Biodistribution of humanized anti-VEGF monoclonal antibody/bevacizumab on peritoneal metastatic models with subcutaneous xenograft of gastric cancer in mice

Perioperative systemic therapy for resectable colorectal peritoneal metastases: Sufficient evidence for its widespread use? A critical systematic review

BACKGROUND/PURPOSE

Despite its widespread use, no randomised studies have investigated the value of perioperative systemic therapy as adjunct to cytoreduction and HIPEC for colorectal peritoneal metastases. This systematic review evaluated the available evidence, which consists of non-randomised studies only.

METHODS

A systematic search identified studies that investigated the influence of neoadjuvant, adjuvant, or perioperative systemic therapy on overall survival (OS).

RESULTS

The 11 included studies (n=1708) were clinically heterogeneous and subject to selection bias. Studies on neoadjuvant systemic therapy revealed OS benefit (n=3), no OS benefit (n=1), and superiority of chemotherapy with bevacizumab vs. chemotherapy (n=2). Studies on adjuvant systemic therapy showed no OS benefit (n=3). Studies on perioperative systemic therapy demonstrated OS benefit (n=1), and superiority of modern vs. conventional systemic therapy(n=1).

CONCLUSION

Significant limitations of available evidence question the widespread use of perioperative systemic therapy in this setting, stress the need for randomised studies, and impede conclusions regarding optimal timing and regimens. Included studies may suggest a survival benefit of neoadjuvant systemic therapy.

BEV-IP: Perioperative chemotherapy with bevacizumab in patients undergoing cytoreduction and intraperitoneal chemoperfusion for colorectal carcinomatosis

Background

Selected patients with peritoneal carcinomatosis (PC) from colorectal cancer (CRC) benefit from cytoreductive surgery (CRS) combined with intraperitoneal chemoperfusion (IPC). However, even after optimal cytoreduction, systemic and locoregional recurrence are common. Perioperative chemotherapy with bevacizumab (BEV) may improve the outcome of these patients.

Methods/Design

The BEV-IP study is a phase II, single-arm, open-label study aimed at patients with colorectal or appendiceal adenocarcinoma with synchronous or metachronous PC. This study evaluates whether perioperative chemotherapy including BEV in combination with CRS and oxaliplatin-based IPC results in acceptable morbidity and mortality (primary composite endpoint). Secondary endpoints are treatment completion rate, chemotherapy-related toxicity, pathological response, progression free survival, and overall survival.

Discussion

The BEV-IP trial is the first prospective assessment of the safety and efficacy of perioperative chemotherapy combined with anti-angiogenic treatment in patients undergoing CRS and IPC for colorectal peritoneal metastases.

Trial registration

ClinicalTrials.gov Identifier: NCT02399410 EudraCT number: 2015-001187-19 (registered March 9, 2015).

Intraperitoneal chemotherapy against peritoneal carcinomatosis: current status and future perspective

Peritoneal carcinomatosis (PC), caused by advanced abdominal malignancies, such as those of the ovarian and gastrointestinal tracts, has an extremely poor prognosis. Intraperitoneal (IP) chemotherapy has been clinically applied for several decades, but its clinical efficacy has not been fully determined. An accumulating body of evidence suggests that cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the optimal treatment for selected patients with ovarian and colorectal cancers with PC. Recent studies suggest that IP administration of taxane with systemic chemotherapy in a neoadjuvant setting improves patient survival in gastric cancer with PC. The pharmacokinetics of IP-administered drugs should be primarily considered in order to optimize IP chemotherapy. Therefore, the development of specific IP drugs using newly emerging molecular targeted reagents or new drug delivery systems, such as nanomedicine or controlled absorption/release methods, is essential to improve the efficacy of IP chemotherapy.

Drug development for intraperitoneal chemotherapy against peritoneal carcinomatosis from gastrointestinal cancer

Intraperitoneal (IP) chemotherapy for peritoneal carcinomatosis (PC) from gastrointestinal cancer has been investigated and applied clinically for several decades. Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy have been considered to be the optimal treatment options for selected patients with colorectal and gastric cancers with PC. Accumulating evidence suggests that the administration of IP paclitaxel for patients with PC from gastric cancer may improve the patient survival. The pharmacokinetics of such treatment should be considered to optimize IP chemotherapy. In addition, newly emerging molecular-targeted therapies and research into new drug delivery systems, such as nanomedicine or controlled absorption/release methods, are essential to improve the effects of IP chemotherapy. This review summarizes the current status and future prospects of IP chemotherapy for the treatment of gastrointestinal cancer.

VEGF is a target molecule for peritoneal metastasis and malignant ascites in gastric cancer: prognostic significance of VEGF in ascites and efficacy of anti-VEGF monoclonal antibody

Background

In gastric cancer, poor prognosis is associated with peritoneal dissemination, which often accompanies malignant ascites. We searched for a target molecule in peritoneal metastasis and investigated its clinical utility as a biomarker.

Methods

Biopsy specimens from both primary lesions and peritoneal metastasis, and if possible, malignant ascites, were obtained from 40 patients with gastric cancer. Vascular endothelial growth factor (VEGF) expression was analyzed by immunohistochemical staining and enzyme-linked immunosorbent assay.

Results

VEGF expression was seen in 70% of peritoneal samples. Of the 40 patients, 35 had malignant ascites. These 35 patients were divided into two groups: 15 with ascites found beyond the pelvic cavity (large group) and 20 whose ascites were within the pelvic cavity (small group). The two groups did not significantly differ by serum VEGF levels, but ascites VEGF levels in the large group were significantly higher than in the small group (P < 0.0001). Serum VEGF and ascites VEGF levels were highly correlated in the large group (r = 0.686). A high ascites VEGF level was found to be a risk factor for survival (P = 0.045). We include a report of a patient with chemoresistant refractory gastric cancer and symptomatic ascites who obtained 8 months of palliation from systemic bevacizumab.

Conclusion

Anti-VEGF therapies are promising, and the ascites VEGF level is an important marker in managing patients with gastric cancer and peritoneal metastasis.

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.

Treatment outcomes of systemic chemotherapy for peritoneal carcinomatosis arising from gastric cancer with no measurable disease: retrospective analysis from a single center

BACKGROUND

Few studies of systemic chemotherapy have focused on gastric cancer with peritoneal carcinomatosis (PC) without measurable lesions. In the present study, we characterized the outcomes of systemic chemotherapy and prognostic factors for gastric cancer with PC, particularly in patients without measurable disease.

METHODS

Clinical data from 211 gastric cancer patients with PC (137 without and 74 with measurable disease) who had received systemic chemotherapy between January 2003 and December 2010 at a single center were reviewed.

RESULTS

The median overall survival (OS) rate of gastric cancer patients with PC with no measurable disease was significantly longer than that of patients with measurable disease (18.0 vs. 11.6 months, p = 0.010). On multivariate analysis, poor performance status [hazard ratio (HR) = 2.15, p < 0.001], the presence of metastatic lymphadenopathy (HR = 2.17, p < 0.001), and high-grade PC (HR = 1.83, p = 0.001) were associated with significantly decreased OS. When patients with low-grade PC were stratified by clinical PC grade, the median OS of those without measurable disease was 19.6 months. The median OS of patients with low-grade PC with no measurable disease was longer than those of patients with high-grade PC without measurable disease, patients with low-grade PC with measurable disease, and patients with high-grade PC with measurable disease (p = 0.001, p = 0.029, and p < 0.001, respectively). Among the patients with low-grade PC, patients who received a gastrectomy had longer survival than patients who did not receive a gastrectomy (p < 0.001).

CONCLUSIONS

In our study, clinically low-grade PC without measurable disease was associated with better outcomes of systemic chemotherapy than the outcomes in the other groups examined. Clinical trials in patients with gastric cancer with PC should be stratified according to PC grade.

Effects of bevacizumab and hyperthermia in a rodent model of hyperthermic intraperitoneal chemotherapy (HIPEC)

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is more and more used in the treatment of patients with peritoneal carcinomatosis (PC) of different primary tumours. However, survival of patients with PC is still poor. The aim of this study was to evaluate the effects of preoperatively administered bevacizumab and temperature of the perfusion in an experimental model of HIPEC.

MATERIALS AND METHODS

A model for peritoneal carcinomatosis of colorectal origin was created by implantation of tumour fragments (HT29) in the abdomen of athymic nude rats. All animals were treated with oxaliplatin-based HIPEC. Animals were randomised into different treatment groups: hyperthermic treatment was compared to normothermic treatment and in both groups there were animals with and without preoperative administration of bevacizumab. Interstitial fluid pressure (IFP), bio-availability (concentrations of the drug in blood and tumour) and tumour growth delay (TGD) were evaluated.

RESULTS

In this study, preoperative bevacizumab lowered IFP but there was no effect on the bio-availability. The effect on the size of the tumour was ambivalent with no statistically significant effect on TGD. The area under the curve (AUC) of platinum was higher in animals treated with hyperthermic perfusion as compared to normothermic perfusion. In the TGD-study a post-operative mortality of 100% was observed in the hyperthermic group, compared to 1 out of 16 rats in the normothermic group.

CONCLUSIONS

The results of this study suggest that bevacizumab is not promising for clinical implementation in the setting of HIPEC: the effects on tumour size were ambivalent and there was no statistically significant benefit in TGD. The effects of hyperthermic perfusion in this study were negative: a higher blood concentration of oxaliplatin as compared to normothermic perfusion, without a higher intra-tumoural concentration. There was a higher mortality rate after hyperthermic perfusion as compared to normothermic perfusion (p < 0.001).

Correlation of the expression of vascular endothelial growth factor and its receptors with microvessel density in ovarian cancer

The present study aimed to investigate the correlation between the expression of vascular endothelial growth factor (VEGF) and its receptors, the Flt-1 and KDR proteins, with clinical pathology and microvessel density (MVD) in ovarian cancer tissue. The protein expression levels of VEGF and its receptors, Flt-1 and KDR/Flk-1, were detected in 48 cases of ovarian cancer using the streptavidin-biotin complex (SABC) immunohistochemical method, and tumor MVD was evaluated using F8 factor (FVIII-RA). The expression of the VEGF, Flt-1 and KDR proteins was not significantly associated with the pathological type, extent of differentiation or clinical stage of ovarian cancer. However, the co-expression of VEGF and Flt-1 was markedly correlated with differentiation and clinical stage (P<0.01). The co-expression levels of VEGF and receptor Flt-1 in malignant neoplasms with lymph node metastasis was significantly higher compared with malignant neoplasms without lymph node metastasis (P<0.05). The expression level of KDR in patients with hepatic metastasis was significantly higher compared with patients without hepatic metastasis (P<0.05). The co-expression level of VEGF and KDR in patients with hepatic metastasis was significantly higher compared with patients without hepatic metastasis (P<0.05) and the Flt-1 expression level in patients with ascites <1,000 ml was significantly lower than that in patients with ascites ≥1000 ml (P<0.05). The mean MVD of VEGF- and KDR-positive patients was significantly higher compared with VEGF- and KDR-negative patients (P<0.05). The expression of VEGF and its receptors is involved in the malignant transformation of ovarian tumors, tumor progression and metastasis, as well as ascites formation and angiogenesis.

Low-dose paclitaxel modulates tumour fibrosis in gastric cancer

Various treatments have been used for peritoneal dissemination, which is the most common mode of metastasis in gastric cancer, but sufficiently good clinical outcomes have not yet been obtained because of the presence of rich fibrous components and acquired drug resistance. Epithelialmesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor-β (TGF-β) has a pivotal function in the progression of EMT. Smad proteins play an important role in the TGF-β signalling pathway. The TGF-β/Smad signalling pathway can be modulated by stabilising microtubules with paclitaxel (PTX). Here, we investigated whether paclitaxel can modulate TGF-β/Smad signalling in human peritoneal methothelial cells (HPMCs). To determine the cytostatic concentrations of antineoplastic agents in HPMCs, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed using PTX, 5-fluorouracil and cisplatin. The minimum concentration that caused significant inhibition of TGF-β1-induced morphological changes in human peritoneal methothelial cells on pre-treatment with PTX was 5 nM at 48 h (cell viability: 87.1±1.5%, P<0.01). The TGF-β signalling cascade and the status of various fibrous components were evaluated by immunofluorescence staining, real-time quantitative PCR and western blotting. TGF-β signalling induced morphological changes, α-SMA expression and collagen I synthesis in HPMCs and PTX treatment suppressed these EMT-like changes. Moreover, PTX treatment markedly suppressed Smad2 phosphorylation. These data suggest that at a low-dose, PTX can significantly suppress the TGF-β/Smad signalling pathway by inhibiting Smad2 phosphorylation in the human peritoneum and that this can reduce stromal fibrosis.

Medikamentöse Therapie der Peritonealkarzinose

<b><i>Hintergrund:</i></b> Die Behandlung der Peritonealkarzinose ist eine interdisziplinäre medizinische Herausforderung. Betreffend der medikamentösen Therapie fehlt bislang eine Standardisierung. <b><i>Methode:</i></b> Relevante Artikel zum Thema Peritonealkarzinose aus den Datenbanken der U.S. National Library of Medicine (PubMed) sowie der Kongressregister der American Society of Clinical Oncology und der European Society of Medical Oncology wurden durchsucht. Die Bedeutung der Berichte für die klinische Praxis wurde zwischen den Autoren diskutiert und interdisziplinär abgestimmt. Es wurden praxisnahe Folgerungen und Empfehlungen abgeleitet. <b><i>Ergebnisse:</i></b> PubMed weist eine ansteigende Zahl an Publikationen zum Thema Peritonealkarzinose auf. In 2012 wurden 563 Arbeiten unter dem Stichwort abgelegt. Die medikamentöse Therapie der Peritonealkarzinose ist ein Teil der multimodalen Behandlung, zu der die lokalen chirurgischen und physikalischen Therapiemaßnahmen zählen. Die Auswahl der Chemotherapeutika richtet sich nach der entsprechenden malignen Grunderkrankung. Aktuelle zielgerichtete Ansätze wie die anti-angiogene Therapie und die gegen das epitheliale Zelladhäsionsmolekül (EpCAM) gerichtete Immuntherapie ergänzen neuerdings das Behandlungsspektrum bei Peritonealkarzinose und malignem Aszites. <b><i>Schlussfolgerungen:</i></b> Die medikamentöse Behandlung der Peritonealkarzinose bleibt eine medizinische Herausforderung. Die zunehmende Zahl an Publikationen und Studien auf dem Gebiet lässt aber mittlerweile mehr evidenzbasierte Entscheidungen zu. Die interdisziplinäre Abstimmung eines individuellen Behandlungskonzepts bleibt bis auf Weiteres der Goldstandard auch für die medikamentöse Therapie der Peritonealkarzinose.

The use and importance of liposomes in positron emission tomography

Among different imaging modalities, Positron Emission Tomography (PET) gained importance in routine hospital practice depending on ability to diagnose diseases in early stages and tracing of therapy by obtaining metabolic information. The combination of PET with Computed Tomography (CT) forms hybrid imaging modality that gives chance to obtain better images having higher resolution by fusing both functional and anatomical images in the same imaging modality at the same time. Therefore, better contrast agents are essentially needed. The advance in research about developing drug delivery systems as specific nanosized targeted systems gained an additional importance for obtaining better diagnosis and therapy of different diseases. Liposomes appear to be more attractive drug delivery systems in delivering either drugs or imaging ligands to target tissue or organ of diseases with higher accumulation by producing in nano-scale, long circulating by stealth effect and specific targeting by modifying with specific ligands or markers. The combination of positron emitting radionuclides with liposomes are commonly in research level nowadays and there is no commercially available liposome formulation for PET imaging. However by conjugating positron emitter radionuclide with liposomes can form promising diagnostic agents for improved diagnosis and following up treatments by increasing image signal/contrast in the target tissue in lower concentrations by specific targeting as the most important advantage of liposomes. More accurate and earlier diagnosis of several diseases can be obtained even in molecular level with the use of stable and effectively radiolabeled molecular target specific nano sized liposomes with longer half-lived positron emitting radionuclides.

Intraperitoneal bevacizumab combined with cytoreductive surgery: a pre-clinical study of tolerance and pharmacokinetics in an animal model

INTRODUCTION

Cytoreductive Surgery (CRS) combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is currently the only potentially curative treatment for peritoneal carcinomatosis (PC). Systemic administration of bevacizumab improves survival in patients with metastatic colorectal or ovarian cancer. Intraperitoneal administration of bevacizumab has been shown to be safe and effective in treating malignant ascites. The combination of CRS with intraperitoneal (IP) bevacizumab could maximize local control and survival from PC, but the associated morbidity from this is unknown. The aim of this study was to evaluate the safety of the combination of CRS with IP bevacizumab and to determine the pharmacokinetics of the drug in a rabbit model.

METHODS

Twenty healthy rabbits underwent a standardized procedure of debulking surgery, including peritonectomy and gastrointestinal anastomosis and were randomized to receive IP bevacizumab (25 mg/kg) or placebo. Another group of three rabbits underwent an instillation of IP bevacizumab (25 mg/kg) without surgery.

RESULTS

One rabbit that received IP bevacizumab died with no complication associated with the use of bevacizumab at autopsy. There was no significant difference between IP bevacizumab and placebo in weight loss, length of surgery or morbidity. The plasma concentration of bevacizumab increased to a peak at 24 h post IP administration. Bevacizumab was not detected in the plasma of animals without surgery.

CONCLUSION

This study suggests that IP bevacizumab does not increase morbidity and mortality of debulking surgery in an animal model. When surgery is performed, the pharmacokinetics of IP bevacizumab are modified in plasma.

Correlation of βig-h3 expression in peritoneal mesothelial cells with pathological parameters and peritoneal metastasis in gastric cancer

AIM: To determine the expression of βig-h3 in peritoneal mesothelial cells in gastric cancer and to explore its relation to pathological parameters and peritoneal metastasis.

METHODS: Peritoneal tissue and peritoneal washing fluid samples were collected during operation from 75 patients with gastric cancer and 14 patients with benign gastric lesions. The expression of βig-h3 in peritoneal mesothelial cells was measured immunohistochemically. The mRNA levels of CEA in ascites and peritoneal washing fluid were measured by RT-PCR. Peritoneal lavage cytological (PLC) examination and pathological examination were also performed.

RESULTS: βig-h3 was positively expressed in the peritoneal tissue in 29 patients with gastric cancer and 1 with benign gastric lesions, and the positive rate was significantly different between the two groups (P = 0.030). In the gastric cancer group, 13 patients had evident peritoneal metastasis, 20 were positive for PLC, and 32 were positive for CEA mRNA. The positive rate of βig-h3 expression was significantly positively correlated with deep invasion (P = 0.016), serious serous type (P = 0.037), peritoneal metastasis (P = 0.002), PLC (+) (P = 0.005), and CEA mRNA (+) (P = 0.027).

CONCLUSION: βig-h3 expression in peritoneal mesothelial cells in gastric cancer patients is closely related with peritoneal metastasis, representing a marker of biological behavior of gastric cancer.

Advances in the treatment of peritoneal metastasis of gastric cancer

The clinical curative effect for patients suffering from peritoneal metastasis of gastric cancer is relatively poor. Early diagnosis and effective treatment are very important for improving the survival rate in these patients. In recent years, in the light of non-radical treatment of peritoneal metastasis, peritoneal resection has been adopted with a view to alleviating the tumor burden to the greatest extent, combined with intraperitoneal chemotherapy and whole-body intravenous chemotherapy during the entire surgical period. In the meantime, with the better understanding of the pathogenesis of peritoneal metastasis of gastric cancer, some experimental studies on immunotherapy and gene therapy have also provided new thoughts and methods for the treatment of this disease. In this paper, we review the recent advances in the treatment of peritoneal metastasis of gastric cancer.

Systematic review of intraperitoneal chemotherapy for gastric cancer

BACKGROUND

Gastric cancer with peritoneal carcinomatosis has a poor prognosis. Intraperitoneal chemotherapy has been proposed as a treatment option. This systematic review examined recent literature to determine the role of intraperitoneal chemotherapy in gastric cancer.

METHODS

Four electronic databases were searched between January 2004 and January 2010 for relevant studies. Defined outcomes of interest were treatment-related morbidity and mortality, long-term survival and sites of recurrence.

RESULTS

Fourteen studies were identified involving 914 patients with gastric cancer, of whom 819 (89·6 per cent) received intraperitoneal chemotherapy. There were two randomized controlled trials, two case-control studies and ten observational studies. Methodological quality was rated as poor in 12 studies, with selection and observer bias apparent in most non-randomized cohorts. Studies were often small and varied in terms of intraperitoneal timing of chemotherapy, chemotherapeutic agents, treatment temperature, and the use of adjuvant therapies. In the better conducted studies, survival was longer in patients receiving intraperitoneal chemotherapy and surgery than in those having surgery alone.

CONCLUSION

There is limited good-quality evidence to determine the role of intraperitoneal chemotherapy in gastric cancer. Intraperitoneal chemotherapy in gastric cancer is worthy of further appraisal. However, the quality of trials must be improved, and studies must be conducted more uniformly to minimize bias and aid comparison between centres.

Intraperitoneal administration of bevacizumab intraoperatively does not affect abdominal wound healing in rats

BACKGROUND

Bevacizumab is a monoclonal antibody targeted at vascular endothelial growth factor (VEGF) to treat advanced colorectal cancer as well as other malignancies, but the ideal time point for its administration in patients scheduled for surgery is not well defined due to serious concerns regarding possible side effects on wound healing. Therefore, we conducted an experimental study in rats to clarify this issue.

METHODS

Four groups of 10 Wistar rats each underwent a 4-cm midline laparotomy and closure of the wound in 2 layers. In the treatment groups (A and B), bevacizumab (Avastin(®)) received a single dose of 5 mg/kg i.p., and an equal amount of saline was given to the control groups (C and D). Groups A and C were sacrificed on the 7th postoperative day, and groups B and D on the 14th postoperative day. Wounds were inspected by two independent observers upon sacrifice and results were recorded; wound tissues were sent for histology to assess the degree of fibrosis and measurement of tissue hydroxyproline levels. Serum levels of endothelin-1, C-reactive protein, pro-oxidant/antioxidant balance and carbonylated proteins were also determined. For statistical analysis, the Mann-Whitney U test was used.

RESULTS

Wound healing did not differ among groups both on the 7th and the 14th postoperative days, and there was also no significant difference regarding the degree of inflammation, fibroblast proliferation and collagen synthesis, as well as hydroxyproline and biochemical marker levels among the groups.

CONCLUSIONS

Intraperitoneal bevacizumab administered intraoperatively does not significantly affect abdominal wound healing in rats.