Fighting fire with fire: rekindling the bevacizumab debate

Breast Cancer Metastatic Dormancy and Relapse: An Enigma of Microenvironment(s)

Multiple factors act in concert to define the fate of disseminated tumor cells (DTC) to enter dormancy or develop overt metastases. Here, we review these factors in the context of three stages of the metastatic cascade that impact DTCs. First, cells can be programmed within the primary tumor microenvironment to promote or inhibit dissemination, and the primary tumor can condition a premetastatic niche. Then, cancer cells from the primary tumor spread through hematogenous and lymphatic routes, and the primary tumor sends cues systematically to regulate the fate of DTCs. Finally, DTCs home to their metastatic site, where they are influenced by various organ-specific aspects of the new microenvironment. We discuss these factors in the context of breast cancer, where about one-third of patients develop metastatic relapse. Finally, we discuss how the standard-of-care options for breast cancer might affect the fate of DTCs.

B Cells versus T Cells in the Tumor Microenvironment of Malignant Lymphomas. Are the Lymphocytes Playing the Roles of Muhammad Ali versus George Foreman in Zaire 1974?

Malignant lymphomas are a heterogeneous group of malignancies that develop both in nodal and extranodal sites. The different tissues involved and the highly variable clinicopathological characteristics are linked to the association between the lymphoid neoplastic cells and the tissues they infiltrate. The immune system has developed mechanisms to protect the normal tissue from malignant growth. In this review, we aim to explain how T lymphocyte-driven control is linked to tumor development and describe the tumor-suppressive components of the resistant framework. This manuscript brings forward a new insight with regard to intercellular and intracellular signaling, the immune microenvironment, the impact of therapy, and its predictive implications. A better understanding of the key components of the lymphoma environment is important to properly assess the role of both B and T lymphocytes, as well as their interplay, just as two legendary boxers face each other in a heavyweight title final, as was the case of Ali versus Foreman.

Fibrocytes: A Novel Stromal Cells to Regulate Resistance to Anti-Angiogenic Therapy and Cancer Progression

An adequate blood supply is essential for cancer cells to survive and grow; thus, the concept of inhibiting tumor angiogenesis has been applied to cancer therapy, and several drugs are already in clinical use. It has been shown that treatment with those anti-angiogenic drugs improved the response rate and prolonged the survival of patients with various types of cancer; however, it is also true that the effect was mostly limited. Currently, the disappointing clinical results are explained by the existence of intrinsic or acquired resistance to the therapy mediated by both tumor cells and stromal cells. This article reviews the mechanisms of resistance mediated by stromal cells such as endothelial cells, pericytes, fibroblasts and myeloid cells, with an emphasis on fibrocytes, which were recently identified as the cell type responsible for regulating acquired resistance to anti-angiogenic therapy. In addition, the other emerging role of fibrocytes as mediator-producing cells in tumor progression is discussed.

Disrupting Tumor Angiogenesis and "the Hunger Games" for Breast Cancer

Angiogenesis, one of the hallmarks of cancers, has become an attractive target for cancer therapy since decades ago. It is broadly thought that upregulation of angiogenesis is involved in tumor progression and metastasis. Though tumor vessels are tortuous, disorganized, and leaky, they deliver oxygen and nutrients for tumor development. Based on this knowledge, many kinds of drugs targeting angiogenesis pathways have been developed, such as bevacizumab. However, the clinical outcomes of anti-angiogenesis therapies are moderate in metastatic breast cancer as well as in metastatic colorectal cancer and non-small cell lung cancer, even combined with traditional chemotherapy. In this chapter, the morphologic angiogenesis patterns and the key molecular pathways regulating angiogenesis are elaborated. The FDA-approved anti-angiogenesis drugs and current challenges of anti-angiogenesis therapy are described. The strategies to overcome the barriers will also be elucidated.

Aflibercept and Ang1 supplementation improve neoadjuvant or adjuvant chemotherapy in a preclinical model of resectable breast cancer

Phase III clinical trials evaluating bevacizumab (an antibody to the angiogenic ligand, VEGF-A) in breast cancer have found improved responses in the presurgical neoadjuvant setting but no benefits in the postsurgical adjuvant setting. The objective of this study was to evaluate alternative antiangiogenic therapies, which target multiple VEGF family members or differentially modulate the Angiopoietin/Tie2 pathway, in a mouse model of resectable triple-negative breast cancer (TNBC). Neoadjuvant therapy experiments involved treating established orthotopic xenografts of an aggressive metastatic variant of the MDA-MB-231 human TNBC cell line, LM2-4. Adjuvant therapies were given after primary tumor resections to treat postsurgical regrowths and distant metastases. Aflibercept (‘VEGF Trap’, which neutralizes VEGF-A, VEGF-B and PlGF) showed greater efficacy than nesvacumab (an anti-Ang2 antibody) as an add-on to neoadjuvant/adjuvant chemotherapy. Concurrent inhibition of Ang1 and Ang2 signaling (through an antagonistic anti-Tie2 antibody) was not more efficacious than selective Ang2 inhibition. In contrast, short-term perioperative BowAng1 (a recombinant Ang1 variant) improved the efficacy of adjuvant chemotherapy. In conclusion, concurrent VEGF pathway inhibition is more likely than Ang/Tie2 pathway inhibition (e.g., anti-Ang2, anti-Ang2/Ang1, anti-Tie2) to improve neoadjuvant/adjuvant chemotherapies for TNBC. Short-term perioperative Ang1 supplementation may also have therapeutic potential in conjunction with adjuvant chemotherapy for TNBC.

Bevacizumab as first-line treatment in HER2-negative advanced breast cancer: pros and cons

PURPOSE

Bevacizumab, a humanized, anti-vascular endothelial growth factor-A monoclonal antibody, has shown efficacy in a number of cancers. However, its use in metastatic breast cancer (MBC) remains controversial.

METHODS

A literature review using the PubMed database was performed to update the currently available clinical trials evidence on bevacizumab in the first-line treatment of breast cancer. In addition, the proceedings of selected oncology annual meetings were searched for relevant presentations.

RESULTS

This article reviews the available evidence for bevacizumab as first-line therapy for MBC and discusses its current and future applicability in the management of MBC. Three phase III trials (ECOG-2100, AVADO, RIBBON-1) demonstrated that the addition of bevacizumab to chemotherapy is well-tolerated and improves progression-free survival and objective response rates in the first-line setting. These findings were supported by a large clinical practice-based study (ATHENA) and a recent clinical trial in which bevacizumab added to paclitaxel showed notable activity in triple-negative MBC. However, bevacizumab has thus far not demonstrated a significant benefit in overall survival.

CONCLUSIONS

The addition of bevacizumab to chemotherapy is well-tolerated and produces substantial improvements in overall response rate and progression-free survival, compared with chemotherapy alone, in advanced HER2-negative breast cancer. Nevertheless, it has thus far not demonstrated a significant benefit in overall survival. Whether prolongation of progression-free survival is enough to consider bevacizumab efficacious is unclear. Based on the available clinical trials results, bevacizumab is a part of the complex therapeutic strategy of advanced HER2-negative breast cancer.

A Phase I Clinical, Pharmacokinetic, and Pharmacodynamic Study of Weekly or Every Three Week Ixabepilone and Daily Sunitinib in Patients with Advanced Solid Tumors

PURPOSE

To evaluate the safety, MTD, pharmacokinetics/pharmacodynamics, and early clinical activity of ixabepilone given either weekly or every 3 weeks in combination with daily sunitinib in patients with advanced solid tumors.

EXPERIMENTAL DESIGN

Eligible patients received either weekly (schedule A) or every 3 weeks (schedule B) ixabepilone at escalating doses (schedule A: 7.5, 15, or 20 mg/m(2); schedule B: 20, 30, or 40 mg/m(2)), and oral sunitinib (37.5 mg daily), starting on day 8 of cycle 1. Dose-limiting toxicities (DLT) were assessed during cycle 1.

RESULTS

The ixabepilone and sunitinib combination was fairly well tolerated. DLTs were observed in 3 subjects (1 in schedule 3A and 2 in schedule 3B). The most common grade 3-4 hematologic and nonhematologic adverse events were leukopenia and fatigue, respectively. Four patients (3 in schedule A) achieved a partial response, while 13 patients had stable disease. Nine of 17 heavily pretreated colorectal cancer patients had clinical benefit. Coadministration of sunitinib with ixabepilone on a weekly (but not every 3 week) schedule was associated with a significant increase in the half-life and a significant decrease in the clearance of ixabepilone. Correlative studies demonstrated a significant association between higher baseline plasma angiogenic activity (PAA) and clinical benefit in schedule A patients. Weekly, but not every 3 weeks, ixabepilone led to a significant decrease in PAA postbaseline.

CONCLUSIONS

Coadministration of ixabepilone with sunitinib has acceptable toxicity and encouraging clinical activity in heavily pretreated patients, particularly in patients with metastatic colorectal cancer. Clin Cancer Res; 22(13); 3209-17. ©2016 AACR.

Fibrocyte-like cells mediate acquired resistance to anti-angiogenic therapy with bevacizumab

Bevacizumab exerts anti-angiogenic effects in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the development of resistance to the treatment. Such resistance can be regulated by various factors, although the underlying mechanisms remain incompletely understood. Here we show that bone marrow-derived fibrocyte-like cells, defined as alpha-1 type I collagen-positive and CXCR4-positive cells, contribute to the acquired resistance to bevacizumab. In mouse models of malignant pleural mesothelioma and lung cancer, fibrocyte-like cells mediate the resistance to bevacizumab as the main producer of fibroblast growth factor 2. In clinical specimens of lung cancer, the number of fibrocyte-like cells is significantly increased in bevacizumab-treated tumours, and correlates with the number of treatment cycles, as well as CD31-positive vessels. Our results identify fibrocyte-like cells as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy.

Tumor Volume Estimation and Quasi-Continuous Administration for Most Effective Bevacizumab Therapy

Background

Bevacizumab is an exogenous inhibitor which inhibits the biological activity of human VEGF. Several studies have investigated the effectiveness of bevacizumab therapy according to different cancer types but these days there is an intense debate on its utility. We have investigated different methods to find the best tumor volume estimation since it creates the possibility for precise and effective drug administration with a much lower dose than in the protocol.

Materials and Methods

We have examined C38 mouse colon adenocarcinoma and HT-29 human colorectal adenocarcinoma. In both cases, three groups were compared in the experiments. The first group did not receive therapy, the second group received one 200 μg bevacizumab dose for a treatment period (protocol-based therapy), and the third group received 1.1 μg bevacizumab every day (quasi-continuous therapy). Tumor volume measurement was performed by digital caliper and small animal MRI. The mathematical relationship between MRI-measured tumor volume and mass was investigated to estimate accurate tumor volume using caliper-measured data. A two-dimensional mathematical model was applied for tumor volume evaluation, and tumor- and therapy-specific constants were calculated for the three different groups. The effectiveness of bevacizumab administration was examined by statistical analysis.

Results

In the case of C38 adenocarcinoma, protocol-based treatment did not result in significantly smaller tumor volume compared to the no treatment group; however, there was a significant difference between untreated mice and mice who received quasi-continuous therapy (p = 0.002). In the case of HT-29 adenocarcinoma, the daily treatment with one-twelfth total dose resulted in significantly smaller tumors than the protocol-based treatment (p = 0.038). When the tumor has a symmetrical, solid closed shape (typically without treatment), volume can be evaluated accurately from caliper-measured data with the applied two-dimensional mathematical model.

Conclusion

Our results provide a theoretical background for a much more effective bevacizumab treatment using optimized administration.

Efficacy of neoadjuvant bevacizumab added to docetaxel followed by fluorouracil, epirubicin, and cyclophosphamide, for women with HER2-negative early breast cancer (ARTemis): an open-label, randomised, phase 3 trial

BACKGROUND

The ARTemis trial was developed to assess the efficacy and safety of adding bevacizumab to standard neoadjuvant chemotherapy in HER2-negative early breast cancer.

METHODS

In this randomised, open-label, phase 3 trial, we enrolled women (≥18 years) with newly diagnosed HER2-negative early invasive breast cancer (radiological tumour size >20 mm, with or without axillary involvement), at 66 centres in the UK. Patients were randomly assigned via a central computerised minimisation procedure to three cycles of docetaxel (100 mg/m(2) once every 21 days) followed by three cycles of fluorouracil (500 mg/m(2)), epirubicin (100 mg/m(2)), and cyclophosphamide (500 mg/m(2)) once every 21 days (D-FEC), without or with four cycles of bevacizumab (15 mg/kg) (Bev+D-FEC). The primary endpoint was pathological complete response, defined as the absence of invasive disease in the breast and axillary lymph nodes, analysed by intention to treat. The trial has completed and follow-up is ongoing. This trial is registered with EudraCT (2008-002322-11), ISRCTN (68502941), and ClinicalTrials.gov (NCT01093235).

FINDINGS

Between May 7, 2009, and Jan 9, 2013, we randomly allocated 800 participants to D-FEC (n=401) and Bev+D-FEC (n=399). 781 patients were available for the primary endpoint analysis. Significantly more patients in the bevacizumab group achieved a pathological complete response compared with those treated with chemotherapy alone: 87 (22%, 95% CI 18-27) of 388 patients in the Bev+D-FEC group compared with 66 (17%, 13-21) of 393 patients in the D-FEC group (p=0·03). Grade 3 and 4 toxicities were reported at expected levels in both groups, although more patients had grade 4 neutropenia in the Bev+D-FEC group than in the D-FEC group (85 [22%] vs 68 [17%]).

INTERPRETATION

Addition of four cycles of bevacizumab to D-FEC in HER2-negative early breast cancer significantly improved pathological complete response. However, whether the improvement in pathological complete response will lead to improved disease-free and overall survival outcomes is unknown and will be reported after longer follow-up. Meta-analysis of available neoadjuvant trials is likely to be the only way to define subgroups of early breast cancer that would have clinically significant long-term benefit from bevacizumab treatment.

FUNDING

Cancer Research UK, Roche, Sanofi-Aventis.

VEGF-A levels in bevacizumab-treated breast cancer patients: a systematic review and meta-analysis

Bevacizumab may improve outcomes of patients with breast cancer, but the absence of an established biomarker hampers patient selection and researchers´ ability to demonstrate a clear survival benefit. Its putative target, circulating VEGF-A, emerged as the main candidate and we sought to identify the relationship between VEGF-A levels and outcomes through systematic review. We searched electronic databases and meeting proceedings for randomized controlled trials (RCTs) comparing the addition of bevacizumab to standard chemotherapy for breast cancer. RCTs were included if outcomes were presented separately according to VEGF-A plasma levels. Random-effects model were applied to calculate the pooled hazard ratios for progression-free survival, event-free survival (EFS), comprising disease recurrence, progression or any-cause death, and overall survival (OS), with respective confidence intervals (95 % CI). High and low VEGF-A levels subgroups followed each trial definition, and results were compared using the interaction test. Heterogeneity was calculated using χ (2) test (I (2)). Three trials enrolled a total of 3748 patients. 1713 patients had baseline VEGF-A levels in plasma available for assessment and were included. One trial added bevacizumab in the adjuvant setting (N = 2591) and two on first-line metastatic disease with taxane-based therapy (N = 1160) There was no interaction between VEGF-A levels and study setting (adjuvant vs. first line therapy). Bevacizumab improved PFS of patients with above median VEGF-A plasma levels (HR 0.56; 95 % CI 0.43-0.73; P < 0.001; I (2) = 0 %), but not of those with below median VEGF-A levels (HR 0.89; 95 % CI 0.68-1.15; P = 0.37; I (2) = 0 %), with relevant differences between these two groups, P-for interaction = 0.02. The same happened with EFS (VEGF-A above median HR 0.62; 95 % CI 0.39-0.79; P < 0.001; I (2) = 11 %; below median HR 0.89; 95 % CI 0.71-1.14; P = 0.98; I (2) = 17 %; P-for interaction = 0.03). OS data were not available. VEGF-A level is a reasonable candidate biomarker for bevacizumab in the treatment of breast cancer. Further studies have to confirm its surrogacy in overall survival and in other scenarios including other anti-angiogenic therapies.

After counterfeit Avastin®--what have we learned and what can be done?

Three years have passed since the FDA announced that it had detected counterfeit versions of the injectable anticancer drug bevacizumab (Avastin(®), Genentech, USA) in the US drug-supply chain. Following this discovery, almost 1,000 FDA warning letters were sent to physicians and medical practices in 48 different states and two US territories, as more batches of counterfeit Avastin were uncovered. In response, criminal prosecutions have been pursued against certain distributors and clinicians, and other individuals who trafficked, sold, purchased, and/or administered an unsafe and ineffective treatment while also defrauding the government. Although limited and targeted legal action has been taken, patients potentially affected by this seminal patient safety event have not been appropriately identified. Hence, despite the clear and documented patient-safety and public-health risks posed by the transnational criminal trade in counterfeit medicines, the case study of counterfeit bevacizumab detection in the USA demonstrates the continued lack of information, knowledge, and solutions that would be necessary to protect those who are most affected--the patients. In response, we call for greater investment in multisector, multistakeholder strategies to enhance surveillance for counterfeit medicines and enable improvements in communication of risk information, to better protect patients with cancer.

Triple-negative breast carcinoma: current and emerging concepts

OBJECTIVES

Triple-negative breast cancer is regarded as an aggressive disease that affects a young patient population and for which effective targeted therapy is not yet available.

METHODS

Intense efforts have been made to gain a better understanding of this heterogeneous group of tumors from the histologic to the genomic and molecular levels.

RESULTS

Progress has been made, including the ability to subtype these tumors and the discovery of biomarkers toward which current therapeutic efforts are focused. Many novel targets under exploration have the potential to affect the clinical course of this disease.

CONCLUSIONS

This article reviews the current concepts regarding the clinicopathologic features of triple-negative breast carcinoma, its histologic subtypes, molecular classification, the prognostic and therapeutic potential of biomarkers, and emerging targeted therapies.

Analysis of acquired resistance to metronomic oral topotecan chemotherapy plus pazopanib after prolonged preclinical potent responsiveness in advanced ovarian cancer

An alternative or follow-up adjunct to conventional maximum tolerated dose (MTD) chemotherapy now in advanced phase III clinical trial assessment is metronomic chemotherapy--the close regular administration of low doses of drug with no prolonged breaks. A number of preclinical studies have shown metronomic chemotherapy can cause long term survival of mice with advanced cancer, including metastatic disease, in the absence of overt toxicity, especially when combined with targeted antiangiogenic drugs. However, similar to MTD chemotherapy acquired resistance eventually develops, the basis of which is unknown. Using a preclinical model of advanced human ovarian (SKOV-3-13) cancer in SCID mice, we show that acquired resistance can develop after terminating prolonged (over 3 months) successful therapy utilizing daily oral metronomic topotecan plus pazopanib, an oral antiangiogenic tyrosine kinase inhibitor (TKI). Two resistant sublines were isolated from a single mouse, one from a solid tumor (called KH092-7SD, referred to as 7SD) and another from ascites tumor cells (called KH092-7AS, referred to as 7AS). Using these sublines we show acquired resistance to the combination treatment is due to tumor cell alterations that confer relative refractoriness to topotecan. The resistant phenotype is heritable, associated with reduced cellular uptake of topotecan and could not be reversed by switching to MTD topotecan or to another topoisomerase-1 inhibitor, CPT-11, given either in a metronomic or MTD manner nor switching to another antiangiogenic drug, e.g. the anti-VEGFR-2 antibody, DC101, or another TKI, sunitinib. Thus, in this case cross resistance seems to exist between MTD and metronomic topotecan, the basis of which is unknown. However, gene expression profiling revealed several potential genes that are stably upregulated in the resistant lines, that previously have been implicated in resistance to various chemotherapy drugs, and which, therefore, may contribute to the drug resistant phenotype.

Relapsed triple-negative breast cancer: challenges and treatment strategies

Triple negative breast cancer (TNBC) is the most lethal form of breast cancer. Treatment options for advanced disease are limited, with a median survival from the time of developing metastases rarely exceeding 1 year. TNBC is heterogeneous, and harbours several molecular alterations. Unfortunately, up to now, clinical trials combining targeted agents and chemotherapy have failed to show substantial survival improvement; therefore, chemotherapy remains the backbone of treatment. No major advances have been made in the field of cytotoxic treatments, and hopefully ongoing trials will contribute to a more precise definition of the role of platinum salts in sporadic and BRCA-mutated TNBC. Moreover, recent gene expression data suggest that TNBC can be further segmented into smaller subgroups, characterized by different activated pathways, which may therefore warrant different targeted treatments. The lack of efficacy that has been observed for the majority of targeted agents in TNBC so far may derive from the inclusion of unselected TNBC patient populations, not enriched for patients presenting an alteration in the target. Therefore, one of the major challenges in the future is to integrate biological data into clinical trials to obtain the highest efficacy from promising targeted treatments such as anti-angiogenetic agents, poly (ADP-ribose) polymerase-1 (PARP), epidermal growth factor receptor, fibroblast growth factor receptor, androgen receptor and phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) inhibitors.

Chemotherapy-related cardiotoxicity

Cardiovascular toxicity caused by cancer therapy is a challenging area which needs thorough evaluation and research. Numerous studies, meta-analyses and reviews have been published in the past discussing cardiotoxicity caused by chemotherapeutic agents. A brief review of the on-target and off-target cardiotoxicities caused by chemotherapeutic agents is presented here. Cardiotoxicities are broadly outlined in terms of left ventricular dysfunction, hypertension and thromboembolic events. The mechanisms leading to the cardiotoxicity profiles of various chemotherapeutic agents are discussed. The management of various cardiotoxicities of chemotherapeutic agents is also discussed.

Strategies for improving the clinical benefit of antiangiogenic drug based therapies for breast cancer

Viewed as a whole, the aggregate outcomes of a number of positive randomized phase III clinical trial results evaluating the VEGF-pathway targeting antiangiogenic drug bevacizumab, with or without concurrent chemotherapy, in metastatic breast cancer patients have been disappointingly modest. In the case of antiangiogenic tyrosine kinase inhibitors (TKIs) the results have been negative. Nevertheless, several findings indicate antiangiogenic drugs, especially bevacizumab, are active and can lead to demonstrable clinical benefit in some patients, thus stimulating research into developing strategies to significantly improve their efficacy and reduce toxicity. Some of these initiatives include: 1) discovery and validation of predictive markers that can prospectively identify patients more likely to benefit from antiangiogenic therapy; 2) recognition that the nature of the chemotherapy partner or backbone can strongly impact outcomes when combined with antiangiogenic drugs such as bevacizumab, and thus developing what may be improved combination chemotherapy partner regimens, e.g. metronomic chemotherapy; 3) evaluating prospectively in more depth whether subtypes of the disease-especially triple negative or inflammatory breast cancer-are more responsive to antiangiogenic therapy than other subtypes; 4) evaluating new agents that inhibit angiogenesis in a VEGF-independent manner and other types of drug that can be effectively combined with antiangiogenics, e.g. c-met inhibitors; 5) uncovering the basis of resistance or relapse/progression on the therapy with antiangiogenic drugs; 6) development of improved predictive preclinical breast cancer models for therapy testing, e.g. treatment of mice with established multi-organ breast cancer metastatic disease or genetically engineered mouse models of breast cancer, or mice bearing patient derived breast cancer tissue xenografts.

Tivozanib: current status and future directions in the treatment of solid tumors

INTRODUCTION

Tivozanib is a novel tyrosine kinase inhibitor (TKI) which inhibits vascular endothelial growth factor (VEGF) receptors-1, -2, and -3 at nanomolar concentrations.

AREAS COVERED

A comprehensive MEDLINE and American Society of Clinical Oncology abstract search was performed to gather all relevant clinical and translational data related to tivozanib. We discuss pre-clinical studies associated with tivozanib, and the results of a Phase I assessment in advanced solid tumors. We highlight combination studies with tivozanib, including pairings of tivozanib with cytotoxic therapy in patients with colorectal cancer and breast cancer. A randomized discontinuation Phase II study and a randomized Phase III study assessing the activity of tivozanib in metastatic renal cell carcinoma (mRCC) are described in detail.

EXPERT OPINION

Tivozanib will face the challenge of entering an already crowded therapeutic space in mRCC-emerging combination studies and biomarker assessments may distinguish this agent among other VEGF-TKIs. The current review will outline the development pathway of tivozanib to date, and offer lessons learned and future opportunities.

Do imaging biomarkers relate to outcome in patients treated with VEGF inhibitors?

The management of solid tumors has been transformed by the advent of VEGF pathway inhibitors. Early clinical evaluation of these drugs has used pharmacodynamic biomarkers derived from advanced imaging such as dynamic MRI, computed tomography (CT), and ultrasound to establish proof of principle. We have reviewed published studies that used these imaging techniques to determine whether the same biomarkers relate to survival in renal, hepatocellular, and brain tumors in patients treated with VEGF inhibitors. Data show that in renal cancer, pretreatment measurements of K(trans) and early pharmacodynamic reduction in tumor enhancement and density have prognostic significance in patients treated with VEGF inhibitors. A weaker, but significant, relationship is seen with subtle early size change (10% in one dimension) and survival. Data from high-grade glioma suggest that pretreatment fractional blood volume and K(trans) were prognostic of overall survival. However, lack of control data with other therapies prevents assessment of the predictive nature of these biomarkers, and such studies are urgently required.

Scheduling of anticancer drugs: timing may be everything

Many cancer patients are treated with a combination of anticancer drugs. Here, we discuss the importance of drug scheduling and the need for studies that investigate the optimal timing of the various anticancer drugs. Positron emission tomography (PET) using radiolabeled anticancer drugs could be an important tool for those studies.

Impact of modern chemotherapy on the survival of women presenting with de novo metastatic breast cancer

Background

Data that directly associate utilization of novel systemic therapies with survival trends in metastatic breast cancer (MBC) are limited. In the setting of de novo MBC, large registry analyses cite positive temporal trends in survival, but the extent to which advances in systemic therapy have contributed to these gains is not clear.

Methods

The City of Hope Cancer Registry was used to identify a consecutive series of patients with de novo MBC who received their first line of therapy between 1985 and 2004. Comprehensive clinicopathologic and treatment-related data were collected for each patient. Univariate analyses were conducted via Cox regression to identify factors associated with improved survival. Multivariate analysis was also conducted via Cox regression and the stepwise procedure was used to identify independent predictors of survival.

Results

A total of 324 patients with de novo MBC were identified. After application of exclusion criteria, including the sole presence of supraclavicular node metastasis, 274 patients were retained in the analysis. The treatment-related characteristics associated with improved survival included: use of endocrine therapy (hazard ratio [HR] 0.60, 95%CI 0.47-0.77; P<0.0001), and addition of bisphosphonates (HR 0.70, 95%CI 0.52-0.96; P=0.02). However, recipients of novel cytotoxic agents (defined as drugs approved for MBC since 1994) had no improvement in survival relative to patients treated with older cytotoxic agents. On multivariate analysis, age (< 50), receipt of aromatase inhibitors, and receipt of zoledronic acid were independent predictors of survival.

Conclusions

The overall survival of women with de novo metastatic breast cancer has improved over the past 20 years. However, the contribution of conventional cytotoxic agents to this improvement is minimal.

Bevacizumab and Breast Cancer: A Meta-Analysis of First-Line Phase III Studies and a Critical Reappraisal of Available Evidence

Background. Randomized studies have shown different magnitude of bevacizumab benefit in the treatment of advanced breast cancer. Regulatory agencies have modified bevacizumab treatment indications across different regions. In this study, we perform a meta-analysis of phase III studies aiming to interrogate the magnitude of bevacizumab benefit for the treatment of first-line HER2-negative metastatic breast cancer (MBC). Methods. Data from studies E2100, AVADO and RIBBON-1 were used to calculate the benefit of bevacizumab in terms of tumor overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and toxicities. Combined statistical estimates of hazard ratios (HR) and odds ratios were calculated using fixed-effects or random-effects models. Results. A total of 2,695 patients were evaluated. Combining bevacizumab with different chemotherapy backbones resulted in a 30% risk reduction of PFS events (HR = 0.70; 95% confidence interval [CI], 0.57–0.86) and increased ORR (odds ratio 1.81; 95% CI, 1.53–2.14). No OS benefit could be demonstrated (HR = 0.95; 95% CI, 0.85–1.06). Bevacizumab significantly increased the incidence of adverse events such as proteinuria, hypertension and cardiovascular events. Conclusions. Bevacizumab combined with chemotherapy in the first-line treatment of MBC significantly improved ORR and PFS, but also increased grade 3-4 toxicities. No significant OS advantage was observed.