Hannah van Malenstein

Esophageal Dilated Intercellular Spaces (DIS) and Nonerosive Reflux Disease

Esophageal mucosal dilated intercellular spaces (DIS) are frequently observed in patients with nonerosive reflux disease (NERD) and patients with esophagitis. The specificity of DIS is questionable, as it is present in up to 30% of asymptomatic healthy subjects and in patients with other esophageal disorders. DIS occurs in parallel with a drop in potential difference, diminished transepithelial resistance, and increased esophageal mucosal permeability. These alterations arise with exposure to acid and pepsin during gastroesophageal reflux, but the exact pathway of damage to the intercellular junctions remains unclear and seems to be multifactorial. Other noxious contents of the refluxate, such as bile acids, are harmful and DIS can also be induced by acute psychological stress. DIS can be assessed quantitatively with electron microscopy (EM), but it is also recognizable with light microscopy (LM). DIS can disappear after treatment with proton pump inhibitors (PPI); however, this is not the case in all NERD patients. A recent study showed that patients with NERD who are refractory to PPI might still have DIS; and animal experiments showed that persistence of DIS might be due to esophageal mucosal exposure to bile acids and/or psychological stress. In conclusion, DIS is a frequent but nonspecific histological feature of NERD. It can be caused by acid reflux, but bile acids in the refluxate and/or psychological stress can modulate the development or persistence of DIS. Although a causal relationship between DIS and heartburn has been proposed, it still needs to be proven and the underlying mechanisms investigated before considering DIS as a target for treatment of NERD.

Tumor initiation and progression in hepatocellular carcinoma: risk factors, classification, and therapeutic targets

Hepatocellular carcinoma (HCC) is a major health problem worldwide responsible for 500 000 deaths annually. A number of risk factors are associated with either the induction of the disease or its progression; these include infection with hepatitis B or C virus, alcohol consumption, non-alcoholic steatohepatitis and certain congenital disorders. In around 80% of the cases, HCC is associated with cirrhosis or advanced fibrosis and with inflammation and oxidative stress. In this review we focus firstly on the different risk factors for HCC and summarize the mechanisms by which each is considered to contribute to HCC. In the second part we look at the molecular processes involved in cancer progression. HCC development is recognized as a multistep process that normally develops over many years. Over this period several mutations accumulate in the cell and that stimulate malign transformation, growth, and metastatic behavior. Over the recent years it has become evident that not only the tumor cell itself but also the tumor microenviroment plays a major role in the development of a tumor. There is a direct link between the role of inflammation and cirrhosis with this microenviroment. Both in vitro and in vivo it has been shown that tumor formation and metastatic properties are linked to epithelial-mesenchymal transition (EMT), a process by which facillitates the tumor cells attempts to migrate to a more favourable microenviroment. Several groups have analyzed the gene expression in HCC and its surrounding tissue by microarray and this has resulted in the molecular classification into a distinct number of classes. Here we also found a role for hypoxia induced gene expression leading to a clinically more aggressive gene expression in HCC. Molecular analysis also helped to identify important cellular pathways and possible therapeutic targets. The first molecule that in this way has shown clinical application for liver cancer is the multikinase inhibitor sorafenib, others are currently in different stages of clinical studies like the mTOR inhibitor everolimus.

Long-term exposure to sorafenib of liver cancer cells induces resistance with epithelial-to-mesenchymal transition, increased invasion and risk of rebound growth.

Sorafenib leads to a survival benefit in patients with advanced hepatocellular carcinoma but its use is hampered by the occurrence of drug resistance. To investigate the molecular mechanisms involved we developed five resistant human liver cell lines in which we studied morphology, gene expression and invasive potential. The cells changed their appearance, lost E-cadherin and KRT19 and showed high expression of vimentin, indicating epithelial-to-mesenchymal transition. Resistant cells showed reduced adherent growth, became more invasive and lost liver-specific gene expression. Furthermore, following withdrawal of sorafenib, the resistant cells showed rebound growth, a phenomenon also found in patients. This cell model was further used to investigate strategies for restoration of sensitivity to sorafenib.

A randomized phase II study of drug-eluting beads versus transarterial chemoembolization for unresectable hepatocellular carcinoma.

Background: Transcatheter arterial chemoembolization (TACE) is the standard treatment in selected patients with unresectable hepatocellular carcinoma (HCC). Drug-eluting particles are developed to reduce side effects and improve efficacy. We present safety data of a prospective randomized phase II study with doxorubicin-eluting superabsorbent polymer (SAP) microspheres. Material and Methods: We prospectively included 30 HCC patients with different Barcelona Clinic Liver Cancer (BCLC) stages (A = 3, B = 19, C = 8) and randomly assigned them to receive conventional TACE (n = 14) (control group) or doxorubicin-eluting SAP microspheres (n = 16). The doxorubicin plasma level was assessed at different time points, biochemical analysis was performed, and side effects were reported following the Common Toxicity Criteria. Tumor response was assessed at 6 weeks according to the modified Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Results: There was a significantly lower plasma peak concentration (Cmax) of doxorubicin and smaller area under the curve (AUC) with SAP microspheres (mean Cmax 495 ± 293.9 ng/ml, mean AUC 69.7 ± 26.9 ng/ml min) compared to controls (mean Cmax 1,928 ± 560.8 ng/ml, mean AUC 165 ± 32.3 ng/ml/min; both p < 0.001). Furthermore, there were less grade 3 and no grade 4 adverse events in the SAP microsphere group. Tumor response was comparable between the groups. Conclusions: TACE with SAP microspheres leads to low plasma levels of the cytotoxic drug and therefore minimizes toxicity compared to conventional TACE.

A seven-gene set associated with chronic hypoxia of prognostic importance in hepatocellular carcinoma

Purpose: Hepatocellular carcinomas (HCC) have an unpredictable clinical course, and molecular classification could provide better insights into prognosis and patient-directed therapy. We hypothesized that in HCC, certain microenvironmental regions exist with a characteristic gene expression related to chronic hypoxia which would induce aggressive behavior. Experimental Design: We determined the gene expression pattern for human HepG2 liver cells under chronic hypoxia by microarray analysis. Differentially expressed genes were selected and their clinical values were assessed. In our hypothesis-driven analysis, we included available independent microarray studies of patients with HCC in one single analysis. Three microarray studies encompassing 272 patients were used as training sets to determine a minimal prognostic gene set, and one recent study of 91 patients was used for validation. Results: Using computational methods, we identified seven genes (out of 3,592 differentially expressed under chronic hypoxia) that showed correlation with poor prognostic indicators in all three training sets (65/139/73 patients) and this was validated in a fourth data set (91 patients). Retrospectively, the seven-gene set was associated with poor survival (hazard ratio, 1.39; P = 0.007) and early recurrence (hazard ratio, 2.92; P = 0.007) in 135 patients. Moreover, using a hypoxia score based on this seven-gene set, we found that patients with a score of >0.35 (n = 42) had a median survival of 307 days, whereas patients with a score of ≤0.35 (n = 93) had a median survival of 1,602 days (P = 0.005). Conclusions: We identified a unique, liver-specific, seven-gene signature associated with chronic hypoxia that correlates with poor prognosis in HCCs. Clin Cancer Res; 16(16); 4278–88. ©2010 AACR.

Transcatheter Chemoembolization of Unresectable Hepatocellular Carcinoma: Current Knowledge and Future Directions

Transarterial chemoembolization (TACE) is considered the gold standard for the treatment of unresectable hepatocellular carcinoma (HCC) in patients with a preserved liver function and in the absence of clear extrahepatic tumor spread. This review article deals with the radiological and clinical workup, the interventional technique of chemoembolization for HCC and gives an overview of the common as well as some rare and dramatic complications of TACE. Finally, some new trends and advances in clinical research with regard to the interventional management of HCC are discussed.

Up‐regulation of breast cancer resistance protein expression in hepatoblastoma following chemotherapy: A study in patients and in vitro

Aim:  Hepatoblastoma (HB), the most common pediatric malignant liver tumor, is treated with chemotherapy to facilitate surgical resection. Previous studies suggest that HB acquires chemoresistance via increased expression of multidrug resistance protein 1 (MDR1, ABCC1). There is no well established evidence that this also occurs in the clinical setting and little is known about the effects of chemotherapeutic treatments on HB in situ.

Giant liver hemangioma: the role of female sex hormones and treatment

Hepatic hemangiomas are the most common focal liver lesions and are especially prevalent in women. Giant hemangiomas are defined as hemangiomas of at least 4 cm in diameter and the majority remains stable in size over time. However, in some cases hemangiomas display growth and give rise to symptoms because of their space-occupying effect. Causes for the enlargement of the tumors are unknown, but a role of female sex hormones has been suggested. Therefore, hormone therapy should be avoided in patients who became symptomatic. In patients with important symptoms, disease control can be obtained by transcatheter arterial embolization. In selected patients, especially in case of Kasabach-Merritt syndrome, there is a good indication for liver transplantation.

Transcatheter Arterial Chemoembolization with Doxorubicin-Eluting Superabsorbent Polymer Microspheres in the Treatment of Hepatocellular Carcinoma: Midterm Follow-up

PURPOSE To investigate prospectively the safety, tolerability, and efficacy of transarterial chemoembolization using superabsorbent polymer (SAP) microspheres loaded with doxorubicin for the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS During the years 2006-2011, 64 patients underwent 144 transarterial chemoembolization with SAP microspheres procedures. Most of the patients were staged as Barcelona Clinic Liver Cancer class B (65%). The most frequent underlying liver diseases were hepatitis C (35%) and alcoholic liver disease (28%) resulting in Child-Pugh A (73.4%) or Child-Pugh B (17%) liver cirrhosis. Tumor response was assessed using modified Response Evaluation Criteria in Solid Tumors with magnetic resonance (MR) imaging performed 4-6 weeks after each procedure. RESULTS Serious adverse events (n = 9) were ischemic or infectious in nature. Transarterial chemoembolization with SAP microspheres resulted in objective response rates of 67.5%, 44.5%, and 25% after first, second, and third sessions. There were 16 patients (25%) who underwent orthotopic liver transplantation after transarterial chemoembolization with SAP microspheres, of whom 2 experienced recurrent disease. During a median follow-up time of 14 months (range, 2-55 mo), 26 patients (40.5%) died. Median overall and transplant-free survivals were 20.5 months (95% confidence interval, 13.2-27.7) and 18 months (95% confidence interval, 14.2-21.8), respectively. CONCLUSIONS Transarterial chemoembolization with SAP microspheres has an excellent safety profile in cirrhotic patients, even in the presence of advanced liver disease (Child-Pugh B) or advanced stages of HCC. This treatment produced meaningful tumor response rates as assessed by MR imaging.

Hypoxia driven gene expression is an independent prognostic factor in stage II and III colon cancer patients

Purpose: Hypoxia is considered a major microenvironmental factor influencing cancer behavior. Our aim was to develop a hypoxia-based gene score that could identify high and low risk within stage II and III colon cancer patients. Experimental Design: Differential gene expression of CaCo-2 colon cancer cells cultured in chronic hypoxia versus normoxia was tested for correlation with prognostic variables in published microarray datasets. These datasets were further used to downsize and optimize a gene score, which was subsequently determined in paraffin-embedded material of 126 patients with colon cancer treated in our center. Results: In the CaCo-2 cells, 923 genes with a 2-fold change and Limma corrected P ≤ 0.0001 were found differentially expressed in hypoxia versus normoxia. We identified 21 genes with prognostic value and overlapping in three different training sets and (n = 224). With a fourth published dataset (n = 177), the six-gene Colon Cancer Hypoxia Score (CCHS) was developed. Patients with low CCHS showed a significant better disease-free survival at three years (77.3%) compared with high CCHS patients (46.4%; log-rank, P = 0.006). This was independently confirmed in an external patient cohort of 90 stage II patients (86.9% vs. 52.2%; P = 0.001). Conclusions: Hypoxia-driven gene expression is associated with high recurrence rates in stage II and III colon cancer. A six-gene score was found to be of independent prognostic value in these patients. Our findings require further validation and incorporation in the current knowledge on molecular classification of colon cancer. Clin Cancer Res; 20(8); 2159–68. ©2014 AACR.