Chemotherapy in Patients with Anthracycline- and Taxane-Pretreated Metastatic Breast Cancer: An Overview

Baseline interleukin-6 is a prognostic factor for patients with metastatic breast cancer treated with eribulin

PURPOSE

Eribulin is a unique anti-cancer drug which can improve overall survival (OS) of patients with metastatic breast cancer (MBC), probably by modulating the tumor immune microenvironment. The aim of this study was to investigate the clinical significance of serum levels of immune-related and inflammatory cytokines in patients treated with eribulin. Furthermore, we investigated the association between cytokines and immune cells, such as myeloid-derived suppressor cells (MDSCs) and cytotoxic and regulatory T cells, to explore how these cytokines might affect the immune microenvironment.

METHODS

Sixty-eight patients with MBC treated with eribulin were recruited for this retrospective study. The relationship of cytokines, including interleukin (IL)-6, to progression-free survival and OS was examined. CD4+ and CD8+ lymphocyte, MDSCs and regulatory T cell levels were determined in the blood by flow cytometry analysis.

RESULTS

In our cohort, patients with high IL-6 at baseline had shorter progression-free survival and OS compared with those with low IL-6 (p = 0.0017 and p = 0.0012, respectively). Univariable and multivariable analyses revealed that baseline IL-6 was an independent prognostic factor for OS (p = 0.0058). Importantly, CD8+ lymphocytes were significantly lower and MDSCs were significantly higher in patients with high IL-6, compared to those with low IL-6.

CONCLUSION

Baseline IL-6 is an important prognostic factor in patients with MBC treated with eribulin. Our results show that high IL-6 is associated with higher levels of MDSCs which suppress anti-tumor immunity, such as CD8+ cells. It appears that eribulin is not particularly effective in patients with high IL-6 due to a poor tumor immune microenvironment.

Natural products derived from medicinal plants and microbes might act as a game-changer in breast cancer: a comprehensive review of preclinical and clinical studies

Breast cancer (BC) is the most prevalent neoplasm among women. Genetic and environmental factors lead to BC development and on this basis, several preventive - screening and therapeutic interventions have been developed. Hormones, both in the form of endogenous hormonal signaling or hormonal contraceptives, play an important role in BC pathogenesis and progression. On top of these, breast microbiota includes both species with an immunomodulatory activity enhancing the host's response against cancer cells and species producing proinflammatory cytokines associated with BC development. Identification of novel multitargeted therapeutic agents with poly-pharmacological potential is a dire need to combat advanced and metastatic BC. A growing body of research has emphasized the potential of natural compounds derived from medicinal plants and microbial species as complementary BC treatment regimens, including dietary supplements and probiotics. In particular, extracts from plants such as Artemisia monosperma Delile, Origanum dayi Post, Urtica membranacea Poir. ex Savigny, Krameria lappacea (Dombey) Burdet & B.B. Simpson and metabolites extracted from microbes such as Deinococcus radiodurans and Streptomycetes strains as well as probiotics like Bacillus coagulans and Lactobacillus brevis MK05 have exhibited antitumor effects in the form of antiproliferative and cytotoxic activity, increase in tumors' chemosensitivity, antioxidant activity and modulation of BC - associated molecular pathways. Further, bioactive compounds like 3,3'-diindolylmethane, epigallocatechin gallate, genistein, rutin, resveratrol, lycopene, sulforaphane, silibinin, rosmarinic acid, and shikonin are of special interest for the researchers and clinicians because these natural agents have multimodal action and act via multiple ways in managing the BC and most of these agents are regularly available in our food and fruit diets. Evidence from clinical trials suggests that such products had major potential in enhancing the effectiveness of conventional antitumor agents and decreasing their side effects. We here provide a comprehensive review of the therapeutic effects and mechanistic underpinnings of medicinal plants and microbial metabolites in BC management. The future perspectives on the translation of these findings to the personalized treatment of BC are provided and discussed.

A layered cancer-on-a-chip system for anticancer drug screening and disease modeling

Recent advances in the development of microfluidic systems for the culture of complex and three-dimensional cell, tissue, and organ models allow their use in toxicity studies and mimicking many diseases. These types of in vitro models are important because of the huge advantages over standard two-dimensional cell cultures: better mimicking of in vivo conditions and more reliable response to the tested drugs. This report presents a new approach to modeling skin cancer (melanoma-on-a-chip) and breast cancer (breast cancer-on-a-chip) using the microfluidic systems. We designed a microfluidic device to co-culture cancer cells with non-malignant cells, which are the main component of the cancer microenvironment. In the construction of the microsystem, we used a scaffold in the form of a porous membrane made of poly(ethylene terephthalate), which enables the regular and reproducible arrangement of cells in the culture and maintains intercellular communication. To demonstrate the functionality of the microsystem, we used it to analyze the effectiveness of photodynamic therapy in the treatment of melanoma and chemotherapy in the treatment of breast cancer. The developed microsystem can be successfully used to model cancer diseases, especially with a layered arrangement of cells in the cancerous tissue, such as melanoma, ductal breast cancer, or breast cancer metastases to the skin.

Recent Advances in Targeted Nanocarriers for the Management of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a life-threatening form of breast cancer which has been found to account for 15% of all the subtypes of breast cancer. Currently available treatments are significantly less effective in TNBC management because of several factors such as poor bioavailability, low specificity, multidrug resistance, poor cellular uptake, and unwanted side effects being the major ones. As a rapidly growing field, nano-therapeutics offers promising alternatives for breast cancer treatment. This platform provides a suitable pathway for crossing biological barriers and allowing sustained systemic circulation time and an improved pharmacokinetic profile of the drug. Apart from this, it also provides an optimized target-specific drug delivery system and improves drug accumulation in tumor cells. This review provides insights into the molecular mechanisms associated with the pathogenesis of TNBC, along with summarizing the conventional therapy and recent advances of different nano-carriers for the management of TNBC.

Immune checkpoint inhibition in early-stage triple-negative breast cancer

INTRODUCTION

Breast cancer cells can evade immune recognition by upregulating programmed death-ligand 1 (PD-L1) leading to decreased T cell function. Anti-PD-1 agents, like pembrolizumab, and anti-PD-L1 agents, such as atezolizumab and durvalumab, in combination with chemotherapy were found to have efficacy in metastatic triple-negative breast cancer (TNBC). With sub-optimal long-term outcomes in early-stage TNBC, this combination of immune checkpoint inhibition with chemotherapy was subsequently investigated. A robust immune microenvironment and extensive tumor antigen exposure in early-stage breast cancer is believed to facilitate response to checkpoint inhibitors.

AREAS COVERED

This review focuses on studies that assess the role of neoadjuvant immune checkpoint inhibition along with chemotherapy. The results of key phase I, II and III trials using checkpoint inhibitors in early-stage breast cancer (ESBC) are reviewed along with foundational data from metastatic TNBC, including the role of biomarkers in predicting response to immunotherapy.

EXPERT OPINION

Despite a clear role for neoadjuvant immune checkpoint inhibition in TNBC, many questions remain. The benefit of these agents in the neoadjuvant versus adjuvant setting is unclear and immune-related toxicity is a major concern. Additional studies are needed to elucidate which immune checkpoint inhibitor is most efficacious and best tolerated in early-stage TNBC.

Hypoxia induces docetaxel resistance in triple-negative breast cancer via the HIF-1α/miR-494/Survivin signaling pathway

Cytotoxic chemotherapy is the major strategy to prevent and reduce triple-negative breast cancer (TNBC) progression and metastasis. Hypoxia increases chemoresistance and is associated with a poor prognosis for patients with cancer. Based on accumulating evidence, microRNAs (miRNAs) play an important role in acquired drug resistance. However, the role of miRNAs in hypoxia-induced TNBC drug resistance remains to be clarified. Here, we found that hypoxia induced TNBC docetaxel resistance by decreasing the miR-494 level. Modulating miR-494 expression altered the sensitivity of TNBC cells to DTX under hypoxic conditions. Furthermore, we identified Survivin as a direct miR-494 target. Hypoxia upregulated survivin expression. In a clinical study, the HIF-1α/miR-494/Survivin signaling pathway was also active in primary human TNBC, and miR-494 expression negatively correlated with HIF-1α and survivin expression. Finally, in a xenograft model, both miR-494 overexpression and the HIF-1α inhibitor PX-478 increased the sensitivity of TNBC to DTX by suppressing the HIF-1α/miR-494/Survivin signaling pathway in vivo. In conclusion, treatments targeting the HIF-1α/miR-494/Survivin signaling pathway potentially reverse hypoxia-induced drug resistance in TNBC.

Protective effects of hesperidin through attenuation of Ki67 expression against DMBA-induced breast cancer in female rats

AIMS

Doxorubicin (Dox) is routinely used for breast cancer treatment but toxicity and drug resistance limit its use. The objective of the study was to investigate the protective effects of hesperidin alone and in combination with doxorubicin against experimentally induced breast cancer in female rats.

METHODS

Breast cancer (BC) was induced by administration of 7,12-dimethylbenz(a)anthracene (DMBA) through subcutaneous injection into the 3rd right mammary gland of female Wistar rats. Hesperidin (Hes) pretreated groups were started with Hes (200 mg/kg) two weeks prior to DMBA induction. Animals were randomly divided into nine groups namely vehicle control, DMBA-induced, Dox 4 mg/kg, Dox 2 mg/kg, Hes (200 mg/kg), Hes (200 mg/kg) plus Dox 4 mg/kg treated groups and Hes pretreated groups treated with DMBA, Dox 4 mg/kg and Dox 2 mg/kg.

KEY FINDINGS

Hes pretreated groups showed reduced tumor occurrence, tumor volume and increased survival rate as compared to DMBA-induced group of animals. Hes pretreated animals treated with Dox 4 mg/kg and 2 mg/kg exhibited significant reduction in malondialdehyde and improvement in levels of glutathione and inflammatory markers like IL-6, TNF-α, NF-κB, IFN-γ as compared to Dox 4 mg/kg and 2 mg/kg treated animals. Histopathology and Ki67 expression depicted better control of tumor with Hes pretreatment groups as compared to DMBA-induced. Histopathology of vital organs of Hes pretreated groups treated with Dox revealed lesser toxicity than Dox treated groups.

SIGNIFICANCE

Hesperidin possesses protective effect against experimentally induced breast cancer in female rats that appears to be related to attenuation of Ki67 expression.

Ultrasound augments on-demand breast tumor radiosensitization and apoptosis through a tri-responsive combinatorial delivery theranostic platform

Advanced inoperable triple-negative breast cancer (TNBC) comprises aggressive tumors with a modest pathological response to neoadjuvant chemotherapy. The concomitant use of chemoradiotherapy improves the pathological response rates. However, the dose-dependent systemic toxicity of clinical radiosensitizers with poor circulation half-life and limited passive bioavailability limits their clinical utility. We address these challenges by rationally designing a stealth and tumor microenvironment responsive nano-conjugate platform for the ultrasound-mediated on-demand spatio-temporal delivery of plant flavonoid curcumin as a combinatorial regimen with clinically approved paclitaxel for the neoadjuvant chemoradiotherapy of locally advanced triple-negative breast cancer (TNBC). Interestingly, the focused application of ultrasound at the orthotopic TNBC xenograft of NOD-SCID mice facilitated the immediate infiltration of nano-conjugates at the tumor interstitium, and conferred in vivo safety over marketed paclitaxel formulation. In addition, curcumin significantly potentiated the in vivo chemoradiotherapeutic efficacy of paclitaxel upon loading into nano-conjugates. This gets further enhanced by the concurrent pulse of ultrasound, as confirmed by PET-CT imaging, along with a significant improvement in the mice survival. The quadrapeutic apoptotic effect by the combination of paclitaxel, curcumin, radiation, and ultrasound, along with a reduction in the tumor microvessel density and cell proliferation marker, confers the broad chemo-radiotherapeutic potential of this regimen for radio-responsive solid tumors, as well as metastatic niches.

Fixed dose combination of capecitabine and cyclophosphamide in metastatic breast cancer: Results from THE ENCLOSE phase 2/3 randomized multicenter study

Aim

To evaluate pharmacokinetics, efficacy and safety of fixed-dose combination (FDC) of oral capecitabine + cyclophosphamide in metastatic breast cancer (MBC) patients progressing after anthracycline and/or taxane chemotherapy.

Methods

In this prospective, adaptive, phase-2/3, open-label study (CTRI/2014/12/005234), patients were randomized (1:1:1) to three FDC doses (doses/day: D1, capecitabine + cyclophosphamide 1400 mg + 60 mg; D2, 1800 mg + 80 mg; D3, 2200 mg + 100 mg) for 14 days, in 21-day cycles. In Part-I, multiple-dose pharmacokinetics and optimal dose(s) were evaluated with futility analysis. Group(s) with <3 responders based on best overall response rate (BOR, complete response [CR]+partial response [PR]), were discontinued. Efficacy (BOR, disease control rates [DCR; CR + PR + stable disease]) and safety of optimal dose(s) were evaluated in Part-II.

Results

Of 66 patients (n = 22/group) in Part-I, pharmacokinetics (D1 = 7/22, D2 = 9/22, D3 = 8/22) showed dose-proportionality for cyclophosphamide and greater than dose-proportionality for capecitabine. Modified intent-to-treat (mITT) analysis showed BOR of 7.14% (1/14) in D1 (discontinued), and 22.22% (4/18) each in D2 and D3, respectively. In Part-II, 50 additional patients were randomized in D2 and D3 (n = 144; total 72 [22 + 50] patients/group). mITT analysis in D2 (n = 54) and D3 (n = 58) showed BOR of 29.63% (16/54, 95%CI: 17.45–41.81%) and 22.41% (13/58, 95%CI: 11.68–33.15%), respectively. DCR in D2 and D3 were 87.04% (47/54, 95%CI: 78.08–96.00%) and 82.76% (48/58; 95%CI: 73.04–92.48%) after 3 and 57.41% (31/54; 95%CI: 52.41–79.50%) and 50.00% (29/58; 95%CI: 40.40–67.00%), after 6-cycles, respectively. Hand-foot syndrome (16.67%), vomiting (9.72%) in D2, and hand-foot syndrome (18.06%), asthenia (15.28%) in D3 were most-common adverse events.

Conclusion

FDC of capecitabine + cyclophosphamide (1800 + 80 mg/day) showed high disease control rates and good safety profile in MBC patients.

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Oral fixed dose combination (FDC) of capecitabine + cyclophosphamide developed.

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FDC showed high efficacy and good safety profiles.

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Effective in MBC patients progressing post anthracycline and/or taxane exposure.

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Oral FDC formulation may reduce pill burden and improve patient compliance.

Genetic variations in 3´UTRs of SMUG1 and NEIL2 genes modulate breast cancer risk, survival and therapy response

Breast cancer (BC) is the most frequent malignancy in women accounting for approximately 2 million new cases worldwide annually. Several genetic, epigenetic and environmental factors are known to be involved in BC development and progression, including alterations in post-transcriptional gene regulation mediated by microRNAs (miRNAs). Single nucleotide polymorphisms (SNPs) located in miRNA binding sites (miRSNPs) in 3'-untranslated (UTR) regions of target genes may affect miRNA-binding affinity and consequently modulate gene expression. We have previously reported a significant association of miRSNPs in the SMUG1 and NEIL2 genes with overall survival in colorectal cancer patients. SMUG1 and NEIL2 are DNA glycosylases involved in base excision DNA repair (BER). Assuming that certain genetic traits are common for solid tumours, we have investigated wherever variations in SMUG1 and NEIL2 genes display an association with BC risk, prognosis, and therapy response in a group of 673 BC patients and 675 healthy female controls. Patients with TC genotype of NEIL2 rs6997097 and receiving only hormonal therapy displayed markedly shorter overall survival (OS) (HR=4.15, 95% CI=1.7-10.16, P= 0.002) and disease-free survival (DFS) (HR=2.56, 95% CI=1.5-5.7, P= 0.02). Our results suggest that regulation of base excision repair glycosylases operated by miRNAs may modulate the prognosis of hormonally treated BC.

Nanovectorization of Prostate Cancer Treatment Strategies: A New Approach to Improved Outcomes

Prostate cancer (PC) is the most frequent male cancer in the Western world. Progression to Castration Resistant Prostate Cancer (CRPC) is a known consequence of androgen withdrawal therapy, making CRPC an end-stage disease. Combination of cytotoxic drugs and hormonal therapy/or genotherapy is a recognized modality for the treatment of advanced PC. However, this strategy is limited by poor bio-accessibility of the chemotherapy to tumor sites, resulting in an increased rate of collateral toxicity and incidence of multidrug resistance (MDR). Nanovectorization of these strategies has evolved to an effective approach to efficacious therapeutic outcomes. It offers the possibility to consolidate their antitumor activity through enhanced specific and less toxic active or passive targeting mechanisms, as well as enabling diagnostic imaging through theranostics. While studies on nanomedicine are common in other cancer types, only a few have focused on prostate cancer. This review provides an in-depth knowledge of the principles of nanotherapeutics and nanotheranostics, and how the application of this rapidly evolving technology can clinically impact CRPC treatment. With particular reference to respective nanovectors, we draw clinical and preclinical evidence, demonstrating the potentials and prospects of homing nanovectorization into CRPC treatment strategies.

Effects of heavy-load resistance training during (neo-)adjuvant chemotherapy on muscle cellular outcomes in women with breast cancer

INTRODUCTION

(Neo-)adjuvant chemotherapy for breast cancer has a deleterious impact on muscle tissue resulting in reduced cardiorespiratory fitness, skeletal muscle mass and function. Physical exercise during treatment may counteract some of these negative effects. However, the effects of resistance training (RT) alone have never been explored. The present study aims to investigate if heavy-load RT during (neo-)adjuvant chemotherapy counteracts deleterious effects on skeletal muscle in women diagnosed with breast cancer. We hypothesize that (neo-)adjuvant treatment with chemotherapy will reduce muscle fiber size, impair mitochondrial function, and increase indicators of cellular stress and that RT during treatment will counteract these negative effects. We also hypothesize that RT during (neo-)adjuvant chemotherapy will increase muscle and blood levels of potential antitumor myokines and reduce treatment-related side effects on muscle strength and cardiorespiratory fitness.

METHODS

Fifty women recently diagnosed with breast cancer scheduled to start (neo-)adjuvant chemotherapy will be randomized to either randomized to either intervention group or to control group.The intervention group will perform supervised heavy-load RT twice a week over the course of chemotherapy (approximately 16-weeks) whereas the control group will be encouraged to continue with their usual activities. Muscle biopsies from m. vastus lateralis will be collected before the first cycle of chemotherapy (T0), after chemotherapy (T1), and 6 months later (T2) for assessment of muscle cellular outcomes. The primary outcome for this study is muscle fiber size. Secondary outcomes are: regulators of muscle fiber size and function, indicators of cellular stress and mitochondrial function, myokines with potential antitumor effects, muscle strength, and cardiorespiratory fitness.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Regional Ethical Review Board in Uppsala, Sweden (Dnr:2016/230/2). Results will be disseminated through presentations at scientific meetings, publications in peer-reviewed journals, social media, and patient organizations.

TRIAL REGISTRATION NUMBER

NCT04586517.

Emerging strategies for treating metastasis

The systemic spread of tumor cells is the ultimate cause of the majority of deaths from cancer, yet few successful therapeutic strategies have emerged to specifically target metastasis. Here we discuss recent advances in our understanding of tumor-intrinsic pathways driving metastatic colonization and therapeutic resistance, as well as immune activating strategies to target metastatic disease. We focus on therapeutically exploitable mechanisms, promising strategies in preclinical and clinical development, and emerging areas with potential to become innovative treatments.

Poly (ADP-ribose) Polymerase Inhibition in Patients with Breast Cancer and BRCA 1 and 2 Mutations

The poly-(ADP-ribose) polymerase (PARP) inhibitors olaparib and talazoparib, have recently been approved for use in patients with metastatic breast cancer (BC) and germline BRCA 1 or 2 mutations due to improved progression-free survival compared to chemotherapy. An increasing number of clinical trials are evaluating the role of PARP inhibitors (PARPi) in BC, alone and in combination with other therapies (including immunotherapy), as well as in earlier stages of the disease. This review describes the unique mechanism of action of these drugs and puts into clinical context the results of pivotal clinical trials. We also discuss the future development of PARPi in BC, their potential combination with other strategies, including chemotherapy and immune-checkpoint inhibitors, and the impact of these treatments in current genetic counselling.

Effect of Hydrophobicity on the Anticancer Activity of Fatty-Acyl-Conjugated CM4 in Breast Cancer Cells

Antimicrobial peptides (AMPs) are important anticancer resources, and exploring AMP conjugates as highly effective and selective anticancer agents would represent new progress in cancer treatment. In this study, we synthesized C4-C16 fatty-acyl-conjugated AMP CM4 and investigated its physiochemical properties and cytotoxicity activity in breast cancer cells. Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reversed-phase high-performance liquid chromatography (RP-HPLC) showed that long-chain fatty acyl (≥C12) conjugation prevented N-acyl-CM4 from trypsin hydrolysis. RP-HPLC and circular dichroism (CD) spectra showed that the hydrophobicity and helical content of N-acyl-CM4 increased with the acyl length. The acyl chain length was positively related to the cytotoxicity of C8-C16 conjugates, and C12-C16 fatty acyl conjugates exhibited significant cytotoxicity against MX-1, MCF-7, and MDA-MB-231 cells, with IC₅₀ values <8 μM. Flow cytometry and confocal laser scanning microscopy results showed that N-acylated conjugation significantly increased the membrane affinity in breast cancer cells, and C12-C16 acyl conjugates were capable of translocating to the intracellular space, thereby targeting mitochondria and inducing apoptosis. N-acyl-CM4 showed low cytotoxicity against normal mammalian cells and erythrocytes, especially ≤C12 fatty acyl conjugates, exhibiting selective cytotoxicity to breast cancer cells. The current work indicated that increasing hydrophobicity by attaching long fatty acyl (≥C12) to AMPs may be an effective method to improve the anticancer activity, together with selectivity and resistance to trypsin hydrolysis. This finding provides a good strategy to develop AMPs as effective anticancer agents in the future.

Anticancer bioactive peptide combined with docetaxel and its mechanism in the treatment of breast cancer

Breast cancer remains a worldwide public-health issue. Novel drugs that increase the sensitivity and reduce the toxic side effects of chemotherapeutic agents are urgently required. The present study investigated the effect and mechanism of the short-term intermittent administration of an anticancer bioactive peptide (ACBP), docetaxel (DTX), ACBP combined with DTX (MIX) and ACBP combined with low dose DTX (L-MIX) to nude mice bearing human breast cancer tumors. The body weight, tumor length, tumor diameter, diet and water consumption of the tumor-bearing nude mice were calculated. The protein and mRNA expression levels of p53, p21 and Ki67 were detected via immunohistochemistry and reverse transcription-quantitative PCR, respectively. The results revealed that the activity level of each group of mice was consistent. However, the food and water consumption of the ACBP group was significantly increased compared with the NS group. Compared with the normal saline group, the tumor weights and volumes of the treatment groups were significantly decreased, indicating an inhibitory effect of the treatment. However, the MIX group exhibited lower tumor weights and volumes compared with the ACBP and DTX groups. Furthermore, no significant cell necrosis, edema or inflammatory cell infiltration was observed upon hematoxylin & eosin staining of the liver and spleen in all groups. The results also revealed that the p21, p53 and Ki67 protein and mRNA levels were decreased in the ACBP, DTX and MIX groups compared with the control group. Additionally, when compared with those in the MIX and L-MIX groups, the p21 and Ki67 protein, and p53 and Ki67 mRNA levels in the ACBP and DTX groups were significantly increased. The results suggested that the short-term intermittent use of ACBP alone had an inhibitory effect on tumor growth and improved the food and water consumption of tumor-bearing nude mice. Furthermore, the combination of ACBP and DTX reduced toxic side effects and the dosage requirement of drugs to achieve therapeutic effects on the tumor-bearing nude mice. Therefore, the antitumor effect of ACBP may be associated with the improvement of immune function in tumor-bearing nude mice and ACBP may serve an antitumor role via the p53-p21 signaling pathway in breast cancer.

Use of eribulin as an earlier-line chemotherapy for patients with HER2-negative metastatic breast cancer

Background: Previous prospective studies have shown that eribulin improves the survival in patients with metastatic breast cancer (MBC). However, the optimal timing of its administration to achieve the longest extended survival and the efficacy of using eribulin monotherapy as earlier-line chemotherapy are yet unclear. Methods: We identified all consecutive female patients with MBC who received any chemotherapeutic intervention for metastatic disease at our institution between July 2012 and December 2017, excluding patients with HER2-positive disease. Those who received eribulin monotherapy for MBC were classified under the eribulin cohort, whereas those who never received eribulin were included in the non-eribulin (Non-E) cohort. Among the patients in the eribulin cohort, those who received eribulin as the first- or second-line chemotherapy for MBC were further classified under the earlier-line eribulin (EE), and otherwise classified under the later-line eribulin (LE) cohorts. The survival of patients was assessed using the log-rank test. A multivariable Cox proportional hazards model was used to assess the independent efficacy and timing of eribulin monotherapy. The inverse probability of treatment weighting (IPTW) estimate was utilized to compare the EE and LE cohorts. Results: Of the 507 patients who were initially screened, 226 were included after an intensive chart review: 93, 49, and 84 patients were included in the Non-E, EE, and LE cohorts, respectively. The eribulin cohort showed significantly longer overall survival than the Non-E cohort (30.3 vs. 22.2 months, p = 0.0217). No significant difference was observed in the progression-free survival of the EE and LE cohorts (3.4 vs. 4.4 months, p = 0.1337) after adjusting for clinically relevant factors using IPTW estimates. LE cohort showed good overall survival (OS) compared with patient group of Non-E and EE by log-rank testing (p = 0.0398), although multivariate analysis did not demonstrate eribulin administration timing as an independent prognostic factor of OS. OS was defined from the initiation of first-line chemotherapy date. Conclusions: Our data provided additional insights regarding the use of eribulin monotherapy as earlier-line chemotherapy. However, the optimal timing of eribulin monotherapy for MBC was not determined in the current study.

Oral vinorelbine versus intravenous vinorelbine, in combination with epirubicin as first-line chemotherapy in Chinese patients with metastatic breast cancer

Oral VRL offers easier administration, better quality of life, and cost saving. This study aimed to evaluate the treatment efficacy in terms of tumor response of the two formulations of vinorelbine (VRL, oral and IV) in combination with epirubicin (EPI); and the effect of EPI co-administration on VRL pharmacokinetics (PK) in Chinese patients with metastatic breast cancer (MBC) using a phase 2, open label, randomized trial. Patients were aged 18–70 years, had histologically confirmed MBC, Karnofsky Performance Status ≥ 70%, and life expectancy ≥ 12 weeks. The treatment consisted of 6 cycles of 3 weeks each. VRL dose was: (Oral-VRL) 60 mg/m² for cycle 1, 80 mg/m² for cycles 2–6, and (IV-VRL) 25 mg/m² for cycle 1 and 30 mg/m² for cycles 2–6. EPI dose of 75 mg/m² was given on day 1 in both arms for all cycles. 133 patients were enrolled: 66 in Oral-VRL and 67 in IV-VRL arms. The median age for Oral-VRL and IV-VRL arms was 48.4 and 50.0 years, respectively. Objective response rates were 50.0% (95% CI 37.4–62.6%) for Oral-VRL and 53.7% (95% CI 41.1–66.0%) for IV-VRL. Both treatment arms met the efficacy objective target of at least 31 responses, demonstrating efficacy as first-line treatment for MBC. Similar blood PK profiles, exposures, and VRL clearance were observed between VRL + EPI vs VRL-only modalities for both arms. Oral VRL is comparable to IV VRL and an effective first-line treatment for Chinese patients with MBC. The activity of VRL + EPI combination is unaltered when VRL is given orally at recommended doses.

Correlation Between Gamma-Glutamyl Transferase Activity and Glutathione Levels in Molecular Subgroups of Breast Cancer

Objective

The gamma-glutamyl cycle catalyzed by gamma-glutamyl transferase (GGT) plays an important role in glutathione (GSH) homeostasis in the cell. In cells continuously exposed to the drug, the main phase of the enzymatic detoxification is the conjugation of the drug with GSH catalyzed by glutathione-S-transferase (GST). Conjugation of drugs with GSH is the first step in the development of chemotherapeutic drug resistance. In this study, we aimed to investigate the relationship between GGT and GSH in molecular subgroups of breast cancer patients.

Materials and Methods

Serum GGT activity and GSH levels for patients diagnosed with breast cancer (n=58) and healthy controls (n=8) were measured by a spectrophotometric method and a colorimetric kit, respectively.

Results

GGT activity was significantly higher in the total patient group and in the molecular subgroups than those in the control groups (p<0.05). Serum GSH levels were higher in the patient groups compared to controls without reaching statistical significance (p>0.05). GGT activity was positively correlated with GSH levels in the total patients and healthy controls (p<0.001 and p<0.05, respectively). There was also a positive correlation between GGT activity and GSH levels in Luminal A, HER2-positive (Human epidermal growth factor receptor 2), and Triple-negative groups (p<0.05).

Conclusion

This is the first study showing the relationship between GGT and GSH in molecular subgroups of breast cancer. An increase in GGT activity may affect intracellular GSH synthesis. Therefore, having a correlation between GGT and GSH in some molecular subgroups may affect the course of treatment in these patients.

Phase II Study of Eribulin Mesylate Administered Biweekly in Patients With Human Epidermal Growth Factor Receptor-2-negative Metastatic Breast Cancer

BACKGROUND

Patients with human epidermal growth factor receptor-2-negative metastatic breast cancer (MBC), whose disease progressed on prior chemotherapy, have a poor prognosis. Eribulin, a microtubule dynamics inhibitor, extends overall survival in previously treated MBC. The most common adverse event associated with eribulin is neutropenia, which may result in dose interruptions or reductions. A modified biweekly dosing schedule of eribulin was assessed for efficacy as well as improvements in hematologic toxicity.

PATIENTS AND METHODS

In this open-label, single-arm, multicenter, phase II study, previously treated (2-5 chemotherapy regimens for metastatic disease) patients with human epidermal growth factor receptor-2-negative MBC received intravenous eribulin 1.4 mg/m² over 2 to 5 minutes on days 1 and 15 of each 28-day cycle. The primary study endpoints were objective response rate (ORR; complete response [CR] + partial responses [PR]) and disease control rate (DCR; CR + PR + stable disease [SD]).

RESULTS

Among 58 treated patients, the ORR was 12% (95% confidence interval [CI], 5%-24%), DCR (CR, n = 1; PR, n = 6; SD, n = 30) was 65%, and the median progression-free survival was 3.6 months (95% CI, 2.9-4.1 months). Grade 3 or 4 neutropenia was 31%; 50% of all patients, and 78% of patients with neutropenia (all grades), received hematopoietic growth-factor support.

CONCLUSION

The efficacy and safety results obtained with a biweekly eribulin schedule in this phase II trial appear similar to those associated with the approved eribulin schedule (1.4 mg/m² on days 1 and 8 of a 21-day cycle) reported in the EMBRACE study.

Microenvironmental Regulation of Long Noncoding RNA LINC01133 Promotes Cancer Stem Cell-Like Phenotypic Traits in Triple-Negative Breast Cancers

The fibrotic tumor microenvironment is a critical player in the pathogenesis of triple-negative breast cancers (TNBCs), with the presence of fibroblastic infiltrates particularly correlating with tumors that are clinically advanced. On this front, we previously demonstrated that TNBCs are highly enriched in fibroblastic stromal progenitor cells called mesenchymal stem/stromal cells (MSCs) and that such cells play critical roles in promoting TNBC initiation and progression. How TNBC cells respond to MSC stimulation, however, is not fully understood, and stands to reveal contextual signals used by TNBC cells during tumor development and provide biomarkers and therapeutic targets of pertinence to TNBC management. Here, we report that MSCs strongly induced the long noncoding RNA (lncRNA) LINC01133 in neighboring TNBC cells. Indeed, although lncRNAs have been tightly associated with cancer development, their contributions to breast cancer in general, and to TNBC pathogenesis in particular, have not been fully elucidated, and we set out to determine if LINC01133 regulated malignant traits in TNBC cells. We establish that LINC01133 is sufficient, on its own, in promoting phenotypic and growth characteristics of cancer stem cell-like cells, and that it is a direct mediator of the MSC-triggered miR-199a-FOXP2 pathway in TNBC models. Furthermore, we show that LINC01133 is a critical regulator of the pluripotency-determining gene Kruppel-Like Factor 4 (KLF4), and that it represents a biomarker and prognosticator of disease outcome in the clinic. Collectively, our findings introduce LINC01133 as a novel functional driver of malignancy and a potential theranostic in TNBC. Stem Cells 2019;37:1281-1292.

The NAME trial: a direct comparison of classical oral Navelbine versus Metronomic Navelbine in metastatic breast cancer

Chemotherapy for metastatic breast cancer (MBC) is in general given in cycles of maximum tolerated doses to potentially maximize the therapeutic outcome. However, when compared with targeted therapies for MBC, conventional and dose intensified chemotherapy has caused only modest survival benefits during the recent decades, often compromising the quality of life considerably. Navelbine is an antineoplastic agent that has shown efficacy in the treatment of a variety of cancer types, including breast cancer. Early clinical trials involving both breast cancer and lung cancer patients suggest that metronomic dosing of Navelbine might be at least as effective as classical administration (once weekly, etc.). The NAME trial compares these two strategies of Navelbine administration in MBC patients.

Clinical benefit of treatment with eribulin mesylate for metastatic triple-negative breast cancer: Long-term outcomes of patients treated in the US community oncology setting

Introduction

Real‐world data are critical to demonstrate the consistency of evidence and external generalizability of randomized controlled trials (RCTs). This study examined characteristics and outcomes of metastatic triple‐negative breast cancer (mTNBC) patients treated with eribulin mesylate at community oncology practices in the United States.

Methods

Physicians identified mTNBC patients initiating eribulin between 1 January 2011 and 1 January 2014 and abstracted data into an electronic case report form (eCRF). Eribulin treatment in the metastatic setting was categorized as early use (EU, first‐/second‐line) and late use (LU, third‐line or later). Patient characteristics, overall survival (OS), disease response (per treating physician), and adverse events (AEs) rates in each group, respectively, are reported.

Results

Overall 252 eCRFs were completed: 125 (49.6%) EU and 127 (50.4%) LU. The median age at metastatic diagnosis was 53 years and 42.1% were stage IV at their initial diagnosis. The median duration of follow‐up from the initiation of first‐line treatment was 24 months. Rates of disease response (complete or partial per treating physician) were 69.9% in the EU group and 48.8% in the LU group. The five most commonly reported adverse events during eribulin were as follows: fatigue (65.1%), weakness (40.1%), decreased appetite (32.5%), neutropenia (31.0%), and leukopenia (27.4%). Discontinuation of eribulin due to AE was observed in 4.0% of patients. Median OS from initiation of eribulin was 23.0 months (95% CI: 18.7‐27.3) among EU and 14.7 (95% CI: 12.6‐16.9) among LU.

Conclusion

In the real‐world eribulin‐treated mTNBC, patients have more sites of metastatic disease and exposure to greater numbers of prior therapies compared to RCTs. The median OS of 14.7 months among LU patients is consistent with, and slightly longer than the 13.1 months and 14.4 months reported in the EMBRACE and Study 301 clinical trials, respectively.

Lobaplatin-based regimens outperform cisplatin for metastatic breast cancer after anthracyclines and taxanes treatment

The goal of this study was to assess the antitumor efficacy and safety of lobaplatin-based regimens as the second line of treatment in patients with metastatic breast cancer (MBC) resistant to anthracyclines and taxanes, compared with that of cisplatin-based regimens. During August 2012 to April 2015, 87 patients who received lobaplatin-based regimens or cisplatin-based regimens were included. Medical records of the patients noted that lobaplatin (30 mg/m2) or cisplatin (25 mg/m2), combined with another chemotherapeutic agent such as Gemcitabine (1000 mg/m2) or Vinorelbine (25 mg/m2), was intravenously given to the patients on a basis of twenty-one days as one treatment cycle. All the patients were followed until August 2017. The endpoint of this study was progression-free survival (PFS), overall survival (OS), and estimated objective response rate (RR). Safety and drug tolerability data were also obtained. Lobaplatin-based regimens prolonged PFS compared to cisplatin-based regimens (median 13.2 vs 4.7 months, hazard ratio = 0.37, 95% confidence intervals: 0.21-0.67, P = .0007), while OS was not significantly different between the two groups (hazard ratio = 0.72, 95% confidence intervals: 0.40-1.30, P = .2767), as was objective RR (37.8% vs 33.4%, x 2 = 0.19, P = .6653). Nausea/vomiting and renal injury were more frequent with cisplatin-based regimens. Our results show that lobaplatin-based regimens are superior to cisplatin in terms of efficacy and are better tolerated.

Change in Topoisomerase 1-Positive Circulating Tumor Cells Affects Overall Survival in Patients with Advanced Breast Cancer after Treatment with Etirinotecan Pegol

Purpose: Preplanned exploratory analyses were performed to identify biomarkers in circulating tumor cells (CTC) predictive of response to the topoisomerase 1 inhibitor etirinotecan pegol (EP).Experimental Design: The BEACON trial treated patients with metastatic breast cancer (MBC) with EP or treatment of physician's choice (TPC). Blood from 656 of 852 patients (77%) was processed with ApoStream to enrich for CTCs. A multiplex immunofluorescence assay measured expression of candidate response biomarkers [topoisomerase 1 (Top1), topoisomerase 2 (Top2), Ki67, RAD51, ABCG2, γH2AX, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)] in CTCs. Patients were classified as Top1 low (Top1Lo) or Top1 high (Top1Hi) based on median CTC Top1 expression. Correlation of CTC biomarker expression at baseline, cycle 2 day 1 (C2D1), and cycle 4 day 1 with overall survival (OS) was investigated using Cox regression and Kaplan-Meier analyses.Results: Overall, 98% of samples were successfully processed, of which 97% had detectable CTCs (median, 47-63 CTCs/mL; range, 0-2,020 CTCs/mL). Top1, Top2, and TUNEL expression was detected in 52% to 90% of samples; no significant associations with OS were observed in pretreatment samples for either group. EP-treated patients with low C2D1Top1⁺ CTCs had improved OS compared with those with higher positivity (14.1 months vs. 11.0 months, respectively; HR, 0.7; P = 0.02); this difference was not seen in TPC-treated patients (HR, 1.12; P = 0.48). Patients whose CTCs decreased from Top1Hi to Top1Lo at C2D1 had the greatest OS benefit from EP (HR, 0.57; P = 0.01).Conclusions: CTC Top1 expression following EP treatment may identify patients with MBC most likely to have an OS benefit. Clin Cancer Res; 24(14); 3348-57. ©2018 AACR.

Current challenges of metastatic breast cancer

Metastasis is one of the most characteristic yet problematic behaviors of cancer cells. Stage IV breast cancer accounts for a large portion of breast cancer-related morbidity and mortality. Despite early detection and improvement in survival owing to advancements in biomedical research and overall improvement of the health system, 6-10% of patients present with stage IV disease in the developed world, with a higher incidence noted elsewhere. Despite advances in biomedical research into cancer, up to 70-80% of patients with stage IV breast cancer die of cancer in 5 years, a disproportionally higher mortality compared with non-metastatic breast cancer. In this article, we review the incidence, survival, heterogeneity, current practice, and challenges in stage IV breast cancer, and we finish by noting new research initiatives to improve poor survival and suggesting future directions. By doing so, we hope to set the basis of future directions for both treating physicians and translational researchers to relieve the suffering of patients with stage IV breast cancer and improve the survival of patients with this dismal disease.

Efficacy and safety of eribulin in taxane-refractory patients in the ‘real world’

Aim: Recent clinical, randomized and observational studies showed that eribulin, an analogous of Halichondrin B, was beneficial and well-tolerated in heavily pretreated metastatic breast cancer patients. Here, we aim to evaluate the effectiveness and safety of eribulin in taxane-refractory metastatic breast cancer patients. Patients & methods: In this subanalysis of the ESEMPIO study database, we selected 91 subjects with well-defined taxane refractoriness and complete data available. Results: 41 patients (45.2%) showed clinical benefit; one complete response (2.2%) and 16 partial responses (17.6%) were observed. Median progression-free survival and median overall survival were 3.1 and 11.6 months, respectively. The most experienced adverse event was asthenia/fatigue (58%), followed by neutropenia (30%). The treatment-related toxicity led to eribulin-dose reduction in 19 patients and suspension in nine. Conclusion: This study shows that eribulin is effective and well tolerated also in taxane-refractory patients in clinical practice.

Capecitabine and cisplatin (XP) combination systemic chemotherapy in heavily pre-treated HER2 negative metastatic breast cancer

PURPOSE/OBJECTIVE(S)

After taxane and anthracycline failure, no standard chemotherapy regimen is established in metastatic breast cancer (MBC). Capecitabine and cisplatin (XP) combination shows promising results in gastrointestinal cancer, but there are relatively scarce data in MBC. We reviewed the clinical outcome of XP regimen in anthracycline and taxane resistant, heavily pretreated MBC patients.

MATERIALS/METHODS

Between Jan. 2010 to Feb. 2016, 48 HER2 negative MBC patients who failed anthracycline and taxane based chemotherapy were enrolled. In 43.8% of patients, more than 4 regimens were administrated before XP. Thirty-four patients (70.8%) were hormone receptor (HR) positive MBC. Patients were treated with XP (capecitabine [2000mg/m2 per oral; day 1-14] plus cisplatin [60mg/m2 IV; day 1], every 3 weeks) regimen.

RESULTS

Median progression-free survival (PFS) in total population was 4.33 months (range 1.1~33.57 months). HR positive patients showed trends for superior PFS compared to triple negative breast cancer (TNBC), without statistical significance (6.53 vs. 3.83 months, P = 0.168). In HR positive group, patients receiving 3 or less lines of chemotherapy showed superior PFS compared to others (10.1 vs. 3.0 months, P = 0.039). In multivariate analysis, HR positive patients receiving 3 or less lines of regimens still showed superior PFS (HR = 2.624, 95% CI; 1.071~6.43, P = 0.032). Most common toxicity was grade 3-4 neutropenia, without treatment-related deaths.

CONCLUSIONS

XP combination regimen showed clinical benefit with tolerable toxicity in heavily pretreated patients, including HR positive patients. After anthracycline and taxane failure, early administration of XP regimen in selected patients may have improve clinical outcome in breast cancer.

A network-based pathway-expanding approach for pathway analysis

Background

Pathway analysis combining multiple types of high-throughput data, such as genomics and proteomics, has become the first choice to gain insights into the pathogenesis of complex diseases. Currently, several pathway analysis methods have been developed to study complex diseases. However, these methods did not take into account the interaction between internal and external genes of the pathway and between pathways. Hence, these approaches still face some challenges. Here, we propose a network-based pathway-expanding approach that takes the topological structures of biological networks into account.

Results

First, two weighted gene-gene interaction networks (tumor and normal) are constructed integrating protein-protein interaction(PPI) information, gene expression data and pathway databases. Then, they are used to identify significant pathways through testing the difference of topological structures of expanded pathways in the two weighted networks. The proposed method is employed to analyze two breast cancer data. As a result, the top 15 pathways identified using the proposed method are supported by biological knowledge from the published literatures and other methods. In addition, the proposed method is also compared with other methods, such as GSEA and SPIA, and estimated using the classification performance of the top 15 expanded pathways.

Conclusions

A novel network-based pathway-expanding approach is proposed to avoid the limitations of existing pathway analysis approaches. Experimental results indicate that the proposed method can accurately and reliably identify significant pathways which are related to the corresponding disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-016-1333-x) contains supplementary material, which is available to authorized users.

Comparison of the Therapeutic Efficacy of the Early and the Delayed Use of Vinorelbine-Based Regimens for Patients with Advanced Breast Cancer

BACKGROUND

The aim of this study was to evaluate the efficacy of vinorelbine-based regimens as first-, second- and more-line therapies in advanced breast cancer (ABC) and to analyze the best timing of vinorelbine treatment.

METHODS

A total of 71 ABC patients were retrospectively reviewed. Of these, 35 patients were treated with vinorelbine-based regimens as first-line chemotherapy, and 36 patients were treated with vinorelbine-based regimens as second-line or more-line therapy. The primary end point of the study was progression-free survival (PFS).

RESULTS

No difference was found in baseline characteristics between the two groups (p > 0.1 for all comparisons). There was a significant difference in the objective response rate (ORR; p = 0.006) and clinical benefit rate (CBR; p = 0.013) between the first-line group and the second- or more-line groups. In the vinorelbine first-line group, the ORR was 68.6% (24 patients), and in the second-line or more-line groups the ORR was 36.1% (13 patients). A significant difference in PFS between the first-line group and the second-line or more-line groups was also observed (p = 0.030). The median PFS in the overall population was 6.3 ± 1.32 months (95% CI 3.69-8.90). The median PFS was 11.1 ± 3.76 months (95% CI 3.73-18.47) in the first-line group compared with 5.2 ± 1.35 months (95% CI 2.54-7.85) in the second-line or more-line groups. In patients treated with vinorelbine-trastuzumab combination as the first-line therapy, a complete response was observed in 1 patient (12.5%) and partial response in 5 patients (62.5%), giving an ORR of 75.0%. Progressive disease was observed in 1 patient (12.5%), and stable disease in 1 patient (12.5%), leading to a CBR of 87.5%. The median PFS was 13.8 ± 2.75 months (95% CI 8.42-19.18), and median OS was 37.0 ± 11.6 months (95% CI 14.18-59.82). No significant difference was found in overall survival (OS) between the groups (p = 0.612).

CONCLUSION

For ABC patients, no significant difference in median OS was found between the early use and delayed use of vinorelbine-based regimens, but the short-term efficacy and PFS of vinorelbine-based regimens were significantly better in the early use group than in the delayed use group.

A meta-analysis of combination therapy versus single-agent therapy in anthracycline- and taxane-pretreated metastatic breast cancer: results from nine randomized Phase III trials

Nowadays, the philosophy of treating metastatic breast cancer (MBC) is slowly evolving. Especially for the anthracycline- and taxane-pretreated MBC patients, no standard therapy exists in this setting. Whether to choose doublet agents or single agent as salvage treatment remains fiercely debated. Thus, we conducted a meta-analysis to resolve this problem. Databases including PubMed, EMBASE, and Cochrane library were searched for Phase III randomized clinical trials (published before August 2015) comparing the efficacy and adverse effects between the combination therapy and single-agent therapy in anthracycline- and taxane-pretreated MBC patients. The primary end point was the overall survival (OS), and the secondary end points were the progression-free survival (PFS), overall response rate (ORR), and grade 3 or 4 toxicities. The pooled hazard ratio (HR) and pooled risk ratio (RR) were used to evaluate the efficacy. Analyses were also performed to estimate the side effects and safety of both groups. In all, nine eligible randomized clinical trials were included in this meta-analysis. Improvements were proven in the doublet agents group on OS (HR 0.90, 95% confidence interval [CI] 0.84–0.96, P=0.002), PFS (HR 0.81, 95% CI 0.76–0.88, P<0.001), and ORR (RR 1.72, 95% CI 1.34–2.21, P<0.001). Notably, subgroup analysis failed to favor the targeted agent-based combination in terms of OS (HR 1.08, 95% CI 0.89–1.31, P=0.365), PFS (HR 1.09, 95% CI 0.88–1.35, P=0.433), and ORR (RR 1.60, 95% CI 0.69–3.71, P=0.278) compared with single agent. In addition, although more hematological and gastrointestinal toxicities were observed in the doublet agents group, they were acceptable and manageable. Taken together, when compared with single-agent therapy, doublet agents should be considered a treatment option because of the superior efficacy and the manageable safety profile for the prior anthracycline- and taxane-treated MBC patients.

Hypoxia can impair doxorubicin resistance of non-small cell lung cancer cells by inhibiting MRP1 and P-gp expression and boosting the chemosensitizing effects of MRP1 and P-gp blockers

BACKGROUND

Non-small cell lung cancers (NSCLCs) frequently exhibit resistance to therapeutic drugs, which seriously hampers their treatment. Here, we set out to assess the roles of the multidrug resistance protein 1 (MRP1) and P-glycoprotein (P-gp) in the doxorubicin (DOX) resistance of NSCLC cells, as well as the putative therapeutic efficacy of MRP1 and P-gp blockers on DOX-treated NSCLC cells.

METHODS

The impact of DOX on cell survival, DOX efflux and MRP1 and P-gp expression was assessed in 5 different NSCLC-derived cell lines (parental CH27, A549, H1299, H460, and DOX resistant CH27) in the absence or presence of MK571 (MRP1 inhibitor) or Verapamil (P-gp inhibitor), under both normoxic and hypoxic conditions.

RESULTS

We found that in response to DOX treatment, NSCLC cells that express high levels of MRP1 and P-gp (such as CH27) showed a better DOX efflux and a higher DOX resistance. MK571 and Verapamil were found to abolish DOX resistance and to act as chemosensitizers for DOX therapy in all cell lines tested. We also found that hypoxia could inhibit MRP1 and P-gp expression in a HIF-1α-dependent manner, abolish DOX resistance and boost the chemosensitizer effect of MK571 and Verapamil on DOX treatment of all the NSCLC cells tested, except the DOX-resistant CH27 cells.

CONCLUSIONS

From our data we conclude that MRP1 and P-gp play critical roles in the DOX resistance of the NSCLC cells tested. MRP1 and P-gp targeted therapy using MK571, Verapamil, CoCl₂ or ambient hypoxia appeared to be promising in abolishing the DOX efflux and DOX resistance of the NSCLC cells. The putative therapeutic efficacies of MRP1 and/or P-gp blockers on NSCLC cells are worthy of note.

Targeted chemotherapy with nanoparticle albumin-bound paclitaxel (nab-paclitaxel) in metastatic breast cancer: which benefit for which patients?

The therapeutic goals in metastatic breast cancer (MBC) remain palliative in nature, aimed at controlling symptoms, improving or maintaining quality of life and prolonging survival. The advent of new drugs and new formulations of standard agents has led to better outcomes in patients with advanced or metastatic disease. These developments have also allowed a tailored therapeutic approach, in which the molecular biology of the tumour, the treatment history, and patient attitudes are taken into account in the decision-making process. Targeting drug delivery to the tumour is a promising mean of increasing the therapeutic index of highly active agents such as the taxanes, and nanoparticle albumin-bound paclitaxel (nab-paclitaxel), the first nanotechnology-based drug developed in cancer treatment, is one such advance. Data from randomized trials support the efficacy of single-agent nab-paclitaxel as first-line and further treatment lines in MBC at the registered 3-weekly schedule of 260 mg/m(2), but emerging evidence suggests its activity as a weekly regimen or combined with other agents in various clinical scenarios. Thus, nab-paclitaxel seems to offer flexibility in terms of dosing schedules, allowing physicians to tailor the dose according to different clinical situations. This paper reviews the clinical trial background for nab-paclitaxel in MBC, focusing on specific 'difficult-to-treat' patient populations, such as taxane-pretreated or elderly women, as well as those with triple-negative, HER2-positive and poor-prognostic-factors disease. Moving beyond evidence-based information, 'real life' available experiences are also discussed with the aim of providing an update for daily clinical practice.

New insights on PI3K/AKT pathway alterations and clinical outcomes in breast cancer

PI3K/AKT signaling pathway plays an important role in tumorigenesis and regulates critical cellular functions including survival, proliferation and metabolism. PIK3CA mutations and AKT activation by phosphorylation (pAKT) are often detected in many cancers and especially at high frequencies in breast cancer. Mounting data suggest that PIK3CA mutations or pAKT are mostly associated with better or insignificant outcomes in estrogen receptor-positive (ER+) early stage breast cancer and tend to be with worse prognosis in ER- disease. pAKT expression has been identified to predict paclitaxel chemotherapy benefit in node-positive breast cancer. Preclinical and neoadjuvant trial data suggest that PIK3CA alterations confer resistance to HER2-targeted therapy and are associated with lower pathological complete response (pCR) rate in HER2-positive breast cancer. However, recent results from randomized clinical trials of adjuvant and metastatic settings show that patients with mutant and wildtype PIK3CA tumors derived similar benefit from anti-HER2 therapy. This article, with our new insights, aims to decipher the mixed data and discusses the influence of the potential confounding factors in the assessments. We also share our views for validation of PI3K/AKT alterations in relation to clinical outcome in the context of specific breast cancer subtypes and treatment modalities towards further advance of the precision medicine for breast cancer treatment.

Gemcitabine and Capecitabine Combination Chemotherapy in Patients with Metastatic Breast Cancer Pretreated with Anthracyclines and/or Taxanes

BACKGROUND

Owing to the need for effective and tolerable new regimens for the treatment of patients with metastatic breast cancer (MBC) previously treated with anthracyclines and/or taxanes, we aimed to assess the activity and safety of the gemcitabine plus capecitabine combination chemotherapy.

METHODS

Sixty-four patients were enrolled. Treatment consisted of gemcitabine 1,000 mg/m2 intravenously on days 1 and 8, plus oral capecitabine at 1,250 mg/m2 twice daily on days 1-14. The primary end point was the overall response rate (ORR). Secondary objectives included the disease control rate (DCR), overall survival (OS), progression-free survival (PFS), toxicity, and predictive factors.

RESULTS

In the 64 patients, the ORR and DCR was 28.1 and 67.2%. Median OS and PFS were 23.6 and 13.4 months, respectively. Toxicities were mild and curable.

CONCLUSION

The combination of gemcitabine and capecitabine is an effective and tolerable treatment for MBC previously treated with anthracyclines and/or taxanes.

Treatment strategies for advanced hormone receptor-positive and human epidermal growth factor 2-negative breast cancer: the role of treatment order

Although survival rates among patients with breast cancer have improved in recent years, those diagnosed with advanced disease with distant metastasis face a 5-year survival rate of less than 25%, making the management of these patients an area still in significant need of continued research. Selecting the optimal treatment order from among the variety of currently available therapy options presents a relevant challenge for medical oncologists. With the understanding that the majority of patients with breast cancer and those who succumb to this disease have HR-positive disease, this review will focus on treatment options and treatment order in patients with HR-positive advanced breast cancer. While endocrine therapy is considered the preferred treatment for first-line therapy in HR-positive/HER2-negative breast cancer, selection of the specific agent depends on the menopausal status of the patient. Palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, is also recommended as first-line treatment in patients with ER-positive/HER2-negative disease. In patients with endocrine therapy-resistant disease, specific strategies include sequencing of other antiestrogen receptor agents, or agents that target other molecular pathways. Future treatment strategies for patients with primary or secondary resistance to endocrine therapy for advanced disease are discussed. These strategies include first-line therapy with high-dose fulvestrant or everolimus (in combination with exemestane or letrozole or with other endocrine therapies), use of the PI3K inhibitors (e.g., buparlisib, alpelisib, pictilisib, taselisib), entinostat, CDK 4/6 inhibitors (e.g., palbociclib, ribociclib, abemaciclib), and novel selective estrogen receptor degradation agents that may enhance the targeting of acquired mutations in the ESR1 gene.

Combination chemotherapy with mitomycin C and methotrexate is active against metastatic HER2-negative breast cancer even after treatment with anthracycline, taxane, capecitabine, and vinorelbine

Background

Combination chemotherapy with mitomycin C and methotrexate (MM) was reported to be effective for 24% of patients with metastatic breast cancer (MBC) who had been treated with anthracycline and taxane. Antimetabolites such as capecitabine and antitubulins such as vinorelbine have been generally used for MBC treatment after anthracycline and taxane. A subsequent choice of chemotherapy should be offered to patients with MBC who have kept good performance status (PS) after being aggressively treated with anthracycline, taxane, capecitabine, and vinorelbine (ATCV), but is not well clear which treatment is superior to others after ATCV. In this study, we examined whether MM treatment is a good choice following ATCV.

Methods

We retrospectively reviewed the medical records of 31 patients with HER2-negative metastatic breast cancer who were treated with MM following ATCV. One cycle of MM was defined as MMC 8 mg/m² on day 1 and MTX 60 mg/m² on day 1 and day 15, administered intravenously every 4 weeks.

Results

Response rate and clinical benefit rate were 9.7 and 19.4%, respectively. Median times to progression and times to failure were 3.9 and 3.7 months, respectively. Adverse events of grade 3 and/or 4 were observed in 36% patients. Thrombocytopenia of grade 3 or 4 was 12.9 and 3.2%. Grades 3 and 4 of leucopenia and anemia were 12.9 and 9.7%, respectively.

Conclusion

MM is effective and tolerable for MBC patients even after aggressive treatment with ATCV. MM is one treatment choice when patients have kept good PS and bone marrow function even after multiple regimens of chemotherapy.

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer patients: prospective evaluation of activity, safety, and quality of life

BACKGROUND

A prospective, multicenter trial was undertaken to assess the activity, safety, and quality of life of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer (MBC).

PATIENTS AND METHODS

Fifty-two women with HER2-negative MBC who were candidates for second-line chemotherapy for the metastatic disease were enrolled and treated at three centers in Northern Italy. All patients had previously received taxane-based chemotherapy in the adjuvant or first-line metastatic setting. Single-agent nab-paclitaxel was given at the dose of 260 mg/m(2) as a 30-minute intravenous infusion on day 1 each treatment cycle, which lasted 3 weeks, in the outpatient setting. No steroid or antihistamine premedication was provided. Treatment was stopped for documented disease progression, unacceptable toxicity, or patient refusal.

RESULTS

All of the enrolled patients were evaluable for the study endpoints. The objective response rate was 48% (95% CI, 31.5%-61.3%) and included complete responses from 13.5%. Disease stabilization was obtained in 19 patients and lasted >6 months in 15 of them; the overall clinical benefit rate was 77%. The median time to response was 70 days (range 52-86 days). The median progression-free survival time was 8.9 months (95% CI, 8.0-11.6 months, range 5-21+ months). The median overall survival point has not yet been reached. Toxicities were expected and manageable with good patient compliance and preserved quality of life in patients given long-term treatment.

CONCLUSION

Our results showed that single-agent nab-paclitaxel 260 mg/m(2) every 3 weeks is an effective and well tolerated regimen as second-line chemotherapy in HER2-negative, taxane-pretreated MBC patients, and that it produced interesting values of objective response rate and progression-free survival without the concern of significant toxicity. Specifically, the present study shows that such a regimen is a valid therapeutic option for that 'difficult to treat' patient population represented by women who at the time of disease relapse have already received the most active agents in the adjuvant and/or metastatic setting (ie, conventional taxanes).

Phase III open-label randomized study of eribulin mesylate versus capecitabine in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline and a taxane

Purpose

This phase III randomized trial (ClinicalTrials.gov identifier: NCT00337103) compared eribulin with capecitabine in patients with locally advanced or metastatic breast cancer (MBC).

Patients and Methods

Women with MBC who had received prior anthracycline- and taxane-based therapy were randomly assigned to receive eribulin or capecitabine as their first-, second-, or third-line chemotherapy for advanced/metastatic disease. Stratification factors were human epidermal growth factor receptor-2 (HER2) status and geographic region. Coprimary end points were overall survival (OS) and progression-free survival (PFS).

Results

Median OS times for eribulin (n = 554) and capecitabine (n = 548) were 15.9 and 14.5 months, respectively (hazard ratio [HR], 0.88; 95% CI, 0.77 to 1.00; P = .056). Median PFS times for eribulin and capecitabine were 4.1 and 4.2 months, respectively (HR, 1.08; 95% CI, 0.93 to 1.25; P = .30). Objective response rates were 11.0% for eribulin and 11.5% for capecitabine. Global health status and overall quality-of-life scores over time were similar in the treatment arms. Both treatments had manageable safety profiles consistent with their known adverse effects; most adverse events were grade 1 or 2.

Conclusion

In this phase III study, eribulin was not shown to be superior to capecitabine with regard to OS or PFS.

Diethylstilbestrol can effectively accelerate estradiol-17-O-glucuronidation, while potently inhibiting estradiol-3-O-glucuronidation

This in vitro study investigates the effects of diethylstilbestrol (DES), a widely used toxic synthetic estrogen, on estradiol-3- and 17-O- (E2-3/17-O) glucuronidation, via culturing human liver microsomes (HLMs) or recombinant UDP-glucuronosyltransferases (UGTs) with DES and E2. DES can potently inhibit E2-3-O-glucuronidation in HLM, a probe reaction for UGT1A1. Kinetic assays indicate that the inhibition follows a competitive inhibition mechanism, with the Ki value of 2.1±0.3μM, which is less than the possible in vivo level. In contrast to the inhibition on E2-3-O-glucuronidation, the acceleration is observed on E2-17-O-glucuronidation in HLM, in which cholestatic E2-17-O-glucuronide is generated. In the presence of DES (0-6.25μM), Km values for E2-17-O-glucuronidation are located in the range of 7.2-7.4μM, while Vmax values range from 0.38 to 1.54nmol/min/mg. The mechanism behind the activation in HLM is further demonstrated by the fact that DES can efficiently elevate the activity of UGT1A4 in catalyzing E2-17-O-glucuronidation. The presence of DES (2μM) can elevate Vmax from 0.016 to 0.81nmol/min/mg, while lifting Km in a much lesser extent from 4.4 to 11μM. Activation of E2-17-O-glucuronidation is well described by a two binding site model, with KA, α, and β values of 0.077±0.18μM, 3.3±1.1 and 104±56, respectively. However, diverse effects of DES towards E2-3/17-O-glucuronidation are not observed in liver microsomes from several common experimental animals. In summary, this study issues new potential toxic mechanisms for DES: potently inhibiting the activity of UGT1A1 and powerfully accelerating the formation of cholestatic E2-17-O-glucuronide by UGT1A4.

Efficacy of eribulin in women with metastatic breast cancer: a pooled analysis of two phase 3 studies

Data from two phase 3 studies of eribulin were pooled in analyses initially requested by the European Medicines Agency to assess whether specific patient subgroups, previously treated with an anthracycline and a taxane, benefited from eribulin. Study 305/EMBRACE included women after two-to-five lines of chemotherapy for advanced breast cancer who were randomized to eribulin mesylate (1.4 mg/m(2) on days 1 and 8 every 21 days) or treatment of physician's choice. In Study 301, patients who had received up to two prior chemotherapy regimens for advanced disease were randomized to eribulin (as above) or capecitabine (1.25 g/m(2) b.i.d. on days 1-14 every 21 days). In the pooled population, overall survival (OS), progression-free survival and response rates were analysed in the intent-to-treat population and selected subgroups. Overall, 1,062 patients were randomized to eribulin and 802 patients to control. Median OS was 15.2 months with eribulin versus 12.8 months with control (hazard ratio [HR] 0.85; 95% CI 0.77, 0.95; P = 0.003). In all subgroups assessed, OS data favoured eribulin; significant improvements occurred in some subgroups, notably in women with human epidermal growth factor receptor 2 (HER2)-negative disease (HR 0.82; P = 0.002), although the effect in those with HER2-negative but hormone-receptor-positive disease did not reach statistical significance; benefits were also seen, among others, in those with estrogen-receptor-negative and triple-negative disease. Eribulin improves OS in various patient subgroups with advanced/metastatic breast cancer who had previously received an anthracycline and a taxane. Women with HER2-negative disease are among those who may obtain benefit from eribulin.

The palladacycle, AJ-5, exhibits anti-tumour and anti-cancer stem cell activity in breast cancer cells

Breast cancer is the most common malignancy amongst women worldwide but despite enormous efforts to address this problem, there is still limited success with most of the current therapeutic strategies. The current study describes the anti-cancer activity of a binuclear palladacycle complex (AJ-5) in oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB-231) breast cancer cells as well as human breast cancer stem cells. AJ-5 is shown to induce DNA double strand breaks leading to intrinsic and extrinsic apoptosis and autophagy cell death pathways which are mediated by the p38 MAP kinase. This study provides evidence that AJ-5 is potentially an effective compound in the treatment of breast cancer.

Enhanced breast cancer therapy with nsPEFs and low concentrations of gemcitabine

Background

Chemotherapy either before or after surgery is a common breast cancer treatment. Long-term, high dose treatments with chemotherapeutic drugs often result in undesirable side effects, frequent recurrences and resistances to therapy.

Methods

The anti-cancer drug, gemcitabine (GEM) was used in combination with pulse power technology with nanosecond pulsed electric fields (nsPEFs) for treatment of human breast cancer cells in vitro. Two strategies include sensitizing mammary tumor cells with GEM before nsPEF treatment or sensitizing cells with nsPEFs before GEM treatment. Breast cancer cell lines MCF-7 and MDA-MB-231 were treated with 250 65 ns-duration pulses and electric fields of 15, 20 or 25 kV/cm before or after treatment with 0.38 μM GEM.

Results

Both cell lines exhibited robust synergism for loss of cell viability 24 h and 48 h after treatment; treatment with GEM before nsPEFs was the preferred order. In clonogenic assays, only MDA-MB-231 cells showed synergism; again GEM before nsPEFs was the preferred order. In apoptosis/necrosis assays with Annexin-V-FITC/propidium iodide 2 h after treatment, both cell lines exhibited apoptosis as a major cell death mechanism, but only MDA-MB-231 cells exhibited modest synergism. However, unlike viability assays, nsPEF treatment before GEM was preferred. MDA-MB-231 cells exhibited much greater levels of necrosis then in MCF-7 cells, which were very low. Synergy was robust and greater when nsPEF treatment was before GEM.

Conclusions

Combination treatments with low GEM concentrations and modest nsPEFs provide enhanced cytotoxicity in two breast cancer cell lines. The treatment order is flexible, although long-term survival and short-term cell death analyses indicated different treatment order preferences. Based on synergism, apoptosis mechanisms for both agents were more similar in MCF-7 than in MDA-MB-231 cells. In contrast, necrosis mechanisms for the two agents were distinctly different in MDA-MB-231, but too low to reliably evaluate in MCF-7 cells. While disease mechanisms in the two cell lines are different based on the differential synergistic response to treatments, combination treatment with GEM and nsPEFs should provide an advantageous therapy for breast cancer ablation in vivo.