Development and External Validation of the Munich Sorafenib Evaluation Score for Hepatocellular Carcinoma.

INTRODUCTION: In recent years, increasing options for systemic HCC treatment have become available. The development of therapy-specific prognostic scores has been encouraged. Tailoring therapy to individual patients requires prognostic scores for treatment success in addition to the Barcelona-Clinic-Liver-Cancer (BCLC) classification. We have developed and validated a prognostic score for patients treated with sorafenib. METHODS: Prognostic factors identified in a multivariate analysis of 108 sorafenib patients were used to construct the Munich Sorafenib Evaluation (M-SE) score. M-SE and 9 established HCC prognostic systems were ranked according to concordance-index and AIC. External M-SE validation was performed in an independent HCC sorafenib cohort (n = 101) derived from the prospective multicenter randomized controlled SORAMIC trial. RESULTS: Ascites (p < 0.0001; HR 2.923), tumor burden ≥50% of the liver (p = 0.0033; HR 1.946), and GOT (p < 0.0001; HR 1.716) were identified as independent prognostic parameters. All three M-SE stages were characterized by significantly different survival times (p < 0.0001). M-SE stage-A patients had a median OS of 18.7 months (95% CI: 15.6-21.8); patients in stage B and C showed a significantly shorter survival of 5.7 (2.7-8.7) and 2.0 months (1.6-2.4), respectively. M-SE (c-index 0.70; AIC 621) outperformed all other prognostic systems. External validation in a prospective cohort confirmed its superior prognostic performance. CONCLUSION: The M-SE score allows classification of sorafenib patients in three distinct prognostic stages. Provided that M-SE successfully passes prospective validation, it can help to predict the outcome of patients evaluated for sorafenib treatment.

A Simple Prognostic Scoring System for Hepatocellular Carcinoma Treated with Selective Internal Radiation Therapy.

INTRODUCTION: Selective internal radiation therapy (SIRT) is a local treatment option for patients with hepatocellular carcinoma (HCC). Its exact role next to other HCC therapies has yet to be defined. In order to identify patients most suitable for SIRT, a SIRT-specific prognostic score should be developed. METHODS: A cohort of 72 SIRT patients treated at the University Hospital of Munich was retrospectively analyzed. The prognostic performance of 12 HCC staging systems and prognostic scores was assessed. Cox-regression analysis was used to identify independent prognostic factors, which formed the basis of the Munich-SIRT score (M-SIRT). All scores were ranked by calculating the c-Index and Akaike information criterion (AIC). External validation was performed in a cohort of 128 SIRT patients treated at the University Hospital of Pamplona, Spain. RESULTS: median overall survival was 13 months (95% confidence interval 9.9-21.9). AFP (p = 0.005; hazard ratio [HR] 2.38), albumin (p < 0.001; HR 5.87), and alkaline phosphatase (p < 0.001; HR 8.38) were identified as independent prognostic factors. M-SIRT comprises 3 prognostic groups with a median survival of 38.9, 14.6, and 7.7 months, respectively (I vs. II: p = 0.003, II vs. III: p < 0.001). AIC (318) and concordance index (0.711) ranked M-SIRT superior to the established HCC staging systems, and the score successfully passed external validation in an independent SIRT cohort (I vs. II: p = 0.03; II vs. III: p = 0.007). CONCLUSION: Therapy-specific prognostic scores can facilitate treatment decisions and prognostication for HCC patients. Considering its performance in 200 SIRT patients, M-SIRT is a promising prognostic tool for HCC patients evaluated for SIRT.

Serial Circulating Tumor DNA Mutational Status in Patients with KRAS-Mutant Metastatic Colorectal Cancer from the Phase 3 AIO KRK0207 Trial.

BACKGROUND: We assessed the usefulness of circulating tumor DNA (ctDNA) pre- or post-treatment initiation for outcome prediction and treatment monitoring in metastatic colorectal cancer (mCRC). METHODS: Droplet digital PCR was used to measure absolute mutant V-Ki-ras2 Kirsten rat sarcoma viral oncogene ((mut)KRAS) ctDNA concentrations in 214 healthy controls (plasma and sera) and in 151 tissue-based mutKRAS positive patients with mCRC from the prospective multicenter phase 3 trial AIO KRK0207. Serial mutKRAS ctDNA was analyzed prior to and 2-3 weeks after first-line chemotherapy initiation with fluoropyrimidine, oxaliplatin, and bevacizumab in patients with mCRC and correlated with clinical parameters. RESULTS: mut KRAS ctDNA was detected in 74.8% (113/151) of patients at baseline and in 59.6% (90/151) at follow-up. mutKRAS ctDNA at baseline and follow-up was associated with poor overall survival (OS) (hazard ratio [HR] =1.88, 95% confidence interval [CI] 1.20-2.95; HR = 2.15, 95% CI 1.47-3.15) and progression-free survival (PFS) (HR = 2.53, 95% CI 1.44-4.46; HR = 1.90, 95% CI 1.23-2.95), respectively. mutKRAS ctDNA clearance at follow-up conferred better disease control (P = 0.0075), better OS (log-rank P = 0.0018), and PFS (log-rank P = 0.0018). Measurable positive mutKRAS ctDNA at follow-up was the strongest and most significant independent prognostic factor on OS in multivariable analysis (HR = 2.31, 95% CI 1.40-3.25). CONCLUSIONS: Serial analysis of circulating mutKRAS concentrations in mCRC has prognostic value. Post treatment mutKRAS concentrations 2 weeks after treatment initiation were associated with therapeutic response in multivariable analysis and may be an early response predictor in patients receiving first-line combination chemotherapy. CLINICALTRIALSGOV IDENTIFIER: NCT00973609.

The Munich-Transarterial Chemoembolisation Score Holds Superior Prognostic Capacities Compared to TACE-Tailored Modifications of 9 Established Staging Systems for Hepatocellular Carcinoma.

BACKGROUND/AIMS: The recently proposed Munich-transarterial chemoembolisation-score (M-TACE) was tailored to suit hepatocellular Carcinoma (HCC) patients evaluated for TACE. M-TACE outperformed the established HCC-staging-systems and successfully passed external validation. Modifications of staging-systems through the rearrangement of stages or by adding prognostic factors are methods of improving prognostic power. M-TACEs performance compared to scores modified this way should be tested. METHODS: Seven well-known HCC staging-systems (including Cancer of the Liver Italian Program-score [CLIP] and Barcelona Clinic liver cancer [BCLC]) and 2 TACE-specific scores (Selection for Transarterial Chemoembolisation Treatment [STATE] and Hepatoma Arterial embolisation Prognostic [HAP]) were rearranged in a cohort of 186 TACE-patients through score-point-analysis and subsequent linking of non-significant adjacent score-points. Additionally, a new score was constructed by combining the top established staging-system in TACE patients (CLIP-TACE) and the prognostic parameter with the highest hazard ratio for death in the TACE-cohort [C-reactive protein (CRP)]. Additionally, the TACE-tailored-scores were applied to an external TACE-cohort (n = 71). -Results: Rearrangement resulted in optimal stratification and monotonicity. CLIP-TACE demonstrated the best prognostic capability of all rearranged scores (c-index 0.668, AIC 1294) and the addition of CRP yielded further prognostic improvement (c-index 0.680, AIC 1289). However, superiority over M-TACE could not be achieved by any of the new scores in the internal and external cohort. CONCLUSION: M-TACE outperforms TACE-tailored modifications of all relevant HCC-staging-systems. Prospective validation of M-TACE to promote its role as the preferred staging-system for TACE-patients is therefore justified.

Dro1/Ccdc80 inactivation promotes AOM/DSS-induced colorectal carcinogenesis and aggravates colitis by DSS in mice.

Colorectal carcinogenesis is a progressive multistep process involving the sequential accumulation of genetic alterations in tumor suppressor genes and oncogenes. Downregulated by oncogenes 1 (Dro1/Ccdc80) has been shown to be a potent tumor suppressor of colorectal carcinogenesis in the genetic ApcMin/+ mouse model. In ApcMin/+ mice, loss of DRO1 strongly increases colonic tumor multiplicity and leads to the regular formation of adenocarcinoma in the colon. To investigate DRO1's role in chemically induced as well as inflammation-associated colorectal carcinogenesis, the effect of Dro1 inactivation was studied in mice subjected to the carcinogen azoxymethane (AOM) and upon combined treatment with AOM and the proinflammatory agent dextran sodium sulfate (DSS), respectively. Loss of DRO1 increases multiplicity of preneoplastic aberrant crypt foci and colonic tumors upon administration of AOM. Combined treatment with AOM and DSS leads to increased colonic tumor number and promotes formation of adenocarcinoma in the colon. Moreover, Dro1 inactivation aggravates histological signs of acute and chronic DSS-induced colitis, strongly enlarges the size of ulcerative lesions in the intestinal lining, and exacerbates clinical signs and morbidity by DSS. Our results demonstrate DRO1 to be a strong tumor suppressor in the chemically induced colon carcinogenic mouse model. Additionally, we demonstrate DRO1 to inhibit colitis-associated colon cancer formation and uncover a novel putative role for DRO1 in inflammatory bowel disease.

Correlation Between Baseline Osteoprotegerin Serum Levels and Prognosis of Advanced-Stage Colorectal Cancer Patients.

BACKGROUND/AIMS: Osteoprotegerin (OPG) is a soluble receptor of the pro-apoptotic cytokine TRAIL which is thought to contribute to tumour development by inhibiting apoptosis or affecting other aspects of tumour biology, including cell proliferation and immune response. Although immunohistochemical studies suggest that OPG correlates with survival in metastatic colorectal cancer (mCRC), only scarce data are available on serum OPG in CRC patients. METHODS: In this pilot study, we assessed the prognostic significance of serum OPG and CEA (Carcinoembryonic antigen) in 81 patients with UICC (Union for International Cancer Control) stage-IV mCRC. OPG was additionally assessed by immunohistochemistry in primary tissue samples from 33 patients of the same cohort. RESULTS: Baseline serum OPG correlated with CEA (r=0.36, p=0.0011), but independently predicted survival of mCRC patients. Life expectancy was poorer in patients with OPG levels above the median concentration of 51ng/ml (median overall survival [95% confidence interval] 1.8 years [1.3-3.0] vs. 1.0 [0.7-1.2] p=0.013). Patients with high levels of both OPG and CEA had an even poorer life expectancy vs. low-OPG/low-CEA patients (0.9 years [0.6-1.5] vs. 3 years [1.2-4.4], p=0.015), indicating that CEA and OPG have additive prognostic significance. Immunohistochemical analysis of OPG failed to show a correlation between OPG staining and survival (p=0.055) or OPG concentration from matched serum samples. CONCLUSIONS: This pilot study provides evidence of independent prognostic significance of serum OPG in patients with advanced mCRC and warrants its further prospective validation.

Methylated free-circulating HPP1 DNA is an early response marker in patients with metastatic colorectal cancer.

Detection of methylated free-circulating DNA (mfcDNA) for hyperplastic polyposis 1 (HPP1) in blood is correlated with a poor prognosis for patients with metastatic colorectal cancers (mCRC). Here, we analyzed the plasma levels of HPP1 mfcDNA in mCRC patients treated with a combination therapy containing a fluoropyrimidine, oxaliplatin and bevacizumab to test whether HPP1 mfcDNA is a suitable prognostic and response biomarker. From 467 patients of the prospective clinical study AIO-KRK-0207, mfcDNA was isolated from plasma samples at different time points and bisulfite-treated mfcDNA was quantified using methylation specific PCR. About 337 of 467 patients had detectable levels for HPP1 mfcDNA before start of treatment. The detection was significantly correlated with poorer overall survival (OS) (HR = 1.86; 95%CI 1.37-2.53). About 2-3 weeks after the first administration of combination chemotherapy, HPP1 mfcDNA was reduced to non-detectable levels in 167 of 337 patients. These patients showed a better OS compared with patients with continued detection of HPP1 mfcDNA (HR HPP1(sample 1: pos/ sample 2: neg) vs. HPP1(neg/neg) = 1.41; 95%CI 1.00-2.01, HPP1(neg,pos/pos) vs. HPP1(neg/neg) = 2.60; 95%CI 1.86-3.64). Receiver operating characteristic analysis demonstrated that HPP1 mfcDNA discriminates well between patients who do (not) respond to therapy according to the radiological staging after 12 or 24 weeks (AUC = 0.77 or 0.71, respectively). Detection of HPP1 mfcDNA can be used as a prognostic marker and an early marker for response (as early as 3-4 weeks after start of treatment compared with radiological staging after 12 or 24 weeks) to identify patients who will likely benefit from a combination chemotherapy with bevacizumab.

E-cadherin's role in development, tissue homeostasis and disease: Insights from mouse models: Tissue-specific inactivation of the adhesion protein E-cadherin in mice reveals its functions in health and disease.

Recent studies uncovered critical roles of the adhesion protein E-cadherin in health and disease. Global inactivation of Cdh1, the gene encoding E-cadherin in mice, results in early embryonic lethality due to an inability to form the trophectodermal epithelium. To unravel E-cadherin's functions beyond development, numerous mouse lines with tissue-specific disruption of Cdh1 have been generated. The consequences of E-cadherin loss showed great variability depending on the tissue in question, ranging from nearly undetectable changes to a complete loss of tissue structure and function. This review focuses on these studies and discusses how they provided important insights into E-cadherin's role in cell adhesion, proliferation and differentiation, and its consequences for biological processes as epithelial-to-mesenchymal transition, vascularization, and carcinogenesis. Lastly, we present some perspectives and possible approaches for future research.

miR-221 Mediates Chemoresistance of Esophageal Adenocarcinoma by Direct Targeting of DKK2 Expression.

BACKGROUND: Chemoresistance is a main obstacle to effective esophageal cancer (EC) therapy. We hypothesize that altered expression of microRNAs (miRNAs) play a role in EC cancer progression and resistance to 5-fluorouracil (5-FU) based chemotherapeutic strategies. METHODS: Four pairs of esophageal adenocarcinoma (EAC) cell lines and corresponding 5-FU resistant variants were established. The expression levels of miRNAs previously shown to be involved in the general regulation of stem cell pathways were analyzed by qRT-PCR. The effects of selected miRNAs on proliferation, apoptosis, and chemosensitivity were evaluated both in vitro and in vivo. We identified a particular miRNA and analyzed its putative target genes in 14 pairs of human EC tumor specimens with surrounding normal tissue by qRT-PCR as well as Wnt pathway associated genes by immunohistochemistry in another 45 EAC tumor samples. RESULTS: MiR-221 was overexpressed in 5-FU resistant EC cell lines as well as in human EAC tissue. DKK2 was identified as a target gene for miR-221. Knockdown of miR-221 in 5-FU resistant cells resulted in reduced cell proliferation, increased apoptosis, restored chemosensitivity, and led to inactivation of the Wnt/ß-catenin pathway mediated by alteration in DKK2 expression. Moreover, miR-221 reduction resulted in alteration of EMT-associated genes such as E-cadherin and vimentin as well as significantly slower xenograft tumor growth in nude mice. RT profiler analysis identified a substantial dysregulation of 4 Wnt/ß-catenin signaling and chemoresistance target genes as a result of miR-221 modulation: CDH1, CD44, MYC, and ABCG2. CONCLUSION: MiR-221 controls 5-FU resistance of EC partly via modulation of Wnt/ß-catenin-EMT pathways by direct targeting of DKK2 expression. MiR-221 may serve as a prognostic marker and therapeutic target for patients with 5-FU resistant EAC.

Screening for Colorectal Cancer Is Associated With Lower Disease Stage: A Population-Based Study.

BACKGROUND & AIMS: Screening for colorectal cancer (CRC) using fecal occult blood tests (FOBT) is associated with reduced CRC incidence and mortality. Population-based FOBT screening has led to identification of CRCs at earlier stages and longer patient survival times. We investigated the stage distribution of CRCs detected by colonoscopy in a large outpatient cohort. METHODS: We performed a retrospective analysis of colonoscopies performed on 524,954 outpatients (age, ≥55 y) in Germany from January 2006 through December 2009. Patients with chronic inflammatory bowel diseases, and those with a personal history of adenoma or CRC, were excluded. Colonoscopy findings were categorized on the basis of the most advanced lesion found; histologic samples were obtained from all patients with suspected cancer and analyzed. Cancers were staged based on Union Internationale Contre le Cancer criteria. We analyzed absolute and relative frequencies of CRCs identified and tumor stages for patients who underwent colonoscopy for screening, evaluation of a positive FOBT, and evaluation of symptoms. RESULTS: Of the 6065 CRCs identified, 1750 were found in the screening group, 1075 in subjects with positive FOBT, and 3240 in patients with symptoms. Stage I CRC was detected more frequently in subjects who received screening colonoscopies (41.15%) or in those with positive FOBT (39.10%), than in individuals with symptoms (24.42%; P < .001). In contrast, the detection rates of stage IV CRC were 10.67%, 10.76%, and 18.64%, respectively (P < .001). We observed a shift toward lower T stages in the screening and FOBT work-up groups compared with the group with symptoms. Compared with subjects with symptoms, the odds of diagnosing CRC at an advanced stage were significantly lower in the screening group (odds ratio, 0.533; 95% confidence interval, 0.451-0.631) and the FOBT work-up group (odds ratio, 0.570; 95% confidence interval, 0.469-0.694). CONCLUSIONS: In this large population-based study, CRC detected by colonoscopies performed for screening and evaluation of positive FOBTs had a lower stage than those diagnosed by colonoscopies in symptomatic patients. These findings support the value of screening colonoscopy to reduce the burden of CRC.

Inactivation of Itf2 promotes intestinal tumorigenesis in Apc(Min/+) mice.

Deregulation of Wnt/ß-catenin signaling following inactivation of the adenomatous polyposis coli (APC) tumor suppressor gene is frequently found in colorectal cancer. We have previously shown that levels of ITF-2B, encoded by the ß-catenin target gene ITF2 that is located on the tumor suppressor gene locus 18q21, are increased in colonic adenomas with deregulated ß-catenin activity. However, during tumor progression ITF-2B levels are reduced, suggesting that ITF-2B interferes with tumor development. To investigate the role of ITF2 in intestinal tumorigenesis, we specifically inactivated Itf2 in the intestinal epithelium of Apc(Min/+) mice. We found that genetic disruption of Itf2 on the Apc(Min/+) background results in earlier death and a significant increase in tumor number and size in the small intestine. Based on these data Itf2 acts as a tumor suppressor gene of the intestinal tract that inhibits tumor initiation and growth.

Pilot randomized trial of selective internal radiation therapy vs. chemoembolization in unresectable hepatocellular carcinoma.

BACKGROUND & AIMS: To compare selective internal radiation therapy (SIRT) with transarterial chemoembolization (TACE), the standard-of-care for intermediate-stage unresectable, hepatocellular carcinoma (HCC), as first-line treatment. METHODS: SIRTACE was an open-label multicenter randomized-controlled pilot study, which prospectively compared primarily safety and health-related quality of life (HRQoL) changes following TACE and SIRT. Patients with unresectable HCC, Child-Pugh ≤B7, ECOG performance status ≤2 and ≤5 liver lesions (≤20 cm total maximum diameter) without extrahepatic spread were randomized to receive either TACE (at 6-weekly intervals until tumour enhancement was not observed on MRI or disease progression) or single-session SIRT (yttrium-90 resin microspheres). RESULTS: Twenty-eight patients with BCLC stage A (32.1%), B (46.4%) or C (21.4%) received either a mean of 3.4 (median 2) TACE interventions (N = 15) or single SIRT (N = 13). Both treatments were well tolerated. Despite SIRT patients having significantly worse physical functioning at baseline, at week-12, neither treatment had a significantly different impact on HRQoL as measured by Functional Assessment of Cancer Therapy-Hepatobiliary total or its subscales. Both TACE and SIRT were effective for the local control of liver tumours. Best overall response-rate (RECIST 1.0) of target lesions were 13.3% and 30.8%, disease control rates were 73.3% and 76.9% for TACE and SIRT, respectively. Two patients in each group were down-staged for liver transplantation (N = 3) or radiofrequency ablation (N = 1). CONCLUSIONS: Single-session SIRT appeared to be as safe and had a similar impact on HRQoL as multiple sessions of TACE, suggesting that SIRT might be an alternative option for patients eligible for TACE.

Intestinal E-cadherin Deficiency Aggravates Dextran Sodium Sulfate-Induced Colitis.

BACKGROUND: E-cadherin is a cell adhesion protein with crucial roles in development, tissue homeostasis, and disease. Loss of E-cadherin in the adult intestinal epithelium disrupts tissue architecture and is associated with impaired localization and function of goblet and Paneth cells, reduced expression of antibacterial factors, and deficiency in clearing enteropathogenic bacteria. Several studies have suggested a role of E-cadherin in human inflammatory bowel disease. AIM: To investigate the role of E-cadherin deficiency in the pathogenesis of inflammatory bowel disease in a mouse model of experimentally induced colitis. METHODS: To induce E-cadherin deficiency, Villin-Cre-ER (T2) ;Cdh1 (fl/fl) mice received intraperitoneal injections of tamoxifen at days 1, 2, 5, and 8. Experimental colitis was induced by oral administration of dextran sodium sulfate (DSS, 3.5 % in the drinking water) for 3 days, starting at the third day after the first tamoxifen injection. RESULTS: E-cadherin deficiency in the adult mouse intestinal epithelium aggravates the clinical and histological features of DSS-induced colitis. Upon DSS treatment, mice deficient in E-cadherin lost more weight, were more severely dehydrated, and showed more frequently blood in the feces. Histologically, intestinal E-cadherin deficiency was associated with exacerbated acute and chronic inflammation and increased regenerative epithelial changes. Finally, the changes in the epithelium were distributed more diffusely in E-cadherin-deficient mice, while the mucosal damage was more focally localized in control animals. CONCLUSIONS: Our findings suggest that E-cadherin may play an important role in the pathogenesis of ulcerative colitis, one of the major clinical forms of inflammatory bowel disease.

Evidence for a role of E-cadherin in suppressing liver carcinogenesis in mice and men.

The cell adhesion molecule E-cadherin has critical functions in development and carcinogenesis. Impaired expression of E-cadherin has been associated with disrupted tissue homeostasis, progression of cancer and a worse patient prognosis. So far, the role of E-cadherin in homeostasis and carcinogenesis of the liver is not well understood. By use of a mouse model with liver-specific deletion of E-cadherin and administration of the carcinogen diethylnitrosamine, we demonstrate that loss of E-cadherin expression in hepatocytes results in acceleration of the growth of hepatocellular carcinoma (HCC). In contrast, liver regeneration is not disturbed in mice lacking E-cadherin expression in hepatocytes. In human HCC, we observed four different expression patterns of E-cadherin. Notably, atypical cytosolic expression of E-cadherin was positively correlated with a poorer patient prognosis. The median overall survival of patients with HCC expressing E-cadherin on the membrane only was 221 weeks (95% confidence interval: 51-391) compared with 131 weeks in patients with cytosolic expression (95% confidence interval: 71-191 weeks; P < 0.05). In conclusion, we demonstrate that impaired expression of E-cadherin promotes hepatocellular carcinogenesis and is associated with a worse prognosis in humans.

Comprehensive analysis of ß-catenin target genes in colorectal carcinoma cell lines with deregulated Wnt/ß-catenin signaling.

BACKGROUND: Deregulation of Wnt/ß-catenin signaling is a hallmark of the majority of sporadic forms of colorectal cancer and results in increased stability of the protein ß-catenin. ß-catenin is then shuttled into the nucleus where it activates the transcription of its target genes, including the proto-oncogenes MYC and CCND1 as well as the genes encoding the basic helix-loop-helix (bHLH) proteins ASCL2 and ITF-2B. To identify genes commonly regulated by ß-catenin in colorectal cancer cell lines, we analyzed ß-catenin target gene expression in two non-isogenic cell lines, DLD1 and SW480, using DNA microarrays and compared these genes to ß-catenin target genes published in the PubMed database and DNA microarray data presented in the Gene Expression Omnibus (GEO) database. RESULTS: Treatment of DLD1 and SW480 cells with ß-catenin siRNA resulted in differential expression of 1501 and 2389 genes, respectively. 335 of these genes were regulated in the same direction in both cell lines. Comparison of these data with published ß-catenin target genes for the colon carcinoma cell line LS174T revealed 193 genes that are regulated similarly in all three cell lines. The overlapping gene set includes confirmed ß-catenin target genes like AXIN2, MYC, and ASCL2. We also identified 11 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that are regulated similarly in DLD1 and SW480 cells and one pathway - the steroid biosynthesis pathway - was regulated in all three cell lines. CONCLUSIONS: Based on the large number of potential ß-catenin target genes found to be similarly regulated in DLD1, SW480 and LS174T cells as well as the large overlap with confirmed ß-catenin target genes, we conclude that DLD1 and SW480 colon carcinoma cell lines are suitable model systems to study Wnt/ß-catenin signaling and associated colorectal carcinogenesis. Furthermore, the confirmed and the newly identified potential ß-catenin target genes are useful starting points for further studies.

Genetic targeting of B-RafV600E affects survival and proliferation and identifies selective agents against BRAF-mutant colorectal cancer cells.

BACKGROUND: Colorectal cancers carrying the B-Raf V600E-mutation are associated with a poor prognosis. The purpose of this study was to identify B-RafV600E-mediated traits of cancer cells in a genetic in vitro model and to assess the selective sensitization of B-RafV600E-mutant cancer cells towards therapeutic agents. METHODS: Somatic cell gene targeting was used to generate subclones of the colorectal cancer cell line RKO containing either wild-type or V600E-mutant B-Raf kinase. Cell-biologic analyses were performed in order to link cancer cell traits to the BRAF-mutant genotype. Subsequently, the corresponding tumor cell clones were characterized pharmacogenetically to identify therapeutic agents exhibiting selective sensitivity in B-RafV600E-mutant cells. RESULTS: Genetic targeting of mutant BRAF resulted in restoration of sensitivity to serum starvation-induced apoptosis and efficiently inhibited cell proliferation in the absence of growth factors. Among tested agents, the B-Raf inhibitor dabrafenib was found to induce a strong V600E-dependent shift in cell viability. In contrast, no differential sensitizing effect was observed for conventional chemotherapeutic agents (mitomycin C, oxaliplatin, paclitaxel, etoposide, 5-fluorouracil), nor for the targeted agents cetuximab, sorafenib, vemurafenib, RAF265, or for inhibition of PI3 kinase. Treatment with dabrafenib efficiently inhibited phosphorylation of the B-Raf downstream targets Mek 1/2 and Erk 1/2. CONCLUSION: Mutant BRAF alleles mediate self-sufficiency of growth signals and serum starvation-induced resistance to apoptosis. Targeting of the BRAF mutation leads to a loss of these hallmarks of cancer. Dabrafenib selectively inhibits cell viability in B-RafV600E mutant cancer cells.

ß-catenin regulates NF-κB activity via TNFRSF19 in colorectal cancer cells.

Wnt/ß-catenin signaling plays a crucial role in the regulation of colon tissue regeneration and the development of colon tumors. Under physiological conditions, ß-catenin activity is tightly controlled. However, the majority of sporadic forms of colorectal cancer are characterized by inactivation of the tumor suppressor gene APC due to loss of heterozygosity (LOH), resulting in deregulation of the protein ß-catenin. Apart from known ß-catenin target genes like MYC, OPG, and DKK4, the gene TNFRSF19, a member of the TNF receptor superfamily, is regulated by ß-catenin in mesenchymal stem cells (hMSC). We found that TNFRSF19 is frequently overexpressed in colorectal cancer cell lines and primary colorectal carcinomas. Further characterization revealed that both isoforms of TNFRSF19, TNFRSF19.1 and TNFRSF19.2, are regulated in a ß-catenin dependent manner. The transcript TNFRSF19.2 encodes a 417 amino acid long protein containing a TRAF-binding site that links the TNFRSF19.2 to NF-κB signaling, whereas the isoform TNFRSF19.1 lacks this TRAF-binding site. Nevertheless both isoform 1 and 2 induced the activity of an NF-κB reporter gene. NF-κB signaling is important for inflammatory processes and chronic inflammatory diseases like ulcerative colitis and Crohn's disease, which are associated with increased risk for developing colorectal cancer. The observation that TNFRSF19 is a ß-catenin target gene and TNFRSF19 receptor molecules activate NF-κB signaling shows that ß-catenin regulates NF-κB activity via TNFRSF19, suggesting that TNFRSF19 may contribute to the development of colorectal tumors with deregulated ß-catenin activity.

Magnetic resonance colonography for the detection of colorectal neoplasia in asymptomatic adults.

BACKGROUND & AIMS: Colonoscopy is the preferred screening test for colorectal neoplasia; the fecal occult blood test (FOBT) detects neoplasias with low levels of sensitivity. Computed tomographic colonography detects neoplasias with high levels of sensitivity but involves exposure to radiation. We investigated whether magnetic resonance colonography (MRC) can be used to screen for colorectal adenomas and cancers. METHODS: We analyzed data from 286 asymptomatic adults (40-82 years old) who underwent 3 Tesla MRC and colonoscopic examinations on the same day. FOBT was performed before bowel preparation. Colonoscopists were initially blinded to the findings on MRC and unblinded after withdrawal from the respective segments. Sensitivities for adenoma and per-patient sensitivities and specificities were calculated based on the unblinded results of colonoscopy. RESULTS: We detected 133 adenomas and 2 cancers in 86 patients; 37 adenomas were ≥6 mm, and 20 adenomas were advanced. Sensitivities of MRC and colonoscopy for adenomas ≥6 mm were 78.4% (95% confidence interval [CI], 61.8-90.2) and 97.3% (95% CI, 85.8-99.9); for advanced adenomas these values were 75% (95% CI, 50.9-91.3) and 100% (95% CI, 83.2-100.0), respectively. MRC identified 87.1% (95% CI, 70.2-96.4), colonoscopy 96.8% (95% CI, 83.3-99.9), and FOBT 10.0% (95% CI, 2.1-26.5) of individuals with adenomas ≥6 mm and 83.8% (95% CI, 58.6-96.4), 100% (95% CI, 81.5-100.0), and 17.6% (95% CI, 3.8-43.4) of individuals with advanced neoplasia. Specificities of MRC, colonoscopy, and FOBT for individuals with adenomas ≥6 mm were 95.3% (95% CI, 91.9-97.5), 96.9% (95% CI, 93.9-98.6), and 91.8% (95% CI, 87.6-94.9), respectively. CONCLUSIONS: 3 Tesla MRC detects colorectal adenomas ≥6 mm and advanced neoplasia with high levels of sensitivity and specificity. Although MRC detects colorectal neoplasia with lower levels of sensitivity than colonoscopy, it strongly outperforms one-time FOBT.

Circulating cell-free methylated DNA and lactate dehydrogenase release in colorectal cancer.

BACKGROUND: Hypermethylation of DNA is an epigenetic alteration commonly found in colorectal cancer (CRC) and can also be detected in blood samples of cancer patients. Methylation of the genes helicase-like transcription factor (HLTF) and hyperplastic polyposis 1 (HPP1) have been proposed as prognostic, and neurogenin 1 (NEUROG1) as diagnostic biomarker. However the underlying mechanisms leading to the release of these genes are unclear. This study aimed at examining the possible correlation of the presence of methylated genes NEUROG1, HLTF and HPP1 in serum with tissue breakdown as a possible mechanism using serum lactate dehydrogenase (LDH) as a surrogate marker. Additionally the prognostic impact of these markers was examined. METHODS: Pretherapeutic serum samples from 259 patients from all cancer stages were analyzed. Presence of hypermethylation of the genes HLTF, HPP1, and NEUROG1 was examined using methylation-specific quantitative PCR (MethyLight). LDH was determined using an UV kinetic test. RESULTS: Hypermethylation of HLTF and HPP1 was detected significantly more often in patients with elevated LDH levels (32% vs. 12% [p = 0.0005], and 68% vs. 11% [p < 0.0001], respectively). Also, higher LDH values correlated with a higher percentage of a fully methylated reference in a linear fashion (Spearman correlation coefficient 0.18 for HLTF [p = 0.004]; 0.49 [p < .0001] for HPP1). No correlation between methylation of NEUROG1 and LDH was found in this study. Concerning the clinical characteristics, high levels of LDH as well as methylation of HLTF and HPP1 were significantly associated with larger and more advanced stages of CRC. Accordingly, these three markers were correlated with significantly shorter survival in the overall population. Moreover, all three identified patients with a worse prognosis in the subgroup of stage IV patients. CONCLUSIONS: We were able to provide evidence that methylation of HLTF and especially HPP1 detected in serum is strongly correlated with cell death in CRC using LDH as surrogate marker. Additionally, we found that prognostic information is given by both HLTF and HPP1 as well as LDH. In sum, determining the methylation of HLTF and HPP1 in serum might be useful in order to identify patients with more aggressive tumors.

Tivantinib for second-line treatment of advanced hepatocellular carcinoma: a randomised, placebo-controlled phase 2 study.

BACKGROUND: Tivantinib (ARQ 197), a selective oral inhibitor of MET, has shown promising antitumour activity in hepatocellular carcinoma as monotherapy and in combination with sorafenib. We aimed to assess efficacy and safety of tivantinib for second-line treatment of advanced hepatocellular carcinoma. METHODS: In this completed, multicentre, randomised, placebo-controlled, double-blind, phase 2 study, we enrolled patients with advanced hepatocellular carcinoma and Child-Pugh A cirrhosis who had progressed on or were unable to tolerate first-line systemic therapy. We randomly allocated patients 2:1 to receive tivantinib (360 mg twice-daily) or placebo until disease progression. The tivantinib dose was amended to 240 mg twice-daily because of high incidence of treatment-emergent grade 3 or worse neutropenia. Randomisation was done centrally by an interactive voice-response system, stratified by Eastern Cooperative Oncology Group performance status and vascular invasion. The primary endpoint was time to progression, according to independent radiological review in the intention-to-treat population. We assessed tumour samples for MET expression with immunohistochemistry (high expression was regarded as ≥2+ in ≥50% of tumour cells). This study is registered with ClinicalTrials.gov, number NCT00988741. FINDINGS: 71 patients were randomly assigned to receive tivantinib (38 at 360 mg twice-daily and 33 at 240 mg twice-daily); 36 patients were randomly assigned to receive placebo. At the time of analysis, 46 (65%) patients in the tivantinib group and 26 (72%) of those in the placebo group had progressive disease. Time to progression was longer for patients treated with tivantinib (1·6 months [95% CI 1·4-2·8]) than placebo (1·4 months [1·4-1·5]; hazard ratio [HR] 0·64, 90% CI 0·43-0·94; p=0·04). For patients with MET-high tumours, median time to progression was longer with tivantinib than for those on placebo (2·7 months [95% CI 1·4-8·5] for 22 MET-high patients on tivantinib vs 1·4 months [1·4-1·6] for 15 MET-high patients on placebo; HR 0·43, 95% CI 0·19-0·97; p=0·03). The most common grade 3 or worse adverse events in the tivantinib group were neutropenia (ten patients [14%] vs none in the placebo group) and anaemia (eight [11%] vs none in the placebo group). Eight patients (21%) in the tivantinib 360 mg group had grade 3 or worse neutropenia compared with two (6%) patients in the 240 mg group. Four deaths related to tivantinib occurred from severe neutropenia. 24 (34%) patients in the tivantinib group and 14 (39%) patients in the placebo group had serious adverse events. INTERPRETATION: Tivantinib could provide an option for second-line treatment of patients with advanced hepatocellular carcinoma and well-compensated liver cirrhosis, particularly for patients with MET-high tumours. Confirmation in a phase 3 trial is needed, with a starting dose of tivantinib 240 mg twice-daily. FUNDING: ArQule, Daiichi Sankyo (Daiichi Sankyo Group).