Search

Quantitative fluorescence endoscopy (QFE) is a new technique that can visualise and quantify fluorescently tagged tumour tissue. In 25 patients with locally advanced rectal cancer (LARC), we evaluated QFE targeting vascular endothelial growth factor A (VEGFA) to detect residual tumour after neoadjuvant chemoradiotherapy (nCRT). QFE detected significantly higher fluorescence in tumour compared with normal rectal tissue and fibrosis, and improved prediction of final pathology results in 16% of patients compared with standard MRI and white-light endoscopy. QFE is a promising technique to aid clinical response assessment in patients with LARC and warrants further validation in larger clinical trials. ClinicalTrials.gov (NCT01972373). Patients with LARC receive nCRT followed by surgery to achieve local disease control. Interestingly, 15%–27% of patients have a pathological complete response, that is, no residual cancer cells are found in the surgical specimen.1–3 There is an increasing interest in identifying patients with a clinical complete response before surgery, as non-operative management for these patients is associated with high survival rates, reduced morbidity and improved functional outcomes.4–8 However, assessing tumour response after nCRT is challenging. White-light endoscopy provides only morphological information, while MRI cannot always distinguish viable tumour from fibrosis.9–11 QFE is a novel endoscopy technique that visualises and quantitatively measures the presence of targeted fluorescence tracers in tissue. We hypothesised that VEGFA-targeted QFE can be of additional value in restaging patients with LARC. In untreated patients, QFE showed clearly enhanced fluorescence in all rectal tumours compared with normal rectal tissue (figure 1A). The tumour-to-normal ratio of 3.1 (figure 1B) signifies QFE can be used to localise rectal cancer. Figure 1 (A) Representative fluorescence images of the quantitative fluorescence endoscopy (QFE) procedure in untreated rectal cancer. From left to right: a high-definition white-light video endoscope image; a white-light image from the QFE fibreoptic, followed by the corresponding near-infrared …

Esophageal cancer (EC) is an aggressive disease with a poor prognosis. Treatment resistance is a major challenge in successful anti-cancer therapy. Pathological complete response after neoadjuvant chemoradiation (nCRT) is low, thus requiring therapy optimization. The Hedgehog (HH) pathway has been implicated in therapy resistance, as well as in cancer stemness. This article focusses on the HH pathway as a putative target in the treatment of EC. Immunohistochemistry on HH members was applied to EC patient material followed by modulation of 3D-EC cell cultures, fluorescence-activated cell sorting (FACS), and gene expression analysis after HH pathway modulation. Sonic Hedgehog (SHH) and its receptor Patched1 (PTCH1) were significantly enriched in EC resection material of patients with microresidual disease (mRD) after receiving nCRT, compared to the control group. Stimulation with SHH resulted in an up-regulation of cancer stemness in EC sphere cultures, as indicated by increased sphere formation after sorting for CD44+/CD24− EC cancer stem-like cell (CSC) population. On the contrary, inhibiting this pathway with vismodegib led to a decrease in cancer stemness and both radiation and carboplatin resistance. Our results strengthen the role of the HH pathway in chemoradiotherapy resistance. These findings suggest that targeting the HH pathway could be an attractive approach to control CSCs.

Research Data for Adherence to pre-set benchmark quality criteria to qualify as expert assessor of dysplasia in Barrett’s esophagus biopsies – towards digital review of Barrett’s esophagus by MJ van der Wel, E Klaver, LC Duits, RE Pouw, CA Seldenrijk, GJA Offerhaus, M Visser, FJW ten Kate, K Biermann, LAA Brosens, M Doukas, C Huysentruyt, A Karrenbeld, G Kats-Ugurlu, JS van der Laan, G van Lijnschoten, FCP Moll, AHAG Ooms, JG Tijssen, JJGHM Bergman and SL Meijer in United European Gastroenterology Journal

The incidence of oesophageal adenocarcinoma (EAC) is steeply rising. Early lesion detection is a critical factor for improving disease prognosis. We developed and investigated wide-field near-infrared fluorescence molecular endoscopy (NIR-FME), using systemic and topical administration of a fluorescence-labelled antibody against vascular endothelial growth factor (VEGFA). Fourteen patients with Barrett’s oesophagus (BE) underwent endoscopic mucosal resection (EMR) combined with NIR-MFE. From a total of 20 confirmed aberrant lesions identified with NIR-FME, 4 lesions were missed by high-definition (HD) narrowband imaging (NBI) and white-light endoscopy (WLE). This overall 25% detection enhancement advocates NIR-FME as a promising ‘red-flag’ technique for improving early oesophageal lesion detection. ClinicalTrials.gov ID NCT02129933. Worldwide, >450 000 people are diagnosed with oesophageal cancer each year. In the western world, at least 80% of these cancers concern EAC.1–4 Late-stage disease detection challenges the efficacy of therapies, resulting in 400 000 deaths each year. Therefore, there is a pressing need for new endoscopic techniques that enable early EAC detection. Endoscopic imaging of targeted fluorescent agents directed against cancer-specific cellular and subcellular moieties, that is, fluorescence molecular endoscopy (FME), has been heralded as a novel method for oesophageal dysplasia and cancer detection.5 FME enables surface and subsurface visualisation of cancer-specific pathophysiology, going beyond the surface-only morphology and tissue discolourations visible with HD-WLE.6–10 In this study, we investigated for the first time real-time NIR-FME of EAC and dysplasia. A pilot study in patients with BE was based on a novel custom-built NIR fluorescence endoscope, paired to a HD-WL clinical scope (online supplementary figure 1) and employed the anti-VEGFA antibody bevacizumab, labelled with the NIR-fluorescent 800CW. The potential of VEGFA as an early discriminating target in BE was first confirmed by immunohistochemistry, demonstrating that all dysplastic tissues expressed VEGFA (online supplementary figure 2). ### Supplementary file 1 [SP1.pdf] The study furthermore compared systemic versus topical tracer administration during clinical inspection of …

Background: Dysplasia assessment of Barrett's esophagus biopsies is associated with low observer agreement; guidelines advise expert review. We have developed a web-based review panel for dysplastic Barrett's esophagus biopsies.Objective: The purpose of this study was to test if 10 gastrointestinal pathologists working at Dutch Barrett's esophagus expert centres met pre-set benchmark scores for quality criteria.Methods: Ten gastrointestinal pathologists twice assessed 60 digitalized Barrett's esophagus cases, enriched for dysplasia; then randomised (7520 assessments). We tested predefined benchmark quality criteria: (a) percentage of 'indefinite for dysplasia' diagnoses, benchmark score ≤14% for all cases, ≤16% for dysplastic subset, (b) intra-observer agreement; benchmark score ≥0.66/≥0.39, (c) percentage agreement with 'gold standard diagnosis'; benchmark score ≥82%/≥73%, (d) proportion of cases with high-grade dysplasia underdiagnosed as non-dysplastic Barrett's esophagus; benchmark score ≤1/78 (≤1.28%) assessments for dysplastic subset.Results: Gastrointestinal pathologists had seven years' Barrett's esophagus-experience, handling seven Barrett's esophagus-cases weekly. Three met stringent benchmark scores; all cases and dysplastic subset, three met extended benchmark scores. Four pathologists lacked one quality criterion to meet benchmark scores.Conclusion: Predefined benchmark scores for expert assessment of Barrett's esophagus dysplasia biopsies are stringent and met by some gastrointestinal pathologists. The majority of assessors however, only showed limited deviation from benchmark scores. We expect further training with group discussions will lead to adherence of all participating gastrointestinal pathologists to quality criteria, and therefore eligible to join the review panel.

Supplemental Material for Adherence to pre-set benchmark quality criteria to qualify as expert assessor of dysplasia in Barrett’s esophagus biopsies – towards digital review of Barrett’s esophagus by MJ van der Wel, E Klaver, LC Duits, RE Pouw, CA Seldenrijk, GJA Offerhaus, M Visser, FJW ten Kate, K Biermann, LAA Brosens, M Doukas, C Huysentruyt, A Karrenbeld, G Kats-Ugurlu, JS van der Laan, G van Lijnschoten, FCP Moll, AHAG Ooms, JG Tijssen, JJGHM Bergman and SL Meijer in United European Gastroenterology Journal

Contains fulltext : 170986pub.pdf (Publisher’s version ) (Closed access) Small and flat adenomas are known to carry a high miss-rate during standard white-light endoscopy. Increased detection rate may be achieved by molecular fluorescence endoscopy with targeted near-infrared (NIR) fluorescent tracers. The aim of this study was to validate vascular endothelial growth factor A (VEGF-A) and epidermal growth factor receptor (EGFR)-targeted fluorescent tracers during ex vivo colonoscopy with an NIR endoscopy platform. METHODS: VEGF-A and EGFR expression was determined by immunohistochemistry on a large subset of human colorectal tissue samples-48 sessile serrated adenomas/polyps, 70 sporadic high-grade dysplastic adenomas, and 19 hyperplastic polyps-and tissue derived from patients with Lynch syndrome-78 low-grade dysplastic adenomas, 57 high-grade dysplastic adenomas, and 31 colon cancer samples. To perform an ex vivo colonoscopy procedure, 14 mice with small intraperitoneal EGFR-positive HCT116(luc) tumors received intravenous bevacizumab-800CW (anti-VEGF-A), cetuximab-800CW (anti-EGFR), control tracer IgG-800CW, or sodium chloride. Three days later, 8 resected HCT116(luc) tumors (2-5 mm) were stitched into 1 freshly resected human colon specimen and followed by an ex vivo molecular fluorescence colonoscopy procedure. RESULTS: Immunohistochemistry showed high VEGF-A expression in 79%-96% and high EGFR expression in 51%-69% of the colorectal lesions. Both targets were significantly overexpressed in the colorectal lesions, compared with the adjacent normal colon crypts. During ex vivo molecular fluorescence endoscopy, all tumors could clearly be delineated for both bevacizumab-800CW and cetuximab-800CW tracers. Specific tumor uptake was confirmed with fluorescent microscopy showing, respectively, stromal and cell membrane fluorescence. CONCLUSION: VEGF-A is a promising target for molecular fluorescence endoscopy because it showed a high protein expression, especially in sessile serrated adenomas/polyps and Lynch syndrome. We demonstrated the feasibility to visualize small tumors in real time during colonoscopy using a NIR fluorescence endoscopy platform, providing the endoscopist a wide-field red-flag technique for adenoma detection. Clinical studies are currently being performed in order to provide in-human evaluation of our approach.

Background. Circumferential resection margins (CRM) for esophageal cancer (EC), defined by the College of American Pathologists (CAP; >0 mm) or the Royal College of Pathologists (RCP; >1 mm) as tumor-free (R0), are based on a surgery-alone approach. We evaluated the usefulness of both definitions in current practice with neoadjuvant chemoradiotherapy (nCRT).Methods. CRMs were measured in 209 patients (104 with nCRT) with locally advanced EC after transthoracic esophagectomy. Local recurrence and cancer related death were scored as events. Patients were followed for at least 2 years or until death. Prognostic factors (P Results. Independent prognostic factors (P Conclusions. nCRT affected the CRM cutoff values. After nCRT, the CRM R0 according to the CAP was only prognostic for 2-year LRFS. However, in the surgery-alone group, it was prognostic for both the 2-year DFS and LRFS.

Background and purpose: Neoadjuvant chemoradiotherapy (nCRT) improves survival in esophageal cancer (EC) patients, but the response to treatment is heterogeneous and little is known regarding prognostic and predictive markers in these patients. CD44, SOX2 and SHH have been implicated in resistance to CRT, possibly through an association with a cancer stem cell phenotype.Material and methods: 101 EC patients treated with nCRT and surgery were included. Sufficient pretreatment biopsy material was present in 71 patients, of which 53 patients were non-complete responders on nCRT (nCR). Protein expression was examined using immunohistochemistry (IHC). Prognostic factors were determined using Cox regression analysis for disease free survival (DFS) and cause specific survival (CSS) in the complete cohort, the pre-treatment biopsies group and post-treatment nCR group.Results: Low CD44 expression in the nCR group was an independent prognostic factor for both DFS and CSS (DFS HR 2.81, p = 0.002 and CSS HR 3.48, p = 0.002). Absent SOX2 expression in pretreatment biopsies was related to systemic recurrence (p = 0.029) while low,SHH in pretreatment biopsies was an independent prognostic factor for a poor DES (HR 2.27, p = 0.036). No relation between marker expression and response to nCRT was observed.Conclusions: Low expression of CD44 and SHH are associated with a poor survival outcome in EC patients treated with nCRT. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

Metastatic rectal cancer patients could benefit from novel therapeutic approaches. The signaling network formed by chemokines and their receptors can promote metastasis and resistance to current anticancer treatments. This study assessed the expression of chemokine receptor 4 (CXCR4) and its ligand CXCL12 immuhistochemically in stage IV rectal tumors. Paraffin-embedded primary tumor collected before and after local radiotherapy and systemic treatment with bevacizumab, oxaliplatin and capecitabine was analyzed. Receptor and ligand expression was assessed in the cytoplasm and nucleus of tumor, stromal and normal rectal crypt cells. Baseline expression of CXCR4 and CXCL12 was correlated with patients' pathologic response to treatment. At diagnosis (n=46), 89% of the rectal tumors expressed cytoplasmic CXCR4 and 81% CXCL12. Nuclear CXCR4 expression in tumor cells was present in 30% and nuclear CXCL12 expression in 35% of the tumors. After radiochemotherapy and administration of bevacizumab, nuclear CXCL12 expression was observed in 79% of residual tumors, as compared to 31% of the paired tumor samples expressing nuclear CXCL12 before treatment (P=0.001). There were no differences in CXCR4 or CXCL12 expression at baseline between the patients who had (n=9) and did not have (n=30) a pathologic complete response. Our results show that CXCR4 and CXCL12 are extensively expressed in primary rectal tumors of patients presenting with metastatic disease, while radiochemotherapy and bevacizumab further upregulate CXCL12 expression. These data indicate the importance of the CXCR4/CXCL12 axis in rectal tumor biology, and may suggest the CXCR4/CXCL12 receptor-ligand pair as a potential therapeutic target in metastatic rectal cancer.

Background: Barrett's oesophagus can progress towards oesophageal adenocarcinoma through a metaplasia-dysplasia-carcinoma sequence, but the underlying mechanisms are poorly understood. The transcription factor GATA6 is known to be involved in columnar differentiation and proliferation, and GATA6 gene amplification was recently linked with poor survival in oesophageal adenocarcinoma.Aim: To study the expression of GATA6 during Barrett's oesophagus development and malignant transformation. To determine the prognostic value of GATA6 in oesophageal adenocarcinoma.Methods: Two retrospective cohorts were derived from the pathological archive of the University Medical Center Groningen. The first cohort contained 130 tissue samples of normal squamous epithelium, metaplasia, dysplasia and oesophageal adenocarcinoma. The second cohort consisted of a tissue microarray containing tissue from 92 oesophageal adenocarcinoma patients. Immunohistochemistry was used to examine GATA6 protein expression and to correlate GATA6 expression in oesophageal adenocarcinoma with overall and disease-free survival.Results: The percentage of GATA6-positive cells was low in squamous epithelium (10%) but increased progressively in Barrett's oesophagus (30%, P Conclusion: GATA6 expression is progressively increased during Barrett's oesophagus development and its malignant transformation. However, no prognostic value of GATA6 expression could be found in oesophageal adenocarcinoma. (C) 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Background. It has been suggested that markers associated with cancer stem cells (CSC) may play a role in esophageal cancer. Our aim was to investigate the expression pattern of proposed CSC markers ALDH1, Axin2, BMI1, CD44, and SOX2 in esophageal adenocarcinoma (EAC) and to relate their expression to survival.Methods. In this study we included 94 EAC patients and examined the expression of the above-mentioned markers by using immunohistochemistry on tissue microarrays. Expression was scored as positive or negative or categorized as low or high in terms of an immunoreactivity score (IRS). Expression rates were related to clinicopathologic characteristics and overall and disease-free survival (DFS).Results. In a multivariate analysis, negative expression of CD44 and of SOX2 were both significant prognostic factors for DFS [hazard ratio (HR), 1.73; 95 % confidence interval (CI), 1.00-2.96; P = 0.046 and HR, 2.06; 95 % CI 1.14-3.70 P = 0.016). When CD44 and SOX2 expression were analyzed together, negative SOX2 expression was an independent prognostic factor for DFS (HR, 1.91; 95 % CI 1.05-3.46; P = 0.034). Low IRS scores for ALDH1 or Axin2 were associated with a reduced median survival (12.8 vs. 28.7 and 12.1 vs. 25.5 months, respectively). However, these markers and BMI1 were not prognostic factors for survival.Conclusions. Loss of CD44 expression and loss of SOX2 expression are prognostic factors of poor survival in EAC patients. This suggests a role of these proteins in EAC that requires further investigation.