Thrombotic events in patients with cancer receiving antiangiogenesis agents

Cancer-Associated Thrombosis: Regulatory Mechanisms and Emerging Directions

Venous thrombosis is a common complication in cancer patients, and some cancer chemotherapies are associated with an increased risk of venous thromboembolism. The regulatory mechanisms that control thrombus formation and subsequent resolution in patients with cancer, however, are incompletely understood, and novel treatments for cancer-associated thrombosis may arise from a better understanding of such mechanisms. In this chapter, pathways that regulate cancer-associated thrombus formation are outlined, and the effects of anti-angiogenic cancer chemotherapies on venous thrombus resolution are highlighted. Potentially pro-thrombotic effects of anti-angiogenic agents are important considerations when managing the complications of venous thrombosis in cancer patients.

Pituitary Apoplexy After Intravitreal Injection of Vascular Endothelial Growth Factor Inhibitor: A Novel Complication

Pituitary adenomas are common in the general population. They can be complicated by intratumoral hemorrhage, otherwise known as apoplexy, which frequently presents with neurologic deficits that may necessitate urgent surgical decompression. Many risk factors for pituitary apoplexy have been suggested in the literature. We present a case of symptomatic apoplexy in a woman following the intravitreal administration of the vascular endothelial growth factor (VEGF) inhibitor ranibizumab. Ophthalmoplegia resolved and visual acuity significantly improved following gross total resection of the tumor via an endoscopic endonasal surgical approach. The association between intravitreal injection of a VEGF inhibitor and pituitary apoplexy has not been previously described, but physicians performing these procedures should be aware of this potential complication.

Bevacizumab promotes venous thromboembolism through the induction of PAI-1 in a mouse xenograft model of human lung carcinoma

Background

An increased incidence of venous thromboembolism (VTE) is associated with anti-vascular endothelial growth factor (VEGF) treatment in cancer. However, the mechanism underlying this effect remains elusive. In this study, we examined the effect of bevacizumab, a humanized monoclonal antibody against VEGF-A, on VTE in a murine xenograft A549 cell tumor model.

Methods

Inferior vena cava stenosis model and FeCl₃-induced saphenous vein thrombosis model were performed in a mouse xenograft models of human lung adenocarcinoma.

Results

We found that treatment with bevacizumab significantly increased the thrombotic response to inferior vena cava obstruction and femoral vein injury. Plasminogen activator inhibitor (PAI-1) expression in tumors, plasma, and thrombi was significantly increased by bevacizumab. However, bevacizumab did not enhance VTE in PAI-1-deficient mice, suggesting that PAI-1 is a major mediator of bevacizumab’s prothrombotic effect. VEGF inhibited expression of PAI-1 by A549 cells, and this effect was neutralized by bevacizumab, suggesting that bevacizumab increases PAI-1 expression in vivo by blocking the inhibitory effect of VEGF on PAI-1 expression by tumor cells. Pharmacological inhibition of PAI-1 with PAI-039 blocked bevacizumab-induced venous thrombosis.

Conclusion

Collectively, these findings indicate that PAI-1 plays a role in VTE associated with antiangiogenic therapy and the inhibition of PAI-1 shows efficacy as a therapeutic strategy for the prevention of bevacizumab-associated VTE.

Guidelines for treatment and prevention of venous thromboembolism among patients with cancer

The association between cancer and thrombosis has been recognized for more than 150 years. Not only are patients with cancer at a substantially increased risk of developing venous thromboembolism (VTE), the link between several coagulation factors and tumor growth, invasion, and the development of metastases has been established. Reported rates of VTE in patients with cancer have increased in recent years likely reflecting, in part, improved diagnosis with sophisticated imaging techniques as well as the impact of more aggressive cancer diagnosis, staging, and treatment. Various therapeutic interventions, such as surgery, chemotherapy, hormonal therapy, targeted therapeutic strategies as well as the frequent use of indwelling catheters and other invasive procedures also place cancer patients at increased risk of VTE. The increasing risk of VTE, the multitude of risk factors, and the greater risk of VTE recurrence and death among patients with cancer represent considerable challenges in modern clinical oncology. The American Society of Clinical Oncology (ASCO) originally developed guidelines for VTE in patients with cancer in 2007. ASCO recently updated clinical practice guidelines on the treatment and prevention of VTE in patients with cancer following an extensive systematic review of the literature. Revised 2013 guidelines have now been presented and will be discussed in this review. Although several new studies were identified and considered, many important questions remain regarding the relationship between thrombosis and cancer and the optimal care of patients at risk for VTE.

The adverse effects of sorafenib in patients with advanced cancers

Sorafenib is the first multi-kinase inhibitor (TKI) approved for the treatment of advanced hepatocellular cancer (HCC) and metastatic renal cell cancer (RCC) and is increasingly being used to treat patients with well-differentiated radioiodine-resistant thyroid cancer (DTC). Sorafenib demonstrates targeted activity on several families of receptor and non-receptor tyrosine kinases that are involved in angiogenesis, tumour growth and metastatic progression of cancer. Sorafenib treatment results in long-term efficacy and low incidence of life-threatening toxicities. Although sorafenib has demonstrated many benefits in patients, the adverse effects cannot be ignored. The most common treatment-related toxicities include diarrhoea, fatigue, hand-foot skin reaction and hypertension. Most of these toxicities are considered mild to moderate and manageable to varying degrees; however, cardiovascular events might lead to death. In this MiniReview, we summarize the adverse effects of sorafenib that commonly occur in patients with advanced cancers.

Practical management of bevacizumab-related toxicities in glioblastoma

Bevacizumab, currently an option for treatment of different types of tumors including glioblastoma, has a peculiar toxicity profile related to its antiangiogenic effect. Because some bevacizumab-related adverse events can be life threatening, it is important to identify risk factors and to establish treatment protocols to minimize treatment-related morbidity and mortality. In glioblastoma patients, the risk of developing certain side effects, such as gastrointestinal perforation, venous thromboembolism, and intracranial hemorrhages, is slightly higher than in patients treated with bevacizumab for other tumor types. We performed a systematic review of the side effects of bevacizumab and their incidence, causal mechanisms, and available treatments. Finally, we identified risk factors and proposed preventive and therapeutic measures for these adverse events.

Bi-modal cancer treatment utilizing therapeutic ultrasound and an engineered therapeutic nanobubble

We developed a bi-modal cancer therapy comprising a sorafenib loaded ultra-sonic responsive nanobubble (SRF-NB) for ultrasonic assisted delivery in hepatocellular carcinoma.

Posterior Reversible Encephalopathy Syndrome and Anti-Angiogenic Therapy

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological entity first described in 1996 by Hinchey et al, most commonly associated with hypertensive encephalopathy, eclampsia in pregnant women, immunosuppressants and cytotoxic agents. In recent years, anti-angiogenic agents as a novel class of anti-cancer therapies have become a standard of care for certain tumours. Correspondingly, there have been an emerging number of case reports documenting PRES associated with these anti-angiogenic therapies. As the manifestations of PRES are often non-specific, but could rarely lead to permanent neurological disability or even death, it is crucial that physicians are aware of PRES in relation to anti-angiogenic therapy to promptly institute appropriate management to achieve the best outcomes for patients.

Retrospective evaluation of thromboembolic events in patients with non-small cell lung cancer treated with platinum-based chemotherapy

OBJECTIVES

Thromboembolic events (TE) are common in patients with cancer and are potentially life-threatening. In lung cancer, little is known about thrombosis during chemotherapy treatment. The aim of this study was to describe the incidence of TE in patients with non-small cell lung cancer (NSCLC), occurring during treatment with platinum-based chemotherapy.

METHODS

We retrospectively selected patients with NSCLC treated with platinum-based chemotherapy at the VU University Medical Center Amsterdam between 2000 and 2012. Patients who underwent recent surgery were excluded. All TE were included that occurred from start of chemotherapy treatment until 30 days after last administration.

RESULTS

Among 784 included patients, 63 (8.0%) patients had 69 TE during treatment. Forty-five venous TE (VTE) and 24 arterial TE (ATE). Six patients had multiple events within treatment period, 3 of which had simultaneous ATE and VTE. In total, 613 patients were treated with cisplatin, 119 patients received carboplatin and 52 patients received both in first- or second-line treatment. In 8% (55/665) of the patients exposed to cisplatin a TE had occurred vs. 5% (8/171) in patients exposed to carboplatin (p=0.42). The majority of TE occurred in the first 2 cycles (70%). History of TE was related to occurrence of TE during chemotherapy (p<0.01). Median PFS was similar in patients with and without TE (6.2 vs. 7.2 months, respectively; p=0.10). Median OS was significantly shorter in patients with TE (9.5 vs. 12.9 months, respectively; p=0.03).

CONCLUSION

In our series, both ATE and VTE were a common finding during chemotherapy. TE was a poor prognostic factor. No difference in TE incidence was found between patients treated with cisplatin or carboplatin.

Risk of thrombosis in women with malignancies undergoing ovarian stimulation for fertility preservation

BACKGROUND

Compared with the general population, cancer patients have a higher risk of venous thromboembolism as well as arterial thrombotic events such as stroke, myocardial infarction and peripheral arterial embolism. Therefore a possible concern for women with malignancies undergoing ovarian stimulation for fertility preservation is the increased risk of venous or arterial thrombosis.

METHODS

In this article, we revised current available literature on the risk of thrombosis in patients with cancer and in women undergoing ovarian stimulation, with the ultimate aim of drawing some indications for preventive measures.

RESULTS

Unfortunately, there are no specific data on the risk of thrombosis in women with cancer undergoing ovarian stimulation for fertility preservation. However, the literature suggests that the cancer type and stage, surgery, and chemotherapy all influence the risk of venous and, possibly, arterial thrombosis. Reports of cases of ovarian stimulation in women without malignancies have shown that venous thrombosis rarely occurs unless a pregnancy is achieved, while arterial thrombosis can occur in the absence of pregnancy but is usually only associated with ovarian hyperstimulation syndrome (OHSS). OHSS increases the risk of thrombotic events, but only the early form of the syndrome is relevant for women undergoing fertility preservation.

CONCLUSIONS

The available evidence on the risks of thrombosis for women undergoing ovarian stimulation for fertility preservation due to a malignancy is reassuring. However the avoidance of the early form of OHSS in women preserving oocytes/embryos due to malignancy is crucial. For these cycles, we advocate the use of a regimen of ovarian stimulation with gonadotrophin releasing hormone (GnRH) antagonists using GnRH agonists to trigger ovulation, an approach that has been shown to markedly reduce the risk of OHSS. Antithrombotic prophylaxis should be administered only to selected subgroups of women such as those with other risk factors or those who do develop early OHSS.

Outcome of acute limb ischemia in cancer patients

The optimal management strategy for acute limb ischemia (ALI) in patients with a concomitant malignancy is not well established. A very high mortality rate (83–100%) at 1 year has been reported in those who are treated surgically. Accordingly, a conservative management approach has been suggested as the main therapeutic modality. Our aim was to evaluate the survival outcomes of cancer patients treated for ALI at our cancer center. Cancer patients treated for ALI at the MD Anderson Cancer Center from 2001 to 2011 were included in this study. Overall survival and amputation-free survival rates were calculated. A total of 74 cancer patients with concomitant ALI were included in the study. Surgery was the most common therapy (36 patients; 49%). Percutaneous catheter-based interventions were used in 21 patients (28%). Eighteen patients (24%) received anticoagulation therapy only, and six patients (8%) received no therapy. The 30-day, 6-month, and 1-year overall survival rates were 80% (95% confidence interval [CI], 69% to 87%), 59% (95% CI, 47% to 69%), and 48% (95% CI, 36% to 59%), respectively. Eight patients (11%) underwent amputation. The 1-year amputation-free survival rate was 47% (95% CI, 35% to 58%). In conclusion, we did not find an invasive approach for the treatment of ALI in cancer patients to be associated with the very high mortality rates previously reported. In our opinion, the indications for surgery or catheter-based intervention in these patients should not differ from patients without cancer.

Targeted therapy with kinase inhibitors in aggressive endocrine tumors

INTRODUCTION

Kinase inhibitors (KIs) are a class of anticancer drugs that inhibit activity of the enzymes protein kinases, which regulate crucial cellular processes and have a demonstrated role in human oncogenesis. Treatment of advanced forms of endocrine cancer which are not responsive to cytotoxic chemotherapies is challenging and use of KIs is gaining a growing role in this field.

AREAS COVERED

The authors summarize the main genetic alterations known to be linked to endocrine tumors, indicating the rationale for utilizing KIs. Furthermore, they present an updated analysis of clinical trials available on PubMed Central, which were pertinent to the activities of KIs in aggressive endocrine cancer. The authors also discuss the adverse effects of KIs and summarize likely involved underlying mechanisms.

EXPERT OPINION

KIs are effective in obtaining a radiological disease control and an improvement of progression-free survival in several forms of endocrine cancer but will never deliver a knockout blow of the disease, due to mechanisms of adaptation to circumvent the specific molecular blockade. The new frontier of KIs treatment is to identify agents that could synergize activity of KIs. The true goal will be to perform an overall genotyping of each tumor, thus predicting the impact of combined targeted therapies in the context of a particular constellation of mutant genes.

Recurrent glioblastoma treated with bevacizumab: contrast-enhanced T1-weighted subtraction maps improve tumor delineation and aid prediction of survival in a multicenter clinical trial

PURPOSE

To compare the capability to aid prediction of clinical outcome measures, including progression-free survival (PFS) and overall survival (OS), between volumetric estimates from contrast material-enhanced (CE) T1-weighted subtraction maps and traditional segmentation in a randomized multicenter clinical trial of recurrent glioblastoma (GBM) patients treated with bevacizumab.

MATERIALS AND METHODS

All patients participating in this study signed institutional review board-approved informed consent at their respective institutions prior to enrolling in the multicenter clinical trial. One-hundred sixty patients with recurrent GBM enrolled as part of a HIPAA-compliant, multicenter clinical trial (AVF3708 g, BRAIN trial). Contrast-enhancing tumor volumes and change in volumes as a response to therapy were quantified by using either conventional segmentation or CE T1-weighted subtraction maps created by voxel-by-voxel subtraction of intensity-normalized nonenhanced T1-weighted images from CE T1-weighted images. These volumes were then tested as predictors of PFS and OS by using log-rank univariate analysis, the multivariate Cox proportional hazards regression model, and receiver operating characteristic analysis.

RESULTS

Use of CE T1-weighted subtraction maps qualitatively improved visualization and improved quantification of tumor volume after bevacizumab treatment. Significant trends between the volume of tumor and change in tumor volume after therapy on CE T1-weighted subtraction maps were found for both PFS and OS (pretreatment volume < 15 cm(3), P < .003; posttreatment volume < 7.5 cm(3), P < .05; percentage change in volume > 25%, P = .004 for PFS and P = .053 for OS). CE T1-weighted subtraction maps were significantly better at aiding prediction of 6-month PFS and 12-month OS compared with conventional segmentation by using receiver operating characteristic analysis (P < .05).

CONCLUSION

Use of CE T1-weighted subtraction maps improved visualization and aided better prediction of patient survival in recurrent GBM treated with bevacizumab compared with conventional segmentation of CE T1-weighted images. Clinical trial registration no. NCT00345163. Online supplemental material is available for this article.

Ursolic acid inhibits colorectal cancer angiogenesis through suppression of multiple signaling pathways

Angiogenesis plays a critical role in the development of solid tumors by supplying nutrients and oxygen to support continuous growth of tumor as well as providing an avenue for hematogenous metastasis. Tumor angiogenesis is highly regulated by multiple intracellular signaling transduction cascades such as Hedgehog, STAT3, Akt and p70S6K pathways that are known to malfunction in many types of cancer including colorectal cancer (CRC). Therefore, suppression of tumor angiogenesis through targeting these signaling pathways has become a promising strategy for cancer chemotherapy. Ursolic acid (UA) is a major active compound present in many medicinal herbs that have long been used in China for the clinical treatment of various types of cancer. Although previous studies have demonstrated an antitumor effect for UA, the precise mechanisms of its anti-angiogenic activity are not well understood. To further elucidate the mechanism(s) of the tumorcidal activity of UA, using a CRC mouse xenograft model, chick embryo chorioallantoic membrane (CAM) model, the human colon carcinoma cell line HT-29 and human umbilical vein endothelial cells (HUVECs), in the present study we evaluated the efficacy of UA against tumor growth and angiogenesis in vivo and in vitro and investigated the underlying molecular mechanisms. We found that administration of UA significantly inhibited tumor volume but had no effect on body weight changes in CRC mice, suggesting that UA can suppress colon cancer growth in vivo without noticeable signs of toxicity. In addition, UA treatment reduced intratumoral microvessel density (MVD) in CRC mice, decreased the total number of blood vessels in the CAM model, and dose and time-dependently inhibited the proliferation, migration and tube formation of HUVECs, demonstrating UA's antitumor angiogenesis in vivo and in vitro. Moreover, UA treatment inhibited the expression of critical angiogenic factors, such as VEGF-A and bFGF. Furthermore, UA suppressed the activation of sonic hedgehog (SHH), STAT3, Akt and p70S6K pathways. Collectively, our findings suggest that inhibition of tumor angiogenesis via suppression of multiple signaling pathways might be one of the mechanisms whereby UA can be effective in cancer treatment.

Neoadjuvant bevacizumab: surgical complications of mastectomy with and without reconstruction

Neoadjuvant therapy (NAC) is commonly used in operable breast cancer. Previous studies have suggested a high rate of postoperative complications after NAC. We prospectively evaluated the surgical complications in a cohort of patients who underwent mastectomy following neoadjuvant adriamycin/cytoxan/taxol (AC/T) plus bevacizumab (bev) and compared the rate of complications to a matched cohort of neoadjuvant AC/T without bev. One hundred patients with HER2-negative breast cancer enrolled in a single-arm trial of neoadjuvant AC/T plus bev (cohort 1), 60 of these patients underwent mastectomy and were matched with 59 patients who received standard neoadjuvant AC/T (cohort 2) over a similar time period in the same healthcare system. All patients underwent mastectomy with or without reconstruction. Fisher's exact tests were used to compare complication rates, with p < 0.05 considered significant. Patients were matched well in terms of demographics. The overall complication rate was 32 % in cohort 1 and 31 % in cohort 2 (p value = 1, Table 1). In cohort 1, 7 of 23 (30 %) patients who underwent immediate expander/implant reconstruction had complications, including 2 patients who had explantation of their reconstructions. In cohort 2, 0 of 8 (0 %) had complications (p value = 0.15). Nearly a third of patients undergoing NAC with AC/T with or without bev developed a postoperative complication after mastectomy. The use of bev was not associated with a significant increase in surgical complications, although this is a nonrandomized data set with a small sample size. As larger data sets become available with the use of neoadjuvant bevacizumab with mastectomy, further refinement may be necessary.

Clinical and genetic factors associated with venous thromboembolism in myeloma patients treated with lenalidomide-based regimens

Lenalidomide has significant antimyeloma activity but it is associated with a significant risk of venous thromboembolism (VTE). In this study, we assessed clinical and genetic risk factors that may predispose for VTE in myeloma patients who were treated with lenalidomide-based regimens. We analyzed common clinical and selected genetic factors in 200 consecutive, unselected myeloma patients who were treated with lenalidomide-based regimens in a single institution. Twelve patients (6%) developed a VTE (nine deep venous thrombosis and three pulmonary embolism). All VTEs occurred in patients who were receiving aspirin prophylaxis; no patient who received LMWH or acenocoumarol had a VTE. The frequency of VTEs was 9.4% in previously untreated and 4.5% in previously treated patients. VTEs were more frequent in patients >65 years (8.1% vs. 1.6%) especially among patients receiving aspirin as prophylaxis (10.4% vs. 1.8% for patients ≤65 years). In patients who received prophylaxis with low dose aspirin a single-nucleotide polymorphism in NFκB1 (rs3774968) gene was associated with increased risk of VTE (OR 3.76, 95%CI 1-16, P = 0.051). None of the patients who developed VTEs had common genetic variations that are associated with increased risk of VTEs in the general population, such as FVLeiden and FIIG20210A. Our data indicated that LMWH or vitamin K antagonists (with a target INR 2-3) effectively reduce the risk of VTEs. In patients who received prophylaxis with aspirin genetic variants of genes that are involved directly or indirectly in inflammatory response may be associated with increased risk of VTE.

Role of bevacizumab in colorectal cancer growth and its adverse effects: A review

Angiogenesis affects both wound healing and malignant cell growth through nutrients and oxygen. Vascular endothelial growth factor (VEGF) is the most important element involved in this complex process. Inhibition of VEGF influences angiogenesis and may restrict tumor growth and metastatic ability. Modern anti-angiogenic therapy is based on this theory. Bevacizumab is a recombinant humanized monoclonal antibody (immunoglobulin G1) which binds with VEGF-A forming a large molecule. It can not be bound with VEGF tyrosine kinase receptors preventing VEGF-A incorporation; thus its activity is inhibited inducing blockage of VEGF-mediated angiogenesis. Bevacizumab, in combination with chemotherapy or other novel targeted therapeutic agents, is currently used more frequently in clinical practice, mainly for managing advanced colorectal cancer. It is also used for managing other malignancies, such as breast cancer, pancreatic cancer, prostate cancer, non small-cell lung cancer, metastatic renal carcinoma and ovarian tumors. Although it is generally considered a safe treatment, there are reports of some rare side effects which should be taken into account. Recent experiments in rats and mice show promising results with a wider therapeutic range.

Combination therapy for scalp angiosarcoma using bevacizumab and chemotherapy: a case report and review of literature

Bevacizumab, an angiogenesis inhibitor, is a recombined humanized monoclonal antibody against vascular endothelial growth factor and a promising therapeutic option for angiosarcoma management. This is a case report and review of the literature using bevacizumab and combination chemotherapy for angiosarcoma. The understanding of the effectiveness of combined therapy of bevacizumab and chemotherapy agents is still limited. The benefits of bevacizumab treatment for angiosarcoma will need to be weighed against the risks of venous thromboembolism in this population.

Targeted agent use in cancer patients at the end of life

CONTEXT

The use of targeted therapy at the end of life has not been well characterized.

OBJECTIVES

To determine the frequency and predictors of targeted therapy use in the last days of life.

METHODS

All adult patients residing in the Houston area who died of advanced cancer between September 1, 2009 and February 28, 2010 and had contact with our institution within the last three months of life were included. We collected baseline demographics and data on chemotherapy and targeted agents.

RESULTS

Eight hundred sixteen patients were included: average age 62 years (range 21-97), female 48% and white 61%. The median interval between the last treatment and death was 47 (interquartile range [IQR] 21-97) days for targeted agents and 57 (IQR 26-118) days for chemotherapeutic agents. Within the last 30 days of life, 116 (14%) patients received targeted agents and 147 (18%) received chemotherapy. Regimens given in the last 30 days of life included a median of one (IQR 1-2) chemotherapeutic or targeted agent and 43 (5%) patients receiving targeted agents had concurrent chemotherapy. The most common targeted agents in the last 30 days of life were erlotinib (n = 25), bevacizumab (n = 20), rituximab (n = 11), gemtuzumab (n = 8), and temsirolimus (n = 8). On multivariate analysis, younger age (odds ratio [OR] 0.98 per year, P = 0.01), hematologic malignancy (OR = 6.1, P < 0.001), and lung malignancy (OR = 2.6, P = 0.05) were associated with increased targeted agent use in the last 30 days of life.

CONCLUSION

Targeted agents were used as often as chemotherapy at the end of life, particularly among younger patients and those with hematologic malignancies. Guidelines on targeted therapy use at the end of life are needed.

Thromboembolic disease in patients with high-grade glioma

Venous thromboembolism (VTE) is common throughout the course of disease in high-grade glioma (HGG). The interactions between the coagulation cascade, endothelium, and regulation of angiogenesis are complex and drive glioblastoma growth and invasion. We reviewed the incidence of VTE in HGG, the biology of the coagulome as related to glioblastoma progression, prevention and treatment of thrombosis, and the putative role of anticoagulants as anti-cancer therapy. VTE can be significantly reduced during the postoperative period with adherence to the use of mechanical and medical thromboprophylaxis. Activation of the coagulation cascade occurs throughout the course of disease because of a variety of complex interactions, including tumor hypoxia, upregulation of VEGR expression, and increases in both tumor cell-specific tissue factor (TF) expression and inducible TF expression in numerous intrinsic regulatory pathways. Long-term anticoagulation to prevent VTE is an attractive therapy; however, the therapeutic window is narrow and current data do not support its routine use. Most patients with proven symptomatic VTE can be safely anticoagulated, including those receiving anti-VEGF therapy, such as bevacizumab. Initial therapy should include low molecular weight heparin (LMWH), and protracted anticoagulant treatment, perhaps indefinitely, is indicated for patients with HGG because of the ongoing risk of thrombosis. A variety of coagulation- and tumor-related proteins, such as TF and circulating microparticles, may serve as potential disease-specific biomarkers in relation to disease recurrence, monitoring of therapy, and as potential therapeutic targets.

Anti-angiogenic therapy in high-grade glioma (treatment and toxicity)

OPINION STATEMENT

Malignant gliomas continue to have a very poor prognosis and treatment responses at recurrence are very limited. Though anti-angiogenic therapy has not yet been shown to extend overall survival in this patient population, there is likely substantial benefit to reducing vasogenic edema, allowing for temporary improvement in neurologic function, and minimizing the side effects of prolonged corticosteroid use. A trial of bevacizumab should be considered in those with worsening vasogenic cerebral edema such as seen in recurrent malignant gliomas, radiation necrosis, or progressive brain metastases. However, not all patients respond to anti-angiogenic treatment and if no radiographic or clinical responses are seen, then patients are not likely to benefit from further infusions. Though it is commonly well tolerated, some side effects, while rare, may be life threatening, and should be discussed with patients and their families. These discussions should also outline the goals of initiating therapy and when treatment should be stopped.

Sorafenib in advanced iodine-refractory differentiated thyroid cancer: efficacy, safety and exploratory analysis of role of serum thyroglobulin and FDG-PET

CONTEXT

Radioactive iodine is a crucial tool for treatment of differentiated thyroid cancer (DTC). In 5% of cases, DTCs lose I-131 avidity and assume an aggressive behaviour. Treatment options for iodine-refractory DTC are limited. We report the experience of off-label use of the tyrosine kinase inhibitor sorafenib for treatment of advanced iodine-refractory DTC.

DESIGN

Patients with progressive DTC refractory to radioactive iodine were treated with sorafenib used off-label independently from their performance status. Primary study end-points were radiological response, progression-free survival (PFS) and safety. Secondary end-points were site-specific radiological response and overall survival (OS). An exploratory analysis of the role of serum thyroglobulin (Tg) and fluorodeoxyglucose (FDG) positron emission tomography (PET) was performed.

RESULTS

A total of 17 patients were included in the study. Median follow-up was 15·5 months. Clinical benefit was obtained in 71% of subjects (30% partial response and 41% stable disease). Sorafenib was mostly well tolerated, but a high incidence of fatal events was reported (three patients died from severe bleeding events and two from cardiac arrest). Median PFS was 9 months. Median OS was 10 months. The best responses were observed in lymph nodes and lung. Baseline Tg levels and the Tg response to treatment were correlated to both radiological response and PFS. Baseline FDG-PET assessment and early FDG-PET response were correlated to radiological response.

CONCLUSIONS

Sorafenib allows morphological disease control in the majority of patients with iodine-refractory DTC. Progression-free survival and overall survival were lower than in previous studies as a consequence of the worse clinical condition of our patients. Sorafenib is mostly well tolerated but could have been responsible for the reported fatal events. Baseline Tg and the Tg response to treatment could be useful for predicting morphological response and clinical outcome. Early FDG-PET response could be helpful for the timely identification of nonresponding patients.

Incidence of venous thromboembolism in patients with cancer - a cohort study using linked United Kingdom databases

BACKGROUND

Accurate population-based data are needed on the incidence of venous thromboembolism (VTE) in patients with different cancers in order to inform guidelines on which hospitalised and ambulatory cancer patients should receive VTE prophylaxis.

METHODS

We conducted a cohort study using data from the Clinical Practice Research Datalink, linked to Hospital Episode Statistics, Cancer Registry data and Office for National Statistics cause of death data. We determined the incidence rates (cases per 1000 person-years) of VTE separately for 24 cancer sites. To determine relative risk, incidence rates were compared to frequency-matched controls (by age) with no record of cancer.

FINDINGS

We identified 83,203 cancer patients and 577,207 controls. New cases of VTE were diagnosed in 3352 cancer patients, and 6353 controls. The absolute rate of VTE in all cancers was 13.9 per 1000 person-years (95% confidence interval [CI] 13.4-14.4), corresponding to an age, sex and calendar year adjusted hazard-ratio of 4.7 (CI 4.5-4.9) between cancer patients and the general population. Rates varied greatly by cancer site (range; 98 (CI 80-119) in pancreatic cancer to 3.1 (CI 1.5-6.5) in thyroid cancer), age (range; 16.9 for patients over 80 years to 4.9 for those under 30 years) and time from diagnosis (range; 75 in the first three months to 8.4, >1 year after diagnosis).

INTERPRETATION

VTE is strongly linked to cancer, but the annual rate varies greatly by cancer site, proximity to diagnosis and age. Prophylaxis guidelines should take account of cancer site and such intervention should also be targeted towards the three months following diagnosis.

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.

Venous thromboembolic events with vascular endothelial growth factor receptor tyrosine kinase inhibitors: a systematic review and meta-analysis of randomized clinical trials

A trial-level meta-analysis was conducted to determine the relative risk (RR) of venous thromboembolic events (VTEs) associated with approved vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI). Eligible studies included randomized phase 2 and 3 trials comparing arms with and without a Food and Drug Administration-approved VEGFR TKI (sunitinib, sorafenib, pazopanib, vandetanib, and axitinib). Statistical analyses calculated the RR and 95% confidence intervals (CI), using random-effects or fixed-effects models based on heterogeneity. A total of 7441 patients from 9 phase III trials and 8 phase II trials were selected. The RR of all grade and high-grade VTEs for the TKI vs. no TKI arms was 1.10 (95% CI 0.73-1.66, p=0.64) and 0.85 (95% CI: 0.58-1.25, p=0.41), respectively. No difference in risk was found based on tumor type, age and trial design. The majority of trials exhibited high quality per Jadad scoring and no heterogeneity or publication bias was found.

Netrin-4 overexpression suppresses primary and metastatic colorectal tumor progression

Tumor angiogenesis is closely associated with clinical staging and has been proposed to correlate with clinical response in terms of subsequent metastases following primary resection. Netrin-4 (NT-4) regulates angiogenic responses. Therefore, we sought to examine the effects of NT-4 on the primary tumor growth of colon cancer cells, liver and lung metastases of colon cancer cells, and responses following primary tumor resection. We used 3 different mouse models of orthotopic primary tumor and liver and lung metastases, comparing 2 human colon cancer cells lines: wild-type (low expression of NT-4) and NT-4 (overexpression of NT-4) LS174 cells. NT-4 overexpression inhibited the primary tumor growth of colorectal LS174 xenografts in nude mice (144.3±12.9 vs. 62.4±4.5 mm3; p<0.0001) as well as its related local and systemic recurrence (38 vs. 0%; p<0.01). NT-4 overexpression also markedly decreased colorectal cancer progression in terms of tumor number and volume of liver metastases in the NT-4 group of the orthotopic liver metastasis model (25 vs. 90% and 4±1 vs. 709±190 mm3, p<0.001 and p<0.05). Collectively, our findings indicate that NT-4 overexpression decreases colorectal lung metastasis and its associated lymph node involvement. NT-4 overexpression decreases tumor recurrence and metastasis after surgical resection, likely via an anti-angiogenic effect. These observations suggest that NT-4 may hold therapeutic potential in the treatment of colorectal cancer growth and major metastatic sites.

The double edged sword of bleeding and clotting from VEGF inhibition in renal cancer patients

Vascular endothelial growth factor (VEGF) inhibitors have significantly improved outcomes in patients with advanced renal cell carcinoma (RCC). Multiple VEGF inhibiting orally administered tyrosine kinase inhibitors (TKIs) have been approved including sunitinib, sorafenib, pazopanib and most recently, axitinib. One VEGF inhibiting monoclonal antibody, bevacizumab, is approved in combination with interferon. However, these agents, besides the known progression-free survival benefits, are associated with a small but real risk of potentially life threatening and contrasting toxicities of thrombosis (both venous and arterial) and bleeding. Appropriate patient selection for VEGF inhibitors and prevention as well as prompt intervention to manage thrombosis and bleeding are necessary to forestall serious morbidities and mortality.

The neurologic side effects of chemotherapeutic agents

Neurologic dysfunction is a common side effect of many chemotherapy drugs. For several agents neurotoxicity is common, severe, and can be dose limiting. As the list of newer chemotherapy agents and systemic targeted therapies grows, so does the number and variety of potential neurotoxicities. This article reviews the clinical features of chemotherapy-induced syndromes involving the central and peripheral nervous systems.

Management of treatment-associated toxicites of anti-angiogenic therapy in patients with brain tumors

Anti-angiogenic therapies, including bevacizumab, are being used with increasing frequency in the management of malignant glioma. Common clinically significant toxicities include hypertension and proteinuria, poor wound healing, and the potential for thromboembolic events. Literature related to the use of bevacizumab in malignant glioma, reported toxicities in this patient population, and management of these toxicities was reviewed. Recommendations for assessment and management are provided. Anti-angiogenic therapies will continue to have a role in the treatment of malignant glioma. Further studies of the prevention, assessment, and management of these toxicities are warranted.

Medical care of patients with brain tumors

PURPOSE OF REVIEW

Patients with brain tumors require close attention to medical issues resulting from their disease or its therapy. Effective medical management results in decreased morbidity and mortality and improved quality of life. The most frequent neurology-related issues that arise in these patients include seizures, peritumoral edema, venous thromboembolism, fatigue, and cognitive dysfunction. This article focuses on the most recent findings for the management of the most relevant medical complications among patients with brain tumors.

RECENT FINDINGS

Increasing evidence suggests that anticoagulation in patients with thromboembolic complications is safe even when they are receiving antiangiogenic therapy. There are also increasing data to support the use of newer, non-enzyme-inducing antiepileptic drugs, which have the advantage of lacking interactions with antineoplastic agents and are as effective as their older counterparts at preventing seizures. Relatively few studies have addressed the management of fatigue and depression, and definitive recommendations cannot be made.

SUMMARY

Corticosteroids to treat vasogenic edema should be used at the minimum amount required to control symptoms and should be tapered as quickly as possible. Anticonvulsants should be used only if patients have had seizures. Non-enzyme-inducing antiepileptic drugs are preferred to minimize interactions with concurrently administered chemotherapy. Thromboembolic complications are common and are preferably treated with low-molecular-weight heparins. Only patients with hemorrhagic complications require an inferior vena cava filter. Cognitive deficits are frequent in patients with brain tumors and include problems such as poor short-term memory, distractibility, personality change, emotional lability, loss of executive function, and decreased psychomotor speed. Stimulants can help to improve these symptoms.

Incidence and predictors of venous thromboembolism (VTE) among ambulatory high-risk cancer patients undergoing chemotherapy in the United States

BACKGROUND

Recent studies suggest that thromboprophylaxis is beneficial in preventing venous thromboembolism (VTE) in cancer outpatients, but this is not widely adopted because of incomplete understanding of the contemporary incidence of VTE and concerns about bleeding. Therefore, the authors examined the incidence and predictors of VTE in ambulatory patients with bladder, colorectal, lung, ovary, pancreas, or gastric cancers.

METHODS

Data were extracted from a large health care claims database of commercially insured patients in the United States between 2004 and 2009. Demographic and clinical characteristics of the cancer cohort (N = 17,284) and an age/sex-matched, noncancer control cohort were evaluated. VTE incidence was recorded during a 3-month to 12-month follow-up period after the initiation of chemotherapy. Multivariate analyses were conducted to identify independent predictors of VTE and bleeding.

RESULTS

The mean age of the study population was 64 years, and 51% of patients were women. VTE occurred in 12.6% of the cancer cohort (n = 2170) over 12 months after the initiation of chemotherapy versus 1.4% of controls (n = 237; P < .0001); incidence ranged by cancer type from 19.2% (pancreatic cancer) to 8.2% (bladder cancer). Predictors of VTE included type of cancer, comorbidities (Charlson Comorbidity Index score or obesity), and commonly used specific antineoplastic or supportive care agents (cisplatin, bevacizumab, and erythropoietin).

CONCLUSIONS

This large, contemporary, real-world analysis confirmed high rates of VTE in select patients with solid tumors and suggested that the incidence of VTE is high in the real-world setting. Awareness of the benefits of targeted thromboprophylaxis may result in a clinically significant reduction in the burden of VTE in this population.

Temsirolimus: a safety and efficacy review

INTRODUCTION

The vascular endothelial growth factor (VEGF) pathway and the mammalian Target of Rapamycin (mTOR) represent the most frequently exploited targets in renal cell carcinoma (RCC). Temsirolimus is an inhibitor of mTOR, and is a unique ester derivative of sirolimus, a macrocyclic lactone, with improved pharmaceutical properties, including stability and solubility. Temsirolimus binds to the cytoplasmic protein FKBP-12, and the complex binds and inhibits mTOR.

AREAS COVERED

This review summarizes the clinical findings and safety of temsirolimus in RCC patients.

EXPERT OPINION

A Phase III clinical trial has demonstrated that temsirolimus has statistically significant advantages over treatment with IFN-α in RCC patients with poor prognosis, in terms of OS (overall survival), PFS (progression-free survival), and tumor response. Median OS was improved 49% compared to IFN-α, and median PFS was approximately doubled. It is now considered the standard for RCC patients with poor prognostic features. The possibility that this agent is useful in metastatic non-clear cell carcinoma patients has also been suggested by a subset analysis of the pivotal Phase III trial. Studies in untreated favorable and intermediate risk clear cell and refractory mRCC patients are required.

Effects of Pien Tze Huang on angiogenesis in vivo and in vitro

OBJECTIVE

To investigate the anti-angiogenic effects of Pien Tze Huang in vivo and in vitro.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with 0 mg/mL, 0.25 mg/mL, 0.5 mg/mL, and 1 mg/mL of PZH for 24 h, 48 h and 72 h, respectively. Chicken embryo chorioallantoic membrane (CAM) model was used to evaluate in vivo angiogenesis. An ECMatrix gel system was used to evaluate in vitro angiogenesis by examining the tube formation of HUVECs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine HUVEC viability. Cell density of HUVECs was observed by phase-contrast microscopy. HUVEC migration was determined by wound healing method. The mRNA and protein expression of vascular endothelial growth factor A (VEGF-A) and basic fibroblast growth factor (bFGF) in both HUVEC and human colon adenocarcinoma cells (HT-29) was examined by reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immune sorbent assay (ELISA), respectively.

RESULTS

PZH treatment significantly reduced the total number of blood vessels compared with the untreated control in the chicken embryos and resulted in a significant decrease in capillary tube formation and cell density of HUVECs (P<0.05). In addition, treatment with 0.25-1 mg/mL of PZH for 24 h, 48 h, and 72 h respectively reduced cell viability by 9%-52%, 24%-87% or 25%-87%, compared with the untreated control cells (P<0.05). Moreover, PZH treatment decreased the migration of HUVECs. Furthermore, PZH dose-dependently suppressed the expression of VEGF-A and bFGF on both mRNA and protein levels (P<0.05).

CONCLUSION

PZH could inhibit angiogenesis in vivo in CAM model and in vitro on HUVECs, suggesting that inhibiting tumor angiogenesis might be one of the mechanisms by which PZH treats cancer.

Preventing venous thromboembolism in hospitalized patients with cancer: improving compliance with clinical practice guidelines

PURPOSE

The use of anticoagulants for the prevention of venous thromboembolism (VTE) in hospitalized medical and surgical oncology patients is discussed.

SUMMARY

Hospitalized patients are often at risk for developing VTE, and risk is increased in patients who have cancer. Moreover, the incidence of VTE appears to be rising in hospitalized cancer patients, who have a 2.2-fold increased risk of mortality with a VTE compared with similar patients without VTE. The literature indicates that these patients are often inadequately anticoagulated, despite strong recommendations for prophylaxis. Although there are few studies that specifically address VTE prophylaxis in cancer patients, there are several large trials that have examined data in cancer subgroups. The trials have directly compared low-molecular-weight heparin (LMWH) with placebo, unfractionated heparin with LMWH, factor Xa inhibitor (fondaparinux) with placebo, and fondaparinux with LMWH. Three important guidelines provide current recommendations for VTE prophylaxis; the American Society of Clinical Oncology (ASCO), the National Comprehensive Cancer Network (NCCN), and the American College of Chest Physicians (ACCP) recommend unfractionated heparin, LMWH, or fondaparinux for VTE prophylaxis when there are no contraindications. Pharmacists can play an essential role in ensuring that VTE prophylaxis is appropriate for individual patients. Interventions to improve compliance with guidelines are particularly important now due to financial incentives from quality-focused organizations whose mandate is to decrease preventable mortality events in hospitals.

CONCLUSION

Hospitalized patients with cancer often do not receive appropriate thromboprophylaxis. Guidelines from ASCO, ACCP, and NCCN recommend unfractionated heparin, an LMWH, or fondaparinux for VTE prophylaxis when there are no contraindications to such therapy.

Evidence-based case report: multiple thrombotic episodes associated with lenalidomide and dexamethasone therapy for multiple myeloma

Lenalidomide in combination with dexamethasone is a treatment for patients with relapsed or refractory myeloma. Although this combination demonstrates a high level of efficacy, it further exacerbates the hypercoaguable state that exists within myeloma. Thromboprophylactic regimen require careful selection and if warfarin is chosen, assiduous monitoring is required to ensure it will be clinically effective. We report the case of one patient who experienced multiple thrombotic events despite anticoagulant or antiplatelet thromboprophylaxis and review the contributing factors.

Pro- and anti-angiogenic agents

The vascular endothelium has been characterized in every organ system, and is described as a selective permeable barrier and as a dynamic and disseminated organ with endocrine function. These activities have been shown to result from the interactions of ligands with membrane-bound receptors as well as through specific junctional proteins and receptors that govern cell-cell interactions. The endothelial cells' movement (e.g., angiogenesis) has been hypothesized to occur following the release of stimuli that could promote the formation of new blood vessels. Angiogenesis has also been reported to be the continued expansion of the vascular tree in avascular regions, as a result of the sprouting of endothelial cells from existing vessels. Most commonly, angiogenesis has been characterized during wound healing and tumour growth. Herein we summarize and discuss the latest results from fundamental laboratory research aimed at proving a link between the proliferation of cancer and angiogenesis, as well as the new rationale around novel pro- and anti-angiogenic molecules.