targeted HER2 therapy, respectively. BRCA1 plays a role in multiple DNA repair pathways, and thus, when mutated, results in sensitivity to certain DNA damaging drugs.

Results

Here, we used a Brca1 murine mammary epithelial cell (MMEC) model to examine the effect of loss of Brca1 on cellular sensitivity to various chemotherapy drugs. To explore novel therapeutic strategies, we included DNA damaging and non-DNA damaging drugs whose mechanisms are dependent and independent of DNA repair, respectively, and drugs that are used in standard and non-standard lines of therapy for breast cancer. To understand the cellular mechanism, we also determined the role that DNA repair plays in sensitivity to these drugs. We found that cisplatin and gemcitabine had the greatest specific therapeutic benefit to Brca1-deficient MMECs, and that when used in combination produced a synergistic effect. This sensitivity may be attributed in part to defective NER, which is one of the DNA repair pathways normally responsible for repairing DNA adducts produced by cisplatin and is shown in this study to be defective in Brca1-deficient MMECs. Brca1-deficient MMECs were not differentially sensitive to the standard breast cancer chemotherapy drugs doxorubicin, docetaxel or 5-FU.

Conclusions

Both cisplatin and gemcitabine should be explored in clinical trials for first line regimens for BRCA1-associated and triple-negative breast cancer.

Clinical outcome of triple negative breast cancer in BRCA1 mutation carriers and noncarriers

BACKGROUND

Women with BRCA1 mutations develop breast cancer with similar pathologic features to sporadic triple negative (TN) breast cancer, a subtype associated with early disease relapse and poor outcome. The clinical outcome of women with and without BRCA1 mutations who had TN breast cancer treated with conventional chemotherapy were compared.

METHODS

Women with stage I to III TN breast cancer who had BRCA1 testing within 36 months of diagnosis and received alkylating chemotherapy were identified from clinical databases and a Specialized Program of Research Excellence (SPORE) specimen bank. BRCA2 mutation carriers were excluded, resulting in a study cohort of 46 BRCA1 carriers and 71 noncarriers. Sites of metastasis, relapse rates, and survival were compared among carriers and noncarriers. The median follow-up was 75 months.

RESULTS

BRCA1 carriers were younger at diagnosis (P < .001) and had smaller tumors (P = .03) than noncarriers. Freedom from distant metastasis at 5 years was 76% for carriers and 70% for noncarriers (hazard ratio [HR] 0.79, P = .5). Sites of distant recurrence did not differ significantly (P = .15), although BRCA1 carriers had a propensity for brain relapse (58% vs 24%, P = .06). Overall survival at 5 years was 82% for carriers and 74% for noncarriers (HR 0.64, P = .25). Adjusting for age and stage, BRCA1 mutation status was not an independent predictor of survival (HR 0.73, P = .48).

CONCLUSIONS

BRCA1 mutation carriers with TN disease had similar survival rates to noncarriers when treated with alkylating chemotherapy. Women with BRCA1-related breast cancer may benefit from novel therapies that target DNA repair, and further study is needed to identify sporadic TN breast cancers with a BRCA-deficient phenotype.

Clinical implications for BRCA gene mutation in breast cancer

To investigate the mutations of BRCA1 and BRCA2 and determine whether clinic-pathological factors related to BRCA gene mutation. Mastectomy specimens from 360 breast cancers were enrolled and examined in the study. The relationship between BRCA gene mutation and clinic-pathological factors was evaluated. Overall, 280 patients were BRCA negative and 80 got BRCA gene mutation. Triple-negative breast cancers--i.e., breast cancers that do not express estrogen receptors (ER), progesterone receptors (PR) or human epidermal growth factor receptor 2 (HER2/neu)--was observed in 53.85% of the BRCA1 mutation patients, in 28.57% of the BRCA2 mutation cases, while 14.29% of BRCA negative patients. BRCA1 mutation patients got a heavy lymph node metastasis and higher nuclear grade tumors than the others (P = 0.004, 0.007). Furthermore, BRCA mutation was also found to be significantly related to ER, PR and HER2/neu status (P < 0.05). BRCA1 expression was not associated with breast cancer-specific survival in the triple-negative breast cancers (P = 0.742). After Cox regression, BRCA1 mutation was not shown to be an independent prognostic factor for breast cancer. These findings substantiated the possibility of tumors associated with BRCA1 mutations divided into two distinct groups, triple-negative and non-triple-negative groups requires further investigation.