Platinum-based chemotherapy in triple-negative advanced breast cancer

CmP Signaling Network Leads to Identification of Prognostic Biomarkers for Triple-Negative Breast Cancer in Caucasian Women

Objective: Triple-negative breast cancer (TNBC) constitutes ∼15% of all diagnosed invasive breast cancer cases with limited options for treatment since immunotherapies that target ER, PR, and HER2 receptors are ineffective. Progesterone (PRG) can induce its effects through either classic, nonclassic, or combined responses by binding to classic nuclear PRG receptors (nPRs) or nonclassic membrane PRG receptors (mPRs). Under PRG-induced actions, we previously demonstrated that the CCM signaling complex (CSC) can couple both nPRs and mPRs into a CmPn signaling network, which plays an important role during nPR(+) breast cancer tumorigenesis. We recently defined the novel CmP signaling network in African American women (AAW)-derived TNBC cells, which overlapped with our previously defined CmPn network in nPR(+) breast cancer cells. Methods: Under mPR-specific steroid actions, we measured alterations to key tumorigenic pathways in Caucasian American women (CAW)- derived TNBC cells, with RNAseq/proteomic and systems biology approaches. Exemption from ethics approval from IRB: This study only utilized cultured NBC cell lines with publicly available TNBC clinical data sets. Results: Our results demonstrated that TNBCs in CAW share similar altered signaling pathways, as TNBCs in AAW, under mPR-specific steroid actions, demonstrating the overall aggressive nature of TNBCs, regardless of racial differences. Furthermore, in this report, we have deconvoluted the CmP signalosome, using systems biology approaches and CAW-TNBC clinical data, to identify 21 new CAW-TNBC-specific prognostic biomarkers that reinforce the definitive role of CSC and mPR signaling during CAW-TNBC tumorigenesis. Conclusion: This new set of potential prognostic biomarkers may revolutionize molecular mechanisms and currently known concepts of tumorigenesis in CAW-TNBCs, leading to hopeful new therapeutic strategies.

Molecular Classification and Future Therapeutic Challenges of Triple-negative Breast Cancer

Triple-negative breast cancer (TNBC) is an extremely diverse group of breast tumors, with aggressive clinical behavior, higher rates of distant recurrence and worse overall survival compared to other types of breast cancers. The genetic, transcriptional histological and clinical heterogeneity of this disease has been an obstacle in the progression of targeted therapeutic approaches, as a ubiquitous TNBC marker has not yet been discerned. In terms of that, current studies focus on the classification of TNBC tumors in subgroups with similar characteristics in order to develop a treatment specialized for each group of patients. To date, a series of gene expression profiles analysis in order to identify the different molecular subtypes have been used. Complementary DNA microarrays, PAM50 assays, DNA and RNA sequencing as well as immunohistochemical analysis are some of the methods utilized to classify TNBC tumors. In 2012, the Cancer Genome Atlas (TCGA) Research Network conducted a major analysis of breast cancers using six different platforms, the genomic DNA copy number arrays, DNA methylation, exome sequencing, messenger RNA arrays, microRNA sequencing and reverse-phase protein arrays, in order to assort the tumors in homogenous subgroups. Since then, an increasing number of breast cancer data sets are being examined in an attempt to distinguish the classification with biological interpretation and clinical implementation. In this review, the progress in molecular subtyping of TNBC is discussed, providing a brief insight in novel TNBC biomarkers and therapeutic strategies.

Efficacy and Safety of Platinum-Based Chemotherapy as First-Line Therapy for Metastatic Triple-Negative Breast Cancer: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Triple-negative breast cancer constitutes approximately 12%-17% of all breast cancer cases, and >33% of patients develop distant metastases. Systemic cytotoxic chemotherapy is the primary treatment for patients with metastatic triple-negative breast cancer; however, the role of first-line platinum-based chemotherapy in these patients remains controversial. This meta-analysis evaluated the efficacy and safety of platinum-based first-line chemotherapy for patients with metastatic triple-negative breast cancer.

METHODS

We systematically searched the PubMed, Embase, Cochrane, and Clinical Trials registry databases up to June 1, 2020 to identify randomized controlled trials that investigated platinum-based vs. first-line platinum-free chemotherapy in patients with metastatic triple-negative breast cancer. We used fixed and random effects models to calculate pooled hazard ratios and odds ratios with 95% confidence intervals for progression-free and overall survival, objective response rates, and grade 3 and 4 adverse events.

RESULTS

Four randomized controlled trials (N = 590 patients) were included. Platinum-based chemotherapy significantly increased the objective response rates from 43.1% to 62.7% (odds ratio 2.34, 95% confidence interval 1.66-3.28, P < 0.001). Three randomized controlled trials (N = 414 patients) reported survival outcomes. Patients administered platinum-based regimens showed significantly longer progression-free survival (hazard ratio 0.55, 95% confidence interval 0.37-0.82, P = 0.004) and a nonsignificant trend toward improved overall survival (hazard ratio 0.76, 95% confidence interval 0.57-1.00, P = 0.05). Only 2 studies reported the rates of grade 3 and 4 adverse events; grade 3-4 thrombocytopenia was more commonly associated with platinum-based chemotherapy (odds ratio 7.54, 95% confidence interval 1.37-41.60, P = 0.02) and grade 3-4 fatigue with platinum-free chemotherapy (odds ratio 0.23, 95% confidence interval 0.08-0.68, P = 0.008).

CONCLUSIONS

First-line platinum-based chemotherapy was associated with significantly increased objective response rates, longer progression-free survival, and a nonsignificant trend toward improved overall survival in patients with metastatic triple-negative breast cancer at the high risk of grade 3-4 thrombocytopenia.

Platinum-based chemotherapy in advanced triple-negative breast cancer: A multicenter real-world study in China

Platinum-based chemotherapy (PBC) has proven benefits in phase III studies for advanced triple-negative breast cancer (TNBC) patients; however, real-world data of large samples from multiple centers are lacking. Our study was to compare the effectiveness of PBC and non-PBC in advanced TNBC patients in multicenter real-world settings. Totally, 495 patients with advanced TNBC receiving PBC (n = 350) or non-PBC (n = 145) at four cancer centers in China between 2003 and 2019 were included. Treatment responses and outcomes were compared between the two groups from first-line to third-line treatment. Of patients with PBC, 249 (71.1%) received PBC from first-line chemotherapy, 86 (24.6%) from second-line and 15 (4.3%) from third-line treatment. In first-line treatment, PBC was superior to non-PBC in objective response rate (ORR, 53.0% vs 32.1%, P < .001) and median progression-free survival (PFS, 8.4 vs 6.0 months, P = .022), whereas overall survival (OS) was similar (19.2 vs 16.8 months, P = .439). When comparing patients receiving non-PBC doublets (n = 221) with those receiving PBC doublets (n = 249), the same trend was observed in ORR (32.6% vs 53.0%, P < .001), median first-line PFS (6.5 vs 8.4 months, P = .041) and median first-line OS(17.8 vs 19.2 months, P = .568). Paclitaxel/docetaxel + platinum was more likely to be used, followed by gemcitabine + platinum. In second/third-line treatment, PBC yielded a similar response and survival compared to non-PBC. Adding PBC in the first-line therapy was better than that in the latter-line of treatment in terms of ORR, PFS and OS (P < .001). Toxic effects of PBC were tolerable and the most common adverse event was neutropenia (38.6%). PBC doublets exhibited superior efficacy and manageable toxicity compared to non-PBC doublets in the first-line treatment for Chinese mTNBC patients.

Anticancer and antimetastatic activity of copper(II)-tropolone complex against human breast cancer cells, breast multicellular spheroids and mammospheres

The goal of this work was to display the anticancer and antimetastatic activity of a copper(II) with tropolone (trp), complex [Cu(trp)₂] toward human breast cancer cells in monolayer (2D) and spheroids (3D). Cytotoxicity assays against MCF7 (IC_50(complex) = 5.2 ± 1.8 μM, IC_50(CDDP) = 19.3 ± 2.1 μM) and MDA-MB-231 (IC_50(complex) = 4.0 ± 0.2 μM, IC_50(CDDP) = 27.0 ± 1.9 μM) demonstrate that [Cu(trp)₂] exert greater antitumor potency than cisplatin (CDDP) on 2D and 3D human breast cancer cell models. Besides, [Cu(trp)₂] inhibits cell migration by reducing the metalloproteinases activities and the compound undergoes the breast cancer cells to apoptosis at lower concentrations (2.5-10 μM). Moreover, [Cu(trp)₂] overcame CDDP presenting an IC₅₀ value 26-fold more lower against breast multicellular spheroids ((IC_50(complex) = 4.9 μM, IC_50(CDDP) = 130 μM)). Also, our results showed that [Cu(trp)₂] inhibited the cell migration and cell invasion of breast multicellular spheroids, showing that [Cu(trp)₂] exhibited antimetastatic properties. On the other hand, [Cu(trp)₂] reduced mammosphere forming capacity affecting the size and number of mammospheres. Taken together, [Cu(trp)₂] exhibited anticancer and antimetastatic properties on monolayer (2D) and spheroids (3D) derived from human breast cancer cells.

Can we cure stage IV triple-negative breast carcinoma?: Another case report of long-term survival (7 years)

RATIONALE

Triple-negative breast cancer has a dismal prognosis, especially once it has spread to other organs, due to the lack of effective treatments available at this time. Finding an effective treatment for metastatic triple-negative breast cancer remains an unmet medical need.

PATIENT CONCERNS

A 60-year-old woman was diagnosed with stage IIIC triple-negative breast cancer after undergoing a mastectomy. Her mastectomy was followed by adjuvant chemotherapy and radiation therapy. Approximately 1 year later, the patient presented with enlarging lymph nodes in her neck. A biopsy of a left supraclavicular lymph node was positive for recurrent disease. Positron emission tomography and computed tomography scans performed after the biopsy showed metabolic activity in the T6 vertebral body and the right level IIB lymph nodes.

DIAGNOSES

The patient was diagnosed with recurrent metastatic triple-negative breast carcinoma with metastases to the bone and lymph nodes.

INTERVENTIONS

The patient was treated with weekly metronomic chemotherapy, sequential chemotherapy regimens, and immunotherapy.

OUTCOMES

The patient is now 68 years old and 7 years out from her diagnosis of metastatic disease. She achieved a complete response to her treatment and routine scans continue to show no evidence of recurrent disease.

LESSONS

Utilizing sequential weekly metronomic chemotherapy regimens in combination with immunotherapy looks to be a promising treatment option for patients with metastatic triple-negative breast carcinoma. This is a second case where we were able to achieve long-term remission by using the above treatment strategy. These exciting results warrant further investigation of this treatment methodology. We hope that the treatment strategy described in this article can provide an outline for researchers and give patients with this disease more treatment options.

Case report of long-term survival with metastatic triple-negative breast carcinoma: Treatment possibilities for metastatic disease

RATIONALE

Breast cancer is the most common as well as one of the most devastating cancers among women in the United States. Prognosis is poor for patients with metastatic breast cancer, especially for patients with so-called "triple-negative" disease. The lack of effective therapies for metastatic triple-negative breast cancer outlines the need for novel and innovative treatment strategies.

PATIENT CONCERNS

A 58-year-old underwent a mastectomy which revealed a recurrent triple-negative breast carcinoma. Afterward, she presented with a growing mass in her left axilla and chest wall. A computed tomography scan showed axillary and supraclavicular adenopathy, nodules in the left upper and lower lobe of the lungs, and 2 areas of disease in the liver. A bone scan showed lesions in the ribs.

DIAGNOSIS

The patient was diagnosed with a recurrent metastatic triple-negative breast carcinoma that spread to the lung, liver, and bones.

INTERVENTIONS

The patient was treated with metronomic chemotherapy, sequential chemotherapy regimens, and immunotherapy.

OUTCOMES

The patient is now over 15 years out from her diagnosis of metastatic disease without any evidence of recurrent disease, likely due to the patient's treatment strategy which included sequential metronomic chemotherapy regimens and immunotherapy.

LESSONS

Sequential metronomic chemotherapy regimens in combination with immunotherapy might be an effective treatment option for patients with metastatic triple-negative breast cancer. We hope that this case can provide some guidance for the treatment of metastatic triple-negative breast cancer and motivate research that can potentially lead to more cases of long-term survival for patients who develop this dismal disease.

Detection of novel germline mutations in six breast cancer predisposition genes by targeted next-generation sequencing

In this study, a customized amplicon-based target sequencing panel was designed to enrich the whole exon regions of six genes associated with the risk of breast cancer. Targeted next-generation sequencing (NGS) was performed for 146 breast cancer patients (BC), 71 healthy women with a family history of breast cancer (high risk), and 55 healthy women without a family history of cancer (control). Sixteen possible disease-causing mutations on four genes were identified in 20 samples. The percentages of possible disease-causing mutation carriers in the BC group (8.9%) and in the high-risk group (8.5%) were higher than that in the control group (1.8%). The BRCA1 possible disease-causing mutation group had a higher prevalence in family history and triple-negative breast cancer, while the BRCA2 possible disease-causing mutation group was younger and more likely to develop axillary lymph node metastasis (P < 0.05). Among the 146 patients, 47 with a family history of breast cancer were also sequenced with another 14 moderate-risk genes. Three additional possible disease-causing mutations were found on PALB2, CHEK2, and PMS2 genes, respectively. The results demonstrate that the six-gene targeted NGS panel may provide an approach to assess the genetic risk of breast cancer and predict the clinical prognosis of breast cancer patients.

Randomised feasibility trial to compare three standard of care chemotherapy regimens for early stage triple-negative breast cancer (REaCT-TNBC trial)

INTRODUCTION

Despite the importance of chemotherapy in the treatment of early stage triple negative breast cancer (TNBC), no one optimal regimen has been identified. We conducted a pilot trial comparing outcomes for the three most commonly used chemotherapy regimens to assess the feasibility of conducting a larger definitive trial.

METHODS

Using integrated consent, newly diagnosed TNBC patients were randomised to one of three standard regimens: dose-dense doxorubicin-cyclophosphamide then paclitaxel, doxorubicin-cyclophosphamide then weekly paclitaxel or 5-FU-epirubicin-cyclophosphamide then docetaxel. Feasibility endpoints included; physician engagement, accrual rates, physician compliance and patient satisfaction with the integrated consent model. Our anticipated pilot trial sample size was 35 randomised patients in one year.

RESULTS

Between August 30th, 2016 and January 31st 2017, 2 patients met eligibility and were randomised. A survey of 10 participating oncologists was performed to identify potential strategies to enhance accrual. Most investigators (9/10) believed that the best regimen for TNBC was unknown, and 4/10 felt this was a pressing clinical question. Physicians' responses suggested that poor accrual was due to: a lack of interest in some study arms as oncologists already had a preferred regimen (4/10) and concerns about trial demands in busy clinics (3/10). The pilot feasibility endpoints were not met and the study was closed.

CONCLUSIONS

Despite initial interest in the trial question and multiple investigators agreeing to approach patients, this trial failed to meet feasibility endpoints. The reasons for poor accrual were multiple and require further evaluation if this important patient-centred question is to be answered.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02688803.

Extended Adjuvant Chemotherapy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) represents a heterogeneous breast cancer subtype with a poor prognosis. The optimal adjuvant chemotherapy regimen is still unknown. Although numerous large randomized trials have established the benefit of adjuvant anthracyclines and/or taxanes in TNBC, there is no preferred regimen for these patients. There is currently no guideline. Moreover, without knowing the optimal treatment backbone, it will not be possible to evaluate whether adding agents such as platinum or other novel therapies is beneficial for TNBC patients. Furthermore, the best duration of adjuvant treatment in TNBC is still unknown. This review will focus on results of clinical trials that analyzed the benefits of extending the duration of adjuvant treatment in TNBCs with maintenance treatments. We will further discuss promising results in favor of other new agents including capecitabine, metronomic treatment, and biological drugs.

Predictive biomarkers for triple negative breast cancer treated with platinum-based chemotherapy

Treatment of triple negative breast cancer (TNBC) has been a big challenge since it is defined. To date, platinum-based chemotherapy has played a significant role in the treatment of TNBC patients. However, some patients do not respond to platinum salts or gradually develop chemoresistance, resulting in little effect, or even some adverse effects. Here, we review numerous preclinical and clinical investigations to summarize possible mechanisms and potential predictive biomarkers of platinum in TNBC. The homologous recombination deficiency (HRD) resulting from the loss of BRCA function is the main rationale of platinum efficacy in TNBC. BRCA mutation and methylation have been demonstrated to be important potential biomarkers. Based on genome-wide effects, BRCA-like classifier can identify the functional loss of BRCA and work as the predictor. HRD score that is able to identify the "BRCAness" and predict the sensitivity of platinum is increasingly considered. Taken together, all findings suggest that HR deficiency profile encompassed by BRCA mutation and high HRD score could predict response to platinum, even to other DNA-damage inducing agents. p53 family members and molecular subtypes of TNBC are also important alternative considerations for predicting platinum response based on the preclinical trials. Currently, tumor infiltrating lymphocyte level and thrombocytopenia are emerging as predictive biomarkers.

Enhancing accrual to chemotherapy trials for patients with early stage triple-negative breast cancer: a survey of physicians and patients

PURPOSE

The optimal chemotherapy regimen for patients with early stage triple-negative breast cancer (TNBC) remains unknown. The purpose of the study is to survey physicians and breast cancer patients about preferred chemotherapy regimens for early stage TNBC and clinical trial strategies.

METHODS

A standardised online questionnaire was developed and circulated to medical oncologists known to treat breast cancer. A separate questionnaire was given to patients who had received chemotherapy for breast cancer.

RESULTS

The questionnaire was completed by 41/84 medical oncologists (48.8% response rate) and 74 patients. The most commonly used neoadjuvant and adjuvant chemotherapy regimens for TNBC were dose-dense doxorubicin and cyclophosphamide (AC)-paclitaxel (P), dose-dense AC followed by weekly P and fluorouracil, epirubicin, cyclophosphamide-docetaxel (FEC-D). The majority of medical oncologists (80%) would be willing to enrol patients in trials evaluating the most effective chemotherapy regimen for TNBC. Oncologists favoured a three arm trial design comparing currently available standard of care treatments (36%) and trials of novel or non-standard of care agents 22% (9/41). Sixty percent (41/74) of patients indicated that they would be willing to be enrolled in trials evaluating various adjuvant regimens for TNBC. Both oncologists and patients were interested in novel consent approaches such as using the integrated consent model.

CONCLUSION

Optimisation of chemotherapy for TNBC is an important and unmet clinical need. It is apparent that various chemotherapy regimens are used for patients with early stage TNBC. The majority of medical oncologists and patients are interested in entering trials to optimise chemotherapy choices.

The Evolution of Triple-Negative Breast Cancer: From Biology to Novel Therapeutics

Triple-negative breast cancer (TNBC) is clinically defined as lacking expression of the estrogen receptor (ER), progesterone receptor (ER), and HER2. Historically, TNBC has been characterized by an aggressive natural history and worse disease-specific outcomes compared with other breast cancer subtypes. The advent of next-generation sequencing (NGS) has allowed for the dissection of TNBC into molecular subtypes (i.e., basal-like, claudin-low). Within TNBC, several subtypes have emerged as "immune-activated," consistently illustrating better disease outcome. In addition, NGS has revealed a host of molecular features characteristic of TNBC, including high rates of TP53 mutations, PI3K and MEK pathway activation, and genetic similarities to serous ovarian cancers, including inactivation of the BRCA pathway. Identified genetic vulnerabilities of TNBC have led to promising therapeutic approaches, including DNA-damaging agents (i.e., platinum salts and PARP inhibitors), as well as immunotherapy. Platinum salts are routinely incorporated into the treatment of metastatic TNBC; however, best outcomes are observed among those with deficiencies in the BRCA pathway. Although the incorporation of platinum in the neoadjuvant care of patients with TNBC yields higher pathologic complete response (pCR) rates, the impact on longer-term outcome is less clear. The presence of immune infiltrate in TNBC has shown both a predictive and prognostic role. Checkpoint inhibitors, including PD-1 and PD-L1 inhibitors, are under investigation in the setting of metastatic TNBC and have shown responses in initial clinical trials. Finally, matching emerging therapeutic strategies to optimal subtype of TNBC is of utmost importance as we design future research strategies to improve patient outcome.

Loss of the oncogenic phosphatase PRL-3 promotes a TNF-R1 feedback loop that mediates triple-negative breast cancer growth

Stimulating tumor cell senescence and apoptosis are proven methods for therapeutically combating cancer. However, senescence and apoptosis are conventionally viewed as parallel, not sequential, processes. We have discovered that the metastasis-promoting phosphatase, PRL-3, is transcriptionally regulated by the NF-ĸB pathway in triple-negative breast cancer (TNBC) cells, and that PRL-3 knockdown elicits an autocrine tumor necrosis factor receptor 1 (TNF-R1) feedback loop that results in TNBC cell senescence followed by apoptosis. Knockdown of PRL-3 leads to rapid G1 cell cycle arrest and induction of a strong TNFα cytokine response that promotes a period of cellular senescence through TNF-R1-mediated activation of NF-ĸB. Senescent PRL-3 knockdown cells subsequently underwent apoptosis as a result of increased TNF-R1 signaling through the TNFα-associated extrinsic death pathway, shunting signaling away from the NF-ĸB cascade. These data suggest that TNF-R1 signaling dynamically re-programs after PRL-3 knockdown, from sustaining cell senescence through NF-ĸB to promoting apoptosis through TNF-R1 internalization and caspase-8 activation. The molecular mechanisms that determine the survival–death balance of TNF-R1 signaling are poorly understood, despite the fact that TNF-R1 has been extensively studied. Our results describe PRL-3 knockdown as a novel survival–death balance modifier of the TNF-R1 pathway, and show that senescent TNBC tumor cells can be sensitized to undergo apoptosis in a sequential manner.

The autophagy inhibitor chloroquine targets cancer stem cells in triple negative breast cancer by inducing mitochondrial damage and impairing DNA break repair

Triple negative breast cancer (TNBC), characterized by an abundance of treatment-resistant breast cancer stem cells (CSCs), has a poorer prognosis than other types of breast cancers. Despite its aggressiveness, no effective targeted therapy exists for TNBC. Here, we demonstrate that CQ effectively targets CSCs via autophagy inhibition, mitochondrial structural damage, and impairment of double-stranded DNA break repair. Electron microscopy demonstrates CQ-induced mitochondrial cristae damage, which leads to mitochondrial membrane depolarization with a significant reduction in the activity of cytochrome c oxidase and accumulation of superoxide and double-stranded DNA breaks. CQ effectively diminishes the TNBC cells' ability to metastasize in vitro and in a TNBC xenograft model. When administered in combination with carboplatin, CQ effectively inhibits carboplatin-induced autophagy. This combination treatment significantly diminishes the expression of DNA repair proteins in CSC subpopulations, resulting in tumor growth reduction in carboplatin-resistant BRCA1 wild-type TNBC orthotopic xenografts. As TNBC's high treatment failure rate has been attributed to enrichment of CSCs, CQ, an autophagy inhibitor with anti-CSC effects, may be an effective adjunct to current TNBC chemotherapy regimens with carboplatin.

Genome-wide functional genetic screen with the anticancer agent AMPI-109 identifies PRL-3 as an oncogenic driver in triple-negative breast cancers

Triple-negative breast cancers (TNBC) are among the most aggressive and heterogeneous cancers with a high propensity to invade, metastasize and relapse. Here, we demonstrate that the anticancer compound, AMPI-109, is selectively efficacious in inhibiting proliferation and inducing apoptosis of multiple TNBC subtype cell lines as assessed by activation of pro-apoptotic caspases-3 and 7, PARP cleavage and nucleosomal DNA fragmentation. AMPI-109 had little to no effect on growth in the majority of non-TNBC cell lines examined. We therefore utilized AMPI-109 in a genome-wide shRNA screen in the TNBC cell line, BT-20, to investigate the utility of AMPI-109 as a tool in helping to identify molecular alterations unique to TNBC. Our screen identified the oncogenic phosphatase, PRL-3, as a potentially important driver of TNBC growth, migration and invasion. Through stable lentiviral knock downs and transfection with catalytically impaired PRL-3 in TNBC cells, loss of PRL-3 expression, or functionality, led to substantial growth inhibition. Moreover, AMPI-109 treatment, downregulation of PRL-3 expression or impairment of PRL-3 activity reduced TNBC cell migration and invasion. Histological evaluation of human breast cancers revealed PRL-3 was significantly, though not exclusively, associated with the TNBC subtype and correlated positively with regional and distant metastases, as well as 1 and 3 year relapse free survival. Collectively, our study is proof-of-concept that AMPI-109, a selectively active agent against TNBC cell lines, can be used as a molecular tool to uncover unique drivers of disease progression, such as PRL-3, which we show promotes oncogenic phenotypes in TNBC cells.

Platinum-based chemotherapy in triple-negative breast cancer: a systematic review and meta-analysis of randomized-controlled trials

The aim of this study was to evaluate the benefits of the addition of platinum agents for the treatment of patients with triple-negative breast cancer on the basis of randomized-controlled trials (RCTs). A fully recursive literature search was performed in the Cochrane Controlled Trials Register Databases, Medline, EMBASE, and Chinese Biomedical Literature Database in any language. RCTs were considered for inclusion. Eight randomized-controlled trials totaling 1142 patients were included. The objective response rate was reported in six RCTs, which were divided into two subgroups: palliative chemotherapy for a metastatic setting and neoadjuvant chemotherapy. Using the fixed-effects model, the difference between the platinum-based group and the non-platinum-based group was found to be statistically significant in the overall study [relative risk (RR)=1.36, P<0.00001], the subgroup of palliative chemotherapy (RR=2.42, P<0.00001), and the subgroup of neoadjuvant (RR=1.15, P=0.01). Pathological complete response rates were based on five studies, and the results between the platinum-based group and the non-platinum-based group also reached statistical significance both in the fixed-effects model (RR=1.43, P<0.0001) and in the random-effects model (RR=1.47, P=0.01). The results seemed to yield a better response rate and pathological complete response rate for platinum-based therapy in triple-negative breast cancer. However, because of the heterogeneous nature of primary trial outcomes, caution should be exercised in coming to this conclusion and further research is necessary to support these findings.

Potentiation of Carboplatin-Mediated DNA Damage by the Mdm2 Modulator Nutlin-3a in a Humanized Orthotopic Breast-to-Lung Metastatic Model

Triple-negative breast cancers (TNBC) are typically resistant to treatment, and strategies that build upon frontline therapy are needed. Targeting the murine double minute 2 (Mdm2) protein is an attractive approach, as Mdm2 levels are elevated in many therapy-refractive breast cancers. The Mdm2 protein-protein interaction inhibitor Nutlin-3a blocks the binding of Mdm2 to key signaling molecules such as p53 and p73α and can result in activation of cell death signaling pathways. In the present study, the therapeutic potential of carboplatin and Nutlin-3a to treat TNBC was investigated, as carboplatin is under evaluation in clinical trials for TNBC. In mutant p53 TMD231 TNBC cells, carboplatin and Nutlin-3a led to increased Mdm2 and was strongly synergistic in promoting cell death in vitro. Furthermore, sensitivity of TNBC cells to combination treatment was dependent on p73α. Following combination treatment, γH2AX increased and Mdm2 localized to a larger degree to chromatin compared with single-agent treatment, consistent with previous observations that Mdm2 binds to the Mre11/Rad50/Nbs1 complex associated with DNA and inhibits the DNA damage response. In vivo efficacy studies were conducted in the TMD231 orthotopic mammary fat pad model in NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NSG) mice. Using an intermittent dosing schedule of combined carboplatin and Nutlin-3a, there was a significant reduction in primary tumor growth and lung metastases compared with vehicle and single-agent treatments. In addition, there was minimal toxicity to the bone marrow and normal tissues. These studies demonstrate that Mdm2 holds promise as a therapeutic target in combination with conventional therapy and may lead to new clinical therapies for TNBC.

Vinorelbine Plus Platinum in Patients with Metastatic Triple Negative Breast Cancer and Prior Anthracycline and Taxane Treatment

Currently, there is no preferred standard chemotherapy regimen available for patients with metastatic triple negative breast cancer (mTNBC) and no cohort studies on the efficacy of vinorelbine plus platinum (NP) regimen in patients with mTNBC who failed to anthracyclines and/or taxanes have been reported. We present the single-center, retrospective experience of NP regimen in a total of 41 patients with mTNBC.All patients were treated with NP regimen, main combination used was vinorelbine-cisplatin in 34 patients (82.9%).The median follow-up was 36.8 months. Objective response rate was 34.1% (n = 14) in the whole study group. Three patients experienced complete response (7.3%), 11 patients acquired partial response (26.8%), stable disease was observed in 14 patients (34.1%), and 10 patients (24.4%) had progressive disease. Response evaluation was not applicable in 3 patients who received the treatment of NP regimen after surgical removal of the metastatic lesions. The median overall survival and progression-free survival were 18.9 months (95% confidence interval, 15.6-22.1 months) and 6.7 months (95% confidence interval, 2.9-10.5 months), respectively. The main adverse events were grade 3/4 neutropenia (n = 20, 48.8%) and grade 1/2 gastrointestinal toxicity (n = 20, 48.8%).NP regimen is active and tolerable in patients with mTNBC pretreated with anthracyclines and/or taxanes. Therefore, among other chemotherapy regimens, NP combination may provide a rational treatment option for this patient subset.

Clinical efficacy of administering oxaliplatin combined with S-1 in the treatment of advanced triple-negative breast cancer

Triple-negative breast cancer (TNBC) is not amenable to current targeted therapies and carries a poor prognosis; however, a specific systemic regimen cannot yet be recommended. The optimal duration of oxaliplatin (OXA) and S-1 combinatorial chemotherapy in patients with advanced breast cancer is not currently known and is likely to be patient-specific based on efficacy and toxicity. In the present study, 52 patients with advanced TNBC received OXA and S-1 chemotherapy. The efficacy and toxicity were observed. The results showed that the median number of regimens was 4 (range 2-6). The therapeutic efficacy was evaluated in all patients. The complete response, partial response, overall response and disease control rates were 3.8, 30.8, 34.6 and 69.2%, respectively. Four patients were lost to follow-up, and the median follow-up time was 13.7 months. The median progression-free survival time was 6.7 months [95% confidence interval (CI), 4.5-9.0] and the median overall survival (OS) time was 13.3 months (95% CI, 9.1-17.5). From the subgroup analysis, it was found that the median OS time of patients with stage IV disease and ≥2 metastases was significantly shorter than that of patients with stage IIIC disease and only 1 metastasis [11.3 vs. 22.7 months, P=0.010 (stage IV vs. stage IIC); 11.3 vs. 15.7 months, P=0.048 (≥2 vs. 1 metastasis)]. The main grade 3/4 toxic effects were neutropenia (11.5%), nausea (7.7%) and nerve toxicity (3.8%). The other toxic effects were mainly of grades 1-2 and included diarrhea, liver dysfunction, stomatitis, anemia and hand-foot syndrome. In conclusion, OXA combined with S-1 is an effective and tolerable regimen for the treatment of patients with advanced TNBC.

Systemic treatment approaches in her2-negative advanced breast cancer-guidance on the guidelines

Despite advancements in the treatment of early-stage breast cancer, many patients still develop disease recurrence; others present with de novo metastatic disease. For most patients with advanced breast cancer, the primary treatment intent is noncurative-that is, palliative-in nature. The goals of treatment should therefore focus on maximizing symptom control and extending survival. Treatments should be evaluated on an individualized basis in terms of evidence, but also with full respect for the wishes of the patient in terms of acceptable toxicity. Given the availability of extensive reviews on the roles of endocrine therapy and her2 (human epidermal growth factor receptor 2)-targeted therapies for advanced disease, we focus here mainly on treatment guidelines for the non-endocrine management of her2-negative advanced breast cancer in a Canadian health care context.

Platinum-based therapy for triple-negative breast cancer treatment: A meta-analysis

The aim of the present study was to evaluate the effect of platinum-based therapy on the short-term efficacy and survival rate in patients with triple-negative breast cancer (TNBC). A search of available databases was conducted, based on specific inclusion and exclusion criteria, for trials conducted between January 2006 and January 2014. The bibliographies of the included studies were examined with the same criteria. Included studies were evaluated using Grading of Recommendations Assessment, Development and Evaluation (GRADE), and extracted data were analyzed using RevMan 5.1 and GRADEprofiler 3.6. Eight studies with a total of 1,349 patients were included. The meta-analysis revealed that the pathological complete response rate and overall response rate in TNBC patients who were treated with a platinum-based regimen was significantly higher than that in those treated with a non-platinum-based regimen (49.2 and 64.3%, respectively). The disease-free survival rate and overall survival rate were not significantly different between TNBC patients treated with a platinum-based regimen and those treated with a non-platinum-based regiment (P>0.05). Platinum-based chemotherapy in TNBC patients resulted in improved short-term efficacy. Platinum-based regimens may therefore be more sensitive to TNBC patients. However, future multicenter randomized controlled trials are required to validate these findings and to determine whether platinum-based chemotherapy can extend the survival rate of TNBC patients.

ERCC1 polymorphisms as prognostic markers in T4 breast cancer patients treated with platinum-based chemotherapy

BACKGROUND

Polymorphisms in the excision repair cross-complimentary group 1 (ERCC1) gene have been involved in the prognosis of various cancers. In the present study, we evaluated the prognostic role of the two most common ERCC1 polymorphisms in patients with T4 breast cancer receiving platinum-based chemotherapy.

METHODS

A total of 47 patients with T4 breast cancer undergoing treatment with a platinum-based regimen were collected and followed up (median 159 months; range, 42-239 months). ERCC1 C8092A (rs3212986) and T19007C (rs11615) polymorphisms were genotyped, using an automated sequencing approach. The same series was screened for BRCA1/2 mutations by DHPLC analysis and DNA sequencing.

RESULTS

Among the tested patients, 16 (34%) and 25 (53%) presented the 8092A (homo-zygosity A/A or heterozygosity A/C) and the 19007C (homozygosity C/C or heterozygosity C/T) genotypes, respectively. The 8092A and 19007C genotypes in ERCC1 were significantly associated with overall survival in T4 breast cancer patients treated with chemotherapy containing platinum (p-values = 0.036 and 0.004, respectively). Univariate and multivariate Cox regression analyses showed that combination of 8092A and 19007C genotypes acts as a significant prognostic factor in women with T4 breast cancer receiving platinum-based chemotherapy (p-values = 0.022 and 0.049, respectively). Two (4.3%) out of 47 cases were found to carry BRCA1/2 mutations; they presented the highest overall survival rates into the series.

CONCLUSIONS

The ERCC1 8092A and 19007C genotypes or their combination may predict a favorable prognosis in T4 breast cancer patients undergoing a platinum-based treatment. Further large-scale, prospective studies are needed to validate our findings.