Anti-tumor activity of capecitabine and vinorelbine in patients with anthracycline- and taxane-pretreated metastatic breast cancer: findings from the EORTC 10001 randomized phase II trial

Oral vinorelbine and capecitabine as first-line therapy in metastatic breast cancer: a retrospective analysis

A retrospective analysis of 70 patients with triple-negative or hormone-resistant advanced breast carcinoma who had not previously received chemotherapy was carried out. Patients received oral vinorelbine 60 mg/m² on day 1 and 8, plus capecitabine 1000 mg/m² bid for 14 consecutive days every 3 weeks. Overall response rate was 53% with a 9% complete response rate. Stable disease was recorded in 27% of the cases. Median progression-free survival was 7.9 months and median overall survival was 29.2 months. Toxicity was generally mild and easily manageable. These data demonstrate that this combination is feasible, safe and active as first-line treatment of triple-negative fully hormone-resistant advanced breast carcinoma patients.

The adoption of metronomic chemotherapy in the treatment of breast cancer is an important step forward in the management of this disease. The fluoropyrimidine capecitabine and the vinca alkaloid vinorelbine have been shown to be at least as active. Our data confirm the activity and safety of this all-oral regimen as first-line metronomic therapy being response rate.

The Place of Chemotherapy in The Evolving Treatment Landscape for Patients With HR-positive/HER2-negative MBC

Endocrine therapy (ET) for the treatment of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR-positive/HER2-negative) metastatic breast cancer (MBC) has changed markedly over recent years with the emergence of new ETs and the use of molecularly targeted agents. Cytotoxic chemotherapy continues, however, to have an important role in these patients and it is important to maximize its efficacy while minimizing toxicity to optimize outcomes. This review examines current HR-positive/HER2-negative MBC clinical guidelines and addresses key questions around the use of chemotherapy in the face of emerging therapeutic options. Specifically, the indications for chemotherapy in patients with HR-positive/HER2-negative MBC and the choice of optimal chemotherapy are discussed.

Virtual and experimental high throughput screening of substituted hydrazones on β-Tubulin polymerization

Microtubule targeting agents that disrupt the dynamic functioning of the mitotic spindle are some of the best chemotherapeutic agents. Interruption of microtubule dynamics through polymerization or depolymerization causes cell arrest leading to apoptosis. We report a novel class of aroylhydrazones with anticancer properties. Tubulin inhibition studies were performed using both computational and biological methods. Docking and pharmacophore mapping showed efficient binding between the ligands and the protein. Tubulin inhibition assay showed the aroylhydrazones to be inhibitors of tubulin polymerization. DFT studies explains the geometrical and electronic properties of the compounds. Furthermore, anticancer studies using lung and liver cancer cell lines gave low IC₅₀ values with the methyl substituted hydrazone MH-2 being the most potent. (IC₅₀ of 0.0896 and 0.1040 µM respectively). The methyl group is responsible for the effective binding to the protein. Thus, a new class of tubulin binding agents have been identified as potential agents in cancer therapy.

Capecitabine for hormone receptor-positive versus hormone receptor-negative breast cancer

BACKGROUND

Retrospective analyses suggest that capecitabine may carry superior activity in hormone receptor-positive relative to hormone receptor-negative metastatic breast cancer. This review examined the veracity of that finding and explored whether this differential activity extends to early breast cancer.

OBJECTIVES

To assess effects of chemotherapy regimens containing capecitabine compared with regimens not containing capecitabine for women with hormone receptor-positive versus hormone receptor-negative breast cancer across the three major treatment scenarios: neoadjuvant, adjuvant, metastatic.

SEARCH METHODS

On 4 June 2019, we searched the Cochrane Breast Cancer Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 5) in the Cochrane Library; MEDLINE; Embase; the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials looking at chemotherapy regimens containing capecitabine alone or in combination with other agents versus a control or similar regimen without capecitabine for treatment of breast cancer at any stage. The primary outcome measure for metastatic and adjuvant trials was overall survival (OS), and for neoadjuvant studies pathological complete response (pCR).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias and certainty of evidence using the GRADE approach. Hazard ratios (HRs) were derived for time-to-event outcomes, and odds ratios (ORs) for dichotomous outcomes, and meta-analysis was performed using a fixed-effect model.

MAIN RESULTS

We included 26 studies with outcome data by hormone receptor: 12 metastatic studies (n = 4325), 6 neoadjuvant trials (n = 3152), and 8 adjuvant studies (n = 13,457). Capecitabine treatment was added in several different ways across studies. These could be classified as capecitabine alone compared to another treatment, capecitabine substituted for part of the control chemotherapy, and capecitabine added to control chemotherapy. In the metastatic setting, the effect of capecitabine was heterogenous between hormone receptor-positive and -negative tumours. For OS, no difference between capecitabine-containing and non-capecitabine-containing regimens was observed for all participants taken together (HR 1.01, 95% confidence interval (CI) 0.98 to 1.05; 12 studies, 4325 participants; high-certainty evidence), for those with hormone receptor-positive disease (HR 0.93, 95% CI 0.84 to 1.04; 7 studies, 1834 participants; high-certainty evidence), and for those with hormone receptor-negative disease (HR 1.00, 95% CI 0.88 to 1.13; 8 studies, 1577 participants; high-certainty evidence). For progression-free survival (PFS), a small improvement was seen for all people (HR 0.89, 95% CI 0.82 to 0.96; 12 studies, 4325 participants; moderate-certainty evidence). This was largely accounted for by a moderate improvement in PFS for inclusion of capecitabine in hormone receptor-positive cancers (HR 0.82, 95% CI 0.73 to 0.91; 7 studies, 1594 participants; moderate-certainty evidence) compared to no difference in PFS for hormone receptor-negative cancers (HR 0.96, 95% CI 0.83 to 1.10; 7 studies, 1122 participants; moderate-certainty evidence). Quality of life was assessed in five studies; in general there did not seem to be differences in global health scores between the two treatment groups at around two years' follow-up. Neoadjuvant studies were highly variable in design, having been undertaken to test various experimental regimens using pathological complete response (pCR) as a surrogate for disease-free survival (DFS) and OS. Across all patients, capecitabine-containing regimens resulted in little difference in pCR in comparison to non-capecitabine-containing regimens (odds ratio (OR) 1.12, 95% CI 0.94 to 1.33; 6 studies, 3152 participants; high-certainty evidence). By subtype, no difference in pCR was observed for either hormone receptor-positive (OR 1.22, 95% CI 0.76 to 1.95; 4 studies, 964 participants; moderate-certainty evidence) or hormone receptor-negative tumours (OR 1.28, 95% CI 0.61 to 2.66; 4 studies, 646 participants; moderate-certainty evidence). Four studies with 2460 people reported longer-term outcomes: these investigators detected no difference in either DFS (HR 1.02, 95% CI 0.86 to 1.21; high-certainty evidence) or OS (HR 0.97, 95% CI 0.77 to 1.23; high-certainty evidence). In the adjuvant setting, a modest improvement in OS was observed across all participants (HR 0.89, 95% CI 0.81 to 0.98; 8 studies, 13,547 participants; moderate-certainty evidence), and no difference in OS was seen in hormone receptor-positive cancers (HR 0.86, 95% CI 0.68 to 1.09; 3 studies, 3683 participants), whereas OS improved in hormone receptor-negative cancers (HR 0.72, 95% CI 0.59 to 0.89; 5 studies, 3432 participants). No difference in DFS or relapse-free survival (RFS) was observed across all participants (HR 0.93, 95% CI 0.86 to 1.01; 8 studies, 13,457 participants; moderate-certainty evidence). As was observed for OS, no difference in DFS/RFS was seen in hormone receptor-positive cancers (HR 1.03, 95% CI 0.91 to 1.17; 5 studies, 5604 participants; moderate-certainty evidence), and improvements in DFS/RFS with inclusion of capecitabine were observed for hormone receptor-negative cancers (HR 0.74, 95% CI 0.64 to 0.86; 7 studies, 3307 participants; moderate-certainty evidence). Adverse effects were reported across all three scenarios. When grade 3 or 4 febrile neutropenia was considered, no difference was seen for capecitabine compared to non-capecitabine regimens in neoadjuvant studies (OR 1.31, 95% CI 0.97 to 1.77; 4 studies, 2890 participants; moderate-certainty evidence), and a marked reduction was seen for capecitabine in adjuvant studies (OR 0.55, 95% CI 0.47 to 0.64; 5 studies, 8086 participants; moderate-certainty evidence). There was an increase in diarrhoea and hand-foot syndrome in neoadjuvant (diarrhoea: OR 1.95, 95% CI 1.32 to 2.89; 3 studies, 2686 participants; hand-foot syndrome: OR 6.77, 95% CI 4.89 to 9.38; 5 studies, 3021 participants; both moderate-certainty evidence) and adjuvant trials (diarrhoea: OR 2.46, 95% CI 2.01 to 3.01; hand-foot syndrome: OR 13.60, 95% CI 10.65 to 17.37; 8 studies, 11,207 participants; moderate-certainty evidence for both outcomes).

AUTHORS' CONCLUSIONS

In summary, a moderate PFS benefit by including capecitabine was seen only in hormone receptor-positive cancers in metastatic studies. No benefit of capecitabine for pCR was noted overall or in hormone receptor subgroups when included in neoadjuvant therapy. In contrast, the addition of capecitabine in the adjuvant setting led to improved outcomes for OS and DFS in hormone receptor-negative cancer. Future studies should stratify by hormone receptor and triple-negative breast cancer (TNBC) status to clarify the differential effects of capecitabine in these subgroups across all treatment scenarios, to optimally guide capecitabine inclusion.

Chemotherapy Options beyond the First Line in HER-Negative Metastatic Breast Cancer

Despite the recent advances in the biological understanding of breast cancer (BC), chemotherapy still represents a key component in the armamentarium for this disease. Different agents are available as mono-chemotherapy options in patients with locally advanced or metastatic BC (MBC) who progress after a first- and second-line treatment with anthracyclines and taxanes. However, no clear indication exists on what the best option is in some populations, such as heavily pretreated, elderly patients, triple-negative BC (TNBC), and those who do not respond to the first-line therapy. In this article, we summarize available literature evidence on different chemotherapy agents used beyond the first-line, in locally advanced or MBC patients, including rechallenge with anthracyclines and taxanes, antimetabolite and antimicrotubule agents, such as vinorelbine, capecitabine, eribulin, ixabepilone, and the newest developed agents, such as vinflunine, irinotecan, and etirinotecan.

Impact of acute kidney injury on anticancer treatment dosage and long-term outcomes: a pooled analysis of European Organisation for Research and Treatment of Cancer trials

BACKGROUND

The impact of kidney dysfunction on long-term outcomes of patients with advanced cancer remains unclear.

METHODS

Patients with advanced cancer included in trials conducted by the European Organisation for Research and Treatment of Cancer were eligible for this retrospective analysis. Acute kidney injury (AKI) was identified using serum creatinine levels and using adverse events reported by investigators. The impact of baseline estimated glomerular filtration rates (eGFRs) on progression-free survival (PFS) and overall survival (OS) was investigated. Pooled estimates of the impact of AKI on dose intensity, treatment duration, PFS and OS were obtained following a meta-analytic process.

RESULTS

Nine trials were included in this study, totalling 2872 metastatic patients with various tumour types and various systemic treatment types. Baseline eGFR had homogeneously no impact on PFS or OS. Most Risk, Injury, Failure, Loss of kidney function and End-stage kidney disease (RIFLE) events occurred early during the course of the treatment. AKI was not associated with an increased rate of treatment discontinuation, while it decreased the study treatment dose intensity. Occurrence of a first RIFLE event significantly and homogeneously reduced PFS (pooled hazard ratio = 1.18, 95% confidence interval 1.07-1.30; P = 0.0012), while its impact on OS was more heterogeneous across trials.

CONCLUSION

AKI is associated with reduced treatment dose intensity and reduced PFS. Therefore, close monitoring of the kidney function during the first months of treatment should be included in clinical trial protocols and probably also in daily practice to enable early AKI diagnosis and management. Collaboration between oncologists and nephrologists is needed to reduce the risk of undertreatment of patients experiencing AKI.

Reference values for the EORTC QLQ-C30 in early and metastatic breast cancer

BACKGROUND

Considering the worldwide incidence of breast cancer (BC) and the importance of health-related quality of life (HRQoL) assessment, there is a growing need to have accurate and up-to-date reference values (RVs). RVs are useful for the design of randomised controlled trials (RCTs) and as benchmarks for comparison of cancer RCTs and health care interventions. This study aimed to provide RVs for the QLQ-C30 in early BC (EBC) and metastatic BC (MBC). General patterns of main results from the EORTC dataset (main dataset) were compared with the PDS dataset (comparison dataset) to see whether they would be consistent across pre-defined covariates.

METHODS

European Organization for Research and Treatment of Cancer (EORTC) (main dataset) and Project Data Sphere (PDS) (comparison dataset) were searched to identify BC RCTs where baseline HRQoL (before treatment) was assessed with the QLQ-C30. RVs were calculated and stratified by disease stage, age, and when available, performance status (PS), comorbidity and region. RVs were reported using descriptive statistics.

RESULTS

Data from three EORTC (n = 4115) and three PDS RCTs (n = 1406) were included in the analysis. While EBC patients presented better HRQoL with high baseline functioning scores and low prevalence of symptoms, MBC patients reported worse HRQoL with lower functioning scores and more prevalence of symptoms. In MBC, poor PS and presence of comorbidities reflected worse baseline HRQoL. No consistent differences were found for age and countries.

CONCLUSION

These up-to-date RVs for the EORTC QLQ-C30 in BC show differences in HRQoL scores between stages, PS, and comorbidities. These findings, supported by an independent dataset, will help the clinical interpretation of scores for BCpatients.

An update on the currently available and future chemotherapy for treating bone metastases in breast cancer patients

INTRODUCTION

Bone metastases in breast cancer patients are a common clinical problem. Many factors influence the treatment decision, including tumor characteristics, previous treatment and tumor burden in the treatment of metastatic breast cancer.

AREAS COVERED

This present review summarizes the new treatment strategies and the chemotherapeutic agents currently available in the management of metastatic breast cancer with bone metastases.

EXPERT OPINION

Patients with bone metastases more often have hormone receptor-positive tumours. Although new treatment agents for metastatic breast cancer have been investigated, endocrine therapy is still considered as the treatment of choice for patients with bone metastases although chemotherapy still has an important place. In recent years, new chemotherapeutic agents such as etirinotecan and nab-paclitaxel have been established though there are few studies that have looked at particular types of metastases. In the last decade, therapies for bone metastasis resistant to endocrine therapy have predominantly focused on radiotherapy, surgical resection, chemotherapy, bone-targeting radiopharmaceuticals and targeted therapeutics. New targeted agents include: Src inhibitors, cathepsin K inhibitors, CXCR4 inhibitors, TGF-B blockade and integrin antagonists while drug delivery systems for chemotherapy have also been developed. These new treatment options could be future treatment options for bone metastatic disease if early promising results are confirmed by clinical trials.

Single-Agent Oral Vinorelbine as First-Line Chemotherapy for Endocrine-Pretreated Breast Cancer With Bone Metastases and No Visceral Involvement: NORBREAST-228 Phase II Study

PURPOSE

Single-agent oral chemotherapy is widely used in patients with bone metastases without visceral involvement, especially in hormone receptor-positive metastatic breast cancer (mBC). However, this option has been poorly evaluated in clinical trials.

METHODS

Eligible patients had mBC with predominantly bone but not visceral metastases, were receiving bisphosphonate therapy, and had previously received endocrine therapy (any setting) but not chemotherapy for mBC. Patients received oral vinorelbine 60 mg/m² on days 1, 8, 15, and 22 every 4 weeks (escalating to 80 mg/m² from cycle 2 in the absence of grade 3/4 toxicity) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included clinical benefit rate (complete/partial response or ≥24 weeks' stable disease), overall survival, and safety.

RESULTS

Seventy patients were treated for a median of 6 cycles (range 1-18). Most (73%) continued treatment until disease progression. After 43 months' median follow-up, median PFS was 8.2 months (95% confidence interval [CI], 5.5-9.8). The clinical benefit rate was 56% (95% CI, 43%-68%). Median overall survival was 35.2 months (95% CI, 26.8-47.1). The most common grade 3/4 adverse event was neutropenia (38% of patients); febrile neutropenia was absent. The most common grade 1/2 adverse events were bone pain, fatigue, and gastrointestinal toxicities. Alopecia was infrequent.

CONCLUSIONS

In patients with hormone receptor-positive mBC, bone disease, and prior endocrine therapy, first-line oral vinorelbine chemotherapy demonstrated long PFS and good tolerability. In this setting, it could be considered as an active oral alternative to intravenous chemotherapy.

A network meta-analysis of everolimus plus exemestane versus chemotherapy in the first- and second-line treatment of estrogen receptor-positive metastatic breast cancer

The goal of this study was to compare the efficacy and toxicity of chemotherapy to exemestane plus everolimus (EXE/EVE) through a network meta-analysis (NMA) of randomized controlled trials. NMA methods extend standard pairwise meta-analysis to allow simultaneous comparison of multiple treatments while maintaining randomization of individual studies. The method enables "direct" evidence (i.e., evidence from studies directly comparing two interventions) and "indirect" evidence (i.e., evidence from studies that do not compare the two interventions directly) to be pooled under the assumption of evidence consistency. We used NMA to evaluate progression-free survival (PFS) and time to progression (TTP) curves in 34 studies, and response rate (RR) and the hazard ratios (HRs) of the PFS/TTP in 36 studies. A number needed to treat (NNT) analysis was also performed as well as descriptive comparison of reported toxicities. The NMA for PFS/TTP curves and for HR shows EXE/EVE is more efficacious than capecitabine plus sunitinib, CMF, megestrol acetate and tamoxifen, with an average of related-PFS/TTP difference ranging from about 10 months for capecitabine plus sunitinib to more than 6 months for tamoxifen. The NMA for overall RR shows that EXE/EVE provides a better RR than bevacizumab plus capecitabine, capecitabine, capecitabine plus sorafenib, capecitabine plus sunitinib, CMF, gemcitabine plus epirubicin plus paclitaxel, EVE plus tamoxifen, EXE, FEC, megestrol acetate, mitoxantrone, and tamoxifen. Finally, the NMA for NNT shows that EXE/EVE is more beneficial as compared to BMF, capecitabine, capecitabine plus sunitinib, CMF, FEC, megestrol acetate, mitoxantrone, and tamoxifen. The combination of EXE/EVE as first- or second-line therapy for ER+ve/HER2-ve metastatic breast cancer is more efficacious than several chemotherapy regimens that were reported in the literature. Toxicities also favored EXE/EVE in most instances.

A Randomized Phase II Trial of Capecitabine Plus Vinorelbine Followed by Docetaxel Versus Adriamycin Plus Cyclophosphamide Followed by Docetaxel as Neoadjuvant Chemotherapy for Breast Cancer

Purpose

Given the promising activity of capecitabine and vinorelbine in metastatic breast cancer, this randomized phase II trial evaluated the efficacy and safety of this combination as neoadjuvant chemotherapy in breast cancer.

Materials and Methods

Patients with operable breast cancer (n=75) were randomly assigned to receive either four cycles of adriamycin 60 mg/m² plus cyclophosphamide 600 mg/m² every 3 weeks followed by four cycles of docetaxel 75 mg/m² every 3 weeks (AC-D) or four cycles of capecitabine 2,000 mg/m² (day 1-14) plus vinorelbine 25 mg/m² (days 1 and 8) every 3 weeks followed by four cycles of docetaxel 75 mg/m² (CV-D). The primary endpoint was pathologic complete response (pCR) in the primary breast (ypT0/is).

Results

Most patients (84%) had locally advanced (n=41) or inflammatory breast cancer (n=22). pCR rates in the primary breast were 15% (95% confidence interval [CI], 7% to 30%) and 11% (95% CI, 4% to 26%) in the AC-D and CV-D groups, respectively. The overall response rates and 5-year progression-free survival rates in the AC-D and CV-D groups were 62% and 64%, and 51.3% (95% CI, 34.6% to 68.0%) and 30.2% (95% CI, 13.3% to 47.1%), respectively. Although both regimens were well tolerated, CV-D showed less frequent grade 3-4 neutropenia and vomiting than AC-D, whereas manageable diarrhea and hand-foot syndrome were more common in the CV-D group.

Conclusion

CV-D is a feasible and active non-anthracycline–based neoadjuvant chemotherapy regimen for breast cancer.

Suprafenacine, an indazole-hydrazide agent, targets cancer cells through microtubule destabilization

Microtubules are a highly validated target in cancer therapy. However, the clinical development of tubulin binding agents (TBA) has been hampered by toxicity and chemoresistance issues and has necessitated the search for new TBAs. Here, we report the identification of a novel cell permeable, tubulin-destabilizing molecule - 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid [1p-tolyl-meth-(E)-ylidene]-hydrazide (termed as Suprafenacine, SRF). SRF, identified by in silico screening of annotated chemical libraries, was shown to bind microtubules at the colchicine-binding site and inhibit polymerization. This led to G₂/M cell cycle arrest and cell death via a mitochondria-mediated apoptotic pathway. Cell death was preceded by loss of mitochondrial membrane potential, JNK - mediated phosphorylation of Bcl-2 and Bad, and activation of caspase-3. Intriguingly, SRF was found to selectively inhibit cancer cell proliferation and was effective against drug-resistant cancer cells by virtue of its ability to bypass the multidrug resistance transporter P-glycoprotein. Taken together, our results suggest that SRF has potential as a chemotherapeutic agent for cancer treatment and provides an alternate scaffold for the development of improved anti-cancer agents.

Human microtubule-associated protein tau mediates targeted killing of CD30(+) lymphoma cells in vitro and inhibits tumour growth in vivo

Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL) are rare lymphoproliferative cancer types. Although most HL patients can be cured by chemo- and radio-therapy, 4-50% of patients relapse and have a poor prognosis. The need for improved therapeutic options for patients with relapsed or refractory disease has been addressed by CD30-specific antibody-based immunotherapeutics. However, available CD30-specific monoclonal antibodies (mAbs), antibody drug conjugates (ADCs) or chimeric immunotoxins suffer from the requirement of a functional host immunity, undesirable immune reactions or heterogeneity and instability, respectively. Here, we present a new fusion protein comprised of the CD30-specific antibody single-chain fragment Ki4(scFv) and the human pro-apoptotic effector protein, microtubule-associated protein tau (MAPT). Ki4(scFv)-MAP selectively induced apoptosis in rapidly proliferating L540cy, L428, and Karpas 299 cells in a dose-dependent manner. Tubulin polymerization assays confirmed that Ki4(scFv)-MAP stabilizes microtubules, suggesting a mechanism for its pro-apoptotic action. Dose-finding experiments proved that Ki4(scFv)-MAP is well tolerated in mice compared to the previously reported Ki4(scFv)-ETA'. Ki4(scFv)-MAP significantly inhibited growth of subcutaneous L540cy xenograft tumours in mice. Our data present a novel approach for the treatment of CD30(+) lymphomas, combining the binding specificity of a target-specific antibody fragment with the selective cytotoxicity of MAPT towards proliferating lymphoma cells.

Stilbene 5c, a microtubule poison with vascular disrupting properties that induces multiple modes of growth arrest and cell death

The stilbene derivative, cis-3,4',5-trimethoxy-3'-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding site in tubulin. The current studies were designed to investigate the effectiveness of stilbene 5c against the HCT-116 human colon cancer cell line and B16/F10 melanoma cells as well as human endothelial cell tube formation and tumor perfusion. Stilbene 5c produced a time-dependent decrease in cell viability in both cell lines and the capacity of the cells to proliferate was not restored upon removal of the drug. Treatment with stilbene 5c also promoted both senescence and autophagy in both cell lines. TUNEL and annexin 5 staining indicated that apoptosis also occurs in stilbene 5c-treated HCT-116 cells, but not in B16/F10 melanoma cells. DAPI staining revealed morphological changes in the cell nuclei (binucleated and micronucleated cells) indicative of mitotic catastrophe in HCT-116 cells but not in the B16/F10 melanoma cells. p53-null HCT-116 cells demonstrated a similar growth arrest/cell death response to stilbene as p53-wild type HCT-116 cells. Stilbene 5c also completely inhibited human endothelial cell tube formation on Matrigel, consistent with potential anti-angiogenic actions. Using a new method developed for monitoring the pharmacodynamic effects of stilbene 5c in vivo, we found that a single injection of stilbene 5c reduced tumor perfusion by 65% at 4h, returning to baseline by 24h, while subsequent daily injections of stilbene 5c produced progressively larger reductions and smaller rebounds. This work indicates that stilbene 5c could potentially be effective against melanoma and colon cancer through the promotion of multiple modes of growth arrest and cell death coupled with anti-angiogenic and antivascular actions.

Microtubule-associated protein tau facilitates the targeted killing of proliferating cancer cells in vitro and in a xenograft mouse tumour model in vivo

Background:

Antibody drug conjugates (ADCs) and immunotoxins (ITs) are promising anticancer immunotherapeutics. Despite their encouraging performance in clinical trials, both ADCs and ITs often suffer from disadvantages such as stoichiometrically undefined chemical linkage of the cytotoxic payload (ADCs) and the potential immunogenicity of toxins derived from bacteria and plants (ITs).

Methods:

Human microtubule-associated protein tau (MAP) was cloned in-frame with human EGF, expressed in E. coli and purified by standard chromatographic methods. The in vitro activity was confirmed by flow cytometry, cell viability assays and tubulin polymerisation assay. The in vivo efficacy was demonstrated using noninvasive far-red in vivo imaging.

Results:

The EGF-MAP selectively induced apoptosis in EGFR-overexpressing proliferating cancer cells through stabilisation of microtubules. Nonproliferating cells were not affected, demonstrating superior selectivity of EGF-MAP for cancer cells. The EGF-MAP was well tolerated at high doses in mice compared with the ETA'-based control. The in vivo efficacy of EGF-MAP was demonstrated in a tumour xenograft mouse model.

Conclusion:

Our data indicate the general mechanism of action for a new class of human immunotherapeutic reagents suitable for the treatment of cancer. This approach combines the binding specificity of targeting ligands with the selective cytotoxicity of MAP towards proliferating cells.

Phase II study of single agent oral vinorelbine as first-line treatment in patients with HER-2 negative metastatic breast cancer

PURPOSE

Previous studies indicated that oral chemotherapy is convenient and preferred by many patients. We hereby report the efficacy and safety of oral vinorelbine as first-line chemotherapy for metastatic breast cancer (MBC).

METHODS

Thirty-one patients with HER-2 negative MBC were enrolled between January 2007 and December 2010 in a prospective phase II trial. Patients were treated every 3 weeks with oral vinorelbine 60 mg/m² Days 1 and 8 for the 1st cycle and thereafter 80 mg/m² Days 1 and 8 every 3 weeks. Treatment was administered until disease progression or unexpected adverse event or patient refusal to continue. Primary endpoint was objective response rate (ORR); secondary endpoints were time-to-progression (TTP), overall survival (OS) and safety. Follow-up results until October 2012 are reported.

RESULTS

Median age was 42 years (range 33-75). 26 (84 %) patients had 2 or more metastatic sites. A median of 6 cycles were administered (range 2-20). ORR was achieved in 9 (29 %) patients including 1 complete and 8 partial responses. 12 (39 %) patients had stable disease, resulting in a disease control rate of 68 %. Median TTP was 5.2 months [95 % CI 2.8-7.5]. Median OS was 16 months [95 % CI 11.3-20.7]. 3 (10 %) patients developed Grade 3-4 neutropenia. No events of febrile neutropenia, cardiac, renal toxicities or alopecia were recorded. Grade 3 thrombocytopenia and nausea-vomiting were reported in 2 (6 %) and 5 (16 %) patients, respectively.

CONCLUSION

Results show a good efficacy and tolerance profile of oral vinorelbine as first-line chemotherapy for HER-2 negative MBC patients.

A systematic review of vinorelbine for the treatment of breast cancer

The purpose of this study was to investigate the efficacy and safety profile of vinorelbine-based chemotherapy in different settings for the treatment of breast cancer. We performed a computerized search using combinations of the following keywords: "breast cancer", "breast neoplasms", "trial", "vinorelbine" and "navelbine". A total of 20 trials were included in this analysis, with a total of 5,080 patients accrued. Taxane was associated with enhanced overall survival (OS; p = 0.027) and response rate (RR; p = 0.037) as compared with vinorelbine in monotherapy, but did not show significantly favored progression-free survival (PFS; p = 0.136). Vinorelbine alone was equivalent to fluoropyrimidine treatment in RR (p = 0.79) for the treatment of metastatic breast cancer. For vinorelbine-combined regimens, the analysis showed that the vinorelbine group gave similar results as other regimens for OS (p = 0.849) and PFS (p = 0.143). The RR of vinorelbine-combined regimens was slightly better than that of the other regimens (OR, 1.17), but the difference was not statistically significant. In neoadjuvant setting, vinorelbine treatment was as active as AC (doxorubicin, cyclophosphamide) or DAC (doxorubicin, cyclophosphamide, docetaxel) regimens with respect to RR (p = 0.76) and pathologic complete response (pCR; p = 0.77), but showed lower occurrence of grade 3/4 adverse effects. The analysis also demonstrated that vinorelbine-containing therapy is effective as adjuvant, front-line or salvage therapy of metastatic breast cancer, even for patients who were previously treated with anthracyclines or taxanes.

Efficacy and toxicity of capecitabine-based chemotherapy in patients with metastatic or advanced breast cancer: results from ten randomized trials

OBJECTIVE

The efficacy and adverse effects of capecitabine-based chemotherapy versus other regimens reported in previous trials were discordant. The aim of the present study was to determine the efficacy and toxicity profiles of capecitabine-based chemotherapy versus capecitabine-free regimens in patients with metastatic and/or advanced breast cancer.

METHODS

Randomized trials in which capecitabine-based chemotherapy was compared with capecitabine-free chemotherapy were included by searching the PubMed database. Differences in efficacy and grade 3-4 toxicities between capecitabine-based chemotherapy and other chemotherapy were compared.

RESULTS

Ten randomized controlled trials were included in our meta-analysis. Compared to patients treated with capecitabine-free chemotherapy, patients treated with capecitabine-based chemotherapy did not have a significantly different complete response (odds ratio (OR): 1.25, 95% confidence interval (CI): 0.87-1.79, p = 0.231), partial response (OR: 1.16, 95% CI: 0.95-1.41, p = 0.147), and overall response (OR: 1.21, 95% CI: 1.00-1.47, p = 0.053). Compared to the capecitabine-free group, less hematological toxicity and more gastrointestinal toxicity occurred in patients treated with capecitabine-based chemotherapy, including neutropenia (OR: 0.34, 95% CI: 0.19-0.59, p <0.001), anemia (OR: 0.41, 95% CI: 0.20-0.85, p = 0.016), leukocytopenia (OR: 0.50, 95% CI: 0.32-0.78, p = 0.002), and diarrhea (OR: 2.35, 95% CI: 1.62-3.42, p < 0.001). Furthermore, patients in the capecitabine group exhibited a significantly higher rate of grade 3 hand-foot syndrome than the capecitabine-free group (OR: 25.16, 95% CI: 12.27-51.58, p < 0.001).

CONCLUSIONS

The present study suggests that capecitabine-based chemotherapy is as effective as capecitabine-free chemotherapy in patients with metastatic and/or advanced breast cancer with different toxicity profiles. Capecitabine-based chemotherapy may be better tolerated than capecitabine-free chemotherapy. Due to several limitations in our study, future large randomized trials are needed.

Structure of the α-tubulin acetyltransferase, αTAT1, and implications for tubulin-specific acetylation

Protein acetylation is an important posttranslational modification with the recent identification of new substrates and enzymes, new links to disease, and modulators of protein acetylation for therapy. α-Tubulin acetyltransferase (αTAT1) is the major α-tubulin lysine-40 (K40) acetyltransferase in mammals, nematodes, and protozoa, and its activity plays a conserved role in several microtubule-based processes. Here, we present the X-ray crystal structure of the human αTAT1/acetyl-CoA complex. Together with structure-based mutagenesis, enzymatic analysis, and functional studies in cells, we elucidate the catalytic mechanism and mode of tubulin-specific acetylation. We find that αTAT1 has an overall fold similar to the Gcn5 histone acetyltransferase but contains a relatively wide substrate binding groove and unique structural elements that play important roles in α-tubulin-specific acetylation. Conserved aspartic acid and cysteine residues play important catalytic roles through a ternary complex mechanism. αTAT1 mutations have analogous effects on tubulin acetylation in vitro and in cells, demonstrating that it is the central determining factor of α-tubulin K40 acetylation levels in vivo. Together, these studies provide general insights into distinguishing features between histone and tubulin acetyltransferases, and they have specific implications for understanding the molecular basis of tubulin acetylation and for developing small molecule modulators of microtubule acetylation for therapy.

Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus

Background

Kalanchoe tubiflora (KT) is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored.

Methods

Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images.

Results

An n-Butanol-soluble fraction of KT (KT-NB) was able to inhibit cell proliferation. After a 48 h treatment with 6.75 μg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase.

Conclusion

KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.

[Antitubulin agents]

Microtubules are dynamic filamentous cytoskeletal proteins that are an important therapeutic target in patients with tumors. Microtubule binding agents have been part of the pharmacopoeia of cancer for decades, and until the advent of targeted therapy microtubules represented the only alternative to DNA as a therapeutic target in cancer. There are currently a variety of available vinca alkaloids and taxanes and other agents, such as ixabepilone and eribulin, have also been approved. Maytansinoids have been used for the production of immunoconjugates, monoclonal antibodies covalently bound to antimitotic molecules. The screening of a variety of botanical species and marine organisms continues to yield promising new antitubulin agents with novel properties. Enhanced tumor specificity, reduced neurotoxicity, and insensitivity to chemoresistance mechanisms are the three main objectives in the current search for novel microtubule binding agents.

Efficacy and safety of palliative chemotherapy for patients with advanced breast cancer pretreated with anthracyclines and taxanes: a systematic review

No standard monotherapy or combination palliative chemotherapy currently exists for patients with advanced breast cancer pretreated with anthracyclines and taxanes. In this systematic review we assess the current knowledge on the efficacy and safety of palliative single-agent chemotherapy drugs--capecitabine, vinorelbine, gemcitabine, and liposomal doxorubicin--commonly used in daily clinical practice. We identified 22 studies, of which ten investigated capecitabine, nine investigated vinorelbine, three investigated gemcitabine, and one investigated liposomal doxorubicin. The greatest amount of information was available for capecitabine and vinorelbine. These two drugs showed good efficacy. The disease control rate differed significantly between the four drugs, which is relevant in terms of how well tumour symptoms can be improved and whether quality of life can be maintained or even improved. To obtain more evidence of the efficacy and safety of chemotherapeutic agents used in this pretreated population of advanced breast cancer patients, randomised comparisons of the various drugs, as monotherapy and in combination with targeted agents, are needed.

First-line chemotherapy for metastatic breast cancer in patients ≥75 years: a retrospective single-centre analysis

Data on chemotherapy for elderly patients with metastatic breast carcinoma (MBC) are limited. We performed a 7-year retrospective analysis of MBC patients at our institution receiving first-line chemotherapy aged ≥75 years. Of 117 patients, 103 received monotherapy (67 capecitabine, 29 vinorelbine, 5 docetaxel, 2 liposomal doxorubicin) and 14 received polychemotherapy (12 anthracycline-based, 2 vinorelbine-gemcitabine). Chemotherapy demonstrated acceptable tolerability. Median progression-free survival (PFS) and overall survival (OS) from initiation of chemotherapy were 6.2 months and 13.8 months, respectively. At 2 years, 25% of patients were alive; however, 25% died within 3 months of beginning chemotherapy. Independent prognostic factors for longer PFS were good performance status, absence of visceral disease and capecitabine treatment. Good performance status and lack of visceral disease were also significant for OS. These results suggest that palliative chemotherapy should not be systematically excluded in this setting, but should be carefully discussed as it appears to be feasible with apparent benefit in selected patients.

Microtubule-binding agents: a dynamic field of cancer therapeutics

Microtubules are dynamic filamentous cytoskeletal proteins composed of tubulin and are an important therapeutic target in tumour cells. Agents that bind to microtubules have been part of the pharmacopoeia of anticancer therapy for decades and until the advent of targeted therapy, microtubules were the only alternative to DNA as a therapeutic target in cancer. The screening of a range of botanical species and marine organisms has yielded promising new antitubulin agents with novel properties. In the current search for novel microtubule-binding agents, enhanced tumour specificity, reduced neurotoxicity and insensitivity to chemoresistance mechanisms are the three main objectives.

Overcoming taxane and anthracycline resistance

With more and more breast cancer (BC) patients receiving taxanes and anthracyclines in the adjuvant setting, the number of patients resistant to these drugs is rising. Herein, we review cellular mechanisms (e.g., overexpression of drug efflux pumps) that are associated with clinical anthracycline and/or taxane-resistant BC. We also discuss therapeutic approaches that have received Food and Drug Administration approval in this setting or are in clinical development, including targeted agents that do not employ a cytotoxic mechanism, as well as novel chemotherapeutics such as the epothilones, a class of microtubule stabilizers less susceptible to common cellular resistance mechanisms.

Vinorelbine and fluorouracil plus leucovorin combination (ViFL) in patients with anthracycline and taxane-pretreated metastatic breast cancer: a phase II study

PURPOSE

This phase II study was designed in order to evaluate efficacy and safety of the combination of vinorelbine (VNB), fluorouracil (FU) and leucovorin (LV) in patients with metastatic breast carcinoma (MBC) previously treated with anthracyclines and taxanes.

METHODS

From 12/2003 to 12/2007, 51 women (median age 59) were treated. Performance status (PS) (ECOG) was 0-2 (median 0). The chemotherapy consisted of VNB 25 mg/sqm on day 1 added to FU and LV (following De Gramont schedule) on day 1 and 2. Treatment was repeated every 14 days. 518 cycles of CT were administered (median 12). Most common sites of metastatic spread were: bone, liver, lymph nodes, lung.

RESULTS

We recorded three cases of G4 neuthropenia and in one case it was febrile; no others G4 toxicities were seen. G3 toxicities were more common, especially neuthropenia (8 patients) asthenia (4) mucositis (2) and Hand-Foot Syndrome (2). Overall response rate was 27.5% (14 patients had a PR) and disease control rate was 76.5%; 12 patients experienced disease progression. Median time to progression (TTP) was 7.70 months and overall survival (OS) was 18.70 months.

CONCLUSIONS

Results demonstrate that the ViFL regimen has substantial activity in patients with MBC already treated with anthracyclines and taxanes. The combination may be considered a valid choice for the treatment of MBC. Better survival results were seen in patients with visceral metastases than bone involvement. The low response rate shows that the ViFL regimen is not suitable for the neoadjuvant setting.

Metastatic breast cancer: the treatment challenge

As therapeutic options have multiplied, chemotherapy for metastatic breast cancer (MBC) has become increasingly complex. Furthermore, advances in the treatment of early-stage breast cancer, in particular the development of taxane-based regimens, have led to increased use of adjuvant chemotherapy. As a result, the decisions regarding the treatment of patients presenting with MBC have become more difficult, because many patients are likely to have received a variety of adjuvant chemotherapy regimens. The primary goal of treatment for MBC is palliation of disease--usually with prolongation of survival--with minimal toxicity. However, there is currently no "gold standard" in this setting, and the literature supports many choices for first- and second-line treatment. Other issues as yet unsettled in these patients are (1) whether to combine >or= 2 drugs or to use each drug alone until disease progression; (2) how to use novel targeted biologic agents; and (3) how to treat patients with HER2-overexpressing tumors after adjuvant treatment with trastuzumab. The role of taxanes, antimetabolites, and targeted agents in patients with MBC will be discussed in this review, particularly in the context of previous adjuvant therapy. The controversy surrounding the use of doublet or sequential therapy will also be discussed. Although considerable advances have been made toward answering these questions, many additional uncertainties have arisen, and further well-designed randomized studies are needed.