Antiangiogenic and antitumor effects of bevacizumab in patients with inflammatory and locally advanced breast cancer

Pancreatic cancer: utility of dynamic contrast-enhanced MR imaging in assessment of antiangiogenic therapy

PURPOSE

To prospectively evaluate the utility of dynamic contrast material-enhanced magnetic resonance (MR) imaging in predicting the response of locally advanced pancreatic cancer to combined chemotherapy and antiangiogenic therapy.

MATERIALS AND METHODS

This prospective, institutional review board-approved, HIPAA-compliant study with informed consent assessed dynamic contrast-enhanced MR imaging in 11 patients (mean age, 54.3 years; six men and five women) with locally invasive pancreatic cancer before and 28 days after combined chemotherapy and antiangiogenic therapy. Axial perfusion images were obtained after injection of 0.1 mmol gadopentetate dimeglumine per kilogram of body weight. Sagittal images of the upper abdominal aorta were obtained for arterial input function calculation. A two-compartment kinetic model was used to calculate the perfusion parameters K(trans) (the rate constant that represents transfer of contrast agent from the arterial blood into the extravascular extracellular space), K(ep) (the rate constant that represents transfer of contrast agent from the extravascular extracellular space to the blood plasma), and volume of distribution (v(e)). Semiquantitative measurements, peak tissue gadolinium concentration (C(peak)), maximum slope of gadolinium increase (slope), and area under the gadolinium curve at 60 seconds (AUC(60)) were also calculated. Perfusion parameters and tumor size changes were correlated with carbohydrate antigen 19-9 levels. Comparisons between pre- and posttreatment studies were performed by using the Wilcoxon signed rank test, and comparisons between responders and nonresponders were performed by using the Mann-Whitney test.

RESULTS

After therapy, K(trans), v(e), C(peak), slope, and AUC(60) decreased significantly (P = .02, .001, .002, .007, and .01, respectively). Tumor size and K(ep) were not significantly changed. Pretreatment K(trans) and K(ep) were significantly higher (P = .02 and .006, respectively) in tumors that showed marker response than in those that did not. A pretreatment K(trans) value (milliliters of blood per milliliter of tissue times minutes) of more than 0.78 mL/mL . min was 100% sensitive and 71% specific for subsequent tumor response. Semiquantative parameters and tumor size were not different between the groups.

CONCLUSION

Pretreatment K(trans) measurement in pancreatic tumors can predict response to antiangiogenic therapy. All perfusion parameters showed substantial reduction after 28 days of combined chemotherapy and antiangiogenic therapy.

Experimental treatment of oestrogen receptor (ER) positive breast cancer with tamoxifen and brivanib alaninate, a VEGFR-2/FGFR-1 kinase inhibitor: a potential clinical application of angiogenesis inhibitors

PURPOSE

Tamoxifen, a selective oestrogen receptor modulator (SERM), and brivanib alaninate, a vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitor, are two target specific agents that result in a substantial decrease in tumour growth when given alone. Tamoxifen activates SERM stimulated breast and endometrial tumour growth. Tamoxifen and brivanib alaninate have side-effects that can affect therapeutic outcomes. The primary goal of the current study was to evaluate the therapeutic effects of lower doses of both agents when given in combination to mice with SERM sensitive, oestrogen stimulated tumour xenografts (MCF-7 E2 tumours). Experiments were conducted to evaluate the response of SERM stimulated breast (MCF-7 Tam, MCF-7 Ral) and endometrial tumours (EnCa 101) to demonstrate the activity of brivanib alaninate in SERM resistant models.

EXPERIMENTAL DESIGN

In the current study, tumour xenografts were minced and bi-transplanted into the mammary fat pads of athymic, ovariectomised mice. Preliminary experiments were conducted to determine an effective oral dose of tamoxifen and brivanib alaninate that had minimal effect on tumour growth. Doses of 125 microg of tamoxifen and 0.05 mg/g of brivanib alaninate were evaluated. An experiment was designed to evaluate the effect of the two agents together when started at the time of tumour implantation. An additional experiment was done in which tumours were already established and then treated, to obtain enough tumour tissue for molecular analysis.

RESULTS

Brivanib alaninate was effective at inhibiting tumour growth in SERM sensitive (MCF-7 E2) and SERM stimulated (EnCa 101, MCF-7 Ral, MCF-7 Tam) models. The effect of the low dose drug combination as an anti-tumour strategy for SERM sensitive (MCF-7 E2) in early treatment was as effective as higher doses of either drug used alone. In established tumours, the combination is successful at decreasing tumour growth, while neither agent alone is effective. Molecular analysis revealed a decreased phosphorylation of VEGFR-2 in tumours that were treated with brivanib alaninate and an increase in VEGFA transcription to compensate for the blockade of VEGFR-2 by increasing the transcription of VEGFA. Tamoxifen increases the phosphorylation of VEGFR-2 and this effect is abrogated by brivanib alaninate. There was also increased necrosis in tumours treated with brivanib alaninate.

CONCLUSION

Historically, tamoxifen has a role in blocking angiogenesis as well as the blockade of the ER. Tamoxifen and a low dose of an angiogenesis inhibitor, brivanib alaninate, can potentially be combined not only to maximise therapeutic efficacy but also to retard SERM resistant tumour growth.

Cellular and soluble markers of tumor angiogenesis: from patient selection to the identification of the most appropriate postresistance therapy

Antiangiogenic drugs are now intensively used in clinical oncology, but some drawbacks still hamper their development. First, it is frequently unclear what patient subpopulation is likely to gain clinical benefit from these expensive therapies; second, there is evidence of (sometimes rapid) development of drug resistance in many patients; third, the results of some preclinical and clinical studies have suggested acceleration of malignant cell aggressiveness when some antiangiogenic therapies are terminated. Here we discuss the role of soluble molecules and cellular markers of neoplastic angiogenesis for patient selection and follow-up during treatment. These markers should help clinicians to decide the right therapy, advise them of the generation of mechanisms of drug resistance during antiangiogenic treatment, and finally suggest the most appropriate next line of therapy according to the new patterns of cancer vascularization induced by antiangiogenic therapies.

Blood-based biomarkers for the optimization of anti-angiogenic therapies

The dependence of tumor growth and metastasis on blood vessels makes tumor angiogenesis a rational target for therapy. Strategies have been pursued to inhibit neovascularization and to destroy existing tumor vessels, or both. These include direct targeting of endothelial cells, and indirect targeting by inhibiting the release of proangiogenic growth factors by cancer or stromal cells. Many patients benefit from antiangiogenic therapies; thus, development of noninvasive biomarkers of disease response and relapse is a crucial objective to aid in their management. A number of non-invasive tools are described with their potential benefits and limitations. We review currently available candidate biomarkers of anti-angiogenic agent effect. Including these markers into clinical trials may provide insight into appropriate dosing for desired biological effects, appropriate timing of additional therapy, and prediction of individual response. This has important consequences for the clinical use of angiogenesis inhibitors and for drug discovery, not only for optimizing the treatment of cancer, but possibly also for developing therapeutic approaches for various other diseases.

Akt phosphorylation at Ser473 predicts benefit of paclitaxel chemotherapy in node-positive breast cancer

PURPOSE

We tested the hypothesis that Akt-Ser473 phosphorylation (pAkt) predicts benefit from the sequential addition of paclitaxel to adjuvant doxorubicin plus cyclophosphamide (AC) chemotherapy in patients with node-positive breast cancer participating in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-28 trial.

PATIENTS AND METHODS

Primary tumors from the NSABP B-28 trial tissue microarray were available from 1,581 of 3,060 patients who were randomly assigned to receive either four cycles of AC alone or followed by four cycles of paclitaxel. Immunohistochemistry and quantitative analysis of pAkt were performed at the National Cancer Institute blinded to clinical outcome. Association between pAkt and clinical outcome was assessed using multivariate Cox modeling adjusting for age, tumor size, number of positive nodes, tumor grade, estrogen receptor status, and human epidermal growth factor receptor 2 status.

RESULTS

With a median follow-up of 9.1 years, there were no differences in disease-free survival (adjusted hazard ratio [HR], 1.02; P = .81) or overall survival (HR, 0.97; P = .80) with and without receiving paclitaxel among 975 patients with pAkt-negative tumors. In 606 patients with pAkt-positive tumors, the sequential addition of paclitaxel resulted in a 26% improvement in disease-free survival (HR, 0.74; P = .02) or a 20% improvement in overall survival (HR, 0.80; P = .17).

CONCLUSION

pAkt significantly predicts disease-free benefit from the sequential addition of paclitaxel to AC chemotherapy in patients with node-positive breast cancer. Patients with pAkt-negative breast tumors do not appear to benefit from the addition of paclitaxel.

Pazopanib: Clinical development of a potent anti-angiogenic drug

Pazopanib is an oral, multi-targeted, tyrosine kinase inhibitor (TKI) that binds to the vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR) and several other key proteins responsible for angiogenesis, tumor growth and cell survival. Pazopanib exhibited in vivo and in vitro activity against tumor growth and, in early clinical trials, was well tolerated with the main side effects being hypertension, fatigue and gastrointestinal disorders. Pazopanib showed clinical activity in several tumors including renal cell cancer (RCC), breast cancer, soft tissue sarcoma, thyroid cancer, hepatocellular cancer and cervical cancer. A phase III clinical trial in metastatic RCC patients showed a significant improvement in progression-free survival, leading to its approval in the US. In metastatic breast cancer, the combination of pazopanib with lapatinib was more effective than lapatinib alone. At the time of the current publication, pazopanib is being evaluated in more than 35 phase II and III trials.

Inflammatory breast cancer: novel preoperative therapies

The treatment of inflammatory breast cancer (IBC) has been hampered by the diagnostic rarity of the disease and its consequent inclusion in clinical trials of preoperative treatment for the more indolent locally advanced breast cancer (LABC). Patients with IBC have a 2-fold greater probability of dying of their disease compared with patients diagnosed with LABC. The aggressive clinical portrait of IBC supports the recent investigative focus on determining molecular changes specific to IBC and developing novel systemic therapies that will favorably affect its poor disease prognosis. A significant amount of laboratory research has been involved in defining a specific "inflammatory signature" for IBC, denoting molecular changes consistently found in IBC. This work has involved human IBC tissue and cell lines and has demonstrated overexpression of several molecules governing metastatic dissemination, such as overexpression of E-cadherin concurrent with a dysfunctional mucin 1. An increased prevalence of mutant TP53, overexpression of RhoC, and vascular endothelial growth factor-A has been found to contribute to the dominant influence of angiogenesis in this disease. A greater understanding of the molecular mechanisms governing the pathophysiology of IBC has led to the development and clinical application of novel targeting agents for preoperative therapy. This study reviews the advances in molecular understanding of IBC and focuses on the efficacy of therapies that target the epidermal growth factor pathway and angiogenesis as well as early investigational therapies involving RhoC and TP53.

Biology and management of inflammatory breast cancer

Inflammatory breast cancer is an aggressive subtype of a locally advanced breast cancer that is thought to account for approximately 1-5% of all newly diagnosed breast cancers diagnosed in the USA. Historically, IBC was considered to be a uniformly fatal disease with less than 5% of patients surviving past 5 years. With the advent of a multidisciplinary approach to management, survival outcomes have improved with 5-year survival rates of over 40% being reported. Research efforts are now focused on trying to better understand the epidemiological and molecular characteristics of this disease to further improve survival. Two genes, Rhoc GTPase and WISP3, have been identified that have been found to be concordantly altered in the majority of inflammatory breast cancer tumors and may serve as potential targets for future therapeutic agents. The purpose of this review is to summarize the latest epidemiological and molecular characteristics of IBC, describe the difficulties encountered in trying to clinically diagnose this entity, highlight the importance of a multidisciplinary approach and present some of the latest data on the management of this disease.

[Management of metastatic HER2-positive breast cancer: present and future]

HER2-positive breast cancer accounts for 20 to 25% of breast cancers. The surexpression of this tyrosine-kinase receptor is often associated with a poor prognosis. However, the management and the outcome of these patients have changed these last ten years with trastuzumab. Despite the encouraging results obtained with this humanized monoclonal antibody directed against the HER2-receptor, used alone or in association with chemotherapy in metastatic patients, progression under trastuzumab are usually observed and resistances to this treatment are described. Thus, many other monoclonal antibodies and tyrosine-kinase inhibitors emerged. These therapeutics, used alone or in association with chemotherapy or trastuzumab have variable properties: anti-HER2 and anti-EGFR such as lapatinib, pertuzumab and neratinib; anti-EGFR such as erlotinib and gefitinib; antiangiogenesis (bevacizumab, pazopanib); anti-mTOR pathway (temsirolimus, everolimus) or inhibitor of HSP90 (tanespimycine). In this paper, we present an overview on validated targeted therapies and those which are currently under investigation and seem promising in first line or after progression under trastuzumab. Data regarding cardiotoxicity and the use of trastuzumab under particular clinical circumstances (brain metastases, pregnancy) are also reviewed.

Vascular endothelial growth factor targeted therapy in the perioperative setting: implications for patient care

Vascular endothelial growth factor (VEGF) targeted therapy, either alone or in combination with chemotherapy, has become the standard of care in several solid tumours, including colorectal cancer, renal-cell carcinoma, breast cancer, non-small-cell lung cancer, and glioblastoma. VEGF is crucial in the process of angiogenesis and wound healing and, thus, its inhibition has the potential to affect wound healing in patients undergoing surgery. In this review, we summarise the data available on the use of VEGF-targeted therapies, and their effect on perioperative wound complications. Surgery in patients receiving VEGF-targeted therapies seems to be safe when an appropriate interval of time is allowed between surgical procedures and treatment. Recommendations regarding this interval are provided in a disease and agent site-specific manner. We also discuss complications arising from the use of VEGF-directed therapies that might require surgical intervention and the considerations important in their management. At this juncture, safety data on the use of VEGF-targeted therapies in the perioperative period are sparse, and investigators are urged to continue to study this issue prospectively in current and future clinical trials to establish firm guidelines.

Vasohibin-1 as a potential predictor of aggressive behavior of ductal carcinoma in situ of the breast

Vasohibin-1 is a recently identified negative feedback regulator of angiogenesis induced by VEGF-A and bFGF. In this study, we first evaluated mRNA expression of vasohibin-1 and CD31 in 39 Japanese female breast carcinoma specimens including 22 invasive ductal carcinoma (IDC) and 17 ductal carcinoma in situ (DCIS) using a real-time quantitative RT-PCR (QRT-PCR) with LightCycler system. In addition, we also immunolocalized vasohibin-1 and CD31 and compared their immunoreactivity to nuclear grades and histological grades of 100 carcinoma cases (50 IDC and 50 DCIS). There were no statistically significant differences of CD31 mRNA expression and the number of CD31 positive vessels between DCIS and IDC (P = 0.250 and P = 0.191, respectively), whereas there was a statistically significant difference in vasohibin-1 mRNA expression and the number of vasohibin-1 positive vessels in DCIS and IDC (P = 0.022 and P < or = 0.001, respectively). There was a significant positive correlation between vasohibin-1 mRNA level and Ki-67 labeling index in DCIS (r(2) = 0.293, P < or = 0.001). In addition, vasohibin-1 mRNA expression was correlated with high nuclear and histological grades in DCIS cases and a significant positive correlation was detected between the number of vasohibin-1 positive vessels and Ki-67 labeling index or nuclear grade or Van Nuys classification of carcinoma cells (P < or = 0.001, respectively). These results all indicate the possible correlation between aggressive biological features in DCIS including increased tumor cell proliferation and the status of neovascularization determined by vasohibin-1 immunoreactivity.

Vascular endothelial growth factor and its relationship to the prognosis and treatment of breast, ovarian, and cervical cancer

Tumor neovascularization is a complex process that plays a crucial role in the development of many different types of cancer. Vascular endothelial growth factor (VEGF) is a potent mitogen that is involved with mitogenesis, angiogenesis, endothelial survival, and the induction of hematopoiesis. By increasing vascular permeability in endothelial cells, it helps tumors recruit wound-healing proteins fibrin and fibrinogen from the plasma, suggesting that tumor formation is a process of abnormal wound healing dependent on the ability to generate a blood supply. The human female reproductive tract is highly dependent on VEGF for normal functions such as endometrial proliferation and development of the corpus luteum. The unique influence of female sex steroid hormones on the expression and activity of VEGF deems angiogenesis an important facet of the development of breast and ovarian cancer. Additionally, the up-regulation of VEGF by the E6 oncoprotein of the human papillomavirus suggests that VEGF plays an important role in the development of cervical cancer. Clinical trials have investigated the humanized monoclonal antibody bevacizumab as potential treatment for all three forms of cancer; the data show that in breast cancer, the use of bevacizumab may lengthen the disease-free survival for women with advanced breast cancer, but does not appear to change their overall survival. It may have a role as salvage chemotherapy for ovarian and cervical cancer, though further research is needed to establish it as a definitive form of treatment.

Use of new imaging techniques to predict tumour response to therapy

Imaging of tumour response to therapy has steadily evolved over the past few years as a result of advances in existing imaging modalities and the introduction of new functional techniques. The use of imaging as an early surrogate biomarker of response is appealing, because it might allow for a window of opportunity during which treatment regimens can be tailored accordingly, depending on the expected response. The clinical effect of this would ultimately result in a reduction in morbidity and undue costs. The aim of this review is to describe the potential of various new imaging techniques as biomarkers of early tumour response. We have reviewed the literature and identified studies that have assessed these techniques, such as diffusion-weighted MRI, dynamic contrast-enhanced MRI, magnetic resonance spectroscopy, and 18-fluorodeoxyglucose-PET as early response indicators, and highlight the current clinical awareness of their use.

Bevacizumab and breast cancer: current therapeutic progress and future perspectives

Bevacizumab is a humanized monoclonal antibody to VEGF, and the incorporation of bevacizumab to chemotherapy is one of the rapidly evolving areas in the treatment of breast cancer. Bevacizumab in combination with chemotherapy versus chemotherapy alone improves progression-free survival and increases the response rate in first-line therapy for locally recurrent or metastatic breast cancer. This approach has been and is still being evaluated for early breast cancer in neoadjuvant and adjuvant settings. Bevacizumab is well tolerated and has an established tolerability profile. Both tumor- and host-related biomarkers of bevacizumab activity, response and benefit are emerging from Phase I, II and III clinical trials. The biomarkers of benefit will ultimately help identify the subgroups of patients who specifically benefit from anti-VEGF therapy with bevacizumab.

Inflammatory breast cancer: what are the treatment options?

An otherwise healthy, 68-year-old woman presents to her primary-care physician complaining of right breast enlargement, warmth, and progressive pink to dark red skin changes over the past month. She denies fever, pain, or breast discharge. Physical examination reveals erythema of the whole right breast, warmth, swelling, induration, and nipple retraction. Palpable axillary lymphadenopathy is appreciated on the right only. The left breast is uninvolved. The physician is concerned that she may have inflammatory breast cancer.

Expression of vascular notch ligand delta-like 4 and inflammatory markers in breast cancer

Delta-like ligand 4 (Dll4) is a Notch ligand that is predominantly expressed in the endothelium. Evidence from xenografts suggests that inhibiting Dll4 may overcome resistance to antivascular endothelial growth factor therapy. The aims of this study were to characterize the expression of Dll4 in breast cancer and assess whether it is associated with inflammatory markers and prognosis. We examined 296 breast adenocarcinomas and 38 ductal carcinoma in situ tissues that were represented in tissue microarrays. Additional whole sections representing 10 breast adenocarcinomas, 10 normal breast tissues, and 16 angiosarcomas were included. Immunohistochemistry was then performed by using validated antibodies against Dll4, CD68, CD14, Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN), CD123, neutrophil elastase, CD31, and carbonic anhydrase 9. Dll4 was selectively expressed by intratumoral endothelial cells in 73% to 100% of breast adenocarcinomas, 18% of in situ ductal carcinomas, and all lactating breast cases, but not normal nonlactating breast. High intensity of endothelial Dll4 expression was a statistically significant adverse prognostic factor in univariate (P = 0.002 and P = 0.01) and multivariate analyses (P = 0.03 and P = 0.04) of overall survival and relapse-free survival, respectively. Among the inflammatory markers, only CD68 and DC-SIGN were significant prognostic factors in univariate (but not multivariate) analyses of overall survival (P = 0.01 and 0.002, respectively). In summary, Dll4 was expressed by endothelium associated with breast cancer cells. In these retrospective subset analyses, endothelial Dll4 expression was a statistically significant multivariate prognostic factor.

Biomarkers of angiogenesis and their role in the development of VEGF inhibitors

Vascular endothelial growth factor (VEGF) has been confirmed as an important therapeutic target in randomised clinical trials in multiple disease settings. However, the extent to which individual patients benefit from VEGF inhibitors is unclear. If we are to optimise the use of these drugs or develop combination regimens that build on this efficacy, it is critical to identify those patients who are likely to benefit, particularly as these agents can be toxic and are expensive. To this end, biomarkers have been evaluated in tissue, in circulation and by imaging. Consistent drug-induced increases in plasma VEGF-A and blood pressure, as well as reductions in soluble VEGF-R2 and dynamic contrast-enhanced MRI parameters have been reported. In some clinical trials, biomarker changes were statistically significant and associated with clinical end points, but there is considerable heterogeneity between studies that are to some extent attributable to methodological issues. On the basis of observations with these biomarkers, it is now appropriate to conduct detailed prospective studies to define a suite of predictive, pharmacodynamic and surrogate response biomarkers that identify those patients most likely to benefit from and monitor their response to this novel class of drugs.

Magnetic resonance imaging: a potential tool in assessing the addition of hyperthermia to neoadjuvant therapy in patients with locally advanced breast cancer

The poor overall survival for patients with locally advanced breast cancers has led over the past decade to the introduction of numerous neoadjuvant combined therapy regimens to down-stage the disease before surgery. At the same time, more evidence suggests the need for treatment individualisation with a wide variety of new targets for cancer therapeutics and also multi modality therapies. In this context, early determination of whether the patient will fail to respond can enable the use of alternative therapies that can be more beneficial. The purpose of this review is to examine the potential role of magnetic resonance imaging (MRI) in early prediction of treatment response and prognosis of overall survival in locally advanced breast cancer patients enrolled on multi modality therapy trials that include hyperthermia. The material is organised with a review of dynamic contrast (DCE)-MRI and diffusion weighted (DW)-MRI for characterisation of phenomenological parameters of tumour physiology and their potential role in estimating therapy response. Most of the work published in this field has focused on responses to neoadjuvant chemotherapy regimens alone, so the emphasis will be there, however the available data that involves the addition of hyperthermia to the regimen will be discussed The review will also include future directions that include the potential use of MRI imaging techniques in establishing the role of hyperthermia alone in modifying breast tumour microenvironment, together with specific challenges related to performing such studies.

Dose-dense adjuvant Doxorubicin and cyclophosphamide is not associated with frequent short-term changes in left ventricular ejection fraction

PURPOSE

Doxorubicin and cyclophosphamide (AC) every 3 weeks has been associated with frequent asymptomatic declines in left ventricular ejection fraction (LVEF). Dose-dense (dd) AC followed by paclitaxel (P) is superior to the same regimen given every third week. Herein, we report the early cardiac safety of three sequential studies of ddAC alone or with bevacizumab (B).

PATIENTS AND METHODS

Patients with HER2-positive breast cancer were treated on two trials: ddAC followed by P and trastuzumab (T) and ddAC followed by PT and lapatinib. Patients with HER2-normal breast cancer were treated with B and ddAC followed by B and nanoparticle albumin-bound P. Prospective LVEF measurement by multigated radionuclide angiography scan before and after every 2 week AC for 4 cycles and at month 6 from all three trials were aggregated to determine the early risks of cardiac dysfunction.

RESULTS

From January 2005 to May 2008, 245 patients were enrolled. The median age was 47 years (range, 27 to 75 years). Median LVEF pre-ddAC was 68% (range, 52% to 82%). LVEF post-ddAC was available in 241 patients (98%) and the median was unchanged at 68% (range, 47% to 81%). Per protocol no patients were ineligible for subsequent targeted biologic therapy based on LVEF decline post-ddAC. In addition, LVEF was available in 222 patients (92%) at 6 months, at which time the median LVEF was similar at 65% (range, 24% to 80%). Within 6 months of initiating chemotherapy, three patients (1.2%; 95% CI, 0.25% to 3.54%) developed CHF, all of whom received T.

CONCLUSION

Dose-dense AC with or without concurrent bevacizumab is not associated with frequent acute or short-term declines in LVEF.

Neoadjuvant chemotherapy for locally advanced breast cancer

Preoperative systemic therapy is the standard of care in locally advanced breast cancer. In this setting, the intent of preoperative systemic therapy is to expand surgical options and to improve survival. Locally advanced and inflammatory breast cancer have different biological features, but they share the use of preoperative (primary, neoadjuvant) systemic therapy as the initial treatment of choice. The management of these patients necessitates involvement of a multidisciplinary team from the onset and during therapy. The eradication of invasive cancer from the breast and axillary lymph nodes, pathologic complete response, is a predictor of outcome associated with improved disease-free and overall survival. However, conventional chemotherapy regimens result in pathologic complete response in only a minority of patients. The management of patients with residual invasive disease after preoperative therapy is a common clinical problem for which additional research is necessary. The differential expression of genes and pathways in locally advanced and inflammatory breast cancer allows for the exploitation of targeted therapy, and early trials have shown exciting target and tumor effects. Much work remains, and future trials combining targeted and conventional therapies based on molecular subtypes and/or specific targets are needed if we hope to improve survival for patients with locally advanced breast cancer.

Bevacizumab in the treatment of breast cancer

Current evidence indicates that angiogenesis plays an important role in the pathogenesis of several malignancies, including breast cancer. Bevacizumab is a monoclonal antibody that targets the vascular endothelial growth factor (VEGF). Recent clinical data have demonstrated that the addition of bevacizumab to first-line chemotherapy improves the progression-free survival (PFS) of patients with advanced breast cancer. This review presents an update on the clinical studies evaluating the role of bevacizumab in combination with chemotherapy, as well as other agents, both in advanced and early disease. Moreover, although no definitive biomarkers have been identified so far, we provide current data regarding potentially useful predictive factors for treatment with bevacizumab. In addition, we review the suggested mechanisms that lead to resistance to VEGF targeted therapies and we present recent data with respect to the toxicity of bevacizumab.

Neoadjuvant chemotherapy shows similar response in patients with inflammatory or locally advanced breast cancer when compared with operable breast cancer: a secondary analysis of the GeparTrio trial data

PURPOSE Neoadjuvant chemotherapy followed by mastectomy is the treatment of choice in patients with inflammatory breast cancer (IBC) or locally advanced breast cancer (LABC), but it is considered less effective in these diseases than in operable breast cancer (OBC). We report a prospective comparison of the GeparTrio trial of patients with IBC (cT4 days) or LABC (cT4a-c or cN3; stage IIIB or IIIC) and patients with OBC (cT2-3). PATIENTS AND METHODS Participants were stratified by stage and were randomly assigned to six or eight cycles of docetaxel/doxorubicin/cyclophosphamide (TAC) or to two cycles of TAC followed by four cycles of vinorelbine/capecitabine. We present results of a secondary aim of the study, which was to compare pathologic complete response (pCR; ie, no remaining invasive/noninvasive tumor in breast and lymph nodes) in different stage groups. Results A total of 287 patients with IBC (n = 93) or LABC (n = 194) and 1,777 patients with OBC were entered onto the trial. At baseline, parameters were as follows for the three types of cancer, respectively: median tumor sizes: 8.0 cm, 7.0 cm, and 4.0 cm (P < .001); multiple lesions: 31.2%, 27.3%, and 19.6% (P < .001); nodal involvement: 86.6%, 71.2%, and 51.6% (P < .001); grade 3: 44.4%, 30.4%, and 39.9% (P = .178); lobular-invasive type: 7.5%, 17.5%, and 13.3% (P = .673); negative hormone receptor status: 38.0%, 20.0%, and 36.4% (P = .008); and positive human growth factor receptor 2 status: 45.1%, 38.9%, and 35.7% (P = .158). Response rates for IBC, LABC, and OBC, respectively, were 8.6%, 11.3%, and 17.7% for pCR (P = .002); 71.0%, 69.6%, and 83.4% for overall response by physical or sonographic examination (P < .001); and 12.9%, 33.0%, and 69.9% for breast conservation (P < .001). All P values were for IBC and LABC versus OBC. However, tumor stage itself was not an independent predictor for pCR in multivariable analysis (odds ratio, 1.51; 95% CI, 0.88 to 2.59; P = .13). CONCLUSION No evidence of a difference in response to neoadjuvant chemotherapy was found by tumor stage when analysis was adjusted for baseline characteristics.

Molecular probes for the in vivo imaging of cancer

Advancements in medical imaging have brought about unprecedented changes in the in vivo assessment of cancer. Positron emission tomography, single photon emission computed tomography, optical imaging, and magnetic resonance imaging are the primary tools being developed for oncologic imaging. These techniques may still be in their infancy, as recently developed chemical molecular probes for each modality have improved in vivo characterization of physiologic and molecular characteristics. Herein, we discuss advances in these imaging techniques, and focus on the major design strategies with which molecular probes are being developed.

Quantifying antivascular effects of monoclonal antibodies to vascular endothelial growth factor: insights from imaging

PURPOSE

Little is known concerning the onset, duration, and magnitude of direct therapeutic effects of anti-vascular endothelial growth factor (VEGF) therapies. Such knowledge would help guide the rational development of targeted therapeutics from bench to bedside and optimize use of imaging technologies that quantify tumor function in early-phase clinical trials.

EXPERIMENTAL DESIGN

Preclinical studies were done using ex vivo microcomputed tomography and in vivo ultrasound imaging to characterize tumor vasculature in a human HM-7 colorectal xenograft model treated with the anti-VEGF antibody G6-31. Clinical evaluation was by quantitative magnetic resonance imaging in 10 patients with metastatic colorectal cancer treated with bevacizumab.

RESULTS

Microcomputed tomography experiments showed reduction in perfused vessels within 24 to 48 h of G6-31 drug administration (P

CONCLUSION

These data suggest that VEGF-specific inhibition induces rapid structural and functional effects with downstream significant antitumor activity within one cycle of therapy. This finding has important implications for the design of early-phase clinical trials that incorporate physiologic imaging. The study shows how animal data help interpret clinical imaging data, an important step toward the validation of image biomarkers of tumor structure and function.

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Key Words

• angiogenesis
• biomarker
• imaging
• vegf

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MESH Headings

• Adolescent
• Angiogenesis Inhibitors/therapeutic use
• Animals
• Antibodies, Monoclonal/pharmacology
• Antibodies, Monoclonal/therapeutic use
• Antibodies, Monoclonal, Humanized
• Bevacizumab
• Cell Line, Tumor
• Colorectal Neoplasms/blood supply
• Colorectal Neoplasms/drug therapy
• Diagnostic Imaging
• Drug Delivery Systems
• Female
• Humans
• Mice
• Mice, Nude
• Neovascularization, Pathologic/drug therapy
• Vascular Endothelial Growth Factor A/immunology
• Xenograft Model Antitumor Assays

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Grants

• A6086 Cancer Research UK
• G0902173 Medical Research Council
• C19221/A6086 Cancer Research UK

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Affiliation(s)

James P B O'Connor Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom. james.o'
Richard A D Carano
Andrew R Clamp
Jed Ross
Calvin C K Ho
Alan Jackson
Geoff J M Parker
Chris J Rose
Franklin V Peale
Michel Friesenhahn
Claire L Mitchell
Yvonne Watson
Caleb Roberts
Lynn Hope
Sue Cheung
Hani Bou Reslan
Mary Ann T Go
Glenn J Pacheco
Xiumin Wu
Tim C Cao
Sarajane Ross
Giovanni A Buonaccorsi
Karen Davies
Jurjees Hasan
Paula Thornton
Olivia del Puerto
Napoleone Ferrara
Nicholas van Bruggen
Gordon C Jayson

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Collaborators Collapse

Chemotherapy response monitoring of colorectal liver metastases by dynamic Gd-DTPA-enhanced MRI perfusion parameters and 18F-FDG PET metabolic rate

In this study, we examined the in vivo relationship between functional tumor vasculature, determined by dynamic contrast-enhanced (DCE-) MRI, and tumor metabolism, determined by dynamic (18)F-FDG PET, during cytotoxic treatment of patients with colorectal liver metastases.

METHODS

Twenty-three patients underwent DCE-MRI (using gadolinium dimeglumine) and dynamic (18)F-FDG PET at baseline and after 3 treatment cycles, unless treatment was terminated because of toxicity. Parameters for vasculature (rate constant between extravascular extracellular space and blood plasma [k(ep)] and volume transfer constant [K(trans)]), extracellular space (v(e)), tumor size (the maximal axial diameter of each included lesion [MAD]), and metabolism (glucose metabolic rates [MR(glc)]) were derived, and changes during treatment were correlated. Overall survival (OS) and progression-free survival (PFS) served as outcome measures for the predictive abilities of pretreatment parameters and of treatment-related parameter changes.

RESULTS

Pretreatment MR(glc) and MAD were individually predictive for OS and PFS. During treatment, K(trans) increased significantly, but this increase could not be confirmed in a lesion-by-lesion analysis. MR(glc) decreased significantly (P < 0.001). No correlations were found for changes in DCE-MRI parameters and DeltaMR(glc). No relationship was found between changes in DCE-MRI parameters and OS or PFS. DeltaMR(glc) was able to predict OS (P = 0.008) after correction for confounders.

CONCLUSION

The efficacy of cytotoxic chemotherapy assessed by reduction in tumor metabolism does not depend on pretreatment properties of the tumor vasculature determined by DCE-MRI. Cytotoxic chemotherapy does not alter DCE-MRI-derived properties of tumor vasculature but decreases glucose consumption of tumor cells.

Dose-dependent effect of radiation on angiogenic and angiostatic CXC chemokine expression in human endothelial cells

Blood vessel growth is regulated by angiogenic and angiostatic CXC chemokines, and radiation is a vasculogenic stimulus. We investigated the effect of radiation on endothelial cell chemokine signaling, receptor expression, and migration and apoptosis. Human umbilical vein endothelial cells were exposed to a single fraction of 0, 5, or 20 Gy of ionizing radiation (IR). All vasculogenic chemokines (CXCL1-3/5-8) increased 3-13-fold after 5 or 20 Gy IR. 20 Gy induced a marked increase (1.6-4-fold) in angiostatic CXC chemokines. CXCR4 expression increased 3.5 and 7-fold at 48 h after 5 and 20 Gy, respectively. Bone marrow progenitor cell chemotaxis was augmented by conditioned media from cells treated with 5 Gy IR. Whereas 5 Gy markedly decreased intrinsic cell apoptosis (0 Gy=16%+/-3.6 vs. 5 Gy=4.5%+/-0.3), 20 Gy increased it (21.4%+/-1.2); a reflection of pro-survival angiogenic chemokine expression. Radiation induces a dose-dependent increase in pro-angiogenic CXC chemokines and CXCR4. In contrast, angiostatic chemokines and apoptosis were induced at higher (20 Gy) radiation doses. Cell migration improved significantly following 5 Gy, but not 20 Gy IR. Collectively, these data suggest that lower doses of IR induce an angiogenic cascade while higher doses produce an angiostatic profile.

DCE-MRI assessment of the effect of vandetanib on tumor vasculature in patients with advanced colorectal cancer and liver metastases: a randomized phase I study

BACKGROUND

Vandetanib is a once-daily oral inhibitor of VEGFR, EGFR and RET signaling pathways. In patients with advanced colorectal cancer and liver metastases, the effect of vandetanib on tumor vasculature was assessed using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

METHODS

Eligible patients received vandetanib 100 or 300 mg/day. DCE-MRI (iAUC(60 )and K(trans)) was used to quantify the primary endpoints of tumor perfusion and vascular permeability. An exploratory assessment of tumor oxygenation was performed using MRI/T2*. All MRI parameters were measured at baseline (twice) and on days 2, 8, 29 and 57.

RESULTS

Twenty-two patients received vandetanib (n = 10, 100 mg; n = 12, 300 mg). Baseline measurements of iAUC(60 )and K(trans )were reproducible, with low intrapatient coefficients of variation (11% and 24%, respectively). Estimates of mean % changes from baseline were -3.4% (100 mg) and -4.6% (300 mg) for iAUC(60), and -4.6% (100 mg) and -2.7% (300 mg) for K(trans); these changes were not significantly different between doses. The exploratory T2* measurement showed a significant increase at 300 mg versus 100 mg (P = 0.006). Both doses of vandetanib were generally well tolerated; common toxicities were fatigue, rash and diarrhea (majority CTC grade 1 or 2). The pharmacokinetic profile of vandetanib was similar to that observed previously. There were no RECIST-defined objective responses; five patients experienced stable disease >/=8 weeks.

CONCLUSION

In this study in patients with advanced colorectal cancer, vandetanib did not modulate gadolinium uptake in tumor vasculature and tissue measured by the DCE-MRI parameters iAUC(60 )and K(trans).

TRIAL REGISTRATION

NCT00496509 (ClinicalTrials.gov); D4200C00050 (AstraZeneca).

Safety and efficacy of bevacizumab with hypofractionated stereotactic irradiation for recurrent malignant gliomas

PURPOSE

Preclinical studies suggest that inhibition of vascular endothelial growth factor (VEGF) improves glioma response to radiotherapy. Bevacizumab, a monoclonal antibody against VEGF, has shown promise in recurrent gliomas, but the safety and efficacy of concurrent bevacizumab with brain irradiation has not been extensively studied. The objectives of this study were to determine the safety and activity of this combination in malignant gliomas.

METHODS AND MATERIALS

After prior treatment with standard radiation therapy patients with recurrent glioblastoma (GBM) and anaplastic gliomas (AG) received bevacizumab (10 mg/kg intravenous) every 2 weeks of 28-day cycles until tumor progression. Patients also received 30 Gy of hypofractionated stereotactic radiotherapy (HFSRT) in five fractions after the first cycle of bevacizumab.

RESULTS

Twenty-five patients (20 GBM, 5 AG; median age 56 years; median Karnofsky Performance Status 90) received a median of seven cycles of bevacizumab. One patient did not undergo HFSRT because overlap with prior radiotherapy would exceed the safe dose allowed to the optic chiasm. Three patients discontinued treatment because of Grade 3 central nervous system intratumoral hemorrhage, wound dehiscence, and bowel perforation. Other nonhematologic and hematologic toxicities were transient. No radiation necrosis was seen in these previously irradiated patients. For the GBM cohort, overall response rate was 50%, 6-month progression-free survival was 65%; median overall survival was 12.5 months, and 1-year survival was 54%.

DISCUSSION

Bevacizumab with HFSRT is safe and well tolerated. Radiographic responses, duration of disease control, and survival suggest that this regimen is active in recurrent malignant glioma.

Imaging of tumor angiogenesis: functional or targeted?

OBJECTIVE

Angiogenesis--the growth of new vessels--is both a normal physiologic response and a critical step in many pathologic processes, particularly cancer. Imaging has long relied on the different enhancement characteristics of cancer compared with normal tissue; the information generated is often primarily morphologic and qualitative. However, more quantitative methods based on functional and targeted imaging have recently emerged.

CONCLUSION

In this article, we review both functional and targeted imaging techniques for assessing tumor angiogenesis.

Strategies to improve long-term outcome in stage IIIB inflammatory breast cancer: multimodality treatment including dose-intensive induction and high-dose chemotherapy

Inflammatory breast cancer (IBC) is a rare clinicopathologic entity with a poor prognosis, lagging far behind any other form of nonmetastatic breast cancer. Since the advent of systemic chemotherapy over 35 years ago, only minimal progress has been made in long-term outcome. Although multiple randomized trials of high-dose chemotherapy and autologous progenitor cell transplantation (ASCT) for the treatment of breast cancer have yielded disappointing results, these data are not necessarily relevant to IBC, a distinct clinical and pathologic entity. Therefore, the optimal multimodality therapy for IBC is not well established, and remains unsatisfactory. We treated 21 women with nonmetastatic IBC with a multimodality strategy including high-dose melphalan (Mel)/etoposide and ASCT. The treatment was overall tolerated with acceptable morbidity, and no post-ASCT 100-day mortality. With a median potential follow-up of approximately 8 years, the estimated progression-free survival (PFS), event-free survival (EFS), and overall survival (OS) at 6 years from on-study date are: 67%, 55%, and 69%, respectively. These results from a small phase II study are among the most promising of mature outcome data for IBC. They strongly suggest, along with results of several already published phase II trials, that ASCT could play a significant role in the first line treatment of IBC.

Predicting survival and early clinical response to primary chemotherapy for patients with locally advanced breast cancer using DCE-MRI

PURPOSE

To evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a tool for early prediction of response to neoadjuvant chemotherapy (NAC) and 5-year survival in patients with locally advanced breast cancer.

MATERIALS AND METHODS

DCE-MRI was performed in patients scheduled for NAC (n = 24) before and after the first treatment cycle. Clinical response was evaluated after completed NAC. Relative signal intensity (RSI) and area under the curve (AUC) were calculated from the DCE-curves and compared to clinical treatment response. Kohonen and probabilistic neural network (KNN and PNN) analysis were used to predict 5-year survival.

RESULTS

RSI and AUC were reduced after only one cycle of NAC in patients with clinical treatment response (P = 0.02 and P = 0.08). The mean and 10th percentile RSI values before NAC were significantly lower in patients surviving more than 5 years compared to nonsurvivors (P = 0.05 and 0.02). This relationship was confirmed using KNN, which demonstrated that patients who remained alive clustered in separate regions from those that died. Calibration of contrast enhancement curves by PNN for patient survival at 5 years yielded sensitivity and specificity for training and testing ranging from 80%-92%.

CONCLUSION

DCE-MRI in locally advanced breast cancer has the potential to predict 5-year survival in a small patient cohort. In addition, changes in tumor vascularization after one cycle of NAC can be assessed.

Phase I dose escalation study of telatinib, a tyrosine kinase inhibitor of vascular endothelial growth factor receptor 2 and 3, platelet-derived growth factor receptor beta, and c-Kit, in patients with advanced or metastatic solid tumors

PURPOSE

Telatinib (BAY 57-9352) is an orally available tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR) -2, VEGFR-3, platelet-derived growth factor receptor-beta, and c-Kit. This phase I dose escalation study was conducted to evaluate the safety and tolerability of telatinib, with additional pharmacokinetic, pharmacodynamic, and efficacy assessments.

PATIENTS AND METHODS

Patients with solid tumors refractory to standard therapies or with no standard therapy available were enrolled. Doses of continuously administered telatinib were escalated from 20 mg once daily to 1,500 mg twice daily.

RESULTS

Fifty-three patients were enrolled. Most frequently observed drug-related adverse events were nausea (26.4%; grade >or= 3, 0%) and hypertension (20.8%; grade 3, 11.3%; grade 4, 0%). Two dose-limiting toxicities were observed: one poorly controlled hypertension (600 mg twice daily), and one grade 2 weight loss, anorexia, and fatigue (1,500 mg twice daily). A formal maximum-tolerated dose was not reached. Telatinib was rapidly absorbed, with median time to peak concentration (t(max)) lower than 3 hours after dose. A nearly dose-proportional increase in exposure was observed with substantial variability. Telatinib half-life averaged 5.5 hours. Biomarker analyses showed dose-dependent increase in VEGF levels and decrease in plasma soluble VEGFR-2 levels, with a plateau at 900 mg twice daily. A decrease in tumor blood flow (K(trans) and IAUC(60)) was observed with dynamic contrast-enhanced magnetic resonance imaging. Best tumor response was stable disease, observed in 50.9% of patients.

CONCLUSION

Telatinib was safe and well tolerated up to 1,500 mg twice daily. Based on pharmacodynamic and pharmacokinetic end points, telatinib 900 mg twice daily is the recommended dose for subsequent phase II studies.

Bevacizumab plus irinotecan in the treatment patients with progressive recurrent malignant brain tumours

MATERIAL AND METHODS

We retrospectively determined the efficacy and safety of a combination of bevacizumab and irinotecan in a consecutive series of 52 heavily pre-treated patients with recurrent high-grade brain tumours. Patients received bevacizumab (10 mg/kg) and irinotecan [340 mg/m(2) for those receiving enzyme-inducing antiepileptic drugs (EIAEDs) and 125 mg/m(2) for those not receiving EIAEDs] every 2 weeks. Fifty-two patients were included and 47 were evaluable for response.

RESULTS

Complete or partial response was observed in 25% of all cases (30% response in grade IV glioma and 15% in grade III glioma). Estimated median progression-free survival (PFS) for both grade IV and grade III glioma was 22 weeks. The 6-month PFS was 32% for all patients, 40% for grade IV glioma and 33% for grade III glioma. Estimated median overall survival was 30 weeks for all patients, 28 weeks for grade IV glioma and 32 weeks for grade III glioma. Four patients discontinued treatment because of unmanageable toxicity: cerebral haemorrhage, cardiac arrhythmia, intestinal perforation and diarrhoea, the latter resulting in death.

DISCUSSION

We conclude that the combination of bevacizumab and irinotecan shows acceptable safety and is a clinically relevant choice of therapy in heavily pre-treated patients with recurrent high-grade brain tumours.

Adverse effects of anticancer agents that target the VEGF pathway

Antiangiogenesis agents that target the VEGF/VEGF receptor pathway have become an important part of standard therapy in multiple cancer indications. With expanded clinical experience with this class of agents has come the increasing recognition of the diverse adverse effects related to disturbance of VEGF-dependent physiological functions and homeostasis in the cardiovascular and renal systems, as well as wound healing and tissue repair. Although most adverse effects of VEGF inhibitors are modest and manageable, some are associated with serious and life-threatening consequences, particularly in high-risk patients and in certain clinical settings. This Review examines the toxicity profiles of anti-VEGF antibodies and small-molecule inhibitors. The potential mechanisms of the adverse effects, risk factors, and the implications for selection of patients and management are discussed.

Molecular targets for treatment of inflammatory breast cancer

Despite progress in combined-modality treatment with chemotherapy, surgery, and radiation therapy, the long-term outcome for patients with inflammatory breast cancer (IBC) remains poor. Therapies that target vasculolymphatic processes--angiogenesis, lymphangiogenesis, and vasculogenesis--have shown potential in the treatment for IBC, as represented by bevacizumab. Although the therapeutic effect of targeting lymphangiogenesis and vasculogenesis requires further investigation, targeting of angiogenesis has potential, not only through true antiangiogenic effects, but also through antitumor effects in concert with other pathways. Therapies that target cell proliferation pathways are the most promising targeted therapies for IBC. In particular, therapies that target human epidermal growth factor receptor 2 (for example, trastuzumab and lapatinib) have performed well in the clinical setting, leading to improved outcomes for patients with IBC. Metastatic pathways could have a unique, key role in the aggressiveness of the IBC phenotype. Further extensive work on the unique molecular characteristics of IBC is essential to ensure improved outcomes for patients with this disease. In this Review we discuss three pathways--vasculolymphatic, cell proliferation and metastatic--that could represent important targets in the treatment of IBC.

Safety, pharmacokinetics, and antitumor activity of AMG 386, a selective angiopoietin inhibitor, in adult patients with advanced solid tumors

PURPOSE AMG 386 is an investigational peptide-Fc fusion protein (ie, peptibody) that inhibits angiogenesis by preventing the interaction of angiopoietin-1 and angiopoietin-2 with their receptor, Tie2. This first-in-human study evaluated the safety, pharmacokinetics (PK), pharmacodynamics, and antitumor activity of AMG 386 in adults with advanced solid tumors. PATIENTS AND METHODS Patients in sequential cohorts received weekly intravenous AMG 386 doses of 0.3, 1, 3, 10, or 30 mg/kg. Results Thirty-two patients were enrolled on the study and received AMG 386. One occurrence of dose-limiting toxicity was seen at 30 mg/kg: respiratory arrest, which likely was caused by tumor burden that was possibly related to AMG 386. The most common toxicities were fatigue and peripheral edema. Proteinuria (n = 11) was observed without clinical sequelae. Only four patients (12%) experienced treatment-related toxicities greater than grade 1. A maximum-tolerated dose was not reached. PK was dose-linear and the mean terminal-phase elimination half-life values ranged from 3.1 to 6.3 days. Serum AMG 386 levels appeared to reach steady-state after four weekly doses, and there was minimal accumulation. No anti-AMG 386 neutralizing antibodies were detected. Reductions in volume transfer constant (K(trans); measured by dynamic contrast-enhanced magnetic resonance imaging) were observed in 10 patients (13 lesions) 48 hours to 8 weeks after treatment. One patient with refractory ovarian cancer achieved a confirmed partial response (ie, 32.5% reduction by Response Evaluation Criteria in Solid Tumors) and withdrew from the study with a partial response after 156 weeks of treatment; four patients experienced stable disease for at least 16 weeks. CONCLUSION Weekly AMG 386 appeared well tolerated, and its safety profile appeared distinct from that of vascular endothelial growth factor-axis inhibitors. AMG 386 also appeared to impact tumor vascularity and showed antitumor activity in this patient population.

Residual breast cancer diagnosed by MRI in patients receiving neoadjuvant chemotherapy with and without bevacizumab

PURPOSE

To investigate the impact of antiangiogenic therapy with bevacizumab on pathological response and the diagnostic performance of magnetic resonance imaging (MRI) in breast cancer patients.

METHODS

Thirty-six patients (aged 31-69 years) with breast cancer were included. Sixteen patients received neoadjuvant chemotherapy (NAC) containing bevacizumab, and 20 patients received the same NAC protocol without bevacizumab. Serial MRI studies were performed to evaluate response. All patients received surgery after completing NAC. The extent of residual disease was examined by histopathology, and classified into three types (pCR-pathologic complete response, confined nodules, and scattered cells). Fisher's exact test and general logistic regression models were applied to analyze differences between two groups.

RESULTS

pCR rates and residual disease (nodular and scattered cell) patterns were comparable between the two groups. The diagnostic accuracy rate of MRI (true positive and true negative) was 13/17 (76%) for patients with bevacizumab, and 14/20 (70%) for patients without bevacizumab. The size measured on MRI was accurate for mass lesions that shrank down to nodules, showing <0.7 cm discrepancy from pathological size. For residual disease presenting as scattered cells within a large fibrotic region, MRI could not predict them correctly, resulting in a high false-negative rate and a large size discrepancy.

CONCLUSION

The pathological response and the diagnostic performance of MRI are comparable between patients receiving NAC with and without bevacizumab. In both groups MRI has a limitation in detecting residual disease broken down to small foci and scattered cells/clusters. When MRI is used to evaluate the extent of residual disease for surgical treatment, the limitations, particularly for nonmass lesions, should be considered.