Assessing the role of platinum agents in aggressive breast cancers

Synergistic Effects of 2-Deoxyglucose and Diclofenac Sodium on Breast Cancer Cells: A Comparative Evaluation of MDA-231 and MCF7 Cells

Resistance of breast cancers to chemotherapy remains a global challenge to date. Drug combination studies between anti-cancer agents are increasingly becoming therapeutic strategies, geared towards alleviating breast cancers. Previously, 2-deoxyglucose has been shown to target and interrupt glycolysis. Available evidence also suggests that diclofenac, which was originally designed as a pain reliever, could inhibit the proliferation of breast cancer cells. However, the reverse Warburg effect and other metabolic reprogramming mechanisms in breast cancers limit the pharmacological application of both 2-deoxyglucose and diclofenac as mono-therapeutic agents. The present study explores the additive anti-cancer effects of 2-deoxyglucose and diclofenac sodium on breast cancer cells. In this study, MDA-231 and MCF7 cells were treated with 2-deoxyglucose and diclofenac sodium in single and combination doses before being evaluated for viability, cell growth, reactive oxygen species, apoptotic and necrotic phases, and migration abilities. Additionally, immunoblotting of pro-apoptotic proteins, Caspase-3 and Caspase-9, and a hypoxia-inducible factor-1 alpha, was also performed. The results showed that combination treatments of the cells with the drugs exhibited additive anti-cancer effects by limiting proliferation, enhancing cytotoxic reactive oxygen species generation, enhancing apoptosis and necrosis, limiting colony formation and expansion of cells, and inhibiting cell migration. The degrees of cytotoxicity of combined treatments were almost similar in both cell lines, although with minimal differences. Put together, these results reveal the novel synergistic effects of 2-deoxyglucose and diclofenac sodium on breast cancer cells, hence potentially elevating their pharmacological profile in the overall breast cancer therapy.

Combination therapy involving HSP90 inhibitors for combating cancer: an overview of clinical and preclinical progress

The molecular chaperone heat shock protein 90 (HSP90) regulates multiple crucial signalling pathways in cancer by driving the maturation of key signalling components, thereby playing a crucial role in tumorigenesis and drug resistance in cancer. Inhibition of HSP90 results in metastable conformational collapse of its client proteins and their proteasomal degradation. Considerable efforts have been devoted to the development of small-molecule inhibitors targeting HSP90, and more than 20 inhibitors have been evaluated in clinical trials for cancer therapy. However, owing to disadvantages such as organ toxicity and drug resistance, only one HSP90 inhibitor has been approved for use in clinical settings. In recent years, HSP90 inhibitors used in combination with other anti-cancer therapies have shown remarkable potential in the treatment of cancer. HSP90 inhibitors work synergistically with various anti-cancer therapies, including chemotherapy, targeted therapy, radiation therapy and immunotherapy. HSP90 inhibitors can improve the pharmacological effects of the above-mentioned therapies and reduce treatment resistance. This review provides an overview of the use of combination therapy with HSP90 inhibitors and other anti-cancer therapies in clinical and preclinical studies reported in the past decade and summarises design strategies and prospects for these combination therapies. Altogether, this review provides a theoretical basis for further research and application of these combination therapies in the treatment of cancer.

A prospective, open-label, multicenter phase IV clinical trial on the safety and efficacy of lobaplatin-based chemotherapy in advanced breast cancer

BACKGROUND

Since lobaplatin (LBP) has been approved to treat metastatic breast cancer in China, this study aimed to evaluate the safety and efficacy of LBP-based chemotherapy in clinical practice.

METHODS

This trial was a prospective, open-label, multicenter phase IV clinical trial that enrolled patients with unresectable locally advanced or recurrent/metastatic breast cancer from 34 sites between July 2013 and March 2017. Patients were treated with LBP monotherapy or in combination for four to six cycles. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR).

RESULTS

A total of 1179 patients were analyzed; 59 (5.0%) were treated with LBP alone, 134 (11.4%) with LBP plus paclitaxel, 263 (22.3%) with LBP plus docetaxel, 237 (20.1%) with LBP plus gemcitabine, 403 (34.2%) with LBP plus vinorelbine, and 83 (7.0%) with other LBP-based regimens. The overall incidence of adverse events (AEs) was 95.2%, and 57.9% of patients had grade >3 AEs. The most common grade >3 AEs were neutropenia (43.9%), leukopenia (39.4%), anemia (17.8%), and thrombopenia (17.7%). LBP monotherapy showed the lowest incidence of grade >3 AEs (39.0%), followed by LBP plus docetaxel (52.9%), LBP plus paclitaxel (59.0%), LBP plus vinorelbine (62.5%), and LBP plus gemcitabine (62.9%). The ORR and DCR were 36.8 and 77.0%, respectively. The median PFS was 5.5 months (95% confidence interval: 5.2-5.9).

CONCLUSION

LBP-based chemotherapy shows favorable efficacy in patients with advanced breast cancer, with manageable safety profile.

TRIAL REGISTRATION

This trial was registered with ChiCTR.org.cn, ChiCTR-ONC-13003471.

Surgical Management of Inherited Breast Cancer: Role of Breast-Conserving Surgery

Recent studies have demonstrated that hereditary breast cancer (BC) has a prevalence of 5-10% among all BC diagnoses. Nowadays, significant technological advances in the identification of an increasingly broad spectrum of genetic mutations allow for the discovery of an ever-growing number of inherited pathogenic (P) or likely pathogenic (LP) variants of breast cancer susceptibility genes. As the management of BC patients carrying mutations in the BRCA1/2 genes or other high-penetrance genes is currently a challenge, extensive research is being carried out and a lively scientific debate has been taking place on what the most appropriate local therapy, especially surgical treatment, of patients with inherited BC should be. In many studies, BC outcomes in BRCA carriers and non-carriers have been compared. A number of them showed that, when compared with mastectomy, breast-conserving surgery in BRCA patients is oncologically safe in terms of overall survival, although an increased risk of ipsilateral recurrence was reported. In these patients, devising a specific therapeutic strategy is an inevitably complex process, as it must take into consideration a series of factors, require a multimodal approach, guarantee personalization, strictly adhere to scientific international guidelines, and consider all available evidence. The present narrative review purposes to identify and illustrate evidence from significant selected studies that discussed those issues, as well as to suggest useful tools to clinicians managing this specific clinical condition in daily clinical practice.

A novel star-shaped trinuclear platinum(II) complex based on a 1,3,5-triazine core displaying potent antiproliferative activity against TNBC by the mitochondrial injury and DNA damage mechanism

Polynuclear platinum(II) complexes represent a class of great prospective Pt-based antitumor drugs that may expand the antitumor spectrum and overcome the clinical problems of drug resistance and side effects of platinum-based drugs. Herein, a novel star-shaped trinuclear platinum(II) complex [Pt₃(L-3H)Cl₃] (1, L = 2,4,6-tris[(2-hydroxybenzyl)(2-pyridylmethyl)amine]-1,3,5-triazine) and its monomer [Pt(L'-H)Cl] (2, L' = (2-hydroxybenzyl)(2-pyridylmethyl)amine) were synthesized and characterized. The in vitro antiproliferative activities of complexes 1 and 2 against a panel of human cancer cell lines including MDA-MB-231 (triple-negative breast cancer, TNBC), MCF-7 (breast), HepG-2 (liver), and A549 (lung) were investigated. The results revealed that 1 exhibited much higher antiproliferative properties than its monomer 2 against the tested cell lines. Importantly, 1 possessed 3.3-fold higher antiproliferative activity as compared with cisplatin against the TNBC cell line MDA-MB-231. Another TNBC cell line MDA-MB-468 is also sensitive to 1. The results indicated that 1 might have the potential to act as a candidate for the treatment of TNBC. Cellular uptake and distribution studies showed that 1 could pass through the membrane of cells and enter into cells and mainly accumulate in the nuclei and mitochondria. 1 could bind to DNA in a cooperative groove-electrostatic-platinating binding mode and induce stronger DNA double-strand breaks (DSBs) and damaging effects on MDA-MB-231 than cisplatin (upregulation of γ-H2AX). Moreover, the DNA damage could not be easily repaired (upregulation of p53), which would exert a much positive influence on the overcoming of drug resistance. Additionally, flow cytometry studies showed that 1 arrested the cell cycle in the G0/G1 phase, induced mitochondrial membrane depolarization, increased ROS generation, and induced cell apoptosis. The results demonstrated that 1 could target simultaneously mitochondria and nuclei that gave rise to mitochondrial injury and DNA damage and ultimately efficiently promote the apoptotic death of tumor cells. Further mechanistic studies showed that 1 induced MDA-MB-231 cell apoptosis via the p53-mediated mitochondrial pathway by upregulating Bax and cytochrome c and downregulating Bcl-2 proteins, leading to the activation of caspase-3 and upregulation of the cleaved-PARP level. Taken together, 1 with such a synergic mechanism has great potential to be an effective anticancer agent that can overcome treatment resistance in TNBC.

A Novel CDK4/6 and PARP Dual Inhibitor ZC-22 Effectively Suppresses Tumor Growth and Improves the Response to Cisplatin Treatment in Breast and Ovarian Cancer

In recent years, three PARP inhibitors and three CDK4/6 inhibitors have been approved by the FDA for the treatment of recurrent ovarian cancer and advanced ER-positive breast cancer, respectively. However, the clinical benefits of the PARPi or CDK4/6i monotherapy are not as satisfied as expected and benefit only a fraction of patients. Current studies have shown therapeutic synergy for combinations of PARPi and CDK4/6i in breast and ovarian cancers with homologous recombination (HR) proficiency, which represents a new synthetic lethal strategy for treatment of these cancers regardless HR status. Thus, any compounds or strategies that can combine PARP and CDK4/6 inhibition will likely have great potential in improving clinic outcomes and in benefiting more patients. In this study, we developed a novel compound, ZC-22, that effectively inhibited both PARP and CDK4/6. This dual-targeting compound significantly inhibited breast and ovarian cancer cells by inducing cell cycle arrest and severe DNA damage both in vitro and in vivo. Interestingly, the efficacy of ZC-22 is even higher than the combination of PARPi Olaparib and CDK4/6i Abemaciclib in most breast and ovarian cancer cells, suggesting that it may be an effective alternative for the PARPi and CDK4/6i combination therapy. Moreover, ZC-22 sensitized breast and ovarian cancer cells to cisplatin treatment, a widely used chemotherapeutic agent. Altogether, our study has demonstrated the potency of a novel CDK4/6 and PARP dual inhibitor, which can potentially be developed into a monotherapy or combinatorial therapy with cisplatin for breast and ovarian cancer patients with HR proficiency.

Nine-Year Median Follow-up of Cardiotoxicity and Efficacy of Trastuzumab Concurrently With Anthracycline-Based and Anthracycline-Free Neoadjuvant Chemotherapy in HER2-Positive Breast Cancer Patients

BACKGROUND

The combination of trastuzumab with anthracycline chemotherapy drugs is associated with synergistic cardiotoxicity. The aim of this study is to compare the efficacy and late-onset cardiac toxicity of neoadjuvant chemotherapy regimens, trastuzumab plus paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide (PH-FECH) versus trastuzumab plus docetaxel and carboplatin (TCH), for human epidermal growth factor receptor 2-positive (HER2⁺) breast cancer (BC).

METHODS

Patients with HER2⁺ BC who received neoadjuvant chemotherapy with PH-FECH or TCH between 2002 and 2009 at MD Anderson Cancer Center were included. The primary endpoint was progression-free survival (PFS). Secondary endpoints included pathological complete response (pCR), overall survival, cardiac events, breast cancer-specific survival, noncardiac toxicities, and chemotherapy interruption.

RESULTS

We identified 249 consecutive patients (184 who received PH-FECH and 65 who received TCH). The 10-year PFS was higher in the PH-FECH group than in the TCH group (83.6% vs. 72.2%; P = .044). The pCR rate was significantly higher in the PH-FECH group (58.2% vs. 41.5%; P = .021). The rate of cardiac events was higher in the PH-FECH group, but the difference was not significant (13.0% vs. 7.7%; P = .352). More patients developed late-onset cardiotoxicity in the PH-FECH group (3.8%) than in the TCH group (1.5%). Hypertension (odds ratio, 4.402 [95% confidence interval, 1.020-18.998]; P = .047) was an independent predictor of late-onset cardiotoxicity.

CONCLUSIONS

Both neoadjuvant regimens are effective and tolerable in patients with HER2⁺ BC. The PH-FECH regimen offers a higher pCR rate and higher PFS but no difference in overall survival or breast cancer-specific survival. Higher frequency of cardiac toxicity with PH-FECH was noted.

Survival benefit of platinum-based regimen in early stage triple negative breast cancer: A meta-analysis of randomized controlled trials

Platinum (Pt)-based chemo-regimens have been proved effective in neoadjuvant and salvage chemotherapy of triple negative breast cancer (TNBC). However, the survival benefit of Pt-based regimens in early stage TNBC(eTNBC) treatment has remained unclear. We conducted a meta-analysis to explore its role in improving the clinical outcomes of eTNBC. We carried out a comprehensive literature search on 15 March 2021 for randomized controlled trials (RCTs) comparing ajuvant/neoadjuvant Pt-based and Pt-free chemo-regimens in eTNBC patients, according to PRISMA 2020. We extracted the survival data and utilized the STATA software to calculate the summarized hazard ratios (HRs) and 95% confidence interval (95% CI) for overall survival (OS) and disease-free survival (DFS). Seven eligible RCTs enrolling a total of 2,027 eTNBC patients were identified in this meta-analysis, with 1,007 receiving Pt-free regimens, and the other 1,020 patients receiving Pt-based regimens, respectively. Patients in Pt-based regimens arm were associated with significant improved DFS (HR = 0.70, 95% CI: 0.58–0.84), and OS (HR = 0.78, 95% CI: 0.61–1.00). The survival benefits of DFS remained consistent in both the two strategies of Pt usage, either adding Pt to standard anthracyclines&taxanes based regimens (A&T + Pt), or combination of Pt and taxanes alone (TPt). The survival benefits also remained consistent in either neoadjuvant or adjuvant use of Pt. The present meta-analysis of RCTs revealed that Pt-based chemo-regimens could significantly improve both DFS and OS for eTNBC patients. Based on efficiency and toxicity, we recommend Pt-based regimens for eTNBC, especially the “A&T + Pt” mode if the toxicities are tolerable, which may lead TNBC therapy into a new era.

A triple combination gemcitabine + romidepsin + cisplatin to effectively control triple-negative breast cancer tumor development, recurrence, and metastasis

PURPOSE

Triple-negative breast cancer (TNBC) is an aggressive, lethal, heterogeneous type of breast cancer (BC). TNBC tends to have a lower response rate to chemotherapy and a lower 5-year survival rate than other types of BC due to recurrence and metastasis. Our previous study revealed that a combination of gemcitabine, romidepsin, and cisplatin was efficacious in controlling TNBC tumor development. In this study, we extended our investigation of gemcitabine + romidepsin + cisplatin in controlling TNBC tumor recurrence and metastasis.

METHODS

We investigated the ability of gemcitabine + romidepsin + cisplatin to control cell survival and invasiveness using cell viability, soft agar colony formation, and transwell invasion assays. We determined the efficacy of gemcitabine + romidepsin + cisplatin in controlling tumor recurrence and metastasis using cell-derived xenograft animal models. We used immunoblotting to study signaling modulators regulated by gemcitabine + romidepsin + cisplatin in TNBC cells and tumor tissues.

RESULTS

Treatment with gemcitabine + romidepsin + cisplatin reduced the TNBC MDA-MB231 and MDA-MB468 cell survival to ~ 50% and ~ 15%, as well as invasiveness to ~ 31% and ~ 13%, respectively. Gemcitabine + romidepsin + cisplatin suppressed modulators involved in epithelial-mesenchymal transition in an ROS-dependent manner. Controlling tumor recurrence, the Gem plus Rom + Cis regimen (~ 112%) was more efficacious than the Gem plus Cis regimen (~ 21%) in tumor growth inhibition. The Gem plus Rom + Cis regimen efficaciously reduced the development of metastatic nodules to 20% in animals.

CONCLUSION

The gemcitabine plus romidepsin + cisplatin regimen was highly efficacious in controlling TNBC tumor development, recurrence, and metastasis in animals. The combination regimen should be poised for efficient translation into clinical trials for controlling the recurrence and metastasis, ultimately contributing to reducing mortality and improving TNBC patients' quality of life.

Gigantol inhibits proliferation and enhances DDP-induced apoptosis in breast-cancer cells by downregulating the PI3K/Akt/mTOR signaling pathway

AIMS

Gigantol is a bibenzyl compound isolated from orchids of the genus Dendrobium. Gigantol has been demonstrated to possess various pharmacologic (including anticancer) effects. Cisplatin (DDP) has been used and studied as the first-line agent for breast cancer (BC) treatment. Often, its efficacy is jeopardized due to intolerance and organ toxicity. We investigated if gigantol could enhance the anticancer effects of DDP in BC cells and its underlying mechanism of action.

MAIN METHODS

The potential pathway of gigantol in BC cells was detected by network-pharmacology and molecular-docking studies. The proliferation and apoptosis of BC cell lines were measured by the MTT assay, colony formation, Hoechst-33342 staining, and flow cytometry. Protein expression was measured by western blotting.

KEY FINDINGS

Gigantol could inhibit proliferation of BC cells and enhance DDP-induced apoptosis. According to the results of western blotting, gigantol reinforced DDP-induced anticancer effects through downregulation of the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway in BC cells. The effects were consistent with those of the pathway inhibitor LY294002.

SIGNIFICANCE

Our data might provide new insights into the underlying antitumor effect of gigantol in BC cells. This enhancement effect in the combination of gigantol and DDP may provide many therapeutic benefits in clinical treatment regimens against BC.

Platinum-based neoadjuvant chemotherapy for triple-negative breast cancer: a systematic review and meta-analysis

Background

Triple-negative breast cancer (TNBC) is associated with higher aggressiveness and mortality than hormone-positive breast cancer because of the lack of approved therapeutic targets. Patients with TNBC who attain a pathological complete response (pCR) after neoadjuvant chemotherapy have improved survival. Platinum-based agents show promising activity in TNBC; however, their use remains controversial. We conducted a meta-analysis to assess the role of platinum-based agents in neoadjuvant chemotherapy in patients with TNBC.

Methods

We performed an extensive literature search of the Pubmed, Embase, and Cochrane databases. We calculated pooled odds ratios (OR) with 95% confidence intervals (CI) for the identified studies.

Results

Eight randomized controlled trials with 1345 patients were included in the analysis. The addition of platinum-based agents improved pCR compared with neoadjuvant therapy based on anthracyclines, cyclophosphamide, taxanes, and fluorouracil (49.1% vs. 35.9%; OR: 1.87, 95% CI: 1.23–2.86). Hematological adverse events were similar in both groups, except for more thrombocytopenia in the platinum-based group (OR: 7.96, 95% CI: 3.18–19.93).

Conclusion

The addition of platinum-based agents to neoadjuvant chemotherapy improved pCR rates in patients with TNBC, with a slight increase in hematological toxicities. Platinum-based agents might thus be an accessible and economically viable option in patients with TNBC.

Platinum-containing regimens for triple-negative metastatic breast cancer

BACKGROUND

In a previous Cochrane Review, we found that for women with metastatic breast cancer unselected for triple-negative disease, there is little or no survival benefit and excess toxicity from platinum-based regimens. In subgroup analyses, however, we found preliminary low-quality evidence of a survival benefit from platinum-based regimens for women with metastatic triple-negative breast cancer (mTNBC). This review updates the evidence from the mTNBC subgroup analyses in the previous Cochrane Review.

OBJECTIVES

To assess the effects of platinum-containing chemotherapy regimens with regimens not containing platinum in the management of women with mTNBC.

SEARCH METHODS

We obtained relevant studies published prior to 2015 and their extracted results from the mTNBC subgroup analysis in the previous Cochrane Review. We searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov between 2015 and 27 September 2019. We identified further potentially relevant studies from previous trial reports, systematic reviews, and meta-analyses.

SELECTION CRITERIA

Randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in women with mTNBC. Individual trials could compare one or more platinum-based regimens to one or more non-platinum regimens; hence there could be more 'treatment-comparisons' (i.e. platinum regimen versus non-platinum regimen comparison) than trials. Trial participants may have been purposely selected for mTNBC or inadvertently selected as a subgroup.

DATA COLLECTION AND ANALYSIS

At least two independent reviewers assessed studies for eligibility and quality, and extracted all relevant data from each study. We derived hazard ratios (HRs) for time-to-event outcomes, where possible, and used fixed-effect models for meta-analyses. We analysed objective tumour response rates (OTRRs) and toxicities as binary (dichotomous) outcomes with risk ratios (RRs) used as measures of effects. We extracted quality of life data, if available. We used GRADE to rate the quality of evidence for time-to-event and tumour response outcomes.

MAIN RESULTS

This review includes 13 treatment-comparisons involving 1349 women from 10 studies. Twelve of the 13 treatment-comparisons were included in one or more meta-analyses. Of the 13 treatment-comparisons, six and eight had published or provided time-to-event data on overall survival (OS) or progression-free survival/time to progression (PFS/TTP), respectively, that could be included in meta-analyses. Ten treatment-comparisons published or provided OTRR data that could be included in meta-analyses. Eight of the 13 treatment-comparisons were from studies that selected participants on the basis of mTNBC status, while the other five treatment-comparisons were from studies that reported mTNBC results as part of subgroup analyses. Analysis of six treatment-comparisons indicated that platinum-containing regimens may have provided a small survival benefit to mTNBC patients (HR 0.85, 95% CI 0.73 to 1.00; 958 women; moderate-quality evidence) with no evidence of heterogeneity (P = 0.41; I2 = 1%). Data from eight treatment-comparisons showed that platinum regimens may improve PFS/TTP (HR 0.77, 95% CI 0.68 to 0.88; 1077 women; very low-quality evidence). There was marked evidence of heterogeneity (P < 0.0001; I2 = 80%). There was also low-quality evidence of better tumour response for platinum recipients (RR 1.40, 95% CI 1.22 to 1.59; 1205 women) with some evidence of heterogeneity (P = 0.01; I2 = 58%). The observed heterogeneity for the PFS/TTP and OTRR outcomes may reflect between-study differences and general difficulties in assessing tumour response, as well as the varying potencies of the comparators. Compared with women receiving non-platinum regimens: rates of grade 3 and 4 nausea/vomiting were higher for platinum recipients (RR 4.77, 95% CI 1.93 to 11.81; 655 women; low-quality evidence) and rates of grade 3 and 4 anaemia were higher for platinum recipients (RR 3.80, 95% CI 2.25 to 6.42; 843 women; low-quality evidence). In general, however, relatively few intervention-comparisons could be included in meta-analyses for adverse events. None of the studies reported quality of life.

AUTHORS' CONCLUSIONS

For women with mTNBC, there was moderate-quality evidence of a small survival benefit from platinum-based regimens compared to non-platinum regimens. This finding is consistent with findings of a PFS/TTP benefit and improved tumour response from platinum-based regimens. These potential benefits, however, should be weighed against previously identified excess toxicities from platinum-based regimens, particularly regimens containing cisplatin. Further randomised trials of platinum-based regimens among women with mTNBC are required.

Consensus Guidelines on Genetic` Testing for Hereditary Breast Cancer from the American Society of Breast Surgeons

BACKGROUND

The purpose of this consensus guideline is to outline recommendations for genetic testing that medical professionals can use to assess hereditary risk for breast cancer.

METHODS

Literature review included large datasets, basic and clinical science publications, and recent updated national guidelines. Genetic testing to assess hereditary risk of cancer is a complex, broad, and dynamic area of medical research. The dominant focus of this guideline is limited in scope to breast cancer.

RESULTS

There is a lack of consensus among experts regarding which genes among many should be tested in different clinical scenarios. There is also variation in the degree of consensus regarding the understanding of risk and appropriate clinical management of mutations in many genes.

CONCLUSIONS

Genetic testing should be made available to all patients with a personal history of breast cancer. Recent data are reviewed that support genetic testing being offered to each patient with breast cancer (newly diagnosed or with a personal history). If genetic testing is performed, such testing should include BRCA1/BRCA2 and PALB2, with other genes as appropriate for the clinical scenario and family history. For patients with newly diagnosed breast cancer, identification of a mutation may impact local treatment recommendations. Patients who had genetic testing previously may benefit from updated testing. Genetic testing should be made available to patients without a history of breast cancer who meet National Comprehensive Cancer Network guidelines. Finally, variants of uncertain significance are not clinically actionable and these patients should be managed based on their individual risk factors.

Chromosome 12p Amplification in Triple-Negative/BRCA1-Mutated Breast Cancer Associates with Emergence of Docetaxel Resistance and Carboplatin Sensitivity

Taxanes are the mainstay of treatment in triple-negative breast cancer (TNBC), with de novo and acquired resistance limiting patient's survival. To investigate the genetic basis of docetaxel resistance in TNBC, exome sequencing was performed on matched TNBC patient-derived xenografts (PDX) sensitive to docetaxel and their counterparts that developed resistance in vivo upon continuous drug exposure. Most mutations, small insertions/deletions, and copy number alterations detected in the initial TNBC human metastatic samples were maintained after serial passages in mice and emergence of resistance. We identified a chromosomal amplification of chr12p in a human BRCA1-mutated metastatic sample and the derived chemoresistant PDX, but not in the matched docetaxel-sensitive PDX tumor. Chr12p amplification was validated in a second pair of docetaxel-sensitive/resistant BRCA1-mutated PDXs and after short-term docetaxel treatment in several TNBC/BRCA1-mutated PDXs and cell lines, as well as during metastatic recurrence in a patient with BRCA1-mutated breast cancer who had progressed on docetaxel treatment. Analysis of clinical data indicates an association between chr12p amplification and patients with TNBC/basal-like breast cancer, a BRCA1 mutational signature, and poor survival after chemotherapy. Detection of chr12p amplification in a cohort of TNBC PDX models was associated with an improved response to carboplatin. Our findings reveal tumor clonal dynamics during chemotherapy treatments and suggest that a preexisting population harboring chr12p amplification is associated with the emergence of docetaxel resistance and carboplatin responsiveness in TNBC/BRCA1-mutated tumors. SIGNIFICANCE: Chr12p copy number gains indicate rapid emergence of resistance to docetaxel and increased sensitivity to carboplatin, therefore sequential docetaxel/carboplatin treatment could improve survival in TNBC/BRCA1 patients. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/16/4258/F1.large.jpg.

DNA Double Strand Break Repair - Related Synthetic Lethality

Cancer is a heterogeneous disease with a high degree of diversity between and within tumors. Our limited knowledge of their biology results in ineffective treatment. However, personalized approach may represent a milestone in the field of anticancer therapy. It can increase specificity of treatment against tumor initiating cancer stem cells (CSCs) and cancer progenitor cells (CPCs) with minimal effect on normal cells and tissues. Cancerous cells carry multiple genetic and epigenetic aberrations which may disrupt pathways essential for cell survival. Discovery of synthetic lethality has led a new hope of creating effective and personalized antitumor treatment. Synthetic lethality occurs when simultaneous inactivation of two genes or their products causes cell death whereas individual inactivation of either gene is not lethal. The effectiveness of numerous anti-tumor therapies depends on induction of DNA damage therefore tumor cells expressing abnormalities in genes whose products are crucial for DNA repair pathways are promising targets for synthetic lethality. Here, we discuss mechanistic aspects of synthetic lethality in the context of deficiencies in DNA double strand break repair pathways. In addition, we review clinical trials utilizing synthetic lethality interactions and discuss the mechanisms of resistance.

Fuplatin: An Efficient and Low-Toxic Dual-Prodrug

As FDA-approved chemotherapeutic agents, cisplatin, oxaliplatin, and 5-fluorouracil are widely used in clinic but limited by severe side-effects. To ameliorate their respective defects, a series of "dual-prodrug" by linking oxoplatin and 5-FU were designed and synthesized. The assembled compounds 10-17, named Fuplatin, exhibited much higher cytotoxicity against the tested cancer cells while lower cytotoxicity toward the human normal lung cells than free drugs or their combinations. Among them, 14 enhanced cellular accumulation with 62- and 825-fold amount of oxaliplatin and 8 at 9 h, respectively, significantly induced DNA damage and cell apoptosis, and inhibited migration and invasion in HCT-116 cells. Compound 14 arrested the cell cycle at S and G2 phases and up-regulated thymidylate synthase and p53, consistent with the results of the combination, suggesting 14 adopted a collaborative mode of 5-FU and oxaliplatin to kill cancer cells. In vivo, compound 14 showed high antitumor effect and no observable toxicity in NOD/SCID mice bearing HCT-116 tumors.

Chlorambucil-conjugated platinum(IV) prodrugs to treat triple-negative breast cancer in vitro and in vivo

Modification of platinum (II) into lipophilic platinum (IV) compounds by introducing biologically active molecules were widely employed to develop new platinum-based prodrugs in the past decade. In this paper, two chlorambucil platinum (IV) complexes, CLB-Pt and CLB-Pt-CLB, were synthesized and displayed very potent antiproliferative activity against all the tested cancer cell lines, such as A549, HeLa and MCF-7, especially to treat the well-known refractory triple-negative breast cancer. CLB-Pt-CLB significantly improved cell-killing effect in triple-negative subtype MDA-MB-231 cells, and showed much stronger cytotoxicity than either monotherapy or combination of cisplatin and chlorambucil. CLB-Pt-CLB prodrug entered cells in dramatically increased amount compared with cisplatin and enhanced DNA damage, inducing cancer cell apoptosis. It exhibited high anticancer activity and no observable toxicity in BALB/c nude mice bearing MDA-MB-231 tumors. The chlorambucil moiety not only greatly assisted the passive diffusion of CLB-Pt-CLB into cells, but also produced the synergism with cisplatin in targeting DNA.

Cisplatin versus carboplatin in combination with paclitaxel as neoadjuvant regimen for triple negative breast cancer

Background

Platinum salts have demonstrated sufficient efficacy and safety for consideration of their use in a neoadjuvant setting for triple negative breast cancer (TNBC).

Patients and methods

We retrospectively analyzed 145 TNBC cases to compare the activity and tolerability of cisplatin and carboplatin. Two groups received weekly paclitaxel and platinum salts.

Results

In total, 87% of patients in the cisplatin group and 82% of patients in the carboplatin group experienced a clinical objective response after four cycles (complete response or partial response; P=0.570). Pathological complete response (pCR) occurred similarly in the cisplatin group and the carboplatin group (44% versus 42%, P=0.789). In survival analysis, there was no difference between the two regimens. The most common grade 3/4 adverse events were neutropenia and leukopenia.

Conclusion

There was no significant difference between the groups in terms of adverse events. Both types of platinum salts and weekly paclitaxel are feasible therapies that achieved high pCR rates and tolerability in TNBC patients.

Efficacy of anthracycline/taxane-based neo-adjuvant chemotherapy on triple-negative breast cancer in BRCA1/BRCA2 mutation carriers

This study aims to estimate the pathologic complete response (pCR) rate after neo-adjuvant chemotherapy and to compare disease-free survival (DFS) and overall survival (OS) between pCR and non-pCR groups of patients with triple-negative breast cancer (TNBC) and deleterious BRCA1 or BRCA2 mutation. We carried out a retrospective analysis of 53 patients including 46 BRCA1, 6 BRCA2, and 1 combined BRCA1 and BRCA2 mutation. All patients had been diagnosed with triple-negative breast cancer (TNBC) between 1997 and 2014. Neo-adjuvant therapy consisted of regimens that were based on anthracycline or an anthracycline-taxane doublet. DFS included any relapse or second cancer. The Kaplan-Meier method and the log-rank test were used to compare pCR and non-pCR groups. A pCR was observed in 23 (42.6% [95% CI, 29.2%-56.8%]) of the TNBC included. The pCR rate was 38.3% [95% CI, 26%-55%] among BRCA1 mutation carriers, and 66% among the 6 BRCA2 mutation carriers. Median follow-up was 4.4 years (range 0.62-16.2 years) and did not differ between the groups (P = .25). Fifteen relapses and six second cancers were recorded during the follow-up period. Eleven deaths occurred, all of which were in the non-pCR group. DFS (P < .01) and OS (P < .01) were significantly better in the pCR group than the non-pCR group. This study shows a high pCR rate after neo-adjuvant therapy in BRCA-mutated triple-negative breast cancer, and the survival results confirm the prognostic value of pCR in this group. These outcomes should be considered as a basis of comparison to be used by future studies about new therapies in this domain.

Platinum-containing regimens for metastatic breast cancer

BACKGROUND

Studies have reported high tumour response rates for platinum-containing regimens in the treatment of women with metastatic breast cancer. Most of these studies were conducted prior to the 'intrinsic subtype' era, and did not specifically focus on metastatic triple-negative breast cancers (mTNBCs).

OBJECTIVES

To identify and review the evidence from randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in the management of women with metastatic breast cancer.

SEARCH METHODS

For this review update, we searched the Cochrane Breast Cancer Group's Specialised Register, CENTRAL, MEDLINE, Embase, the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov on 28 May 2015. We identified further potentially relevant studies from handsearching references of previous trials, systematic reviews, and meta-analyses. Prior to this review update, the most recent search for studies was conducted in May 2003 for the original 2004 review.

SELECTION CRITERIA

Randomised trials comparing platinum-containing chemotherapy regimens with regimens not containing platinum in women with metastatic breast cancer.

DATA COLLECTION AND ANALYSIS

At least two independent reviewers assessed studies for eligibility and quality, and extracted all relevant data from each study. Hazard ratios (HRs) were derived for time-to-event outcomes, where possible, and fixed-effect models were used for meta-analyses. Objective tumour response rates (OTRRs) and toxicities were analysed as binary (dichotomous) outcomes with risk ratios (RRs) used as measures of effects. Quality of life data were extracted where available. GRADE was used to rate the quality of evidence for survival and tumour response outcomes at the level of subgroups selected and unselected for mTNBC, and for toxicity outcomes based on combining data from selected and unselected populations.

MAIN RESULTS

This update includes 15 new eligible treatment-comparisons from 12 studies. In total, 28 treatment-comparisons, involving 4418 women, from 24 studies are now included in one or more meta-analyses. Of the 28 treatment-comparisons, 19 and 16 had published or provided extractable time-to-event data on overall survival (OS) or progression-free survival/time to progression (PFS/TTP), respectively. All 28 treatment-comparisons provided OTRR data that could be included in meta-analyses. Most women recruited to the studies were not selected on the basis of mTNBC status.In a subgroup of three treatment-comparisons assessing women with mTNBC, platinum-containing regimens may have provided a survival benefit (HR 0.75, 95% CI 0.57 to 1.00; low-quality evidence). In women unselected for intrinsic subtypes such as mTNBC, there was little or no effect on survival (HR 1.01, 95% CI 0.92 to 1.12; high-quality evidence). This effect was similar to the combined analysis of survival data for both populations (HR 0.98, 95% CI 0.89 to 1.07; I2 =39%, 1868 deaths, 2922 women; 19 trials). The difference in treatment effects between mTNBC women compared with unselected women was of borderline statistical significance (P = 0.05).Data from three treatment-comparisons with mTNBC participants showed that platinum regimens may improve PFS/TTP (HR 0.59, 95% CI 0.49 to 0.72; low-quality evidence). Thirteen treatment-comparisons of unselected metastatic participants showed that there was probably a small PFS/TTP benefit for platinum recipients, although the confidence interval included no difference (HR 0.92, 95% CI 0.84 to 1.01; moderate-quality evidence). Combined analysis of data from an estimated 1772 women who progressed or died out of 2136 women selected or unselected for mTNBC indicated that platinum-containing regimens improved PFS/TTP (HR 0.85, 95% CI 0.78 to 0.93). There was marked evidence of heterogeneity (P = 0.0004; I2 = 63%). The larger treatment benefit in mTNBC women compared with unselected women was statistically significant (P < 0.0001).There was low-quality evidence of better tumour response in both subgroups of women with mTNBC and unselected women (RR 1.33, 95% CI 1.13 to 1.56; RR 1.11, 95% CI 1.04 to 1.19, respectively). Combined analysis of both populations was closer to the effect in unselected women (RR 1.15, 95% CI 1.08 to 1.22; 4130 women). There was considerable evidence of heterogeneity (P < 0.0001; I2 = 64%), which may reflect between-study differences and general difficulties in assessing response, as well as the varying potencies of the comparators.Compared with women receiving non-platinum regimens: rates of grade 3 and 4 nausea/vomiting were probably higher among women receiving cisplatin- (RR 2.65, 95% CI 2.10 to 3.34; 1731 women; moderate-quality evidence) but the effect from carboplatin-containing regimens was less certain (RR 0.77, 95% CI 0.47 to 1.26; 1441 women; moderate-quality evidence); rates of grade 3 and 4 anaemia were higher among women receiving cisplatin- (RR 3.72, 95% CI 2.36 to 5.88; 1644 women; high-quality evidence) and carboplatin-containing regimens (RR 1.72, 95% CI 1.10 to 2.70; 1441 women; high-quality evidence); rates of grade 3 and 4 hair loss (RR 1.41, 95% CI 1.26 to 1.58; 1452 women; high-quality evidence) and leukopenia (RR 1.38, 95% CI 1.21 to 1.57; 3176 women; moderate-quality evidence) were higher among women receiving platinum-containing regimens (regardless of platinum agent).

AUTHORS' CONCLUSIONS

In women with metastatic breast cancer who do not have triple-negative disease, there is high-quality evidence of little or no survival benefit and excess toxicity from platinum-based regimens. There is preliminary low-quality evidence of a moderate survival benefit from platinum-based regimens for women with mTNBC. Further randomised trials of platinum-based regimens in this subpopulation of women with metastatic breast cancer are required.

PARP inhibitor combination therapy

In 2014, olaparib (Lynparza) became the first PARP (Poly(ADP-ribose) polymerase) inhibitor to be approved for the treatment of cancer. When used as single agents, PARP inhibitors can selectively target tumour cells with BRCA1 or BRCA2 tumour suppressor gene mutations through synthetic lethality. However, PARP inhibition also shows considerable promise when used together with other therapeutic agents. Here, we summarise both the pre-clinical and clinical evidence for the utility of such combinations and discuss the future prospects and challenges for PARP inhibitor combinatorial therapies.

Reduced PAK1 activity sensitizes FA/BRCA-proficient breast cancer cells to PARP inhibition

Cells that are deficient in homologous recombination, such as those that have mutations in any of the Fanconi Anemia (FA)/BRCA genes, are hypersensitive to inhibition of poly(ADP-ribose) polymerase (PARP). However, FA/BRCA-deficient tumors represent a small fraction of breast cancers, which might restrict the therapeutic utility of PARP inhibitor monotherapy. The gene encoding the serine-threonine protein kinase p21-activated kinase 1 (PAK1) is amplified and/or overexpressed in several human cancer types including 25-30% of breast tumors. This enzyme controls many cellular processes by phosphorylating both cytoplasmic and nuclear substrates. Here, we show that depletion or pharmacological inhibition of PAK1 down-regulated the expression of genes involved in the FA/BRCA pathway and compromised the ability of cells to repair DNA by Homologous Recombination (HR), promoting apoptosis and reducing colony formation. Combined inhibition of PAK1 and PARP in PAK1 overexpressing breast cancer cells had a synergistic effect, enhancing apoptosis, suppressing colony formation, and delaying tumor growth in a xenograft setting. Because reduced PAK1 activity impaired FA/BRCA function, inhibition of this kinase in PAK1 amplified and/or overexpressing breast cancer cells represents a plausible strategy for expanding the utility of PARP inhibitors to FA/BRCA-proficient cancers.

Synthetic lethality: the road to novel therapies for breast cancer

When the BRCA1 and BRCA2 tumour suppressor genes were identified in the early 1990s, the immediate implications of mapping, cloning and delineating the sequence of these genes were that individuals in families with a BRCA gene mutation could be tested for the presence of a mutation and their risk of developing cancer could be predicted. Over time though, the discovery of BRCA1 and BRCA2 has had a much greater influence than many might have imagined. In this review, we discuss how the discovery of BRCA1 and BRCA2 has not only provided an understanding of the molecular processes that drive tumourigenesis but also reignited an interest in therapeutically exploiting loss-of-function alterations in tumour suppressor genes.

The kinesin Eg5 inhibitor K858 induces apoptosis but also survivin-related chemoresistance in breast cancer cells

Inhibitors of kinesin spindle protein Eg5 are characterized by pronounced antitumor activity. Our group has recently synthesized and screened a library of 1,3,4-thiadiazoline analogues with the pharmacophoric structure of K858, an Eg5 inhibitor. We herein report the effects of K858 on four different breast cancer cell lines: MCF7 (luminal A), BT474 (luminal B), SKBR3 (HER2 like) and MDA-MB231 (basal like). We demonstrated that K858 displayed anti-proliferative activity on every analyzed breast cancer cell line by inducing apoptosis. However, at the same time, we showed that K858 up-regulated survivin, an anti-apoptotic molecule. We then performed a negative regulation of survivin expression, with the utilization of wortmannin, an AKT inhibitor, and obtained a significant increase of K858-dependent apoptosis. These data demonstrate that K858 is a potent inhibitor of replication and induces apoptosis in breast tumor cells, independently from the tumor phenotype. This anti-proliferative response of tumor cells to K858 can be limited by the contemporaneous over-expression of survivin; consequently, the reduction of survivin levels, obtained with AKT inhibitors, can sensitize tumor cells to K858-induced apoptosis.

Chemotherapy-induced anterior necrotising scleritis: A case report

Purpose

We describe a case of anterior necrotising scleritis secondary to Gemcitabine and Carboplatin chemotherapy agents in a patient with metastatic breast cancer, which has not been previously reported.

Observations

A 50-year-old lady with recurrent metastatic breast cancer presented with unilateral subconjunctival haemorrhage secondary to severe thrombocytopenia eight days following palliative chemotherapy in the form of Gemcitabine and Carboplatin. Twelve days following the initial presentation, the subconjunctival haemorrhage had resolved, however there was evidence of anterior necrotising scleritis with anterior chamber reaction and hypotony with choroidal effusion. This resolved with three days of intravenous Methylprednisolone along with topical steroids and the area of necrosis remained stable.

Conclusions and importance

Due to the chronological order of events, we infer a Gemcitabine and Carboplatin-induced anterior necrotising scleritis, which has not been previously reported.

Neoadjuvant, anthracycline-free chemotherapy with carboplatin and docetaxel in triple-negative, early-stage breast cancer: a multicentric analysis of rates of pathologic complete response and survival

INTRODUCTION

Triple-negative breast cancer (TNBC) has the highest mortality rates of all subtypes. Anthracycline and taxane regimens yield unsatisfactorily low rates of pathologic complete response (pCR) and are often not feasible in cardiac comorbidity. This study seeks to increase pCR and survival by introducing platin agents.

PATIENTS AND METHODS

In this multicentric, open-label study with six cycles of docetaxel (75 mg/m(2)) and carboplatin AUC 6 q3w, patients were unwilling or unsuitable for anthracycline-based regimens. Primary endpoint was pCR (ypT0/ypTis ypN0) and survival.

RESULTS

pCR rate was 50%. After 2 and 5 years, overall survival (OS) was 96.7 and 89.7%, disease-free-survival (DFS) 96.7 and 85.7%, DDFS 96.7 and 89.6%. Grade 3/4 toxicities were rare. Ninety-three per cent of patients completed six cycles. No toxicity-related treatment discontinuation or febrile neutropaenia was recorded.

CONCLUSION

This regimen is highly effective and feasible in TNBC and may be combined with anthracyclines.

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.