The potential of anti-vascular endothelial growth factor therapy in metastatic breast cancer: clinical experience with anti-angiogenic agents, focusing on bevacizumab

Upconversion and NIR-II luminescent rare earth nanoparticles combined with machine learning for cancer theranostics

How to develop contrast agents for cancer theranostics is a meaningful and challenging endeavor, and rare earth nanoparticles (RENPs) may provide a possible solution. In this study, we initially modified RENPs through the application of photodynamic agents (ZnPc) and targeted the bevacizumab antibody for cancer theranostics, which was aimed at improving the therapeutic targeting and efficacy. Subsequently, we amalgamated anthocyanin with the modified RENPs, creating a potential cancer diagnosis platform. When the spectral data were obtained from the composite of cells, the crucial information was extracted through a competitive adaptive reweighted sampling feature algorithm. Then, we employed a machine learning classification model and classified both the individual spectral data and fused spectral data to accurately predict distinctions between breast cancer and normal tissue. The results indicate that the amalgamation of fusion techniques with machine learning algorithms provides highly precise predictions for molecular-level breast cancer detection. Finally, in vitro and in vivo experiments were carried out to validate the near-infrared luminescence and therapeutic effectiveness of the modified nanomedicine. This research not only underscores the targeted effects of nanomedicine but also demonstrates the potent synergy between optical spectral technology and machine learning. This innovative approach offers a comprehensive strategy for the integrated treatment of breast cancer.

Immunoexpression of HER2 pathway related markers in HER2 invasive breast carcinomas treated with trastuzumab

PURPOSE

We evaluated the immunoexpression of potential markers involved in the HER2 pathway in invasive breast carcinoma with HER2 amplification treated with trastuzumab.

METHODS

Samples of ninety patients diagnosed and treated at two public Brazilian hospitals with overexpressed invasive carcinoma between 2009 and 2018 were included. Several markers (Bcl-2, CDK4, cyclin D1, EGFR, IGF1, IGF-1R, MDM2, MUC4, p16, p21, p27, p53, PTEN, RA, TNFα, and VEGF) were immune analyzed in the tumor by immunohistochemistry and then correlated with clinicopathological variables.

RESULTS

Tumor sample expression results determined potential markers of good prognosis with statistically significant values: cyclin D1 with a nuclear grade, and recurrence; IGF-1 with tumor size, and death; p16 with a response after treatment; PTEN with a response after treatment, and death. Markers of poor prognosis: p53 with histological, and nuclear grade; IGF-1R with a compromised lymph node. The treatment resistance rate after trastuzumab was 40%; the overall survival was 4.13 years (95% CI 5.1-12.5) and the disease-free survival was 3.6 years (95% CI 5.1-13.1).

CONCLUSIONS

The tumor samples profile demonstrated that cyclin D1, IGF-1, p16, and PTEN presented the potential for a good prognosis and p53 and IGF-1R for worse.

The role of bevacizumab for treatment-refractory intracranial meningiomas: a single institution's experience and a systematic review of the literature

INTRODUCTION

Meningiomas account for over 30% of all primary brain tumors. While surgery can be curative for these tumors, several factors may lead to a higher likelihood of recurrence. For recurrent meningiomas, bevacizumab may be considered as a therapeutic agent, but literature regarding its efficacy is sparse. Thus, we present a systematic review of the literature and case series of patients from our institution with treatment-refractory meningiomas who received bevacizumab.

METHODS

Patients at our institution who were diagnosed with recurrent meningioma between January 2000 and September 2020 and received bevacizumab monotherapy were included in this study. Bevacizumab duration and dosages were noted, as well as progression-free survival (PFS) after the first bevacizumab injection. A systematic review of the literature was also performed.

RESULTS

Twenty-three patients at our institution with a median age of 55 years at initial diagnosis qualified for this study. When bevacizumab was administered, 2 patients had WHO grade I meningiomas, 10 patients had WHO grade II meningiomas, and 11 patients had WHO grade III meningiomas. Median PFS after the first bevacizumab injection was 7 months. Progression-free survival rate at 6 months was 57%. Two patients stopped bevacizumab due to hypertension and aphasia. Systematic review of the literature showed limited ability for bevacizumab to control tumor growth.

CONCLUSION

Bevacizumab is administered to patients with treatment-refractory meningiomas and, though its effectiveness is limited, outperforms other systemic therapies reported in the literature. Further studies are required to identify a successful patient profile for utilization of bevacizumab.

Efficacy of Bevacizumab in High-Grade Meningiomas: A Retrospective Clinical Study

OBJECTIVE

We investigated the role of bevacizumab (BV) in high-grade meningiomas (HGMs) by retrospective analysis.

METHODS

We retrospectively analyzed the clinical data of 139 patients with HGMs. The chi-square test was used to compare progression-free survival (PFS) and overall survival (OS) between patients who received BV and those who did not. According to whether they received BV treatment, we divided the patients into the BV group and non-BV group, and the effect of BV on PFS and OS was compared. In addition, we compared Karnofsky performance status (KPS) and steroid doses between the BV and non-BV groups.

RESULTS

There were statistically differences in PFS and OS between the BV and non-BV groups at 12 and 36 months after surgery (P<0.05). However, there was no significant difference in PFS and OS between the two groups at 60 months postoperatively (P>0.05). Using survival curves drawn by the Kaplan Meier method, we found that the PFS and OS of the BV group were greater than those of the non-BV group, and the difference was statistically significant (P<0.05).

CONCLUSION

BV could improve PFS and OS at 12 and 36 months after surgery in patients with HGMs. In addition, BV was associated with lower preoperative steroid use.

Therapeutic Potential of Thymoquinone in Triple-Negative Breast Cancer Prevention and Progression through the Modulation of the Tumor Microenvironment

To date, the tumor microenvironment (TME) has gained considerable attention in various areas of cancer research due to its role in driving a loss of immune surveillance and enabling rapid advanced tumor development and progression. The TME plays an integral role in driving advanced aggressive breast cancers, including triple-negative breast cancer (TNBC), a pivotal mediator for tumor cells to communicate with the surrounding cells via lymphatic and circulatory systems. Furthermore, the TME plays a significant role in all steps and stages of carcinogenesis by promoting and stimulating uncontrolled cell proliferation and protecting tumor cells from the immune system. Various cellular components of the TME work together to drive cancer processes, some of which include tumor-associated adipocytes, fibroblasts, macrophages, and neutrophils which sustain perpetual amplification and release of pro-inflammatory molecules such as cytokines. Thymoquinone (TQ), a natural chemical component from black cumin seed, is widely used traditionally and now in clinical trials for the treatment/prevention of multiple types of cancer, showing a potential to mitigate components of TME at various stages by various pathways. In this review, we focus on the role of TME in TNBC cancer progression and the effect of TQ on the TME, emphasizing their anticipated role in the prevention and treatment of TNBC. It was concluded from this review that the multiple components of the TME serve as a critical part of TNBC tumor promotion and stimulation of uncontrolled cell proliferation. Meanwhile, TQ could be a crucial compound in the prevention and progression of TNBC therapy through the modulation of the TME.

Survival analysis of bevacizumab plus taxane treatment in luminal metastatic breast cancer

Background

The treatment of luminal metastatic breast cancer is based on endocrine therapy and chemotherapy treatment is limited to the progression of this treatment.

Materials & methods

We analyzed the efficacy of treatment with bevacizumab plus paclitaxel in 43 patients with hormone receptor-positive and HER2-negative metastatic breast cancer.

Discussion

Paclitaxel plus bevacizumab combination is a useful treatment in metastatic luminal breast cancer with an impressive overall survival of 31 months, similar to combination to endocrine therapy and targeted therapy in first line. In patients with hormone resistance, endocrine therapy saw worse results thus the taxol plus bevacizumab combination could be a better option. This combination does not influence the results of subsequent treatments; therefore, it could provide a good option for patients.

Efficacy of bevacizumab combined with chemotherapy in the treatment of HER2-negative metastatic breast cancer: a network meta-analysis

BACKGROUND

It is not known what combination of bevacizumab and chemotherapy agents is the best therapeutic regimen. Comparative study results among the efficacies of bevacizumab plus chemotherapy remain controversial in patients with HER2-negative metastatic breast cancer.

METHODS

We searched Pubmed, Embase, and Cochrane Library Central Resister of Controlled Trials through were July 2019 for randomized controlled trials that evaluated the efficacy of bevacizumab plus chemotherapy in HER2-negative metastatic breast cancer. Data on included study characteristics, outcomes, and risk of bias were abstracted by two reviewers.

RESULTS

A total of 16 RCT studies involving 5689 patients were included. The results showed that bevacizumab (Bev) - taxanes (Tax) - capecitabine (Cap) has highest-ranking and is probably more effective for prolonging progression-free survival (PFS) than Tax, Cap, Bev-Tax and Bev-Cap, which was no convincing differences among Bev-Cap-vinorelbine, Bev-Tax-everolimus, Bev-Tax-trebananib, Bev-exemestane, Bev-Cap-cyclophosphamide in Bev-containing regimens. For overall response rate (ORR), Bev-Tax-Cap is superior to Tax, Cap and Bev-Cap, while Bev-Tax-trebananib is superior to Cap. The cumulative probability ranking showed that Bev-Tax-Cap or Bev-Tax-trebananib may have best pathological response rate in HER2-negative metastatic breast cancer.

CONCLUSION

Our results provide moderate quality evidence that bevacizumab-taxanes-capecitabine maybe the most effective bevacizumab plus chemotherapy on PFS and ORR in HER2-negative metastatic breast cancer, however it should be also considered that bevacizumab may add toxicity to chemotherapy and whether improve overall survival (OS) or not.

Role of bevacizumab for treatment-refractory meningiomas: A systematic analysis and literature review

Background

Meningiomas are the most prevalent primary tumor of the central nervous system (CNS), and although the majority of these neoplasms are classified as benign, nearly one fourth of the lesions display an aggressive profile characterized by pleomorphic histology, high recurrence rates, and overall resistance to standard treatment. Despite the ubiquitous nature of these tumors, no adjuvant therapeutic regimen has been identified which effectively controls disease recurrence and progression after surgery and radiation, leading to a dismal prognosis in this patient population. The primary focus of this research study is, hence, to assess the recently emerging use of bevacizumab, an anti-angiogenic agent, in the treatment of meningiomas. This systematic literature review analyzes the efficacy and safety of therapeutic bevacizumab for treatment-refractory meningiomas.

Methods

A systematic PubMed search was conducted according to PRISMA guidelines to identify all relevant reports investigating the anti-angiogenic agent bevacizumab in the treatment of intracranial meningiomas. The reported parameters from pertinent retrospective reviews, prospective studies, and case studies were volumetric reduction, radiographic response, clinical stability, overall survival (OS), and progression free survival (PFS) measured at 6 and 12 months postinitiation of treatment. Complications were cataloged based on the range and severity of the therapy-related toxicities.

Results

A total of 11 articles, 5 retrospective series, 2 prospective trials, and 4 case reports, reporting on a total of 92 patients, were included in this review. The use of bevacizumab therapy for intracranial meningiomas demonstrated median overall PFS of 16.8 months (range: 6.5-22 months) and PFS-6 of 73% (range: 44%-93%).

Conclusions

Therapeutic bevacizumab, either alone or with combination chemotherapies, for select patient populations with recurrent or progressive meningiomas, offers a treatment option that confers improved overall progression-free survival. To assess OS parameters, larger randomized controlled trials assessing the use of anti-angiogenic agents for recurrent/progressive meningiomas are warranted.

Anti-angiogenic agents for the treatment of solid tumors: Potential pathways, therapy and current strategies - A review

Recent strategies for the treatment of cancer, other than just tumor cell killing have been under intensive development, such as anti-angiogenic therapeutic approach. Angiogenesis inhibition is an important strategy for the treatment of solid tumors, which basically depends on cutting off the blood supply to tumor micro-regions, resulting in pan-hypoxia and pan-necrosis within solid tumor tissues. The differential activation of angiogenesis between normal and tumor tissues makes this process an attractive strategic target for anti-tumor drug discovery. The principles of anti-angiogenic treatment for solid tumors were originally proposed in 1972, and ever since, it has become a putative target for therapies directed against solid tumors. In the early twenty first century, the FDA approved anti-angiogenic drugs, such as bevacizumab and sorafenib for the treatment of several solid tumors. Over the past two decades, researches have continued to improve the performance of anti-angiogenic drugs, describe their drug interaction potential, and uncover possible reasons for potential treatment resistance. Herein, we present an update to the pre-clinical and clinical situations of anti-angiogenic agents and discuss the most recent trends in this field.

Clinical results of randomized trials and 'real-world' data exploring the impact of Bevacizumab for breast cancer: opportunities for clinical practice and perspectives for research

INTRODUCTION

Angiogenesis plays a fundamental role in breast cancer (BC) growth, progression and metastatic spread. After the promising introduction of bevacizumab for the treatment of advanced BC, the initial enthusiasm decreased when the FDA withdrew its approval in 2011. Nevertheless, several clinical studies exploring the role of bevacizumab have been subsequently published. Areas covered: The aim of this study is to review the available clinical trials exploring the potential effectiveness of bevacizumab in BC, regardless of the disease setting. Expert opinion: Even if the evidence suggests that bevacizumab must be ruled out from the HER2-positive and adjuvant setting, bevacizumab's benefit remains uncertain in the neoadjuvant setting and in the advanced treatment of HER2-negative patients. In the first setting, the addition of bevacizumab to chemotherapy increased the pathological complete response (pCR) rate in most clinical trials. However, the current absence of evidence that pCR is a trial-level surrogate for survival requires waiting for long-term results. In the advanced setting, all trials showed a benefit in progression-free survival, but not in overall survival, highlighting an increase of adverse events. The lack of predictors of response represents the main unmet need in which future clinical research will undoubtedly invest.

The efficacy of bevacizumab plus paclitaxel as first-line treatment for HER2-negative metastatic breast cancer: a meta-analysis of randomized controlled trials

Although both bevacizumab and paclitaxel significantly improve the efficacy of chemotherapy for human epidermal growth factor receptor 2 (HER2)-negative patients with metastatic breast cancer (MBC), little have changed with overall survival rates when they have been used alone or combined with other chemotherapy. Thus, a meta-analysis was conducted to evaluate the efficacy of bevacizumab combined with paclitaxel in HER2-negative MBC patients. Pubmed and Embase were systematically reviewed for studies published up to September 2013 in which bevacizumab plus paclitaxel were compared with other chemotherapy. Primary outcomes comprised overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Eight phase II/III clinical trials met the inclusion criteria, with a total of 3,758 patients. The pooled results showed that combination of bevacizumab and paclitaxel significantly improved the PFS (HR = 0.63, 95% CI, 0.55-0.73, P = 0.011), ORR (RR = 1.28, 95% CI, 0.96-1.70, P = 0.0), but had no effect on OS (HR = 0.91, 95% CI, 0.81-1.01, P = 0.855). The meta-analysis confirms the benefits of bevacizumab-paclitaxel combination therapy in HER2 negative metastatic breast cancer, with an improvement in both progression free survival and objective response rate. However, no significant OS benefit was observed.

Identification and In Vitro Characterization of Phage-Displayed VHHs Targeting VEGF

Vascular endothelial growth factor (VEGF) is a potential target for cancer treatment because of its role in angiogenesis and its overexpression in most human cancers. Currently, anti-VEGF antibodies have been shown to be promising tools for therapeutic applications. However, large size, poor tumor penetration, immunogenicity, and production in cost- and labor-intensive conditions are major drawbacks of such agents. The antigen-binding regions of camelid single-chain antibodies (VHHs), due to their unique biophysical characteristics, offer an alternative to conventional antibodies for tumor-targeting purposes. The present study was undertaken to generate and characterize anti-VEGF VHHs from an immune VHH library using phage display. Four rounds of panning were performed, and selected VHHs were characterized using various immunological techniques. Assessment of the antigenic profile of VHHs was done using competition enzyme-linked immunosorbent assay (ELISA). Selected VHHs reacted strongly to VEGF in indirect ELISA and cross-reactivity ELISA tests. The binding affinity of three VHHs, ZFR-1, ZFR-2, and ZFR-5, ranged from 2.5 to 80 nM, and among them, ZFR-5, which was selected for proliferation assay, significantly inhibited the endothelial cell growth in a dose-dependent manner. Taken together, our results indicate that ZFR-5 and other VHHs may be promising tools in cancer research and treatment.

A randomized, phase II, three-arm study of two schedules of ixabepilone or paclitaxel plus bevacizumab as first-line therapy for metastatic breast cancer

The aim of this phase II trial was to estimate the objective response rate (ORR) of two different schedules of ixabepilone [weekly or every 3 weeks (Q3W)] combined with bevacizumab, relative to a reference arm of weekly paclitaxel and bevacizumab. Patients with human epidermal growth factor receptor 2-normal, chemotherapy-naïve metastatic breast cancer (MBC) were randomized 3:3:2 to ixabepilone 16 mg/m(2) weekly plus bevacizumab 10 mg/kg Q2W (Arm A: n = 46); ixabepilone 40 mg/m(2) Q3W (reduced to 32 mg/m(2) after four cycles of treatment) plus bevacizumab 15 mg/kg Q3W (Arm B: n = 45); or paclitaxel 90 mg/m(2) weekly plus bevacizumab 10 mg/kg intravenous infusion Q2W (Arm C: n = 32). Of 123 randomized patients, 122 were treated. All were followed for ≥19 months; 5 % of patients remained on study treatment at the time of this analysis. Grade 3 or 4 neutropenia was more common in Arm B (60 %) than Arms A (16 %) or C (22 %); other adverse events were similar. The investigator-assessed ORR was 48, 71, and 63 % for Arms A, B, and C, respectively. Median progression-free survival (randomized patients) was 9.6 months in Arm A, 11.9 months in Arm B, and 13.5 months in Arm C. In conclusion, ixabepilone Q3W plus bevacizumab has clinical activity as first-line therapy for MBC relative to paclitaxel plus bevacizumab, but with significantly greater risk of grade 3 or 4 neutropenia. In addition, these data suggest that weekly dosing of ixabepilone may be less active than Q3W dosing, but with less neutropenia.

Maintenance bevacizumab beyond first-line paclitaxel plus bevacizumab in patients with Her2-negative hormone receptor-positive metastatic breast cancer: efficacy in combination with hormonal therapy

Background

Data on efficacy of bevacizumab (B) beyond first-line taxane -including regimen (BT) as first-line treatment are lacking. Although preclinical results that anti-angiogenic agents combined with hormonal therapy (HT) could be active, no clinical data exist about combination of maintenance Bevacizumab (mBev) with HT.

Methods

Thirty-five patients who experienced a response after first-line BT, were given mBev at the dose of 15 mg/kg every 3 weeks. Among 30 pts with hormonal receptor-positive metastatic breast cancer (MBC), 20 (66.6%) received HT with mBev (mHTBev). Objective of the study was the outcome and safety of mBev and in two groups of patients receiving HT or not.

Results

Complete response and partial response was achieved/maintained in 4 (11.4%) and 13 (37.1%) patients, respectively (overall response rate: 48.5%). Clinical benefit was obtained on 23 patients (65.7%). Median of mBev PFS and clinical benefit were 6.8 months (95% CI: 0.8-12.7) and 17.1 months (95% CI :12.2-21.9), respectively. Median PFS of patients who received mHTBev was longer than mBev without HT (13 months and 4.1 months, respectively, p = 0.05). The most common severe toxicities were proteinuria (11.4%) and hypertension (8.5%). No additional toxicity was observed with HTBev.

Conclusion

Maintenance bevacizumab with or without anti-hormonal therapy in patients with hormone receptor positive breast cancer is tolerable and associated with long-term clinical outcome; these results encourage the strategy of prolonging bevacizumab until progression in combination with anti-hormonal agents.

Triple-negative breast cancer: multipronged approach, single-arm pilot phase II study

Anthracyclines (A) and taxanes (T) are standard first-line chemotherapy agents for patients with advanced breast cancer. Platinum analogues have also shown activity in the triple-negative breast cancer (TNBC) histology, but clinical data are limited. Here we report the long-term follow-up of a phase II study on TNBC treated with a combined modality therapy, including induction with AT, cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) with concurrent radiation therapy, and a dose-dense consolidation chemotherapy (HDCT) with carboplatin (CBDCA), ifosfamide (IFX), etoposide (VP-16). Patients' median age was 44 years, with 73% premenopausal. Epirubicin 75 mg/m(2) and docetaxel 75 mg/m(2) were administered to 70 patients with TNBC: as neoadjuvant and adjuvant therapy to 12 and 58 patients, respectively. Postoperative radiation therapy, 5000 cGy, was delivered, synchronous with triweekly CMF. After radiation therapy, two courses of HDCT with CBDCA, IFX, VP-16, were given, with hematological growth factors. After a median follow-up of 81 months, all patients were evaluable for toxicity and response. Most important toxicity were grade 3 skin reaction and grade 4 hematological in 3% and 31% of patients, respectively. Pathological complete response was observed in 25% of patients receiving preoperative chemotherapy. Treatment failures were as follows: eight visceral, four contralateral breast cancer, four locoregional, and one leukemia. Five-year progression-free survival and overall survival rate were 78% and 91%, respectively. Induction chemotherapy, followed by chemoradiation therapy and HDCT, provides a prolonged disease-free period and a significant increase in overall survival in TNBC, with an acceptable toxicity profile.

Vascular-endothelial-growth-factor (VEGF) targeting therapies for endocrine refractory or resistant metastatic breast cancer

BACKGROUND

Vascular-endothelial-growth-factor (VEGF) is a key mediator of angiogenesis. VEGF-targeting therapies have shown significant benefits and been successfully integrated in routine clinical practice for other types of cancer, such as metastatic colorectal cancer. By contrast, individual trial results in metastatic breast cancer (MBC) are highly variable and their value is controversial.

OBJECTIVES

To evaluate the benefits (in progression-free survival (PFS) and overall survival (OS)) and harms (toxicity) of VEGF-targeting therapies in patients with hormone-refractory or hormone-receptor negative metastatic breast cancer.

SEARCH METHODS

Searches of CENTRAL, MEDLINE, EMBASE, the Cochrane Breast Cancer Group's Specialised Register, registers of ongoing trials and proceedings of conferences were conducted in January and September 2011, starting in 2000. Reference lists were scanned and members of the Cochrane Breast Cancer Group, experts and manufacturers of relevant drug were contacted to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) to evaluate treatment benefit and non-randomised studies in the routine oncology practice setting to evaluate treatment harms.

DATA COLLECTION AND ANALYSIS

We performed data collection and analysis according to the published protocol. Individual patient data was sought but not provided. Therefore, the meta-analysis had to be based on published data. Summary statistics for the primary endpoint (PFS) were hazard ratios (HRs).

MAIN RESULTS

We identified seven RCTs, one register, and five ongoing trials from a total of 347 references. The published trials for VEGF-targeting drugs in MBC were limited to bevacizumab. Four trials, including a total of 2886 patients, were available for the comparison of first-line chemotherapy, with versus without bevacizumab. PFS (HR 0.67; 95% confidence interval (CI) 0.61 to 0.73) and response rate were significantly better for patients treated with bevacizumab, with moderate heterogeneity regarding the magnitude of the effect on PFS. For second-line chemotherapy, a smaller, but still significant benefit in terms of PFS could be demonstrated for patients treated with bevacizumab (HR 0.85; 95% CI 0.73 to 0.98), as well as a benefit in tumour response. However, OS did not differ significantly, neither in first- (HR 0.93; 95% CI 0.84 to 1.04), nor second-line therapy (HR 0.98; 95% CI 0.83 to 1.16). Quality of life (QoL) was evaluated in four trials but results were published for only two of these with no relevant impact. Subgroup analysis stated a significant greater benefit for patients with previous (taxane) chemotherapy and patients with hormone-receptor negative status. Regarding toxicity, data from RCTs and registry data were consistent and in line with the known toxicity profile of bevacizumab. While significantly higher rates of adverse events (AEs) grade III/IV (odds ratio (OR) 1.77; 95% CI 1.44 to 2.18) and serious adverse events (SAEs) (OR 1.41; 95% CI 1.13 to 1.75) were observed in patients treated with bevacizumab, rates of treatment-related deaths were lower in patients treated with bevacizumab (OR 0.60; 95% CI 0.36 to 0.99).

AUTHORS' CONCLUSIONS

The overall patient benefit from adding bevacizumab to first- and second-line chemotherapy in metastatic breast cancer can at best be considered as modest. It is dependent on the type of chemotherapy used and limited to a prolongation of PFS and response rates in both first- and second-line therapy, both surrogate parameters. In contrast, bevacizumab has no significant impact on the patient-related secondary outcomes of OS or QoL, which indicate a direct patient benefit. For this reason, the clinical value of bevacizumab for metastatic breast cancer remains controversial.

Phase I trial of combretastatin A4 phosphate (CA4P) in combination with bevacizumab in patients with advanced cancer

PURPOSE

The vascular disrupting agent (VDA) combretastatin A4 phosphate (CA4P) induces significant tumor necrosis as a single agent. Preclinical models have shown that the addition of an anti-VEGF antibody to a VDA attenuates the revascularization of the surviving tumor rim and thus significantly increases antitumor activity.

EXPERIMENTAL DESIGN

Patients with advanced solid malignancies received CA4P at 45, 54, or 63 mg/m(2) on day 1, day 8, and then every 14 days. Bevacizumab 10 mg/kg was given on day 8 and at subsequent cycles four hours after CA4P. Functional imaging with dynamic contrast enhanced-MRI (DCE-MRI) was conducted at baseline, after CA4P alone, and after cycle 1 CA4P + bevacizumab.

RESULTS

A total of 63 mg/m(2) CA4P + 10 mg/kg bevacizumab q14 is the recommended phase II dose. A total of 15 patients were enrolled. Dose-limiting toxicities were grade III asymptomatic atrial fibrillation and grade IV liver hemorrhage in a patient with a history of hemorrhage. Most common toxicities were hypertension, headache, lymphopenia, pruritus, and pyrexia. Asymptomatic electrocardiographic changes were seen in five patients. Nine of 14 patients experienced disease stabilization. A patient with ovarian cancer had a CA125 response lasting for more than a year. DCE-MRI showed statistically significant reductions in tumor perfusion/vascular permeability, which reversed after CA4P alone but which were sustained following bevacizumab. Circulating CD34(+) and CD133(+) bone marrow progenitors increased following CA4P as did VEGF and granulocyte colony-stimulating factor levels.

CONCLUSIONS

CA4P in combination with bevacizumab appears safe and well tolerated in this dosing schedule. CA4P induced profound vascular changes, which were maintained by the presence of bevacizumab.

A multicenter phase II study of TSU-68, a novel oral multiple tyrosine kinase inhibitor, in patients with metastatic breast cancer progressing despite prior treatment with an anthracycline-containing regimen and taxane

PURPOSE

TSU-68 is a novel multiple tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor and fibroblast growth factor receptor. TSU-68 demonstrated a strong anti-tumor effect against established human breast cancer xenografts in nude mice without apparent toxicity. We conducted a phase II study to evaluate the efficacy and safety of TSU-68 monotherapy in patients with metastatic breast cancer progressing despite prior treatment with an anthracycline-containing regimen and taxane.

METHODS

TSU-68 was administered daily at a dose of 400 mg twice a day after meals in 20 patients. The primary endpoint was objective overall response rate according to the Response Evaluation Criteria in Solid Tumors guideline version 1.0. Secondary endpoints included clinical benefit rate (complete response, partial response and stable disease lasting for at least 24 weeks), exploratory assessments of change in mRNA levels of biological markers associated with angiogenesis in tumor tissue at the end of Cycle 1, and safety of TSU-68.

RESULTS

Twenty patients were enrolled into the study from October 2002 through April 2003. TSU-68 monotherapy produced objective overall response in none of the patients; however, clinical benefit was seen in 5 % of the patients. The mRNA levels of CD31, Flt-1 and Flk-1/KDR showed a decreasing trend in all 4 patients who provided additional written informed consent for collection of tumor tissue. However, no significant difference was observed in the change in mRNA level due to the small sample size. The most common adverse drug reaction (ADR) was tumor pain (60 %); hematological ADRs rarely occurred, and they were mild in severity. Only one patient experienced grade 2 rash and no patient experienced hypertension. No patients experienced a grade 4 ADR and no episode of death related to the study treatment occurred in the 20 patients.

CONCLUSIONS

TSU-68 monotherapy produced clinical benefit in only 5 % of the patients and did not produce objective overall response; however, the treatment was well tolerated. Further evaluation of the efficacy of TSU-68 will be worthwhile because the mRNA levels of CD31, Flt-1 and Flk-1/KDR decreased in 4 patients.

Bevacizumab based chemotherapy in first line treatment of HER2 negative metastatic breast cancer: results of a Moroccan observational institutional study

BACKGROUND

In metastatic breast cancer (MBC) patients, randomised controlled trials evaluated Bevacizumab as first-line treatment showed improvements in tumour response rate and progression-free survival (PFS) when added to chemotherapy. In Morocco, we conducted an observational study to investigate clinical features, treatment and prognosis associated with Bevacizumab based chemotherapy in first line treatment of HER2 negative MBC.

FINDINGS

Nineteen women were included in this study. All these women were diagnosed as having HER2 negative MBC at the National Institute of Oncology in Rabat, Morocco, between January 2009 and December 2010. The median age of patients was 48.1 years. Four patients (21%) had metastatic disease at diagnosis and 15 patients (79%) had received treatment for first metastatic relapse. Bone, liver and lung were the most frequent metastasis sites. Patients were followed up until April 2011. Most patients had objective response; 15.8% of complete response, 47.3% of partial response and 21.1% of stabilisation. Median PFS was estimated at 11.5 months. Sub-groups analysis showed a statistically significant difference (Log-rank test: p = 0.01); PFS for patients receiving Bevacizumab - weekly Paclitaxel was estimated at 18.1 months, and at 9.1 months for patients receiving the combination Bevacizumab - Docetaxel. This benefit in PFS was associated with an acceptable safety profile.

CONCLUSION

As demonstrated in this study, Bevacizumab based chemotherapy in first line treatment of HER2 negative MBC in Morocco and particularly in combination with Taxanes extends PFS, as confirmed in a recent meta-analysis of 3 randomised controlled phase III studies.

A multicenter phase II study of TSU-68, an oral multiple tyrosine kinase inhibitor, in combination with docetaxel in metastatic breast cancer patients with anthracycline resistance

BACKGROUND

TSU-68 is a novel multiple tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor, and fibroblast growth factor receptor. This open-label, non-comparative, multicenter phase II study evaluated TSU-68 in combination with docetaxel in patients with metastatic breast cancer that had relapsed within 1 year despite prior treatment with an anthracycline-containing regimen.

METHODS

TSU-68 was orally administered on days 1-21, and docetaxel was intravenously delivered on day 1. The regimen was repeated every 21 days. Primary endpoint was objective response rate according to the RECIST guidelines version 1.0.

RESULTS

TSU-68 in combination with docetaxel produced objective responses in 21.1% and clinical benefits in 42.1% of the patients, respectively (1 complete response, 3 partial response, and 4 stable disease for at least 24 weeks, n = 19). Median time to progression was 148 days, and median overall survival was 579 days. The common adverse drug reactions were leukopenia, neutropenia, nail disorder, malaise, dysgeusia, alopecia, and edema.

CONCLUSIONS

TSU-68 in combination with docetaxel showed a promising antitumor response with manageable toxicity in patients with anthracycline-resistant metastatic breast cancer. Further studies are warranted in a different population of breast cancer or other solid cancers.

Bevacizumab: a review of its use in combination with paclitaxel or capecitabine as first-line therapy for HER2-negative metastatic breast cancer

Bevacizumab (Avastin™) is a humanized monoclonal antibody directed against vascular endothelial growth factor. In patients with human epidermal growth factor receptor type 2 (HER2)-negative metastatic breast cancer, bevacizumab is indicated as first-line therapy in combination with paclitaxel, or in combination with capecitabine when treatment with other chemotherapy options, including taxanes or anthracyclines, is not considered appropriate. This article reviews the efficacy and tolerability of these combination therapies in the first-line treatment of patients with metastatic breast cancer, and summarizes the pharmacological properties of bevacizumab. In randomized, controlled, phase III trials in patients with predominantly HER2-negative metastatic or locally recurrent breast cancer, the addition of bevacizumab to paclitaxel or capecitabine significantly prolonged progression-free survival (PFS; investigator assessment) by a median of 5.9 and 2.9 months, respectively, relative to paclitaxel or capecitabine alone. It also significantly increased the objective response rate, but not overall survival. Independent reviews of data supported the results of the primary analyses of investigator-assessed PFS. However, as the efficacy of bevacizumab in combination with capecitabine appears to be less than that of other available options, it should be used only if treatment with other chemotherapy options are not considered appropriate. The addition of bevacizumab to paclitaxel had no significant adverse effects on health-related quality of life. Efficacy data from two routine clinical practice studies were generally consistent with those from the phase III trials. Bevacizumab had generally acceptable tolerability when administered in combination with paclitaxel or capecitabine as first-line therapy in these studies, and adverse events were consistent with the known tolerability profiles of the individual agents. The most common adverse events associated with bevacizumab combination therapy in phase III trials were sensory neuropathy and grade ≥3 hypertension, occurring more frequently with combination therapy than with chemotherapy alone. Potentially life-threatening events, such as venous thromboembolism, gastrointestinal perforation, arterial thromboembolism, haemorrhage and left ventricular dysfunction, occurred in ≤5% of patients receiving combination therapy in these trials. In conclusion, bevacizumab administered in combination with paclitaxel, or in combination with capecitabine if other chemotherapy regimens are not appropriate, may be considered as an option for the first-line treatment of patients with HER2-negative metastatic breast cancer.

Effects of anti-VEGF on pharmacokinetics, biodistribution, and tumor penetration of trastuzumab in a preclinical breast cancer model

Both human epidermal growth factor receptor 2 (HER-2/neu) and VEGF overexpression correlate with aggressive phenotypes and decreased survival among breast cancer patients. Concordantly, the combination of trastuzumab (anti-HER2) with bevacizumab (anti-VEGF) has shown promising results in preclinical xenograft studies and in clinical trials. However, despite the known antiangiogenic mechanism of anti-VEGF antibodies, relatively little is known about their effects on the pharmacokinetics and tissue distribution of other antibodies. This study aimed to measure the disposition properties, with a particular emphasis on tumor uptake, of trastuzumab in the presence or absence of anti-VEGF. Radiolabeled trastuzumab was administered alone or in combination with an anti-VEGF antibody to mice bearing HER2-expressing KPL-4 breast cancer xenografts. Biodistribution, autoradiography, and single-photon emission computed tomography-X-ray computed tomography imaging all showed that anti-VEGF administration reduced accumulation of trastuzumab in tumors despite comparable blood exposures and similar distributions in most other tissues. A similar trend was also observed for an isotype-matched IgG with no affinity for HER2, showing reduced vascular permeability to macromolecules. Reduced tumor blood flow (P < 0.05) was observed following anti-VEGF treatment, with no significant differences in the other physiologic parameters measured despite immunohistochemical evidence of reduced vascular density. In conclusion, anti-VEGF preadministration decreased tumor uptake of trastuzumab, and this phenomenon was mechanistically attributed to reduced vascular permeability and blood perfusion. These findings may ultimately help inform dosing strategies to achieve improved clinical outcomes.

Combined-modality radioimmunotherapy: synergistic effect of paclitaxel and additive effect of bevacizumab

INTRODUCTION

This study was undertaken to investigate the effect of paclitaxel and bevacizumab on the therapeutic efficacy of (90)Y-labeled B3 monoclonal antibody, directed against Le(y) antigen, for the treatment of Le(y)-positive A431 tumors implanted subcutaneously in the right hind flank of nude mice.

METHODS

When the tumor size reached ~200 mm(3), the mice received a single dose of intravenous (iv) (90)Y-labeled B3 (60 μCi/150 μg or 100 μCi/150 μg B3), intraperitoneal paclitaxel (40 mg/kg) or iv bevacizumab (5 mg/kg) for monotherapy. To investigate the effect of combined therapies on survival, the mice were treated with two or three agents in the following combinations: (90)Y-B3 on day 0 and paclitaxel on day 1; bevacizumab on -1 day and (90)Y-B3 on day 0; bevacizumab on -1 day and paclitaxel on day 1; bevacizumab, (90)Y-B3 and paclitaxel each at 1-day intervals. The mice with no treatment were used as a control. The tumor volume at 1000 mm(3) was used as a surrogate end point of survival.

RESULTS

Compared to control animals, paclitaxel delayed tumor growth with a significantly longer median survival time (P<.001), whereas bevacizumab alone showed a less pronounced effect on a median survival time (P=.18). (90)Y-B3 increased the median survival time in a dose-dependent manner (P<.05). The combined therapy of bevacizumab with paclitaxel produced a trend toward an increase of the median survival time compared to paclitaxel alone (P=.06), whereas bevacizumab combined with (90)Y-B3 showed a statistically insignificant increase in the median survival time compared to (90)Y-B3 alone (P=.25). The tumor sizes of all animals in these groups reached the surrogate end point of survival by day 35. In contrast, the combined therapy involving (90)Y-B3 with paclitaxel showed a striking synergistic effect in shrinking tumors and prolonging the survival time (P<.001); on day 120, three of nine mice (33%) and six of six mice (100%) were alive without tumor when treated with 60 μCi (90)Y-B3 and 100 μCi (90)Y-B3, respectively. The addition of bevacizumab treatment 1 day before the combined therapy of 60 μCi (90)Y-B3 with paclitaxel did not produce a statistically significant increase in survival when compared to the (90)Y-B3 with paclitaxel (P>.10). Fluorescence microscopy analysis indicated that paclitaxel increased, whereas bevacizumab decreased, the accumulation and penetration of Alexa Fluor 647-B3 into tumor microenvironment compared to the control (P<.05).

CONCLUSION

Our findings on the paclitaxel effect support a hypothesis that the increased tumor accumulation and penetration of (90)Y-B3 as well as the high radiosensitization of tumor cells by paclitaxel may be the major factors responsible for the synergistic effect of the combined therapy involving (90)Y-B3 with paclitaxel.

Differential microstructure and physiology of brain and bone metastases in a rat breast cancer model by diffusion and dynamic contrast enhanced MRI

Pharmacological approaches to treat breast cancer metastases in the brain have been met with limited success. In part, the impermeability of the blood brain barrier (BBB) has hindered delivery of chemotherapeutic agents to metastatic tumors in the brain. BBB-permeable chemotherapeutic drugs are being developed, and noninvasively assessing the efficacy of these agents will be important in both preclinical and clinical settings. In this regard, dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) are magnetic resonance imaging (MRI) techniques to monitor tumor vascular permeability and cellularity, respectively. In a rat model of metastatic breast cancer, we demonstrate that brain and bone metastases develop with distinct physiological characteristics as measured with MRI. Specifically, brain metastases have limited permeability of the BBB as assessed with DCE and an increased apparent diffusion coefficient (ADC) measured with DWI compared to the surrounding brain. Microscopically, brain metastases were highly infiltrative, grew through vessel co-option, and caused extensive edema and injury to the surrounding neurons and their dendrites. By comparison, metastases situated in the leptomenengies or in the bone had high vascular permeability and significantly lower ADC values suggestive of hypercellularity. On histological examination, tumors in the bone and leptomenengies were solid masses with distinct tumor margins. The different characteristics of these tissue sites highlight the influence of the microenvironment on metastatic tumor growth. In light of these results, the suitability of DWI and DCE to evaluate the response of chemotherapeutic and anti-angiogenic agents used to treat co-opted brain metastases, respectively, remains a formidable challenge.

Upregulated expression of indoleamine 2, 3-dioxygenase in primary breast cancer correlates with increase of infiltrated regulatory T cells in situ and lymph node metastasis

IDO has been reported to induce immunotolerance and promote metastasis in solid malignancy, but the mechanisms involved were not fully understood. In this study, the expression of IDO in primary breast cancer was examined and the correlation between the expression levels of IDO and the densities of Foxp3⁺ Tregs in situ was studied. The IDO stably-expressing CHO cells(IDO/CHO) were generated to evaluate the induction of Foxp3⁺ Tregs after coculturing with CD3⁺ T cells in vitro. The IDO expression in cancer was higher than that in benign diseases both at RNA and protein levels. The IDO expression was significantly upregulated in tumors of more advanced stages and with more extensive lymph node metastasis, and displayed positive linear correlation with the density of Foxp3⁺ Tregs. We further demonstrated that CD4⁺CD25⁺CD127⁻ Tregs could be amplified by coculturing CD3⁺ T cells with IDO/CHO cells in vitro which displayed increasing Foxp3 expression both at mRNA and protein levels. Our results implied that up-regulation of IDO in primary breast cancer may inhibit local immune surveillance and promote metastasis by favoring development and infiltration of Foxp3⁺ Tregs in the tumor microenvironment.

Management options in triple-negative breast cancer

Notorious for its poor prognosis and aggressive nature, triple-negative breast cancer (TNBC) is a heterogeneous disease entity. The nature of its biological specificity, which is similar to basal-like cancers, tumors arising in BRCA1 mutation carriers, and claudin-low cancers, is currently being explored in hopes of finding the targets for novel biologics and chemotherapeutic agents. In this review, we aim to give a broad overview of the disease's nomenclature and epidemiology, as well as the basic mechanisms of emerging targeted therapies and their performance in clinical trials to date.

Immunohistochemical study of the angiogenetic network of VEGF, HIF1α, VEGFR-2 and endothelial nitric oxide synthase (eNOS) in human breast cancer

BACKGROUND

The role of Nitric Oxide (NO) in angiogenesis has not been fully clarified yet. A dual role for NO, either inductive or inhibitory, has been proposed on the basis of different effects that high or low concentrations of NO may exert on the angiogenic process. Additionally, it has been referred that NO may induce VEGF production, while VEGF may induce NO production via up-regulation of the endothelial nitric oxide synthase (eNOS), the two pathways being reverse. The aim of the current study was to investigate the expression of key molecules involved in these opposite pathways in primary breast cancer.

METHODS

Representative tumor samples from 242 patients with early-stage breast cancer (invasive ductal breast carcinomas) were investigated for the expression of VEGF, VEGFR-2, HIF1α, iNOS, and eNOS using immunohistochemistry.

RESULTS

Endothelial NOS was found in 159 cases, VEGF in 131 cases, HIF-1α in 139 cases, VEGFR2 in 185 cases and inducible NOS (iNOS) in 22 cases. There was a significant correlation between the expression of VEGF and VEGFR-2, eNOS and VEGF, eNOS and VEGFR-2, eNOS and HIF1α. No statistically significant correlation was found between iNOS and the rest of the studied molecules.

CONCLUSIONS

In breast cancer cases, the major molecules regulating NO and VEGF production can be co-expressed in the individual carcinomas implying a possibility for the relevant pathways to be active; however appropriate functional experiments remain to be conducted to prove such a hypothesis.

Multitargeted receptor tyrosine kinase inhibition: an antiangiogenic strategy in non-small cell lung cancer

In the United States, the leading cause of cancer-related deaths is lung cancer, of which more than 85% of cases are categorized as non-small cell lung cancer. The process of angiogenesis, which results in the formation of vasculature, is a complex and coordinated process that is required for cancer growth and metastasis. Pathways that promote angiogenesis have been targeted as a therapeutic approach in multiple types of cancer, including non-small cell lung cancer. Of these, the vascular endothelial growth factor pathway has been the most well studied, but more recently, the platelet-derived growth factor and fibroblast growth factor pathways have been identified as regulators of angiogenesis and potential mediators of resistance to vascular endothelial growth factor inhibition. Bevacizumab, a monoclonal antibody that binds to vascular endothelial growth factor, is currently the only antiangiogenic drug approved for the treatment of non-small cell lung cancer; however, several tyrosine kinase inhibitors that target vascular endothelial growth factor receptors as well as platelet-derived growth factor receptors and/or fibroblast growth factor receptors are being developed. This article reviews the role of the fibroblast growth factor and platelet-derived growth factor pathways in angiogenesis and provides a summary of dual (e.g., sorafenib, sunitinib) and triple (e.g., BIBF 1120, pazopanib) antiangiogenic tyrosine kinase inhibitors currently in development for the treatment of non-small cell lung cancer.

Noncardiac vascular toxicities of vascular endothelial growth factor inhibitors in advanced cancer: a review

The introduction of molecularly targeted anticancer therapies has brought the promise of longer survival times for select patients with cancers previously considered untreatable. However, it has also brought new toxicities that require understanding and management, sometimes for long periods of time. Vascular endothelial growth factor inhibitors are associated with a broad range of adverse effects, with vascular toxicity being particularly serious. This review focuses on the current understanding of the pathophysiology and mechanisms of macrovascular toxicities (hypertension, hemorrhage, and thromboembolism), their incidence and severity, the current clinical management, and implications in the advanced cancer setting. Movement of these agents into the early disease setting will alter the impact of these toxicities. Search Strategy and Selection Criteria. Information for this review was collected by searching PubMed/Medline and American Society of Clinical Oncology abstract databases. The medical subject heading terms used included toxicity, hypertension, thromboembolism, hemorrhage, intestinal perforation, risk factors, pharmacokinetics, and metabolism, combined with free text search terms including, but not limited to, VEGF inhibitor*, bevacizumab, sunitinib, and sorafenib. Articles published in English before March 2010 were included, in addition to information from case reports and pharmaceutical agent package inserts.

Sex steroids and breast cancer metastasis

Sex steroids, particularly estrogen and progesterone, promote normal breast tissue growth and differentiation. Prolonged exposure of estrogen and/or progesterone is considered a risk factor for breast cancer carcinogenesis, and the effects of sex steroids on breast cancer metastasis are controversial. Emerging evidence indicates that sex steroids regulate breast cancer metastatic processes via nongenomic and genomic mechanisms. Through the regulation of actin-binding proteins estrogen and progesterone rapidly provoke actin cytoskeleton reorganization in breast cancer cells, leading to formation of membrane structures facilitating breast cancer cell migration and invasion. In addition, steroid receptors interact and trans-activate receptor tyrosine kinases (including epidermal growth factor receptor and insulin-like growth factor receptor), resulting in growth factor-like effects that promote cancer cell invasive behavior. Moreover, sex steroids regulate the expression of metastasis-associated molecules, such as E-cadherin, matrix metalloproteinases, growth factors, chemokines and their receptors, leading to epithelial-to-mesenchymal-like transition. However, there is also evidence that sex steroids and their receptors protect against breast cancer cell invasiveness through distinct mechanisms. Here, we present an overview of the currently identified actions of sex steroids on breast cancer metastasis and their potential clinical implications.

Heterogeneity of vascular and progenitor cell compartments in tumours from MMTV-PyVmT transgenic mice during mammary cancer progression

Transgenic mice are important tools for our study of breast cancer pathobiology. In order to evaluate changes in cell phenotype with breast cancer progression, we examined vascular and progenitor cell characteristics in tumours derived from MMTV-PyVmT mice. We performed dual-immunofluorescence staining for Tie2, pTie2Y1100, VEGFR2 and PDGFR-β and the pan-endothelial marker PECAM-1 (CD31) in 39 tumours from MMTV-PyVmT transgenic mice grouped by nuclear grade and tumour morphology. Immunohistochemical staining for Aldh1a1 was performed in MMTV-PyVmT-derived tumours and in non-transgenic mouse mammary glands. Tumour blood vessels were heterogeneous in all samples analysed, with the proportion of Tie2-, pTie2 (Y1100)-, VEGFR2- and PDGFR-β-positive tumour blood vessels ranging from 18-98%, 7-40%, 19-86% and 16-94% respectively. We observed a statistically significant difference in vascular pTie2Y1100 levels between low-nuclear-grade tumours and intermediate-/high-nuclear-grade tumours (P=0.03) and an increase in the proportion of PDGFR-β-positive tumour blood vessels in tumours with high vs. Intermediate-nuclear grade tumours (P<0.01). Aldh1a1-positive mammary epithelial cells were observed in the terminal end buds of non-transgenic mammary glands and Aldh1a1-positive mammary tumour cells were observed in tumours from MMTV-PyVmT transgenic mice. We observed a decrease in the average number of Aldh1a1-positive cells in tumours with a non-invasive vs. solid morphology (P=0.03), and in the average number of Aldh1a1-positive mammary tumour cells in low vs. intermediate and low vs. High-nuclear grade tumours (P<0.001). Our findings suggest heterogeneous expression of several molecules important for tumour angiogenesis and tumour progression that are currently under investigation as therapeutic targets for metastatic breast cancer.

Phase III Study of Bevacizumab Plus Docetaxel Compared With Placebo Plus Docetaxel for the First-Line Treatment of Human Epidermal Growth Factor Receptor 2–Negative Metastatic Breast Cancer

Purpose

The efficacy and safety of combining bevacizumab (7.5 and 15 mg/kg) with docetaxel as first-line therapy for human epidermal growth factor receptor 2 (HER2) –negative, locally recurrent or metastatic breast cancer (MBC) was investigated in a three-arm, placebo-controlled, phase III trial.

Patients and Methods

Patients (N = 736) were randomly assigned to docetaxel 100 mg/m2 plus either placebo or bevacizumab 7.5 or 15 mg/kg every 3 weeks. The primary end point was progression-free survival (PFS); secondary end points included best overall response, duration of response, time to treatment failure, overall survival, and safety.

Results

Combination of bevacizumab 15 mg/kg, but not 7.5 mg/kg, with docetaxel showed superior median PFS (mPFS) to placebo plus docetaxel in unstratified analysis (placebo mPFS, 8.2 months; 7.5 mg/kg mPFS, 9.0 months [hazard ratio (HR), 0.86; P = .12]; 15 mg/kg mPFS, 10.1 months [HR, 0.77; P = .006]) and stratified analysis (placebo mPFS, 8.1 months; 7.5 mg/kg mPFS, 9.0 months [HR, 0.80; P = .045]; 15 mg/kg mPFS, 10.0 months [HR, 0.67; P < .001]). Response rates in patients with measurable disease at baseline also increased with bevacizumab 15 mg/kg (46% [placebo] v 55% [7.5 mg/kg; P = .07] and 64% [15 mg/kg; P < .001]). Combination with bevacizumab had limited impact on the known toxicity profile of docetaxel.

Conclusion

Combination of bevacizumab with docetaxel did not significantly impact on the safety profile of docetaxel. Bevacizumab 15 mg/kg every 3 weeks significantly increased PFS when combined with docetaxel as first-line therapy for MBC compared with docetaxel plus placebo.

Vascular endothelial growth factor secreted by activated stroma enhances angiogenesis and hormone-independent growth of estrogen receptor-positive breast cancer

"Reactive" or activated stroma characterizes many malignancies including breast cancers. Recently, we isolated a reactive mouse mammary gland stromal cell line called BJ3Z. These cells express alpha-smooth muscle actin and stromal cell-derived factor 1 (SDF-1) and are tumorigenic when injected into mice. Here we show that, in vivo, BJ3Z cells influence the angiogenesis and proliferation of xenografted estrogen receptor (ER)-positive MCF-7 human breast cancer cell-derived solid tumors. The growth-promoting effects of BJ3Z cells are equivalent to those of estradiol (E(2)). BJ3Z cells also increase the proliferation of normal mouse mammary luminal cells adjacent to tumors. In vitro, BJ3Z cells reorganize and increase the proliferation of cocultured malignant MCF-7 and normal human breast MCF10A cells grown as organoids in three-dimensional culture. The effects of BJ3Z cells on MCF-7 cells are equivalent to those of E(2). In contrast, BJ3Z cells do not alter the growth of highly aggressive ER-negative MDA-MB-231 human breast cancer cells. We show that BJ3Z cells secrete vascular endothelial growth factor (VEGF). The growth of MCF-7 organoids induced by BJ3Z can be inhibited by antagonists of VEGF and SDF-1. Conversely, recombinant VEGF stimulates the proliferation of MCF-7, but not MDA-MB-231, organoids. We conclude that, in addition to angiogenesis, VEGF released by activated stroma increases the growth of ER-positive malignant epithelial cells and of adjacent normal epithelium. Because activated stroma can substitute for E(2) and fosters hormone-independent growth of ER-positive tumors, we suggest that breast cancers exhibiting intrinsic hormone resistance may respond to antiangiogenic therapies.

Pazopanib: an antiangiogenic drug in perspective

Pazopanib, a tyrosine kinase inhibitor targeted to angiogenesis, has been tested in preclinical and clinical trials and has shown promising activity against a variety of solid tumors, such as renal cancer, all of which are related to the angiogenic pathway. It has a safety profile related to this mechanism of action. Diarrhea, hypertension, hair depigmentation and nausea are the most common side effects. Pazopanib is currently under evaluation as monotherapy and in combination with some potentially synergistic agents of proven activity.

Myeloid-derived suppressor cells in mammary tumor progression in FVB Neu transgenic mice

Female mice transgenic for the rat proto-oncogene c-erb-B2, under control of the mouse mammary tumor virus (MMTV) promoter (neuN), spontaneously develop metastatic mammary carcinomas. The development of these mammary tumors is associated with increased number of GR-1(+)CD11b(+) myeloid derived suppressor cells (MDSCs) in the peripheral blood (PB), spleen and tumor. We report a complex relationship between tumor growth, MDSCs and immune regulatory molecules in non-mutated neu transgenic mice on a FVB background (FVB-neuN). The first and second tumors in FVB-neuN mice develop at a median of 265 (147-579) and 329 (161-523) days, respectively, resulting in a median survival time (MST) of 432 (201 to >500) days. During tumor growth, significantly increased number of MDSCs is observed in the PB and spleen, as well as, in infiltrating the mammary tumors. Our results demonstrate a direct correlation between tumor size and the number of MDSCs infiltrating the tumor and an inverse relationship between the frequency of CD4(+) T-cells and MDSCs in the spleen. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assessment of enzyme and cytokine transcript levels in the spleen, tumor, tumor-infiltrating non-parenchymal cells (NPCs) and mammary glands revealed a significant increase in transcript levels from grossly normal mammary glands and tumor-infiltrating NPCs during tumor progression. Tumor NPCs, as compared to spleen cells from wild-type (w/t) mice, expressed significantly higher levels of arginase-1 (ARG-1), nitric oxide synthase (NOS-2), vascular endothelial growth factor (VEGF-A) and significantly lower levels of interferon (IFN)-gamma, interleukin (IL)-2 and fms-like tyrosine kinase-3 ligand (Flt3L) transcript levels. Transcript levels in the spleens of tumor-bearing (TB) mice also differed from normal mice, although to a lesser extent than transcript levels from tumor-infiltrating NPCs. Furthermore, both spleen cells and NPCs from TB mice, but not control mice, suppressed alloantigen responses by syngeneic control spleen cells. Correlative studies revealed that the number of MDSCs in the spleen was directly associated with granulocyte colony stimulating factor (G-CSF) transcript levels in the spleen; while the number of MDSCs in the tumors was directly correlated with splenic granulocyte macrophage stimulating factor (GM-CSF) transcript levels, tumor volume and tumor cell number. Together our results support a role for MDSCs in tumor initiation and progressive, T-cell depression and loss of function provide evidence which support multiple mechanisms of MDSC expansion in a site-dependent manner.

The role of antiangiogenesis therapy: bevacizumab and beyond

The importance of angiogenesis in tumour growth and development is well known. Overexpression of vascular endothelial growth factor (VEGF), the key mediator of angiogenesis, is associated with poor prognosis in cancer. As a result, several therapeutic agents that inhibit the actions of VEGF or its receptors are currently in development for use in advanced solid tumours, such breast, colorectal, lung and renal cancer. Clinical data from trials of anti-VEGF agents in this group of tumours are discussed, with a particular focus on the efficacy and safety of bevacizumab, the anti-VEGF agent at the most advanced stage of development in those tumour types. Future potential uses of bevacizumab in cancer therapy will be discussed.

Novel therapeutic approaches to the treatment of metastatic breast cancer

Metastatic breast cancer is ultimately an incurable disease, although recent data have shown that its incidence is decreasing and that patients with metastatic breast cancer live longer. This improvement in survival seems to be linked with the introduction of new therapeutic agents, novel combinations of existing therapies and targeted therapies. Our increasing understanding of the molecular biology of metastatic disease has allowed the development of therapies aimed at specific molecular targets. Some of these have already been approved for the treatment of metastatic breast cancer in combination with cytotoxics, and others have shown promising results regarding disease-free survival, overall response rates and time to disease progression. Given the enormous amount of information about drug discovery in cancer, it is important to be familiar with the present state of the treatment of metastatic breast cancer. The purpose of this review is to provide an update on the development of some of the most promising novel agents and treatment strategies in metastatic breast cancer.

Engineered therapeutic antibodies with improved effector functions

In the past decade, more than 20 therapeutic antibodies have been approved for clinical use and many others are now at the clinical and preclinical stage of development. Fragment crystallizable (Fc)-dependent antibody functions, such as antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and a long half-life, have been suggested as important clinical mechanisms of therapeutic antibodies. These functions are primarily triggered through direct interaction of the Fc domain with its corresponding receptors: FcgammaRIIIa for ADCC, C1q for CDC, and neonatal Fc receptor for prolongation of the clearance rate. However, current antibody therapy still faces the critical issues of insufficient efficacy and the high cost of the therapeutic agents. A possible solution to these issues could be to engineer antibody molecules to enhance their antitumor activity, leading to improved therapeutic outcomes and reduced doses. Here, we review advanced Fc engineering approaches for the enhancement of effector functions, some of which are now ready for evaluation of their effectiveness in clinical trials.

Triple-negative breast cancer

PURPOSE OF REVIEW

Triple-negative breast cancer has been of great interest to oncologists because these cancers do not benefit from hormonal therapies or treatments targeted against human epidermal growth factor receptor 2 receptors. The only systemic therapy currently available is chemotherapy, and prognosis remains poor. We would like to describe recent pathological and genetic advancements and their possible implications on the development of new treatment strategies.

RECENT FINDINGS

Increasing pathological and molecular knowledge has led to a better understanding of breast cancer in general. Triple-negative breast cancer, however, remains a heterogeneous subgroup with difficult-to-define subtypes. New targeted therapies are currently being developed and researched.

SUMMARY

The recent advances in pathological and molecular knowledge have changed the landscape of breast cancer, with triple-negative breast cancer emerging as a pathological and clinical heterogeneous group. The main challenge lies in the development of new tailored treatment strategies for the various subgroups, with receptor kinase inhibition as the most promising new evolution to date. Further trials are needed to validate these new treatment options.

Modes of resistance to anti-angiogenic therapy

Angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signalling pathways are affording demonstrable therapeutic efficacy in mouse models of cancer and in an increasing number of human cancers. However, in both preclinical and clinical settings, the benefits are at best transitory and are followed by a restoration of tumour growth and progression. Emerging data support a proposition that two modes of unconventional resistance underlie such results: evasive resistance, an adaptation to circumvent the specific angiogenic blockade; and intrinsic or pre-existing indifference. Multiple mechanisms can be invoked in different tumour contexts to manifest both evasive and intrinsic resistance, motivating assessment of their prevalence and importance and in turn the design of pharmacological strategies that confer enduring anti-angiogenic therapies.