Hepatic arterial infusion of bevacizumab in combination with oxaliplatin reduces tumor growth in a rat model of colorectal liver metastases

Unleashing the potential: transarterial chemoembolization combined with intra-arterial infusion of bevacizumab for unresectable hepatocellular carcinoma

BACKGROUND

The purpose of this study is to compare the efficacy and safety of transarterial chemoembolization (TACE) alone with transarterial chemoembolization combined with the arterial infusion of bevacizumab (TACE + Bev) in patients with unresectable hepatocellular carcinoma (uHCC).

METHODS

A retrospective analysis was conducted on 446 uHCC patients treated with TACE or TACE + Bev between January 2021 and March 2023. The study evaluated objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and adverse events in both treatment groups.

RESULTS

Finally, the TACE group comprised 295 patients, and the TACE + Bev group comprised 151 patients. Patients in the TACE + Bev group exhibited significantly prolonged median PFS (7.9 months vs. 10.3 months, P = 0.013) and median OS (16.1 months vs. 21.4 months, P = 0.041), improved ORR (26.8% vs. 37.7%, P = 0.017) and DCR (71.5% vs. 80.8%, P = 0.033) compared to the TACE group. Multifactorial Cox analysis identified alpha-fetoprotein (AFP) > 400 ng/ml as an independent prognostic factor for PFS and OS. Meanwhile, portal vein cancer thrombosis and distant metastasis are poor prognostic factors for OS. The overall incidence of adverse events was similar between the two groups.

CONCLUSION

In comparison with the TACE group, the TACE + Bev group demonstrated efficacy in improving outcomes for patients with uHCC with a manageable safety profile.

Applications of image-guided locoregional transarterial chemotherapy in patients with inoperable colorectal cancer: a review

With the development of comprehensive treatment, locoregional transarterial chemotherapy has become an alternative conversion therapy, palliative therapy, and neoadjuvant therapy for many solid malignant tumors. Locoregional transarterial chemotherapy, which is most frequently used for treating liver cancer, has the characteristics of high regional efficacy and few systemic adverse reactions. In recent years, the number of relevant reports of locoregional chemotherapy for treating initially inoperable colorectal cancer (CRC), including non-metastatic and metastatic CRC, has gradually increased. However, the specific treatment options for such locoregional therapy are not the same, and its indications, medication regimens and combined treatments have not reached any consensus. In this review, the application status of locoregional transarterial chemotherapy in primary and metastatic CRC patients has been reviewed and summarized to provide a reference for future clinical work and scientific research.

Electrochemotherapy with intravenous, intratumoral, or combined administration of bleomycin in the treatment of colorectal hepatic metastases in a rat model

Electrochemotherapy (ECT) combines the reversible electroporation (rEP) with intravenous (i.v.) or intratumoral (i.t.) administration of chemotherapeutic drugs. We conducted this study to compare the efficacy of i.v., i.t., and i.v. + i.t. injection of bleomycin (BLM) in ECT treatment of colorectal hepatic metastases in a rat model. WAG/Rij rats were randomized into three groups and underwent ECT with i.v., i.t., or i.v. + i.t. injection of BLM. Tumor volumes and oxygenation were measured by means of ultrasound and photoacoustic imaging. Moreover, liver and tumor tissue were analyzed by histology and immunohistochemistry. The i.v. and i.v. + i.t. groups exhibited a 44.0% and 46.6% reduction in oxygen saturation of the tumor tissue when compared to pretreatment values, whereas the i.t. group only showed a reduction of 35.2%. The extent of tumor tissue necrosis did not statistically differ between the groups. However, the i.t. group showed a tendency towards a lower necrosis rate. Cell proliferation, apoptotic cell death, vascularization, and immune cell infiltration were comparable in the treated tumors of the three groups. ECT with i.v. administration of BLM should be preferred in clinical practice, as the combined i.v. + i.t. therapy did not show superior oncological outcomes in the present study.

Hepatic Artery Infusion Chemotherapy for Primary and Secondary Malignancies of the Liver: State of the Art and Current High-Level Evidence

BACKGROUND

Hepatic artery infusion chemotherapy (HAI) has been proposed as a valuable adjunct for multimodal therapy of primary and secondary liver malignancies. This review provides an overview of the currently available evidence of HAI, taking into account tumor response and long-term oncologic outcome.

SUMMARY

In colorectal liver metastases (CRLM), HAI in combination with systemic therapy leads to high response rates (85-90%) and conversion to resectablity in primary unresectable disease in up to 50%. HAI in combination with systemic therapy in CRLM in the adjuvant setting shows promising long-term outcomes with up to 50% 10-year survival in a large, non-randomized single-center cohort. For hepatocellular carcinoma patients, response rates as high as 20-40% have been reported for HAI and long-term outcomes compare well to other therapies. Similarly, survival for patients with unresectable intrahepatic cholangiocarcinoma 3 years after treatment with HAI is reported as high as 34%, which compares well to trials of systemic therapy where 3-year survival is usually below 5%. However, evidence is mainly limited by highly selected, heterogenous patient groups, and outdated chemotherapy regimens. The largest body of evidence stems from small, often non-randomized cohorts, predominantly from highly specialized single centers.

KEY MESSAGE

In well-selected patients with primary and secondary liver malignancies, HAI might improve response rates and, possibly, long-term survival. Results of ongoing randomized trials will show whether a wider adoption of HAI is justified, particularly to increase rates of resectability in advanced malignant diseases confined to the liver.

Hepatic arterial infusion with nanoliposomal irinotecan leads to significant regression of tumor size of colorectal liver metastases in a CC531 rat model

Long-term therapy for unresectable colorectal liver metastases remains challenging. Intraarterial treatments aim to avoid systemic adverse effects of chemotherapy. Nanoliposomal cytotoxic drugs manage to increase the drug concentration within the tumor while reducing toxicity in healthy tissue.  In this study we analyzed the effect of hepatic arterial infusion (HAI) with nanoliposomal irinotecan with or without the combination of embolization particles in a rat model for colorectal liver metastases. For the study 32 WAG/Rij rats received subcapsular tumor implantation with CC531 rat colonic adenocarcinoma cells. After ten days tumor size was assessed via ultrasound and animals underwent HAI. One group served as control receiving NaCl 0.9 % (Sham), the three treatment groups received either nanoliposomal irinotecan (HAI nal iri), Embocept® S (HAI Embo) or Embocept® S and nanoliposomal irinotecan (HAI Embo+nal iri). Three days after treatment animals were sacrificed after assessment of tumor size. As a result all treatment groups showed a significant reduction in tumor growth compared to Sham (p<0.05). Expression of the apoptosis marker caspase-3 was enhanced in HAI nal iri and HAI Embo+nal iri compared to Sham and HAI Embo and  even significantly enhanced after HAI Embo+nal iri in comparison to Sham (p<0.05). We were able to show that HAI with Embocept® S led to significantly reduced tumor growth while HAI with nanoliposomal irinotecan alone or in combination with Embocept® S even led to a reduction of tumor size. Thus, we demonstrate that intraarterial treatment with nanoliposomal irinotecan effectively inhibits tumor growth in a rat model of colorectal liver metastases and demands further investigation.

Evaluation of Electrochemotherapy with Bleomycin in the Treatment of Colorectal Hepatic Metastases in a Rat Model

BACKGROUND

The available ablative procedures for the treatment of hepatic cancer have contraindications due to the heat-sink effect and the risk of thermal injuries. Electrochemotherapy (ECT) as a nonthermal approach may be utilized for the treatment of tumors adjacent to high-risk regions. We evaluated the effectiveness of ECT in a rat model.

METHODS

WAG/Rij rats were randomized to four groups and underwent ECT, reversible electroporation (rEP), or intravenous injection of bleomycin (BLM) eight days after subcapsular hepatic tumor implantation. The fourth group served as Sham. Tumor volume and oxygenation were measured before and five days after the treatment using ultrasound and photoacoustic imaging; thereafter, liver and tumor tissue were additionally analysed by histology and immunohistochemistry.

RESULTS

The ECT group showed a stronger reduction in tumor oxygenation compared to the rEP and BLM groups; moreover, ECT-treated tumors exhibited the lowest levels of hemoglobin concentration compared to the other groups. Histological analyses further revealed a significantly increased tumor necrosis of >85% and a reduced tumor vascularization in the ECT group compared to the rEP, BLM, and Sham groups.

CONCLUSION

ECT is an effective approach for the treatment of hepatic tumors with necrosis rates >85% five days following treatment.

Intra-arterial hepatic bevacizumab and systemic chemotherapy in hepatic metastasis of colorectal cancer: A phase II multicentric trial in second-line treatment

INTRODUCTION

Intra-arterial hepatic (IAH) treatment has shown promising results in the management of patients with unresectable colorectal liver metastases (CRLM) the prognosis of which is poor. Bevacizumab adjunction to standard chemotherapy has been shown to improve survival of this patient population. This prospective study was conducted to assess the efficacy and safety of IAH bevacizumab combined to systemic chemotherapy after first-line treatment failure in patients with CRLM.

METHODS

Included patients had dominant or isolated unresectable CRLM progressing after standard first-line treatment for metastases of colorectal cancer. Three patients had less than 30% liver invasion, three patients between 30 and 50%, two more than 50% and data was missing in two patients. An intra-hepatic catheter was implanted surgically or percutaneously. Bevacizumab 7.5 mg/kg was administered once every 3 weeks in combination with capecitabine 2000 mg/m² per day for 2 weeks and oxaliplatin 130 mg/m² or irinotecan 200 mg/m² once every 3 weeks. The primary end-point was the objective response rate.

RESULTS

Between June 2013 and February 2015, 10 patients were included. The trial was prematurely closed because of the lack of financial support and poor accrual. The patients had a median of 6 [1-9] cycles of treatment. Partial response was achieved in 2 patients (20%) and a R0 liver metastases resection in one another. All patients died of disease progression. The median overall and progression-free survival rates were respectively 14.0 (95% IC [4.8 - 25.8] and 5.4 months (95% IC [1.6 - 6.2]). Four patients had severe side effects but no toxic death occurred.

CONCLUSION

IAH bevacizumab combined to systemic chemotherapy is feasible and safe in patients with unresectable isolated or dominant CRLM progressing after a first-line systemic treatment. Based on the low number of patients included in our study, our results suggest that this treatment does not increase dramatically the response rate versus an adapted systemic treatment. However, considering the safety data provided in this study, arterial infusion of bevacizumab in adjunction to chemotherapeutic agents could be evaluated in the future.

A randomized phase II trial of hepatic arterial infusion of oxaliplatin plus raltitrexed versus oxaliplatin plus 5-fluorouracil for unresectable colorectal cancer liver metastases

Background

The purpose was to compare the efficacy and safety of hepatic arterial infusion (HAI) of oxaliplatin plus raltitrexed (TOMOX) to those of oxaliplatin plus 5-fluorouracil (FOLFOX) for unresectable colorectal cancer liver metastases (CRCLM).

Methods

Patients with unresectable CRCLM were randomly assigned to receive HAI of TOMOX or FOLFOX. The primary end points were progression-free survival (PFS) measured from the date of randomisation until the date of disease progression and objective response rate (ORR). The secondary end points were overall survival (OS) measured from the date of randomisation until the date of death from any cause, disease control rate (DCR), and adverse events.

Results

113 patients were randomly assigned. With a median follow-up of 39.5 months, the PFS was 5.8 months [95% CI, 4.838–6.762]) and 4.6 months [95% CI, 3.419–5.781; P = 0.840], and the median OS was 17.6 months [95% CI, 13.828–21.372] and 13.1 months [95% CI, 11.215–14.985; P = 0.178] for the FOLFOX and TOMOX arm, respectively. The ORR were 26.1% vs 22.4% and DCR were 80.4% vs 71.4% in the FOLFOX and TOMOX arms. The most common severe adverse event was elevation of liver enzymes and pain, which did not differ in the two arms.

Conclusion

HAI chemotherapy was effective for unresectable CRCLM. HAI of FOLFOX has similar efficacy to TOMOX, and HAI of TOMOX had shorter arterial infusion time.

Clinical Trial Registration

https://clinicaltrials.gov/, identifier NCT02557490.

Retrospective Study of the Efficacy and Safety of Chemoembolization with Drug-Eluting Microspheres Combined with Intra-Arterial Infusion of Bevacizumab for Unresectable Hepatocellular Carcinoma

Purpose

To evaluate the efficacy and safety of chemoembolization with drug-eluting microspheres (DEM-TACE) combined with intra-arterial infusion of bevacizumab in patients with unresectable hepatocellular carcinoma (uHCC) and to identify possible prognostic factors.

Patients and Methods

Between November 2014 and December 2020, 34 patients underwent DEM-TACE combined with intra-arterial infusion of bevacizumab for Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) beyond the Up-to-seven criteria or BCLC stage C HCC. Patients with extrahepatic metastasis or inferior vena cava invasion were excluded. The primary endpoint was overall survival (OS). The secondary endpoints were safety (assessed using Common Terminology Criteria for Adverse Events v5.0), the response rate at 1 month, and the identification of prognostic factors. The median OS was calculated using the Kaplan-Meier method. The response rate was evaluated according to the modified Response Evaluation Criteria in Solid Tumors. Prognostic factors were investigated by univariate and multivariable analysis using the Cox proportional hazards model.

Results

The median OS was 13 months. BCLC stage and presence of portal vein invasion were not significantly associated with OS. There were no grade ≥3 adverse events. The Child-Pugh class did not decline after treatment in 31 of 34 patients. The overall response rate was 14.2% and the disease control rate was 100%. Significant prognostic factors were alcoholic liver disease, Child-Pugh score of ≥8, and microsphere size of 50-100 μm.

Conclusion

DEM-TACE combined with intra-arterial infusion of bevacizumab is safe and effective, and it could be a treatment option for unresectable HCCs.

Cryoablation combined with transarterial infusion of pembrolizumab (CATAP) for liver metastases of melanoma: an ambispective, proof-of-concept cohort study

BACKGROUND

The presence of liver metastasis correlates with poor therapeutic response of PD-1 blockade therapy in melanoma. A novel treatment protocol by combining cryoablation with transarterial infusion of pembrolizumab (CATAP) was proposed, and its feasibility and safety was assessed among this group of patients.

METHODS

This registered ambispective cohort study enrolled fifteen melanoma patients with multiple hepatic metastases who received planned two-stage CATAP therapy: in the combined stage, subtotal cryoablation on day 1, in which one to two intrahepatic lesions were ablated completely with other lesions left untreated, sequentially combined transarterial infusion of pembrolizumab on day 3, every three weeks, for at least one cycle; in the infusion stage, arterial infusion of pembrolizumab was recommended at three-week interval until disease progression. The primary endpoint was objective response rate by RECIST (version 1.1); secondary end points included progression-free survival (PFS) and safety; exploratory endpoints were changes of cytokines and immune cell compositions in peripheral blood samples.

RESULTS

Of the 15 patients enrolled, no grade 3-4 adverse events or major complications were observed. One patient (6.7%) achieved complete response, and 3 (20.0%) achieved partial response. The overall response rates of CATAP for the entire cohort and patients with cutaneous melanoma were 26.7% (95% confidence interval (CI) 4.3-49.0%) and 33.3% (95% CI 2.5-64.1%), respectively. Clinical response was observed in a proportion of patients (2/6; 33.3%) who failed first-line intravenous pembrolizumab treatment. The median overall PFS time and hepatic PFS time were 4.0 (95% CI 2.5-5.5) and 5.73 (95% CI 1.1-10.4) months, respectively. A significant increase in CD3-CD16 + CD56 + cells (natural killer cells; P = 0.0124) and a marginally significant decrease in CD4 + CD25 + cells (regulatory T cells; P = 0.0546) were observed three weeks after the first cycle of treatment in the combined stage.

CONCLUSIONS

The CATAP therapy demonstrated positive clinical activity and a favorable safety profile for melanoma patients with liver metastasis.

Body surface area-based versus concentration-based intraperitoneal perioperative chemotherapy in a rat model of colorectal peritoneal surface malignancy: pharmacologic guidance towards standardization

Worldwide, cytoreductive surgery (CRS) and hyperthermic intraperitoneal perioperative chemotherapy (HIPEC) are used in current clinical practice for colorectal peritoneal surface malignancy (PSM) treatment. Although, there is an acknowledged standardization regarding the CRS, we are still lacking a much-needed standardization amongst the various intraperitoneal (IP) chemotherapy protocols, including the HIPEC dosing regimen. We should rely on pharmacologic evidence building towards such a standardization. The current IP chemotherapy dosing regimens can be divided into body surface area (BSA)-based and concentration-based protocols. A preclinical animal study was designed to evaluate pharmacologic advantage (PA), efficacy and survival. WAG/Rij rats were IP injected with the rat colonic carcinoma cell line CC-531. Animals were randomized into three groups: CRS alone or CRS combined with oxaliplatin-based HIPEC (either BSA- or concentration-based). There was no difference in PA between the two groups (p=0.283). Platinum concentration in the tumor nodule was significantly higher in the concentration-based group (p<0.001). Median survival did not differ between the treatment groups (p<0.250). This preclinical study, in contrast to previous thinking, clearly demonstrates that the PA does not provide any information about the true efficacy of the drug and emphasizes the importance of the tumor nodule as pharmacologic endpoint.

Hepatic arterial infusion of irinotecan and EmboCept® S results in high tumor concentration of SN-38 in a rat model of colorectal liver metastases

Intraarterial chemotherapy for colorectal liver metastases (CRLM) can be applied alone or together with embolization particles. It remains unclear whether different types of embolization particles lead to higher intratumoral drug concentration. Herein, we quantified the concentrations of CPT-11 and its active metabolite SN-38 in plasma, liver and tumor tissue after hepatic arterial infusion (HAI) of irinotecan, with or without further application of embolization particles, in a rat model of CRLM. Animals underwent either systemic application of irinotecan, or HAI with or without the embolization particles Embocept^® S and Tandem™. Four hours after treatment concentrations of CPT-11 and SN-38 were analyzed in plasma, tumor and liver samples by high-performance liquid chromatography. Additionally, DNA-damage and apoptosis were analyzed immunohistochemically. Tumor tissue concentrations of SN-38 were significantly increased after HAI with irinotecan and EmboCept^® S compared to the other groups. The number of apoptotic cells was significantly higher after both HAI with irinotecan and EmboCept^® S or Tandem™ loaded with irinotecan compared to the control group. HAI with irinotecan and EmboCept^® S resulted in an increased SN-38 tumor concentration. Both HAI with irinotecan and EmboCept^® S or Tandem™ loaded with irinotecan were highly effective with regard to apoptosis.

Target hepatic artery regional chemotherapy and bevacizumab perfusion in liver metastatic colorectal cancer after failure of first-line or second-line systemic chemotherapy

Colorectal cancer liver metastasis (CRLM) is a refractory disease after failure of first-line or second-line chemotherapy. Bevacizumab is recommended as first-line therapy for advanced colorectal cancer, but is unproven in CRLM through the hepatic artery. We report favorable outcomes with targeted vessel regional chemotherapy (TVRC) for liver metastatic gastric cancer. TVRC with FOLFOX and bevacizumab perfusion through the hepatic artery was attempted for CRLM for efficacy and safety evaluation. In a single-institution retrospective observational study, 246 patients with CRLM after at least first-line or second-line failure of systemic chemotherapy received TVRC with FOLFOX (i.e. oxaliplatin, leucovorin, and 5-fluorouracil). Of 246 patients, 63 were enrolled into two groups: group 1 (n=30) received bevacizumab and TVRC following tumor progression during previous TVRC treatments; group 2 (n=33) received TVRC plus bevacizumab for CRLM on initiating TVRC. There were no significant differences in the median survival time (14.7 vs. 13.2 months, P=0.367), although the median time to progression was significant (3.3 vs. 5.5 months, P=0.026) between groups. No severe adverse events related to TVRC plus bevacizumab perfusion occurred. Target vessel regional chemotherapy with FOLFOX plus bevacizumab perfusion through the hepatic artery was effective and safe in CRLM. The optimal combination of TVRC and bevacizumab needs further confirmation in future phase II-III clinical trials.

Hepatic arterial infusion plus systemic chemotherapy as third-line or later treatment in colorectal liver metastases

BACKGROUNDS

The present study aimed to evaluate benefit of hepatic arterial infusion chemotherapy (HAI) combined with systemic chemotherapy (SCT) for patients with colorectal liver metastases (CLMs) in a palliative setting.

METHODS

This was a retrospective single-center study including 43 consecutive patients with CLM after failure of standard SCT. Among them, 20 (47 %) patients underwent HAI combined with SCT (Group A) and 23 historical control patients who had received SCT with or without targeted agent treatment (Group B).

RESULTS

The two groups had similar characteristics. Compared with SCT alone, HAI combined with SCT prolonged survival (median 19.8 vs. 9.0 months; P = 0.045). Median hepatic progression-free survival was significantly longer for HAI combined with SCT vs. SCT alone (median 8.1 vs. 4.7 months; P = 0.027), as were response rates (25 and 0 %; P = 0.038) and progression-free survival (median 5.7 vs. 3.0 months; P = 0.02). Three patients (15 %) achieved conversion to potentially curative surgery. Grade 3/4 toxicities for Group A and Group B were neutropenia (5 and 8.7 %, respectively), anemia (5 and 0 %, respectively), and hyperbilirubinemia (0 and 4.3 %, respectively). Other complications were mostly grade 1 or 2.

CONCLUSIONS

HAI combined with SCT treatment can improve overall survival compared with SCT alone in highly advanced CLM refractory to intravenous chemotherapy.

Cilostazol improves hepatic blood perfusion, microcirculation, and liver regeneration after major hepatectomy in rats

Major hepatectomy or small-for-size liver transplantation may result in postoperative liver failure. So far, no treatment is available to improve liver regeneration. Herein, we studied whether cilostazol, a selective phosphodiesterase III inhibitor, is capable of improving liver regeneration after major hepatectomy. Sprague-Dawley rats (n = 74) were treated with cilostazol (5 mg/kg daily) or a glucose solution and underwent either 70% liver resection or a sham operation. Before and after surgery, hepatic arterial and portal venous blood flow and hepatic microvascular perfusion were analyzed. Liver morphology, function, and regeneration were studied with histology, immunohistochemistry, western blotting, and bile excretion analysis. Cilostazol significantly increased hepatic blood flow and microcirculation before and after hepatectomy in comparison with sham-operated controls. This was associated with an elevation of hepatic vascular endothelial growth factor expression, an increase of hepatocellular proliferation, and an acceleration of liver regeneration. Furthermore, cilostazol protected the tissue of the remnant liver as indicated by an attenuation of hepatocellular disintegration. In conclusion, cilostazol increases hepatic blood perfusion, microcirculation, and liver regeneration after a major hepatectomy. Thus, cilostazol may represent a novel strategy to reduce the rate of liver failure after both extended hepatectomy and small-for-size liver transplantation.

Tumour growth of colorectal rat liver metastases is inhibited by hepatic arterial infusion of the mTOR-inhibitor temsirolimus after portal branch ligation

Portal branch ligation (PBL) can be performed before major hepatic resection of colorectal liver metastases (mCRC) to increase the remnant liver mass. However, PBL may also stimulate mCRC growth through hepatic arterial hyperperfusion and growth factor release. Herein, we studied whether hepatic arterial infusion (HAI) of the mTOR-inhibitor temsirolimus (Tem) is capable of inhibiting the growth of colorectal liver metastases after PBL. WAG/Rij rats were randomized to four groups (n=6 each) and underwent subcapsular implantation of 5×10(5) CC531 cells into the left liver lobe. The animals of two groups underwent simultaneous PBL of the tumour bearing liver lobe. Ten days later animals underwent a HAI either of temsirolimus (Tem and PBL Tem) or saline solution (Sham and PBL Sham). Tumour size was analyzed at days 10 and 13 using three-dimensional ultrasound. In Sham controls tumour volume increased by 43%. After PBL Sham tumour volume increased by 52%. In contrast, in animals undergoing HAI of temsirolimus the tumour growth was not only completely inhibited, but tumour volume was found decreased, irrespective of PBL. After HAI of temsirolimus immunohistochemistry revealed an increased cleaved caspase-3 activity, indicating stimulation of apoptotic cell death. In parallel temsirolimus treatment was associated with a significant reduction of PECAM-1 positive cells within the tumour tissue, implying a reduced tumour vascularisation. HAI of temsirolimus is capable of inhibiting the growth of CC531 colorectal rat liver metastases also after PBL.

Vascular endothelial growth factor accelerates establishment of a model of hepatic metastasis in Walker-256 tumor-bearing rats

BACKGROUND

Animal models of secondary liver cancer are limited by the time required for the development of hepatic metastases. The authors administered vascular endothelial growth factor (VEGF) to stimulate tumor growth in a model of hepatic metastasis.

METHODS

A 0.5 to 1.0 mm³ Walker-256 carcinosarcoma tumor tissue was implanted into the livers of 45 Sprague-Dawley rats, randomly assigned to 3 equal groups to receive daily injections (0.1 mL), for 1 week, of either normal saline (control group), 20 mg/L VEGF (VEGF-20 group) or 40 mg/L VEGF (VEGF-40 group). Tumor growth was assessed by magnetic resonance imaging after 3, 7 and 14 days, and overall survival was recorded.

RESULTS

Three days after implantation, no tumors were detected by magnetic resonance imaging in the control group. In contrast, tumors were observed in 50% of rats in the VEGF-20 group and 66.7% of rats in the VEGF-40 group (P < 0.05). By day 7, tumors were detected in 92.8% of rats in the VEGF-20 group, 86.7% of rats in the VEGF-40 group, but only 21.4% of rats in the control group (P < 0.05). Tumor size increased progressively, reaching 1.81 ± 0.08, 2.51 ± 0.12 and 2.67 ± 0.10 cm³ in the control, VEGF-20 and VEGF-40 groups, respectively, 14 days after implantation of tumor tissue. Median survival times were significantly shorter in the VEGF-40 group (15 days) than in the control and VEGF-20 groups (27 and 25, respectively) (both P < 0.05).

CONCLUSIONS

Daily VEGF injection (20 mg/L, 1 week) accelerates tumorigenesis without compromising survival, potentially extending the period in which experiments can be conducted in this model.

Mechanical ventilation drives pneumococcal pneumonia into lung injury and sepsis in mice: protection by adrenomedullin

Introduction

Ventilator-induced lung injury (VILI) contributes to morbidity and mortality in acute respiratory distress syndrome (ARDS). Particularly pre-injured lungs are susceptible to VILI despite protective ventilation. In a previous study, the endogenous peptide adrenomedullin (AM) protected murine lungs from VILI. We hypothesized that mechanical ventilation (MV) contributes to lung injury and sepsis in pneumonia, and that AM may reduce lung injury and multiple organ failure in ventilated mice with pneumococcal pneumonia.

Methods

We analyzed in mice the impact of MV in established pneumonia on lung injury, inflammation, bacterial burden, hemodynamics and extrapulmonary organ injury, and assessed the therapeutic potential of AM by starting treatment at intubation.

Results

In pneumococcal pneumonia, MV increased lung permeability, and worsened lung mechanics and oxygenation failure. MV dramatically increased lung and blood cytokines but not lung leukocyte counts in pneumonia. MV induced systemic leukocytopenia and liver, gut and kidney injury in mice with pneumonia. Lung and blood bacterial burden was not affected by MV pneumonia and MV increased lung AM expression, whereas receptor activity modifying protein (RAMP) 1–3 expression was increased in pneumonia and reduced by MV. Infusion of AM protected against MV-induced lung injury (66% reduction of pulmonary permeability p < 0.01; prevention of pulmonary restriction) and against VILI-induced liver and gut injury in pneumonia (91% reduction of AST levels p < 0.05, 96% reduction of alanine aminotransaminase (ALT) levels p < 0.05, abrogation of histopathological changes and parenchymal apoptosis in liver and gut).

Conclusions

MV paved the way for the progression of pneumonia towards ARDS and sepsis by aggravating lung injury and systemic hyperinflammation leading to liver, kidney and gut injury. AM may be a promising therapeutic option to protect against development of lung injury, sepsis and extrapulmonary organ injury in mechanically ventilated individuals with severe pneumonia.

Effect of combined bevacizumab and temozolomide treatment on intramedullary spinal cord tumor

STUDY DESIGN

C6 glioma cells and an intramedullary spinal cord tumor model were used to evaluate the effect of bevacizumab (Avastin) or temozolomide (TMZ).

OBJECTIVE

In this study, we hypothesized that treatment with bevacizumab accelerates the therapeutic effect of TMZ on intramedullary gliomas in an animal model.

SUMMARY OF BACKGROUND DATA

Recently therapies for the management of intramedullary malignant gliomas include surgery, chemotherapy, and radiotherapy. Concurrent or adjuvant TMZ has been considered an emerging new treatment for intramedullary malignant gliomas; however, high-dose application of TMZ has limitation of side effect.

METHODS

C6 glioma cells were injected into the T5 level of the spinal cord, and TMZ and bevacizumab were administered 5 days after C6 inoculation (n = 7 for each group). Tumor size was analyzed using histology and magnetic resonance imaging at 13 days after tumor inoculation.

RESULTS

Histological analyses and magnetic resonance imaging findings showed that combined treatment with TMZ and bevacizumab reduced tumor mass. The tumor volume of control group was 2.8-fold higher than combined therapy (P < 0.05). Neurological outcomes demonstrated that combined therapy improved hind limb function more than TMZ-alone group or control group (P < 0.05).

CONCLUSION

This study shows that bevacizumab could be useful in combination with TMZ to increase the therapeutic benefits of TMZ for intramedullary spinal cord tumors.

LEVEL OF EVIDENCE

N/A.

Hepatic arterial infusion of temsirolimus inhibits tumor growth of colorectal rat liver metastases even after a growth stimulating procedure like liver resection

BACKGROUND

Hepatic arterial infusion (HAI) of specific anti-tumor drugs can be more effective compared with systemic drug application. Herein, we studied whether HAI of temsirolimus is effective to inhibit tumor growth of colorectal liver metastases after liver resection.

MATERIALS AND METHODS

Twenty-four Wistar Albino Glaxo from Rijswijk (WAG/Rij) rats were randomized to four groups and underwent subcapsular implantation of CC531 colorectal cancer cells in the left liver lobe. In two groups, a 70% liver resection (Phx) was performed simultaneously. After 10 d, animals received either a HAI of temsirolimus (CCI-779) or saline solution (controls). Tumor growth was determined on d 10 and 13 using three-dimensional ultrasound. On d 13, tumor tissue was removed for histologic and immunohistochemical analysis.

RESULTS

Sham controls revealed a tumor growth of ∼40% from d 10 to d 13. HAI of temsirolimus completely inhibited this tumor growth. Controls with Phx showed a tumor growth of >60%. In contrast, HAI of temsirolimus in Phx animals did not only inhibit tumor growth but was even capable of decreasing the tumor size by ∼8%. Immunohistochemical analysis of the tumors showed a decreased proliferation rate and an increased cleaved caspase-3 activity, which was associated with a significant reduction of platelet endothelial cell adhesion molecule (PECAM)-1-positive cells after HAI of temsirolimus.

CONCLUSIONS

HAI of temsirolimus inhibits tumor growth of CC531 colorectal liver metastases even if a growth-stimulating procedure like Phx is performed. Inhibition of tumor growth is provided by a decrease of tumor vascularization associated with an inhibition of tumor cell proliferation and an induction of tumor cell apoptosis.

Hepatic arterial infusion but not systemic application of cetuximab in combination with oxaliplatin significantly reduces growth of CC531 colorectal rat liver metastases

PURPOSE

Systemic chemotherapy still represents the gold standard in the treatment of irresectable colorectal liver metastases. Modern anticancer agents like the monoclonal antibody cetuximab have improved the outcome of patients in clinical studies. As hepatic arterial infusion (HAI) is capable to potentially increase the anticancer effect of cytostatics, we herein studied whether HAI of cetuximab (CE) as a single agent or in combination with oxaliplatin (OX) exerts increased anticancer effects compared to the systemic application (SYS) of the drugs.

METHODS

WAG/Rij rats were randomized to eight groups and underwent 10 days after subcapsular hepatic tumor implantation either HAI or SYS of CE, OX, or the combination of both agents (CE + OX). Saline-treated animals served as controls. Tumor volume was measured at days 10 and 13 using three-dimensional ultrasound. On day 13, liver and tumor tissue was sampled for histological and immunohistochemical analysis.

RESULTS

In controls, the tumor volume significantly increased from day 10 to 13. Application of OX alone via HAI or SYS did not inhibit tumor growth compared to controls. SYS of CE or CE + OX did also not reduce tumor growth. In contrast, HAI of CE and CE + OX significantly inhibited tumor growth. HAI of CE significantly reduced tumor vascularization as measured by the number of platelet endothelial cell adhesion molecule-1-positive cells and significantly increased the number of apoptotic tumor cells as measured by the cellular caspase-3 expression.

CONCLUSION

HAI of CE and CE + OX reduces tumor growth of colorectal rat liver metastases involving the inhibition of angiogenesis and induction of tumor cell apoptosis.

Liver-directed chemotherapy of cetuximab and bevacizumab in combination with oxaliplatin is more effective to inhibit tumor growth of CC531 colorectal rat liver metastases than systemic chemotherapy

Colorectal carcinoma is, through to its high rate of liver metastasis (mCRC), the second most cause of cancer death worldwide. Tumor resection represents the only potential cure. In cases of unresectable disease systemic chemotherapy (sCHT) remains the therapy of choice. Modern sCHT regimens including biological agents can induce tumor response that leads to curative surgery of initially unresectable mCRC. However, liver-directed therapy via hepatic arterial infusion (HAI) may produce higher response rates than sCHT. Herein we studied whether a HAI of cetuximab (CE) plus bevacizumab (BE) with or without oxaliplatin (OX) can inhibit tumor growth in a rat model. WAG/Rij rats underwent subcapsular hepatic tumor implantation. After 10 days animals received either HAI or sCHT of CE plus BE, OX or all three drugs. Saline-treated animals served as controls. Tumor growth was estimated at day 10 and 13. On day 13 liver and tumor tissue was studied histologically and immunohistochemically. In controls the tumors grew about 50 %. OX alone was not capable of inhibiting tumor growth. In contrast, CE plus BE given as HAI significantly reduced tumor growth compared to sCHT (p < 0.05). HAI of CE plus BE combined with OX yielded an even more pronounced inhibition of tumor growth. Immunohistochemistry revealed a decreased tumor cell proliferation and tumor vascularization. The present study demonstrates that HAI of CE plus BE is effective to inhibit tumor growth. This effect is even more pronounced in combination with OX. Systemic application of these agents cannot achieve comparable effects.