Vinorelbine in the management of breast cancer: New perspectives, revived role in the era of targeted therapy

Current Perspectives in the Application of Medicinal Plants Against Cancer: Novel Therapeutic Agents

Background:

Cancer is a disease characterized by uncontrolled cell growth and proliferation. It has become a major health problem in the past decades and is now the second leading cause of death globally. Although, there are different types of treatment such as chemotherapy, immune therapy, radiation, hormone therapy and targeted therapy used against cancer, they have possible side effects and significant deficiencies.

Methods:

This review aims to outline the benefits of medicinal plants and plant-derived products and highlight why they should be used as novel anti-cancer therapeutics. Electronic databases, including PubMed, Scopus, ScienceDirect, Cochrane library, and MedlinePlus were searched to summarize in vitro, in vivo and clinical studies on anticancer effects of medicinal plants and their bioactive compounds up-to-date.

Results:

In recent years, a number of medicinal plants have been administered to cancer patients in order to prevent and treat cancer as an alternative therapy. These plants were used because of their rich anticarcinogenic and chemoprotective potentials. In addition to these remarkable properties, these plants have less toxic anticancer, anti-tumor and anti-proliferation agents than traditional therapeutics. Nevertheless, only a small number of natural anti-tumor products including vinblastine, vincristine, podophyllotoxin, paclitaxel (Taxol) and camptothecin have been tested clinically, while vinflunine ditartrate, anhydrovinblastine, NK-611, tafluposide, paclitaxel poliglumex, combretastatins, salvicine, curcumin, indirubin, triptolide, homoharringtonine are still on trial.

Conclusion:

Consequently, more effective anticancer compounds are identified during the clinical trials; these natural products could be a key source of antitumor agents in modern anticancer therapy. It is expected that novel anticancer phytopharmaceuticals produced from medicinal plants could be effectively used in prevention and therapy for the cancers.

Phase I/II Trial of Sorafenib in Combination with Vinorelbine as First-Line Chemotherapy for Metastatic Breast Cancer

Background

Preclinical models have reported a synergistic interaction between sorafenib and vinorelbine. We investigated the toxicity, efficacy, and pharmacokinetics interaction of this combination as first-line treatment for patients with metastatic breast cancer.

Methods

Patients were HER2-negative and treated with vinorelbine 30 mg/m² IV days 1,8 every 21 plus daily oral sorafenib. In the phase I portion (3+3 design) patients received sorafenib 200 mg BID (cohort 1) or 400 mg BID (cohort 2). In the phase II expansion, 21 more evaluable patients were planned to receive the maximum tolerated dose (MTD). Pharmacokinetic analysis was performed in 6 patients: blood concentrations were compared for each drug in the presence or absence of the other drug.

Results

In cohort 1, one patient experienced a dose-limiting toxicity (DLT) (grade 3 pancreatitis), requiring the expansion of this cohort to 6 patients, without further documented DLTs. In cohort 2, one patient of six experienced a grade 4 DLT (asymptomatic rise in amylase not requiring drug discontinuation), establishing this dose level as the MTD (sorafenib 400 mg BID). After expansion at the MTD, a total of 27 patients (median age 57) were treated for a median of 8 cycles. One grade 5 febrile neutropenia occurred. With repeated cycles, 52% of patients required at least 1 dose reduction of either drug. One patient experienced a sustained grade 3 fatigue resulting in treatment discontinuation. The response rate was 30%. Median PFS was 5.7 months (95% CI 4.4–7.6), and clinical benefit (absence of disease progression at 6 months) was 48%. PK analysis showed a significant interaction between the two drugs, resulting in a higher Cmax of vinorelbine in the presence of sorafenib.

Conclusion

The combination of sorafenib and vinorelbine at full doses is feasible but not devoid of toxicity, likely also due to a significant PK interaction.

Trial Registration

ClinicalTrials.gov NCT00764972

Prequels to Synthetic Biology: From Candidate Gene Identification and Validation to Enzyme Subcellular Localization in Plant and Yeast Cells

Natural compounds extracted from microorganisms or plants constitute an inexhaustible source of valuable molecules whose supply can be potentially challenged by limitations in biological sourcing. The recent progress in synthetic biology combined to the increasing access to extensive transcriptomics and genomics data now provide new alternatives to produce these molecules by transferring their whole biosynthetic pathway in heterologous production platforms such as yeasts or bacteria. While the generation of high titer producing strains remains per se an arduous field of investigation, elucidation of the biosynthetic pathways as well as characterization of their complex subcellular organization are essential prequels to the efficient development of such bioengineering approaches. Using examples from plants and yeasts as a framework, we describe potent methods to rationalize the study of partially characterized pathways, including the basics of computational applications to identify candidate genes in transcriptomics data and the validation of their function by an improved procedure of virus-induced gene silencing mediated by direct DNA transfer to get around possible resistance to Agrobacterium-delivery of viral vectors. To identify potential alterations of biosynthetic fluxes resulting from enzyme mislocalizations in reconstituted pathways, we also detail protocols aiming at characterizing subcellular localizations of protein in plant cells by expression of fluorescent protein fusions through biolistic-mediated transient transformation, and localization of transferred enzymes in yeast using similar fluorescence procedures. Albeit initially developed for the Madagascar periwinkle, these methods may be applied to other plant species or organisms in order to establish synthetic biology platform.

Strategies for the Optimization of Natural Leads to Anticancer Drugs or Drug Candidates

Natural products have made significant contribution to cancer chemotherapy over the past decades and remain an indispensable source of molecular and mechanistic diversity for anticancer drug discovery. More often than not, natural products may serve as leads for further drug development rather than as effective anticancer drugs by themselves. Generally, optimization of natural leads into anticancer drugs or drug candidates should not only address drug efficacy, but also improve absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles and chemical accessibility associated with the natural leads. Optimization strategies involve direct chemical manipulation of functional groups, structure-activity relationship directed optimization and pharmacophore-oriented molecular design based on the natural templates. Both fundamental medicinal chemistry principles (e.g., bioisosterism) and state-of-the-art computer-aided drug design techniques (e.g., structure-based design) can be applied to facilitate optimization efforts. In this review, the strategies to optimize natural leads to anticancer drugs or drug candidates are illustrated with examples and described according to their purposes. Furthermore, successful case studies on lead optimization of bioactive compounds performed in the Natural Products Research Laboratories at UNC are highlighted.

Capecitabine combined with docetaxel versus vinorelbine followed by capecitabine maintenance medication for first-line treatment of patients with advanced breast cancer: Phase 3 randomized trial

BACKGROUND

In this prospective study, progression-free survival (PFS) and the safety profiles of docetaxel/capecitabine (TX) and vinorelbine/capecitabine (NX) followed by capecitabine maintenance therapy were compared in patients with metastatic breast cancer.

METHODS

Patients with advanced metastatic breast cancer were randomly assigned to a TX group (n = 104) and an NX group (n = 102), both of which included capecitabine maintenance medication. The primary endpoint was progression-free survival (PFS).

RESULTS

The trial met its primary endpoint and was closed to accrual subsequent to interim analysis. Forty-eight patients in the TX group (46.2%) and 42 patients in the NX group (41.2%) received maintenance medication. The median PFS (8.4 vs 7.1 months; P = .0026; 95% confidence interval, 1.18-2.3; hazard ratio, 1.65), the response duration (7.8 vs 6.6 months; P = .0451), and the median overall survival (OS) (35.3 vs 19.8 months; P = .1349; 95% confidence interval, 0.88-2.47; hazard ratio, 1.48) in the TX group appeared to be longer compared with those in the NX group, although the difference did reach not statistical significance. Patients aged ≥40 years who were postmenopausal and presented with visceral metastases were more likely to benefit from the TX regimen in terms of PFS and OS, whereas positive hormone receptor and human epidermal growth factor receptor 2 status or a history of taxane treatments did not affect differences in PFS and OS between the TX and NX groups. Hand-foot syndrome occurred more frequently in the TX group than in the NX group (47% vs 16.7%; P < .0001), but the frequencies of other minor adverse effects were similar in both groups.

CONCLUSIONS

A TX regimen for advanced breast cancer followed by capecitabine maintenance medication led to longer PFS and response duration than an NX regimen, even for patients who had previously received taxane in (neo)adjuvant settings. Cancer 2015. © 2015 American Cancer Society. Cancer 2015;121:3435-43. © 2015 American Cancer Society.

Phase I and II Study of Gemcitabine and Vinorelbine in Heavily Pretreated Patients with Metastatic Breast Cancer and Review of the Literature

Background: Many phase II trials investigated the combination of Gemcitabine (G) and Vinorelbine (V) in the treatment of metastatic breast cancer (MBC) with variable outcomes. This study was conducted to explore whether this combination was effective and tolerable in MBC patients who were heavily pretreated with anthracyclines and taxanes. Methods: A phase I study was conducted first to establish the maximum tolerated dose (MTD) of the G and V combination in MBC patients. Then, a phase II study evaluated the response rates, the median time to progression (TTP), the overall survival (OS) as well as the toxicities resulting from this combination at the MTD. Results: Nine patients were enrolled in the phase I study. The MTD was identified as 700mg/m² of G on days 1 and 8 in combination with 15 mg/m² of V on days 2 and 9, every 21 days. Twenty-one of 25 patients involved in the phase II study were evaluable for response. No complete or partial responses were achieved; 6 patients (24.0%) had stable disease and 15 (60.0%) progressed. The median TTP was 2 months and the median OS 10 months. Grade 3/4 Neutropenia was the major hematologic toxicity, occurring in 52% of the cycles. The most common non-hematologic grade 3/4 toxicities were fatigue (18%), myalgias (17%) and arthralgias (13%). Conclusion: In heavily pretreated patients with MBC, the combination of G and V at the doses stated above was ineffective as it did not induce partial or complete responses. Other chemotherapy agents or combinations should be evaluated in future studies.

Phase I/II trial of vinorelbine and sorafenib in metastatic breast cancer

PURPOSE

We investigated the efficacy and toxicity of sorafenib, a multikinase inhibitor of vascular endothelial growth factor receptor tyrosine kinase, in combination with vinorelbine therapy in a phase I/II trial in patients with metastatic breast cancer.

PATIENTS AND METHODS

We enrolled 11 patients in the phase I portion to determine the maximum tolerated dose (MTD) of the combination, followed by 35 extra patients treated at the MTD in phase II. The median age of patients was 54 years old (range, 31-72 years old). Tumors were estrogen receptor and progesterone receptor (ER/PR) positive in 54% (22/54) of patients, and triple negative (ER(-), PR(-), HER2(-)) in 41% (17/54) of patients. Of all patients, 22% received sorafenib and vinorelbine as first-line therapy, 37% as second-line therapy, and 41% as third-line therapy.

RESULTS

In total, 41 patients were treated at the MTD (6 during phase I; 35 in phase II). The observed 44% 4-month progression-free survival rate was similar to the estimated historical rate of 43% with vinorelbine treatment. The combination was tolerated with expected toxicities. Patients treated at the MTD who had received prior bevacizumab treatment received a median of 1.5 cycles (range, 1-10 cycles) compared with a median of 5 cycles (range, 2-12 cycles) for patients without prior bevacizumab treatment.

CONCLUSION

Further evaluation of vinorelbine and sorafenib in bevacizumab-naive patients may be of interest if specific biomarkers guiding patient selection can be identified.

A synthetic podophyllotoxin derivative exerts anti-cancer effects by inducing mitotic arrest and pro-apoptotic ER stress in lung cancer preclinical models

Some potent chemotherapy drugs including tubulin-binding agents had been developed from nature plants, such as podophyllotoxin and paclitaxel. However, poor cytotoxic selectivity, serious side-effects, and limited effectiveness are still the major concerns in their therapeutic application. We developed a fully synthetic podophyllotoxin derivative named Ching001 and investigated its anti-tumor growth effects and mechanisms in lung cancer preclinical models. Ching001 showed a selective cytotoxicity to different lung cancer cell lines but not to normal lung cells. Ching001 inhibited the polymerization of microtubule resulting in mitotic arrest as evident by the accumulation of mitosis-related proteins, survivin and aurora B, thereby leading to DNA damage and apoptosis. Ching001 also activated pro-apoptotic ER stress signaling pathway. Intraperitoneal injection of 2 mg/kg Ching001 significantly inhibited the tumor growth of A549 xenograft, while injection of 0.2 mg/kg Ching001 decreased the lung colonization ability of A549 cells in experimental metastasis assay. These anti-tumor growth and lung colonization inhibition effects were stronger than those of paclitaxel treatment at the same dosage. The xenograft tumor tissue stains further confirmed that Ching001 induced mitosis arrest and tumor apoptosis. In addition, the hematology and biochemistry tests of blood samples as well as tissue examinations indicated that Ching001 treatment did not show apparent organ toxicities in tested animals. We provided preclinical evidence that novel synthetic microtubule inhibitor Ching001, which can trigger DNA damage and apoptosis by inducing mitotic arrest and ER stress, is a potential anti-cancer compound for further drug development.

A Novel Active Targeting Preparation, Vinorelbine Tartrate (VLBT) Encapsulated by Folate-Conjugated Bovine Serum Albumin (BSA) Nanoparticles: Preparation, Characterization and in Vitro Release Study

Vinorelbine tartrate (VLBT), as a kind of high hydrophilic and temperature-induced degradation drug, was prepared into nanoparticles by a desolvation procedure. Bovine serum albumin (BSA), as a drug carrier, was stabilized by chemical cross-linking with glutaraldehyde. Firstly, the optimization process of preparing VLBT-loaded BSA nanoparticles (VLBT-BSANPs) was accomplished using response surface methodology (RSM) by desolvation. Then VLBT-BSANPs were conjugated with folate, namely Fa-BSANPs-VLBT. Hence targeting drug carrier delivery system loading VLBT was produced. In this study, the characteristics of the nanoparticles, such as the amount of folate conjugation, surface morphology, surface chemistry, physical status of VLBT in Fa-BSANPs-VLBT, stability of Fa-BSANPs-VLBT with mannitol and in vitro drug release behavior were all investigated. The VLBT-BSANPs were obtained under optimum conditions, with a mean particle size (MPS) of 155.4 nm and a zeta potential (ZP) of −32.97 mV at a pH value of 5.4. Drug loading efficiency (DLE) and drug entrapment efficiency (DEE) of this obtained drug were approximately 45.6% and 90.6%, respectively.

Mitomycin C in combination with vinorelbine in anthracycline- and/or taxane-pretreated patients with metastatic breast cancer

BACKGROUND

Patients with metastatic breast cancer (MBC) with disease progression after anthracycline-and/or taxane-containing therapy need an effective drug regimen with low toxicity. Mitomycin C (MMC) and vinorelbine (VNR) are suitable candidates for combination therapy in the second-/third-line treatment of MBC. This study evaluates the safety and efficacy of an MMC/VNR combination chemotherapy in pretreated patients with MBC.

PATIENTS AND METHODS

In a phase II trial, patients with anthracycline-and/or taxane-pretreated MBC were treated with MMC 8 mg/m(2) (day 1) and VNR 25 mg/m(2) (days 1 and 8) every 4 weeks for up to 6 cycles or until disease progression.

RESULTS

In 51 eligible patients, 13 (26%) partial remissions (PRs), 20 (39%) stable diseases (SDs) and 18 (35%) progressive diseases (PDs) were observed. The median progression-free survival (PFS) was 5.0 months. The main grade 3/4 toxicities were neutrocytopenia (41%), granulocytopenia (37%), and thrombocytopenia (4%). Other hematological and non-hematological toxicities were mostly mild.

CONCLUSION

The combination of MMC and VNR is an effective and relatively well-tolerated regimen for anthracycline- and/or taxane-pretreated patients with MBC and is suitable for outpatient therapy.

The predictive value of epidermal growth factor receptor expression for sensitivity to vinorelbine in breast cancer

Breast cancer patients with positive epidermal growth factor receptor (EGFR) expression have significantly worse post-relapse prognosis than patients with negative EGFR expression. Vinorelbine (NVB) is usually reserved as a salvage therapy after anthracyclines and taxanes in patients with breast cancer. To see whether EGFR expression has a predictive value in NVB-mediated effect on human breast cancer cells, we examined 50 primary breast cancer samples. Of these, 42% were found to be NVB sensitive by ATP-tumour chemosensitivity assay. Sensitivity was correlated with EGFR expression level (p = 0.001). To dynamically examine EGFR's effect on NVB sensitivity in breast cancer cells, we used the real-time cell electronic sensing system with EGFR-positive and EGFR-negative breast cancer cell lines, MCF-7 and MDA-MB-435s, respectively. MCF-7 is NVB sensitive, while MDA-MB-435 is NVB resistant. NVB-induced cytotoxicity to MCF-7 can be partly reversed with inhibitory anti-EGFR antibody. NVB up-regulated EGFR expression in MCF-7 cells, which affects ERK1/2 phosphorylation. This cellular response mechanism may cause greater input to non-lethally damaged cells. These data suggest that EGFR expression can be used as a prognostic factor for breast cancer sensitivity to NVB, which could help identify appropriate treatments for breast cancer.

On the elucidation of the mechanism of Vinca alkaloid fluorination in superacidic medium

Detailed investigations on one of the key steps of the superacidic fluorination of Vinca alkaloids that is the origin of C20' activation are reported. While two different pathways can be envisioned for the emergence of the transient secondary carbocationic intermediate, isotopic labeling experiments unambiguously revealed the involvement of a 1,2-hydride shift mechanism.

Targeted photodynamic therapy of breast cancer cells using antibody-phthalocyanine-gold nanoparticle conjugates

A 4-component antibody-phthalocyanine-polyethylene glycol-gold nanoparticle conjugate is described for use as a potential drug for targeted photodynamic cancer therapy. Gold nanoparticles (4 nm) were stabilised with a self-assembled layer of a zinc-phthalocyanine derivative (photosensitiser) and a heterobifunctional polyethylene glycol. Anti-HER2 monoclonal antibodies were covalently bound to the nanoparticles via a terminal carboxy moiety on the polyethylene glycol. The nanoparticle conjugates were stable towards aggregation, and under irradiation with visible red light efficiently produced cytotoxic singlet oxygen. Cellular experiments demonstrated that the nanoparticle conjugates selectively target breast cancer cells that overexpress the HER2 epidermal growth factor cell surface receptor, and that they are effective photodynamic therapy agents.

Algorithms for the treatment of patients with metastatic breast cancer and prior exposure to taxanes and anthracyclines

At present, metastatic breast cancer (MBC) remains an incurable disease, with the goals of care aimed at maximizing the patient's duration and quality of life. Treatment options for a patient with MBC have become more efficacious and numerous. In addition to endocrine and chemotherapy agents, a number of targeted agents, including trastuzumab and bevacizumab, are available. The option to use novel agents combined with a multitude of standard chemotherapies has further enhanced the landscape of therapeutic options. As such, specific regimens must be evaluated within the framework of the individual patient, answering such questions as whether to treat with sequential single agents or combination regimens as well as which agents to use and in what sequence. The concept of personalized care is even more apparent in the setting of MBC, where the goal of palliation is intrinsically more nuanced than that of curative intent. This review will broadly assess the evidence for current treatment options with attention to varying clinical scenarios. Ultimately, delivering quality of care necessitates balancing an understanding of evidence-based data with sensitive attention to quality-of-life goals.

Pharmacogenetics in breast cancer: steps toward personalized medicine in breast cancer management

There is wide individual variability in the pharmacokinetics, pharmacodynamics, and tolerance to anticancer drugs within the same ethnic group and even greater variability among different ethnicities. Pharmacogenomics (PG) has the potential to provide personalized therapy based on individual genetic variability in an effort to maximize efficacy and reduce adverse effects. The benefits of PG include improved therapeutic index, improved dose regimen, and selection of optimal types of drug for an individual or set of individuals. Advanced or metastatic breast cancer is typically treated with single or multiple combinations of chemotherapy regimens including anthracyclines, taxanes, antimetabolites, alkylating agents, platinum drugs, vinca alkaloids, and others. In this review, the PG of breast cancer therapeutics, including tamoxifen, which is the most widely used therapeutic for the treatment of hormone-dependent breast cancer, is reviewed. The pharmacological activity of tamoxifen depends on its conversion by cytochrome P450 2D6 (CYP2D6) to its abundant active metabolite, endoxifen. Patients with reduced CYP2D6 activity, as a result of either their genotype or induction by the coadministration of other drugs that inhibit CYP2D6 function, produce little endoxifen and hence derive limited therapeutic benefit from tamoxifen; the same can be said about the different classes of therapeutics in breast cancer. PG studies of breast cancer therapeutics should provide patients with breast cancer with optimal and personalized therapy.

Capecitabine and Vinorelbine as an All-Oral Chemotherapy in HER2-Negative Locally Advanced and Metastatic Breast Cancer

BACKGROUND: The oral formulation of vinorelbine together with capecitabine allows for an all-oral combination chemotherapy which promises to raise quality of life of patients with advanced breast cancer. PATIENTS AND METHODS: Patients with HER2-negative, locally advanced, inoperable or metastatic breast cancer were included in this prospective observational trial (treatment schedule: capecitabine 500 mg/m2 twice daily, days 1-14; vinorelbine 60 mg/m2, days 1+8; repeated in 3-week cycles). RESULTS: All 32 patients (median age 50 years) were evaluable for toxicity, and 30 patients for response. Twentyfour patients received therapy as first-line treatment, and 8 patients as beyond first-line treatment. Median time to progression was 8 months, and median overall survival was 32 months. Complete response was observed in 1 patient (3%), partial response in 10 patients (33%), and disease stabilization for more than 6 months (SD > 6) in 10 patients (33%). This results in an overall response rate (ORR) of 37% and a clinical benefit rate (ORR + SD > 6) of 70%. The only grade 3/4 toxicities were neutropenia (19%) and hand-foot syndrome (9%). CONCLUSIONS: The all-oral combination of capecitabine/vinorelbine at this schedule appears to be an effective, well-tolerated regimen for treatment of advanced breast cancer, and offers a promising alternative to single-agent capecitabine and vinorelbine as well as intravenous polychemotherapy.

Trastuzumab with either docetaxel or vinorelbine as first-line treatment for patients with HER2-positive advanced breast cancer: a retrospective comparison

BACKGROUND

Combinations of trastuzumab with either docetaxel or vinorelbine are considered valuable treatment options for HER2-positive metastatic breast cancer patients. We performed a retrospective comparison of the clinical outcomes associated with either one of these combinations.

METHODS

From a multi-institutional database we retrieved 179 patients treated with either docetaxel or vinorelbine plus trastuzumab as first-line therapy for HER2-positive advanced breast cancer.

RESULTS

Docetaxel-trastuzumab was superior to vinorelbine-trastuzumab in terms of response rate (RR: 77 vs 57%, p = 0.01) and median overall survival (OS: 35 vs 23 months, p = 0.04), but not in median time to progression (TTP: 12 vs 10 months, p = 0.53). At multivariate analysis, type of treatment was not associated with TTP but was an independent predictor of OS, with a significant reduction in the risk of death in favor of docetaxel-trastuzumab (HR 0.474, 95% IC 0,303-0.742, p < 0.01).

CONCLUSION

Docetaxel or vinorelbine, when combined with trastuzumab, provide excellent rates of tumor control in patients with previously untreated HER2-positive advanced breast cancer. Docetaxel may offer some advantage in terms of response rate and resulted in a significantly prolonged overall survival, which, because of the retrospective design of our study, deserves further investigation in prospective trials.

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.

Vinorelbine as first-line or second-line therapy for advanced breast cancer: a Phase I-II trial by the Danish Breast Cancer Co-operative Group

INTRODUCTION

This study was conducted to establish the maximum tolerated dose (MTD) of intravenous vinorelbine and on the determined dose to assess efficacy and safety in patients with metastatic breast cancer previously treated with epirubicin.

PATIENTS AND METHODS

Patients had histologically proven breast cancer and had received a prior epirubicin based regimen either adjuvant or as first line therapy for advanced disease. Vinorelbine was administered intravenously day 1 and 8 in a 3 weeks' schedule. Subsequently 48 additional patients were treated at one dose-level below MTD.

RESULTS

Fifty-five patients were included in the dose-escalation study, which defined 40 mg/m(2) as the MTD. Neutropenia of short duration and autonomic neuropathy causing constipation were the most common dose-limiting toxicities. At the 35 mg/m(2) dose-level 60 patients were included in total. Seven (12%; 95% CI 6 to 22) had a partial response and 16 additional patients had stable disease. 27% had stable disease (clinical benefit rate 38%, 95% CI 27 to 51). The median overall survival was 45 weeks and 39% of the patients were alive after one year.

DISCUSSION

The clinical benefit rate was 38% with an overall intention to treat response rate of only 12%. The results were, however, achieved with low subjective burdens of toxicity.

Treatment options for breast cancer resistant to anthracycline and taxane

Breast cancer is the most common noncutaneous malignancy among every major ethnic group of women in the United States. Anthracyclines and taxanes are the most active and widely used chemotherapeutic agents for breast cancer, but the increased use of these agents at an early stage of disease often renders tumors resistant to these drugs by the time the disease recurs, thereby reducing the number of treatment options for metastatic disease. Moreover, even when these agents can be used in the metastatic setting, treatment failure occurs in most cases, and as a result the 5-year survival rates of patients with metastatic breast cancer are low. This outcome underscores the need for new, effective treatments of metastatic breast cancer and has led to investigation of novel ways to overcome the problem of drug resistance. This article reviews the current treatment options for breast cancer resistant to anthracycline and taxane and provides recommendations for disease management. Published sources for this review were found by searching PubMed (https://www.ncbi.nlm.nih.gov/pubmed) and congress Web sites.

Treatment options for breast cancer resistant to anthracycline and taxane

Breast cancer is the most common noncutaneous malignancy among every major ethnic group of women in the United States. Anthracyclines and taxanes are the most active and widely used chemotherapeutic agents for breast cancer, but the increased use of these agents at an early stage of disease often renders tumors resistant to these drugs by the time the disease recurs, thereby reducing the number of treatment options for metastatic disease. Moreover, even when these agents can be used in the metastatic setting, treatment failure occurs in most cases, and as a result the 5-year survival rates of patients with metastatic breast cancer are low. This outcome underscores the need for new, effective treatments of metastatic breast cancer and has led to investigation of novel ways to overcome the problem of drug resistance. This article reviews the current treatment options for breast cancer resistant to anthracycline and taxane and provides recommendations for disease management. Published sources for this review were found by searching PubMed (https://www.ncbi.nlm.nih.gov/pubmed) and congress Web sites.

Emerging drugs in metastatic breast cancer

BACKGROUND

Breast cancer is the most common cancer among women and comprises 26% of all cancers diagnosed in women in the United States. Among presenting patients, 3 - 6% already have metastatic disease, and 50 - 70% of the remaining patients develop systemic relapse. Recently many new drugs, particularly molecular targeted therapies, have been developed in the field.

OBJECTIVE

To review the current and emerging data on the treatment of metastatic breast cancer, with emphasis on novel therapies that show promise.

METHODS

PubMed and ASCO annual meeting abstracts were used for a literature search.

RESULTS/CONCLUSIONS

Despite improved response rates, conventional treatments still result only in transient remission in most cases. New therapeutic alternatives and new strategies to overcome drug resistance are needed to improve these results.

Pharmacokinetics and pharmacogenomics in breast cancer chemotherapy

Locally advanced or metastatic breast cancer is typically treated with chemotherapy. Multiple combinations of chemotherapy regimens are available, including anthracyclines, taxanes, antimetabolites, alkylating agents, platinum drugs and vinca alkaloids. This review discusses the pharmacokinetic and pharmacogenomic information available for commonly used breast cancer chemotherapy drugs. Pharmacogenomic associations for many drugs have yet to be identified or validated in breast cancer. Further work is needed to identify markers to screen breast cancer patients prior to therapy selection.

Tubulin-interactive natural products as anticancer agents

This review provides an overview of the discovery, structures, and biological activities of anticancer natural products that act by inhibiting or promoting the assembly of tubulin to microtubules. The emphasis is on providing recent information on those compounds in clinical use or in advanced clinical trials. The vinca alkaloids, the combretastatins, NPI-2358, the halichondrin B analogue eribulin, dolastatin 10, noscapine, hemiasterlin, and rhizoxin are discussed as tubulin polymerization inhibitors, while the taxanes and the epothilones are the major classes of tubulin polymerization promoters presented, with brief treatments of discodermolide, eleutherobin, and laulimalide. The challenges and future directions of tubulin-interactive natural products-based drug discovery programs are also discussed briefly.

Optimal treatment strategies in postmenopausal women with hormone-receptor-positive and HER2-negative metastatic breast cancer

Metastatic breast cancer (MBC) is unfortunately still considered incurable; treatment aims to prolong progression-free and overall survival, relieve disease symptoms, and maintain quality of life. Treatment can include endocrine therapy, radiotherapy, chemotherapy, bisphosphonates, and/or targeted therapy; which is used depends on the characteristics of the disease [e.g., hormone receptor status, disease site(s), and response to previous treatment] and the patient (age, comorbidity, and personal preferences). For most patients with hormone-receptor-positive tumors, the first choice of treatment is further endocrine therapy, but endocrine resistance is a common problem in advanced disease. Several novel anticancer agents have been developed with the aim of overcoming endocrine resistance, many of which target intracellular signaling pathways implicated in disease progression or resistance. Among these, inhibitors of growth factor receptor tyrosine kinases and of mammalian target of rapamycin have shown the most promise in clinical trials. Chemotherapy is the cornerstone of MBC treatment in most women. Important considerations when choosing chemotherapy include the choice of agents, and whether to use single-agent or combination therapy. Anthracyclines are one of the most active cytotoxic agents currently used for the treatment of breast cancer, and for many women, further anthracycline therapy at progression or relapse would be the preferred option. However, lifetime exposure to anthracyclines is limited by cumulative cardiotoxicity, which often prevents rechallenge in later lines of therapy. Newer anthracycline formulations have been developed with lower cardiotoxicity than the conventional anthracycline doxorubicin, but these agents still impair cardiac function, and have maximum recommended lifetime doses. Recently, the concomitant use of cardioprotective agents, such as dexrazoxane, has emerged as an effective approach to reducing the cardiotoxic effects of anthracyclines, thus permitting retreatment. Bisphosphonates, which are not associated with the acute toxicities of cytotoxic chemotherapy drugs, are the established standard of care for patients with metastatic bone disease, and have greatly improved outcomes over the last decade. The search is ongoing for novel agents that will, hopefully, bring a cure closer to reality.

Vinorelbine-based salvage therapy in HER2-positive metastatic breast cancer patients progressing during trastuzumab-containing regimens: a retrospective study

BACKGROUND

The vinka-alkaloyd vinorelbine is a potentially valuable treatment in patients with HER2-positive, trastuzumab-resistant advanced breast cancer. We sought to document the clinical activity of vinorelbine-based salvage treatments in this clinical setting.

METHODS

We analyzed a cohort of 424 consecutive women receiving trastuzumab-based therapy for HER2-positive advanced breast cancer. Of these, 299 were identified as progressing during the initial trastuzumab-based treatment, and 77 received vinorelbine-based therapy as first salvage treatment. Central review of pathological specimens revealed that 70 patients had HER2-amplification detected by FISH. For these patients we determined overall response rate (ORR = complete-CR + partial-PR) and clinical benefit (CB = CR+PR+ Stable disease lasting at least 6 months), time to progression (TTP) and overall survival (OS) from the initiation of vinorelbine-based salvage therapy.

RESULTS

In 60 patients who were evaluable for tumor response, ORR and CB rates were 28% (95% C.I. 18%-41%) and 50% (95% C.I. 38%-62%), respectively. Median follow-up from the initiation of salvage therapy was 15 months (range 1-63 months). Median TTP and OS were 7.1 months (95% C.I. 6.6-7.7 months) and 21 months (95% C.I. 14.3-27.7 months), respectively. No differences in clinical outcomes were observed according to whether vinorelbine was administered as a single agent or in combination with other cytostatics, or whether trastuzumab was stopped or continued beyond disease progression.

CONCLUSION

our findings suggests that vinorelbine-based combinations are active and should be further evaluated in studies conducted in trastuzumab-resistant patients, including those evaluating newer HER2-targeting agents.

Radioembolization in patients with hepatic metastases from breast cancer

PURPOSE

To determine the safety of and survival outcomes associated with single-session, whole-liver radioembolization with Yttrium-90 (90Y)-labelled resin microspheres in patients with nonresectable liver metastases from breast cancer that were refractory to other treatments.

MATERIALS AND METHODS

Thirty patients underwent radioembolization with 90Y-labeled resin microspheres infusion in a single-session, whole-liver treatment. All patients had undergone polychemotherapy regimens including at least anthracyclines and taxanes, hormonal therapy, and trastuzumab where applicable. Follow-up data were available for 23 patients. After treatment, the authors assessed tumor response with computed tomography and/or magnetic resonance imaging by using Response Evaluation Criteria in Solid Tumors (RECIST), laboratory and clinical toxicities, and survival.

RESULTS

A mean activity of 1.9 GBq of 90Y was delivered. Follow-up at a median of 4.2 months demonstrated partial response, stable disease, and progressive disease in 61%, 35%, and 4% of patients, respectively. With respect to tumor diameters, imaging revealed a maximum and minimum response of -64.8% to +23.6%, respectively (mean, 29.2%; median, 39.7%). The median follow-up time was 14.2 months. The median overall survival was 11.7 months. The median survival of responders and nonresponders was 23.6 and 5.7 months, respectively, and the median survival of patients with and patients without extrahepatic disease was 9.6 and 16 months. Clinically significant toxicities with the appearance of increasing transaminase level, increasing bilirubin level, nausea and vomiting, gastric ulcers, and ascites occurred in eight of 30 patients. One patient's death was attributed to treatment-related hepatic toxicity.

CONCLUSIONS

Single-session, whole-liver 90Y radioembolization can be performed with an acceptable toxicity profile in patients with liver metastases from breast cancer. Response to radioembolization in these patients is supported by the decrease in tumor size. Further investigation is warranted to prove survival benefit.

Comparative study of the radiosensitizing and cell cycle effects of vinflunine and vinorelbine, in vitro

Background

Vinca alkaloids are an important class of anticancer agents and semisynthetic vinca alkaloids are developed to improve the therapeutic index of this class of drugs. In the present study, a direct comparison was made between vinflunine and vinorelbine regarding their radiosensitising and cell cycle effects.

Methods

Four human tumour cell lines were tested under identical experimental conditions, using equitoxic concentrations of vinflunine and vinorelbine.

Results

Vinflunine and vinorelbine induced a comparable radiosensitising effect (p-value never below 0.01) when cells were incubated for 24 h immediately prior to radiation. Regarding the cell cycle effects, a statistically significant concentration-dependent G2/M block was seen after 24 h incubation with vinorelbine in all tested cell lines. Similar results, with small cell line-related differences, were observed with vinflunine.

Conclusion

The radiosensitising effects of both semisynthetic vinca alkaloids were comparable (not statistically different) and nearly always cell line-specific and concentration-dependent. The cell cycle effects could be related to the observed radiosensitising effects. Considering the more favourable toxicity profile of vinflunine, this agent might be more promising than vinorelbine for chemoradiation studies in the clinic.

Natural products as leads to anticancer drugs

Throughout history, natural products have afforded a rich source of compounds that have found many applications in the fields of medicine, pharmacy and biology. Within the sphere of cancer, a number of important new commercialised drugs have been obtained from natural sources, by structural modification of natural compounds, or by the synthesis of new compounds, designed following a natural compound as model. The search for improved cytotoxic agents continues to be an important line in the discovery of modern anticancer drugs. The huge structural diversity of natural compounds and their bioactivity potential have meant that several products isolated from plants, marine flora and microorganisms can serve as "lead" compounds for improvement of their therapeutic potential by molecular modification. Additionally, semisynthesis processes of new compounds, obtained by molecular modification of the functional groups of lead compounds, are able to generate structural analogues with greater pharmacological activity and with fewer side effects. These processes, complemented with high-throughput screening protocols, combinatorial chemistry, computational chemistry and bioinformatics are able to afford compounds that are far more efficient than those currently used in clinical practice. Combinatorial biosynthesis is also applied for the modification of natural microbial products. Likewise, advances in genomics and the advent of biotechnology have improved both the discovery and production of new natural compounds.

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

The aim of this randomized phase II study was to evaluate the anti-tumor activity and safety of capecitabine and vinorelbine in patients with metastatic breast cancer pretreated with taxanes and anthracyclines. We planned to randomize 72 patients to capecitabine 1250 mg/m(2) orally bid days 1-14 or vinorelbine 30 mg/m(2) i.v. days 1 and 8, both given every 3 weeks. The study was stopped due to poor accrual with 47 patients enrolled. Responses were seen in 2/23 patients treated with capecitabine (8.7%; 95% CI 1.1-29.0) and 3/24 patients treated with vinorelbine (12.5%; 95% CI 2.7-32.4). Median progression-free survival was 2.8 and 2.6 months, and median overall survival was 9.3 and 11.0 months, in the capecitabine and vinorelbine arms, respectively. There was more hematologic toxicity, neurotoxicity, and nausea/vomiting with vinorelbine and more diarrhea and hand-foot syndrome with capecitabine. The anti-tumor activity of capecitabine and vinorelbine seems to be comparable, but the toxicity profiles are different.

Oral vinorelbine: role in the management of metastatic breast cancer

The treatment of advanced breast cancer is continually evolving, with the aim of improving the quality and duration of remission and, in some instances, survival. In this setting, the importance of quality of life cannot be underestimated, and growing attention is being paid to treatment convenience and compliance. New anticancer agents have improved efficacy, but for many of them, toxicity often remains a problem. Vinorelbine seems to represent both an active and a well tolerated treatment for metastatic breast cancer. In particular, the oral formulation has similar efficacy to that of the injectable formulation and has demonstrated generally favourable tolerability, with a high degree of acceptance by both patients and physicians. The availability of this and other novel, well tolerated and effective treatments provides greater potential to tailor treatment to meet individual patient needs and, therefore, also provide the potential to improve patient outcomes. Preliminary data suggest that oral vinorelbine may permit continued, effective chemotherapy when further parenteral therapy with more intensive and more toxic agents is considered inappropriate. Early findings also suggest that oral vinorelbine, when administered together with another new oral agent, capecitabine, may be a valid choice in metastatic breast cancer treatment. Furthermore, vinorelbine plus the monoclonal antibody trastuzumab, with or without oral capecitabine, appears to be another regimen that may be worthy of additional study in patients with human epidermal growth factor-2 positive advanced breast cancer.

Results from an observational trial with oral vinorelbine and trastuzumab in advanced breast cancer

PURPOSE

We evaluated the efficacy and tolerability of oral vinorelbine plus trastuzumab (OV + T) in Her2 positive advanced breast cancer as first line chemotherapy or after progressing on earlier treatment.

PATIENTS AND METHODS

Thirty consecutive patients (median age: 59 years) were included. Patients received OV in a dose of 60 mg/m(2) on day 1 and 8, q=21, without dose escalation. Trastuzumab was administered every 3 weeks at a dose of 6 mg/kg bodyweight after a loading dose of 8 mg/kg. Response was evaluated every three cycles using UICC criteria. Time to progression (TTP) and overall survival (OS) were estimated using the Kaplan-Meier product limit method. A multivariate analysis was performed to evaluate factors potentially influencing response rate and TTP.

RESULTS

Median time of observation was 20 months. We observed a complete response in 18% of patients, partial remission in 50%, stable disease >or= 6 months in 21%, and progressive disease in 11%. TTP was median 9 months. OS was not reached. Response rate and TTP were influenced by line of treatment only. The main toxicities consisted of neutropenia and nausea.

CONCLUSIONS

OV + T appears to be an effective and safe treatment option in advanced breast cancer at the dose and schedule chosen.

Metastatic breast cancer: an updating

This article reports on recent advances on metastatic breast cancer. Detection, prognostic factors, predictors of response to therapy and therapy, with particular regard to targeted therapies, were examined.

DETECTION

Unlike current guidelines that yet do not routinely recommend intensive clinical-instrumental post-operative follow-up of breast cancer patients, relatively large data collected in the last decades have shown that an intensive post-operative follow-up with 'dynamic evaluation' of a suitable tumour marker panel precedes a few months as average the clinical and/or instrumental sign of a pending relapse in most relapsed patients and largely limits the use of the common instrumental examinations.

PROGNOSIS AND THERAPY PREDICTORS

Disease-free interval (DFI)<or=24 months, adjuvant chemotherapy, liver and distant soft tissue involvement or DFI>24 months and disease confined to bony skeleton are prognostic factors more often correlated with relatively poor or prolonged survival, respectively. Estrogen receptor (ER) expression in primary tumour and at the relapse correlates strongly with response to salvage hormone therapy and data from large trials showed that 38-59% of ER and/or PR+ post-menopausal patients had clinical benefit from first line tamoxifen or aromatase inhibitors. An inverse correlation of ER with epidermal growth factor receptor (EGFR) has been found. The co-expression of HER-2/neu and/or elevated serum HER-2/neu protein level were associated with a low rate and shorter duration of response of ER+ patients to first line hormone therapy. Accordingly, ER-EGFR- compared with ER-EGFR+ tumours are usually more responsive to endocrine therapy. High class III beta-tubulin expression or fall in insulin-like growth factor binding protein-3 (IGFBP-3) from baseline levels have been found to significantly predict resistance to chemotherapeutic agents.

THERAPY

Liposomes as carrier of doxorubicin (Caelix, Evacet, Myocet) is one approach to decrease the anthracycline-related cardiac toxicity. Weekly paclitaxel or docetaxel and oral formulation of vinorelbine and 5-fluorouracil (5-FU) (capecitabine) provide new effective and well tolerated options that reach greater dose intensity and cumulative dose than with the conventional schedules. As to the so called 'tailored' or targeted therapies, the more potent and highly selective third generation of aromatase inhibitors (letrozole, anastrozole, exemestane) targeting ER+ tumours by estrogen deprivation, challenge tamoxifen as current standard first line therapy in postmenopausals. One pilot study showed that stimulation of cellular immunity by the addition of beta-interferon-interleukin-2 sequence in patients on clinical benefit on first line tamoxifen significantly prolonged median overall survival (OS) and duration of response compared to that observed in similar patients only treated with tamoxifen. Trastuzumab, a humanised monoclonal antibody to extracellular domain of HER-2, plus conventional chemotherapy has become a standard of care for women with overexpressing HER-2 tumours. Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor (VEGF) that in refractory metastatic breast cancer doubled the response rate of capecitabine although it did not affect survival. Finally, the so called 'oligometastatic' and a few stage IV diseases are conditions amenable to be rendered with no evidence of disease (NED) after local surgery and/or radiation. In both, as well as in complete responders to chemotherapy, minimal residual disease (m.r.d.) likely continues to be present. Recent data suggest that 'biological' therapy (immunomodulators and/or retinoids with or without hormone therapy), might be suitable to be successfully tested in these patients as maintenance treatment given soon after local intervention or chemotherapy.