Gemcitabine transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma.

BACKGROUND/AIMS: Transcatheter arterial chemoembolization (TACE) has been shown to increase survival in patients with unresectable hepatocellular carcinoma (HCC), however toxicity from commonly used agents limits its use in unresectable disease. Gemcitabine is a well tolerated chemotherapeutic agent with a high first pass clearance. In this study we evaluated a cohort of patients with unresectable HCC treated with gemcitabine-TACE alone. METHODOLOGY: A review of all patients that underwent gemcitabine-TACE for unresectable HCC from 2002 to 2006 was performed. No patients were eligible for resection, liver transplantation or ablation. All patients received gemcitabine-TACE alone. The primary outcome measure was survival from first treatment. Secondary outcome measures included radiological response and toxicity. RESULTS: 55 patients underwent a total of 172 gemcitabine-TACE treatments for unresectable HCC. Median age was 64.7 years. All patients had Barcelona-Clinic Liver Cancer (BCLC) stage B (44%) or C (56%) disease. Median survival following gemcitabine-TACE was 8.8 months. 22% demonstrated a partial response and 61% had stable disease. 6% experienced grade 3/4 adverse events. There was 1 treatment related death. CONCLUSIONS: Gemcitabine-TACE is well tolerated and appears to provide an alternative agent for patients with unresectable HCC undergoing chemoembolization.

Intravenous delivery of the plasma fraction of stored packed erythrocytes promotes pancreatic cancer growth in immunocompetent mice.

BACKGROUND: Perioperative blood transfusion in pancreatic cancer patients has been linked to decreased survival; however, a causal mechanism has not been determined. During the processing and storage of packed erythrocytes, biologically active molecules accumulated in the acellular plasma fraction; therefore, the authors hypothesized that the plasma fraction of stored packed erythrocytes promoted tumor progression. METHODS: Proliferation and migration of murine pancreatic cancer and control cells were determined in vitro in response to the plasma fraction from leukocyte and nonleukocyte-reduced fresh versus stored packed erythrocytes. Last, an immunocompetent murine model was used to assess the effect of the plasma fraction of stored and processed packed erythrocytes on pancreatic cancer progression. RESULTS: Incubation of pancreatic cancer cells with the plasma fraction of packed erythrocytes increased proliferation and migration. Intravenous delivery of the acellular plasma fraction to mice with pancreatic cancer significantly increased the tumor weight in both leukocyte-reduced and nonleukocyte-reduced packed-erythrocyte groups (P<.01), although tumor growth and morbidity were greatest in the nonleukocyte-reduced group. CONCLUSIONS: The plasma fraction of stored packed erythrocytes promoted murine pancreatic cancer proliferation and migration in vitro and when administered intravenously, significantly augmented pancreatic cancer growth in immunocompetent mice.

Laparoscopic resection of benign hepatic cysts: a new standard.

BACKGROUND: We sought to evaluate the feasibility and outcomes of laparoscopic resection of symptomatic hepatic cysts. STUDY DESIGN: Fifty-one patients underwent laparoscopic resections for symptomatic hepatic cysts. Resection was accomplished laparoscopically with an Endo-GIA vascular stapler. Data were collected in a prospective database. RESULTS: Median patient age was 60 years, with a median lesion diameter of 13 cm. Indication for surgical treatment was pain in 92% of patients. Laparoscopic resection was successful in 100% of patients. A pure laparoscopic approach was used in 58% of patients, the remaining used a hand port. Median operating time was 178 minutes. Preoperative diagnosis was polycystic liver in 88% and simple cyst in 12% diagnosed by preoperative imaging. Histologic examination showed 90% to be simple cysts and 10% cystadenomas. There were nine minor perioperative complications. Median hospital stay was 2 days. Relief of symptoms was achieved in all patients operated on for pain, with a median followup of 13 months. Two patients required reoperation for recurrence of the same cyst. CT or MRI was used for yearly followup. CONCLUSIONS: Laparoscopic resection of symptomatic liver cysts is a feasible and effective method to relieve symptoms with minimal surgical trauma. This series represents the largest report of laparoscopic management for benign hepatic cysts and provides evidence for a routine laparoscopic approach to benign symptomatic cysts. Traditional surgical methods should be reserved for when a malignancy is expected, laparoscopy is contraindicated, or for recurrence after an initial laparoscopic approach.

Surgical management of hepatocellular adenoma: take it or leave it?

BACKGROUND: Hepatocellular adenoma (HA) is a rare benign tumor of the liver. Surgical resection is generally indicated to reduce risks of hemorrhage and malignant transformation. We sought to evaluate clinical presentation, surgical management, and outcomes of patients with HA at our institution. METHODS: We performed a retrospective review of 41 patients who underwent surgical resection for HA between 1988 and 2007. RESULTS: Thirty-eight patients were women, and the median age at presentation was 36 years (range, 19-65 years). The most common clinical presentation was abdominal pain (70%) followed by incidental radiological finding (17%). Twenty-two patients had a history of oral contraceptive use. Median number of HA was one (range, 1-3). There were 32 open cases (3 trisectionectomy, 15 hemihepatectomy, 7 sectionectomy, 4 segmentectomy, and 3 wedge resection), and 9 laparoscopic cases (1 hemihepatectomy, 5 sectionectomy, 1 segmentectomy, and 2 wedge resection). The median estimated blood loss was 225 mL (range, 0-3400 mL). The median length of stay was 6 days (range, 1-15 days). Surgical morbidities included pleural effusion requiring percutaneous drainage (n = 2), pneumonia (n = 1), and wound infection (n = 1). There was no perioperative mortality. Twelve patients had hemorrhage from HA. Hepatocellular carcinoma was observed in two patients with HA. Median follow-up was 23 months (range, 1-194 months), at which time all patients were alive. CONCLUSION: In view of 29% hemorrhagic and 5% malignant complication rates, we recommend surgical resection over observation if patient comorbidities and anatomic location of HA are favorable. A laparoscopic approach can be safely used in selected cases.

Bridging locoregional therapy for hepatocellular carcinoma prior to liver transplantation.

INTRODUCTION: The impact of locoregional therapy prior to liver transplantation for hepatocellular carcinoma utilizing either transcatheter arterial chemoembolization (TACE), yttrium-90 ((90)Y), radiofrequency ablation (RFA), or resection prior to orthotopic liver transplantation (OLT) is largely unknown. We sought to examine locoregional therapies and their effect on survival compared with transplantation alone. METHODS: A retrospective review of a prospectively collected database. RESULTS: 123 patients were included. Patients were analyzed in two groups. Group I consisted of 50 patients that received therapy (20 TACE; 16 (90)Y; 13 RFA, 3 resections). Group II consisted of 73 patients transplanted without therapy. Median list time was 28 days (range 2-260 days ) in group I, and 24 days (range 1-380 days) in group II. Median time from therapy to OLT was 3.8 months (range 9 days to 68 months). Twelve patients (24%) were successfully downstaged (8 TACE, 2 (90)Y, 2 RFA/resection). Overall 1-, 3-, and 5-year survival were 81%, 74%, and 74%, respectively. Survival was not statistically significantly different between the two groups (P = 0.53). The 12 patients downstaged did not have a significant difference in survival as compared with the patients who received therapy but did not respond or the patients who were transplanted without therapy (P = 0.76). CONCLUSION: Our report addresses locoregional therapy for hepatocellular carcinoma as a bridge to transplant. There was no statistical difference in overall survival between patients treated and those not treated prior to transplant. We provide further evidence that locoregional therapy is a safe tool for patients on the transplant list, does not impact survival, and can downstage selected patients to allow life-saving liver transplantation.

Vascular endothelial growth factor receptor 2 mediates macrophage infiltration into orthotopic pancreatic tumors in mice.

Macrophages are an abundant inflammatory cell type in the tumor microenvironment that can contribute to tumor growth and metastasis. Macrophage recruitment into tumors is mediated by multiple cytokines, including vascular endothelial growth factor (VEGF), which is thought to function primarily through VEGF receptor (VEGFR) 1 expressed on macrophages. Macrophage infiltration is affected by VEGF inhibition. We show that selective inhibition of VEGFR2 reduced macrophage infiltration into orthotopic pancreatic tumors. Our studies show that tumor-associated macrophages express VEGFR2. Furthermore, peritoneal macrophages from tumor-bearing animals express VEGFR2, whereas peritoneal macrophages from non-tumor-bearing animals do not. To our knowledge, this is the first time that tumor-associated macrophages have been shown to express VEGFR2. Additionally, we found that the cytokine pleiotrophin is sufficient to induce VEGFR2 expression on macrophages. Pleiotrophin has previously been shown to induce expression of endothelial cell markers on macrophages and was present in the microenvironment of orthotopic pancreatic tumors. Finally, we show that VEGFR2, when expressed by macrophages, is essential for VEGF-stimulated migration of tumor-associated macrophages. In summary, tumor-associated macrophages express VEGFR2, and selective inhibition of VEGFR2 reduces recruitment of macrophages into orthotopic pancreatic tumors. Our results show an underappreciated mechanism of action that may directly contribute to the antitumor activity of angiogenesis inhibitors that block the VEGFR2 pathway.

Forced expression of MMP9 rescues the loss of angiogenesis and abrogates metastasis of pancreatic tumors triggered by the absence of host SPARC.

Pancreatic adenocarcinoma is characterized by desmoplasia, local invasion, and metastasis. These features are regulated in part by MMP9 and SPARC. To explore the interaction of SPARC and MMP9 in cancer, we first established orthotopic pancreatic tumors in SPARC-null and wild-type mice with the murine pancreatic adenocarcinoma cell line, PAN02. MMP9 expression was higher in tumors from wild-type compared to SPARC-null mice. Coincident with lower MMP9 expression, tumors grown in SPARC-null mice were significantly larger, had decreased ECM deposition and reduced microvessel density compared to wild-type controls. In addition, metastasis was enhanced in the absence of host SPARC. Therefore, we next analyzed the orthotopic tumor growth of PAN02 cells transduced with MMP9 or a control empty vector. Forced expression of MMP9 by the PAN02 cells resulted in larger tumors in both wild-type and SPARC-null animals compared to empty vector controls and further diminished ECM deposition. Importantly, forced expression of MMP9 within the tumor reversed the decrease in angiogenesis and abrogated the metastatic potential displayed by control tumors grown in SPARC-null mice. Finally, contrary to the in vivo results, MMP9 increased cell migration in vitro, which was blocked by the addition of SPARC. These results suggest that SPARC and MMP9 interact to regulate many stages of tumor progression including ECM deposition, angiogenesis and metastasis.

Selective blockade of vascular endothelial growth factor receptor 2 with an antibody against tumor-derived vascular endothelial growth factor controls the growth of human pancreatic adenocarcinoma xenografts.

BACKGROUND: Vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, is critical for growth of human pancreatic adenocarcinoma. Preclinical studies demonstrate that blockade of VEGF activity can control the growth of pancreatic tumors in mice. In this study, we evaluated the efficacy of 2C3, an antibody that inhibits VEGF receptor 2 activation by human VEGF, to inhibit the growth of human pancreatic adenocarcinoma in mice. METHODS: Human pancreatic cancer cell lines (MiaPaca-2, Panc-1, and Capan-1) were used to establish xenografts in nu/nu mice. The expression of VEGF and its receptors was determined in each cell line. Proliferation of tumor cells in vitro and tumor growth in vivo in the presence of 2C3 or a control antibody was evaluated. The effect of 2C3 on tumor weight, total vessel density, number of pericyte-associated vessels, and tumor perfusion was determined, and the level of 2C3 in the serum of animals was measured by enzyme-linked immunosorbent assay. RESULTS: 2C3 did not affect the proliferation of cells in culture. 2C3 was present and active in the serum of tumor-bearing animals treated with 2C3, and these animals showed a decrease in tumor burden compared with control-treated mice. Therapy with 2C3 resulted in reduced vascular function, measured by a decrease in vessel density and in the percentage of vessels associated with pericytes. Furthermore, tumors derived from Capan-1 cells demonstrated decreased perfusion after treatment with 2C3. CONCLUSIONS: Blockade of VEGF receptor 2 activation by tumor-derived VEGF decreases tumor vessel function and growth of some human pancreatic adenocarcinoma cell lines in mice.

Combination of a monoclonal anti-phosphatidylserine antibody with gemcitabine strongly inhibits the growth and metastasis of orthotopic pancreatic tumors in mice.

Pancreatic cancer continues to have a dismal prognosis and novel therapy is needed. In this study, we evaluate a promising new target for therapy, phosphatidylserine (PS). PS is an anionic phospholipid located normally on the inner leaflet of the plasma membrane in mammalian cells. In the tumor microenvironment, PS becomes externalized on vascular endothelium. The monoclonal antibody 3G4 binds PS and promotes an inflammatory response against tumor blood vessels, resulting in reduction of tumor growth. Mice with orthotopic pancreatic tumors were treated with 3G4, gemcitabine or a combination of both drugs. Tumor burden including pancreas weight and metastatic lesions (liver, lymph node and peritoneal) were reduced 3- to 5-fold by the combination therapy as compared with 1.5- to 2-fold with 3G4 and gemcitabine alone, respectively. Treatment of tumor-bearing animals with the combination therapy increased macrophage infiltration into the tumor mass 10-fold and reduced microvessel density in the tumor by 2.5-fold compared with tumors from untreated animals. Gemcitabine alone and 3G4 alone were less effective than the combination of the 2 agents together. The additive therapeutic effect of both agents appears to be because chemotherapy increases PS exposure on tumor vascular endothelium and amplifies the target for attack by 3G4. In conclusion, 3G4 enhanced the anti-tumor and anti-metastatic activity of gemcitabine without contributing to toxicity.

Molecular consequences of silencing mutant K-ras in pancreatic cancer cells: justification for K-ras-directed therapy.

Mutation of the K-ras gene is an early event in the development of pancreatic adenocarcinoma and, therefore, RNA interference (RNAi) directed toward mutant K-ras could represent a novel therapy. In this study, we examine the phenotypic and molecular consequences of exposure of pancreatic tumor cells to mutant-specific K-ras small interfering RNA. Specific reduction of activated K-ras via RNAi in Panc-1 and MiaPaca-2 cells resulted in cellular changes consistent with a reduced capacity to form malignant tumors. These changes occur through distinct mechanisms but likely reflect an addiction of each cell line to oncogene stimulation. Both cell lines show reduced proliferation after K-ras RNAi, but only MiaPaca-2 cells showed increased apoptosis. Both cell lines showed reduced migration after K-ras knockdown, but changes in integrin levels were not consistent between the cell lines. Both cell lines showed alteration of the level of GLUT-1, a metabolism-associated gene that is downstream of c-myc, with Panc-1 cells demonstrating decreased GLUT-1 levels, whereas MiaPaca-2 cells showed increased levels of expression after K-ras knockdown. Furthermore, after K-ras RNAi, there was a reduction in angiogenic potential of both Panc-1 and MiaPaca-2 cells. Panc-1 cells increased the level of expression of thrombospondin-1, an endogenous inhibitor of angiogenesis, whereas MiaPaca-2 cells decreased the production of vascular endothelial growth factor, a primary stimulant of angiogenesis in pancreatic tumors. We have found that silencing mutant K-ras through RNAi results in alteration of tumor cell behavior in vitro and suggests that targeting mutant K-ras specifically might be effective against pancreatic cancer in vivo.

Increased expression of Cyr61 (CCN1) identified in peritoneal metastases from human pancreatic cancer.

BACKGROUND: Identification of extracellular matrix proteins (ECM) associated with tumor cell metastasis may generate targets for future therapy against pancreatic cancer metastases. We hypothesized that comparison of ECM-associated gene expression in primary and metastatic pancreatic tumors would identify ECM proteins associated with pancreatic metastasis. STUDY DESIGN: A clinically relevant model of pancreatic cancer was used to generate RNA from primary and metastatic tumors; it was evaluated by microarray analysis with subsequent cluster analysis. Target genes (Cyr61 and integrins alpha(v) and beta(3)) identified by microarray analysis were confirmed by reverse transcription polymerase chain reaction and immunohistochemistry analysis. RESULTS: Peritoneal metastases at sites distant from the primary tumor were present in all animals bearing orthotopic tumors. High-density microarray comparison of gene expression in metastases versus primary pancreatic tumors identified a greater than twofold increase in the expression of Cyr61, a secreted matricellular protein that binds to integrins. Reverse transcription polymerase chain reaction confirmed the microarray results, and immunohistochemistry analysis demonstrated increased Cyr61 protein and persistent alpha(v)beta(3) expression in peritioneal metastases. Additionally, immunohistochemistry demonstrated increased collocalization of Cyr61 and alpha(v) in metastases relative to primary tumor. CONCLUSIONS: The ECM protein Cyr61 shows increased expression in metastatic lesions in a clinically relevant model of pancreatic adenocarcinoma. Protein analysis confirms the microarray results and collocalization of Cyr61, and alpha(v) suggests that interaction between Cyr61 and alpha(v)beta(3) promotes formation of peritoneal metastases.