http://repub.eur.nl/res/aut/18000/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/40025/ 2013-07-01T00:00:00Z Although anti-EGFR therapy has established efficacy in metastatic colorectal cancer, only 10-20% of unselected patients respond. This is partly due to KRAS and BRAF mutations, which are currently assessed in the primary tumor. To improve patient selection, assessing mutation status in circulating tumor cells (CTCs), which possibly better represent metastases than the primary tumor, could be advantageous. We investigated the feasibility of KRAS and BRAF mutation detection in colorectal CTCs by comparing three sensitive methods and compared mutation status in matching primary tumor, liver metastasis and CTCs. CTCs were isolated from blood drawn from 49 patients before liver resection using CellSearch™. DNA and RNA was isolated from primary tumors, metastases and CTCs. Mutations were assessed by co-amplification at lower denaturation temperature-PCR (Transgenomic™), real-time PCR (EntroGen™) and nested Allele-Specific Blocker (ASB-)PCR and confirmed by Sanger sequencing. In 43 of the 49 patients, tissue RNA and DNA was of sufficient quantity and quality. In these 43 patients, discordance between primary and metastatic tumor was 23% for KRAS and 7% for BRAF mutations. RNA and DNA from CTCs was available from 42 of the 43 patients, in which ASB-PCR was able to detect the most mutations. Inconclusive results in patients with low CTC counts limited the interpretation of discrepancies between tissue and CTCs. Determination of KRAS and BRAF mutations in CTCs is challenging but feasible. Of the tested methods, nested ASB-PCR, enabling detection of KRAS and BRAF mutations in patients with as little as two CTCs, seems to be superior. What's new? Circulating tumor cells (CTCs) are present in the blood stream of patients with metastatic colorectal cancer and provide the opportunity to characterize tumor cells without biopsy. The authors isolated CTCs to assess the status of KRAS and BRAF mutations, which severely limit effectiveness of anti-EGFR therapies. The analysis was challenged by the presence of more than 1,000 leukocytes in CTC-enriched fractions, but was successful in detecting mutations in as little as two CTCs when a specific, nested Allele-Specific Blocker PCR strategy was employed. These results underscore the potential of CTC analysis as an alternative to commonly used invasive approaches to test patients for mutations repeatedly during the course of the disease and treatment. Copyright http://repub.eur.nl/res/pub/40198/ 2013-04-20T00:00:00Z Purpose Esophageal adenocarcinoma (EAC) is a highly aggressive disease with poor long-term survival. Despite growing knowledge of its biology, no molecular biomarkers are currently used in routine clinical practice to determine prognosis or aid clinical decision making. Hence, this study set out to identify and validate a small, clinically applicable immunohistochemistry (IHC) panel for prognostication in patients with EAC. Patients and Methods We recently identified eight molecular prognostic biomarkers using two different genomic platforms. IHC scores of these biomarkers from a UK multicenter cohort (N = 374) were used in univariate Cox regression analysis to determine the smallest biomarker panel with the greatest prognostic power with potential therapeutic relevance. This new panel was validated in two independent cohorts of patients with EAC who had undergone curative esophagectomy from the United States and Europe (N = 666). Results Three of the eight previously identified prognostic molecular biomarkers (epidermal growth factor receptor [EGFR], tripartite motif-containing 44 [TRIM44], and sirtuin 2 [SIRT2]) had the strongest correlation with long-term survival in patients with EAC. Applying these three biomarkers as an IHC panel to the validation cohort segregated patients into two different prognostic groups (P < .01). Adjusting for known survival covariates, including clinical staging criteria, the IHC panel remained an independent predictor, with incremental adverse overall survival (OS) for each positive biomarker (hazard ratio, 1.20; 95% CI, 1.03 to 1.40 per biomarker; P = .02). Conclusion We identified and validated a clinically applicable IHC biomarker panel, consisting of EGFR, TRIM44, and SIRT2, that is independently associated with OS and provides additional prognostic information to current survival predictors such as stage. http://repub.eur.nl/res/pub/39649/ 2013-04-01T00:00:00Z Background & Aims: Acid exposure contributes to the development of Barrett's esophagus (BE) and its progression toward esophageal adenocarcinoma. Patients with BE are frequently treated with acid suppressants, but it is unclear whether these prevent the development of BE-related cancer. We investigated whether acid suppression reduces the risk of neoplastic progression in patients with BE. Methods: We performed a multicenter prospective cohort study of 540 patients with BE. We collected information on medication use at each surveillance visit, which was cross-checked with pharmacy records. Patients also completed a questionnaire about their use of over-the-counter medication. Incident cases of high-grade dysplasia and esophageal adenocarcinoma were identified during a median follow-up period of 5.2 years. Time-dependent Cox regression models were used to investigate the effect of acid suppression on the risk of neoplastic progression. Results: Forty patients (7%) developed high-grade dysplasia or esophageal adenocarcinoma during the follow-up period. Use of histamine-2 receptor antagonists did not affect the incidence of neoplastic progression. However, use of proton pump inhibitors (PPIs) at inclusion in the study or during the follow-up period reduced the risk of neoplastic progression (hazard ratio, 0.41; 95% confidence interval, 0.18-0.93 and hazard ratio, 0.21; 95% confidence interval, 0.07-0.66). Prolonged use of PPIs and good adherence were associated with an additional protective effect. The prevalence of esophagitis decreased during PPI use, but length of BE was not affected. Conclusions: In a multicenter prospective cohort study, PPI use was associated with a reduced risk of neoplastic progression in patients with BE. © 2013 AGA Institute. http://repub.eur.nl/res/pub/39666/ 2013-03-29T00:00:00Z Background and study aims: A recent international guideline recommends surveillance of premalignant gastric lesions for patients at risk of progression to gastric cancer. The aim of this study was to identify the role of the distribution and severity of premalignant lesions in risk categorization. Patients and methods: Patients with a previous diagnosis of atrophic gastritis, intestinal metaplasia, or low grade dysplasia were invited for surveillance endoscopy with non-targeted biopsy sampling. Biopsy specimens were evaluated by pathologists (four general and one expert) using the Sydney and the operative link for gastric intestinal metaplasia (OLGIM) systems, and scores were compared using kappa statistics. Results: 140 patients were included. In 37 % (95 % confidence interval [CI] 29 % - 45 %) the severity of premalignant lesions was less than at baseline, while 6 % (95 %CI 2 % - 10 %) showed progression to more severe lesions. Intestinal metaplasia in the corpus was most likely to progress to more than one location (57 %; 95 %CI 36 % - 76 %). The proportion of patients with multilocated premalignant lesions increased from 24 % at baseline to 31 % at surveillance (P = 0.014). Intestinal metaplasia was the premalignant lesion most frequently identified in subsequent endoscopies. Intestinal metaplasia regressed in 27 % compared with 44 % for atrophic gastritis and 100 % for low grade dysplasia. Interobserver agreement was excellent for intestinal metaplasia (k = 0.81), moderate for dysplasia (k = 0.42), and poor for atrophic gastritis (k < 0). Conclusions: Premalignant gastric lesions found in the corpus have the highest risk of progression, especially intestinal metaplasia, which has excellent interobserver agreement. This supports the importance of intestinal metaplasia as marker for follow-up in patients with premalignant gastric lesions. http://repub.eur.nl/res/pub/40015/ 2013-03-01T00:00:00Z Aim: To evaluate the interobserver agreement among pathologists in grading the quality of specimens obtained with a new 19-gauge endoscopic ultrasound histology needle. Methods and results: This multicentre prospective study involved 50 slides prepared using material obtained with the new needle. Five experienced pathologists independently reviewed all of the samples, and made assessments of the following features: the presence of a core, the adequacy of the specimen, the interpretability of the specimen, and the possibility of performing additional analyses using the material. Interobserver agreement, determined by Fleiss' kappa statistic and 95% confidence intervals (CIs), was used as the primary outcome measure. Overall, the presence of a core was reported in 88% of cases with good agreement among the pathologists (κ = 0.61; 95% CI 0.52-0.70). The specimens were adequate in 91.2% of cases, and Fleiss' κ was 0.73 (95% CI 0.61-0.81). The interpretation of the specimens was reported to be 'easy' in approximately 87% of cases, with moderate agreement among the pathologists (κ = 0.44; 95% CI 0.35-0.53). The possibility of performing additional analyses from the same sample was rated as positive in approximately 91%, with good agreement (κ = 0.66; 95% CI 0.58-0.75). Conclusions: There was excellent interobserver agreement among pathologists in the assessment of the histological material, especially with regard to sample adequacy. http://repub.eur.nl/res/pub/37725/ 2012-09-01T00:00:00Z Background: Occasionally patients undergoing resection for presumed malignancy of the pancreatic head are diagnosed postoperatively with benign disease. Autoimmune pancreatitis (AIP) is a rare disease that mimics pancreatic cancer. We aimed to determine the prevalence of benign disease and AIP in patients who underwent pancreatoduodenectomy (PD) over a 9-year period, and to explore if and how surgery could have been avoided. Methods: All patients undergoing PD between 2000 and 2009 in a tertiary referral centre were analyzed retrospectively. In cancer-negative cases, postoperative diagnosis was reassessed. Preoperative index of suspicion of malignancy was scored as non-specific, suggestive, or high. In AIP patients, diagnostic criteria systems were checked. Results: A total of 274 PDs were performed for presumed malignancy. The prevalence of benign disease was 8.4 %, overall prevalence of AIP was 2.6 %. Based on preoperative index of suspicion of malignancy, surgery could have been avoided in 3 non-AIP patients. All AIP patients had sufficient index to justify surgery. If diagnostic criteria would have been checked; however, surgery could have been avoided in one to five AIP patients. Conclusions: The prevalence of benign disease in patients who underwent PD for presumed malignancy was 8.4 %, nearly one-third attributable to AIP. Although misdiagnosis of AIP as carcinoma is a problem of limited quantitative importance, every effort to establish the correct diagnosis should be undertaken considering the major therapeutic consequences. IgG4 measurement and systematic use of diagnostic criteria systems are recommended for every candidate patient for PD when there is no histological proof of malignancy. http://repub.eur.nl/res/pub/38765/ 2012-09-01T00:00:00Z Background: Occasionally patients undergoing resection for presumed malignancy of the pancreatic head are diagnosed postoperatively with benign disease. Autoimmune pancreatitis (AIP) is a rare disease that mimics pancreatic cancer. We aimed to determine the prevalence of benign disease and AIP in patients who underwent pancreatoduodenectomy (PD) over a 9-year period, and to explore if and how surgery could have been avoided. Methods: All patients undergoing PD between 2000 and 2009 in a tertiary referral centre were analyzed retrospectively. In cancer-negative cases, postoperative diagnosis was reassessed. Preoperative index of suspicion of malignancy was scored as non-specific, suggestive, or high. In AIP patients, diagnostic criteria systems were checked. Results: A total of 274 PDs were performed for presumed malignancy. The prevalence of benign disease was 8.4 %, overall prevalence of AIP was 2.6 %. Based on preoperative index of suspicion of malignancy, surgery could have been avoided in 3 non-AIP patients. All AIP patients had sufficient index to justify surgery. If diagnostic criteria would have been checked; however, surgery could have been avoided in one to five AIP patients. Conclusions: The prevalence of benign disease in patients who underwent PD for presumed malignancy was 8.4 %, nearly one-third attributable to AIP. Although misdiagnosis of AIP as carcinoma is a problem of limited quantitative importance, every effort to establish the correct diagnosis should be undertaken considering the major therapeutic consequences. IgG4 measurement and systematic use of diagnostic criteria systems are recommended for every candidate patient for PD when there is no histological proof of malignancy. http://repub.eur.nl/res/pub/32002/ 2012-01-01T00:00:00Z BACKGROUND: Patients with gastric mucosa-associated lymphoid tissue lymphoma or diffuse large B-cell lymphoma have an increased risk of developing gastric carcinoma (GC). Identifying patients at high GC risk may lead to improved survival and prognosis. The aim of this case-control study was to evaluate whether premalignant gastric lesions are more prevalent and severe in gastric lymphoma (GL) patients with a subsequent diagnosis of GC than in those without GC. METHODS: Patients with a first GL diagnosis from 1991-2008 were identified in the Dutch histopathology registry (PALGA). Cases were patients with a diagnosis of GL and a subsequent diagnosis of GC. Controls were patients with a diagnosis of GL without GC development. RESULTS: In total, eight cases (mean follow-up 5.5 years) and 31 controls (mean follow-up 5.3 years) were included (mean age 60 years). At lymphoma diagnosis, six (75%) cases were diagnosed with premalignant lesions, whereas in the control group, 21 (68%) had histological evidence for premalignant lesions (P=0.69). At GC diagnosis, five (63%) cases showed intestinal metaplasia in the surrounding gastric mucosa. In 22 (71%) controls premalignant lesions were present at the end of follow-up (P=0.47). CONCLUSION: No differences were demonstrated in the prevalence of premalignant lesions of cases and controls at GL diagnosis or the end of follow-up. As the prevalence of premalignant lesions is substantial in both the groups of patients, careful endoscopic surveillance of GL patients is warranted not only for recurrence of lymphoma, but also for progression to adenocarcinoma. http://repub.eur.nl/res/pub/37207/ 2012-01-01T00:00:00Z Background: Screening for colorectal cancer is widely recommended, but the preferred strategy remains unidentified. We aimed to compare participation and diagnostic yield between screening with colonoscopy and with non-cathartic CT colonography. Methods: Members of the general population, aged 50-75 years, and living in the regions of Amsterdam or Rotterdam, identified via the registries of the regional municipal administration, were randomly allocated (2:1) to be invited for primary screening for colorectal cancer by colonoscopy or by CT colonography. Randomisation was done per household with a minimisation algorithm based on age, sex, and socioeconomic status. Invitations were sent between June 8, 2009, and Aug 16, 2010. Participants assigned to CT colonography who were found to have one or more large lesions (≥10 mm) were offered colonoscopy; those with 6-9 mm lesions were offered surveillance CT colonography. The primary outcome was the participation rate, defined as number of invitees undergoing the examination relative to the total number of invitees. Diagnostic yield was calculated as number of participants with advanced neoplasia relative to the total number of invitees. Invitees and screening centre employees were not masked to allocation. This trial is registered in the Dutch trial register, number NTR1829. Findings: 1276 (22%) of 5924 colonoscopy invitees participated, compared with 982 (34%) of 2920 CT colonography invitees (relative risk [RR] 1·56, 95% CI 1·46-1·68; p<0·0001). Of the participants in the colonoscopy group, 111 (9%) had advanced neoplasia of whom seven (<1%) had a carcinoma. Of CT colonography participants, 84 (9%) were offered colonoscopy, of whom 60 (6%) had advanced neoplasia of whom five (<1%) had a carcinoma; 82 (8%) were offered surveillance. The diagnostic yield for all advanced neoplasia was 8·7 per 100 participants for colonoscopy versus 6·1 per 100 for CT colonography (RR 1·46, 95% CI 1·06-2·03; p=0·02) and 1·9 per 100 invitees for colonoscopy and 2·1 per 100 invitees for CT colonography (RR 0·91, 0·66-2·03; p=0·56). The diagnostic yield for advanced neoplasia of 10 mm or more was 1·5 per 100 invitees for colonoscopy and 2·0 per 100 invitees for CT colonography, respectively (RR 0·74, 95% CI 0·53-1·03; p=0·07). Serious adverse events related to the screening procedure were post-polypectomy bleedings: two in the colonoscopy group and three in the CT colonography group. Interpretation: Participation in colorectal cancer screening with CT colonography was significantly better than with colonoscopy, but colonoscopy identified significantly more advanced neoplasia per 100 participants than did CT colonography. The diagnostic yield for advanced neoplasia per 100 invitees was similar for both strategies, indicating that both techniques can be used for population-based screening for colorectal cancer. Other factors such as cost-effectiveness and perceived burden should be taken into account when deciding which technique is preferable. Funding: Netherlands Organisation for Health Research and Development, Centre for Translational Molecular Medicine, and the Nuts Ohra Foundation. http://repub.eur.nl/res/pub/30566/ 2011-12-01T00:00:00Z Seminomas and embryonal carcinomas (EC) are both type II germ cell tumor (GCT) entities and develop from the same precursor lesion (carcinoma-in situ, CIS). However, they show significant differences in growth behavior, differentiation potential, and gene expression. Although ECs are prone to differentiate into all three germ layers and give rise to the non-seminomatous GCT entities teratoma, choriocarcinoma, and yolk-sac tumor, differentiation of seminomas to these entities is only rarely observed. This might reflect the ability of seminomas to actively inhibit differentiation processes evoked by environmental cues. Also, it is not known why CIS gives rise to seminoma in some patients and to non-seminoma in the others. Here, we treated the seminoma-like cell line TCam-2 with the HDAC-inhibitor Depsipeptide, the global demethylating agent 5-aza-2'-deocycytidine, all-trans retinoic acid and the monaminooxidase inhibitor Tranylcipromine and also used knock down approaches to reduce expression of the pluripotency marker NANOG and/or the inhibitor of primordial germ cell differentiation TFAP2C. We found that TCam-2 cells induce apoptosis when treated with Depsipeptide (>10 nM) but are resistant to treatments with 5-aza-2'-deocycytidine, all-trans retinoic acid and Tranylcipromine, highlighting Depsi as a treatment option for seminomas. We show that TCam-2 cells up-regulate endoderm- and throphectoderm-associated genes after down-regulation of NANOG expression; however, morphologically no indications of differentiation could be found. Instead, we observed up-regulation of OCT3/4 and SOX17 in TCam-2-NANOG knockdown and speculate that this compensates for the loss of the NANOG protein. Hence, NANOG is not a primary target gene responsible for the inhibition of differentiation in seminomas. http://repub.eur.nl/res/pub/31126/ 2011-08-25T00:00:00Z Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27-IgG+and CD27+IgM+B cells are derived from primary germinal center reactions, and CD27+IgA+and CD27+IgG+B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27-IgA+memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27-IgA+cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases. http://repub.eur.nl/res/pub/31238/ 2011-08-01T00:00:00Z Human type II germ cell tumours (GCTs) originate from an embryonic germ cell, either as a primordial germ cell or gonocyte. This start determines the biological as well as clinical characteristics of this type of cancer, amongst others their totipotency as well as their overall (exceptional) sensitivity to DNA damaging agents. The histology of the precursor lesion, either carcinoma in situ or gonadoblastoma, depends on the level of testicularization (i.e. testis formation) of the gonad. The impact of either intrinsic (genetic) - and environmental factors involved in the pathogenesis is demonstrated by disorders of sex development as well as testicular dysgenesis syndrome as risk factors, including cryptorchidism, hypospadias and disturbed fertility as parameters. This knowledge allows identification of individuals at risk for development of this type of cancer, being a population of interest for screening. Factors known to regulate pluripotency during embryogenesis are proven to be of diagnostic value for type II GCTs, including OCT3/4, even applicable for non-invasive screening. In addition, presence of stem cell factor, also known as KITLG, allows distinction between delayed matured germ cells and the earliest stages of malignant transformation. This is of special interest because of the identified association between development of type II GCTs of the testis and a limited number of single nucleotide polymorphisms, including some likely related to KITL. Transition from the precursor lesion to an invasive cancer is associated with gain of the short arm of chromosome 12, in which multiple genes might be involved, including KRAS2 and possibly NANOG (pseudogenes). While most precursor lesions will progress to an invasive cancer, only a limited number of cancers will develop treatment resistance. Putative explanatory mechanisms are identified, including presence of microsatellite instability, BRAF mutations, apoptosis suppression and p21 sub-cellular localization. It remains to be investigated how these different pathways integrate to each other and how informative they are at the patient-individual level. Further understanding will allow development of more targeted treatment, which will benefit quality of life of these young cancer patients. © 2011 The Authors. International Journal of Andrology http://repub.eur.nl/res/pub/31287/ 2011-08-01T00:00:00Z OCT3/4, NANOG, SOX2 and, most recently, LIN28 have been identified as key regulators of pluripotency in mammalian embryonic and induced stem cells, and are proven to be crucial for generation of the mouse germ-cell lineage. These factors are a hallmark of certain histological types of germ-cell tumours (GCTs). Here, we report novel information on the temporal and spatial expression pattern of LIN28 during normal human male germ-cell development as well as various types of GCTs. To investigate LIN28 expression, immunohistochemical analyses and quantitative proximity ligation assay-based TaqMan protein assays were applied on snap-frozen and formalin-fixed, paraffin-embedded samples as well as representative cell lines. LIN28 was found in primordial germ cells, gonocytes and pre-spermatogonia, in contrast to OCT3/4 and NANOG, which were found only in the first two stages. LIN28 was also found in all precursor lesions (carcinoma in situ and gonadoblastoma) of type II GCTs, as well as the invasive components seminoma and the non-seminomatous elements embryonal carcinoma and yolk sac tumour. Choriocarcinoma showed a heterogeneous pattern, while teratomas and spermatocytic seminomas (type III GCTs) were negative. This expression pattern suggests that LIN28 is associated with malignant behaviour of type II GCTs. Cell line experiments involving siRNA knockdown of LIN28, OCT3/4 and SOX2 showed that LIN28 plays a role in the maintenance of the undifferentiated state of both seminoma and embryonal carcinoma, closely linked to, and likely upstream of OCT3/4 and NANOG. In conclusion, LIN28 regulates the differentiation status of seminoma and embryonal carcinoma and is likely to play a related role in normal human germ-cell development. © 2011 The Authors. International Journal of Andrology http://repub.eur.nl/res/pub/26123/ 2011-06-02T00:00:00Z http://repub.eur.nl/res/pub/26133/ 2011-06-01T00:00:00Z Background: EUS-guided FNA is an efficacious technique for sampling intraintestinal and extraintestinal mass lesions. However, cytology has limitations to its final yield and accuracy, which may be overcome if histological specimens are provided to the pathologist. Objective: To evaluate feasibility, yield, and diagnostic accuracy of a newly developed 19-gauge, fine-needle biopsy (FNB) device. Design: Multicenter, pooled, cohort study. Setting: Five medical centers. Patients: This study involved 109 consecutive patients with 114 intraintestinal or extraintestinal mass lesions and/or peri-intestinal lymph nodes. Intervention: EUS-guided FNB (EUS-FNB) with a newly developed, 19-gauge, FNB device. Main Outcome Measurements: Percentage of cases in which pathologists classified the sample quality as optimal for histological evaluation and the overall diagnostic accuracy compared with a composite criterion-standard diagnosis. Results: We evaluated 114 lesions (mean [± standard deviation] size 35.1 ± 18.7 mm; 84 malignant [73.7%] and 30 [26.3%] benign). EUS-FNB was technically feasible in 112 lesions (98.24%). Sample quality was adequate for full histological assessment in 102 lesions (89.47%). In 98 cases (85.96%), diagnosis proved to be correct according to criterion-standard diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for diagnosis of malignancy were 90.2%, 100%, 100%, 78.9%, and 92.9%, respectively. Limitations: Use of a surrogate criterion-standard diagnosis, including clinical follow-up when no surgical specimens were available, mainly in benign diagnoses. Conclusion: Performing an EUS-FNB with a new 19-gauge histology needle is feasible for histopathology diagnosis of intraintestinal and extraintestinal mass lesions, offering the possibility of obtaining a core sample for histological evaluation in the majority of cases, with an overall diagnostic accuracy of over 85%. http://repub.eur.nl/res/pub/25779/ 2011-05-01T00:00:00Z Background: Helicobacter pylori is the main risk-factor for gastric cancer through a cascade from gastritis through atrophic gastritis (AG), intestinal metaplasia (IM), dysplasia (DYS) to malignancy. The presence of these lesions in the general population predicts the gastric cancer incidence in the coming decades. Prevalence data are mostly obtained from serological studies and endoscopy data in symptomatic patients. Aim: To investigate the prevalence of H. pylori infection and its related gastric changes in asymptomatic subjects. Methods: 383 Patients undergoing routine colonoscopy were included. All subjects underwent upper GI endoscopy and completed the Gastrointestinal Symptom Rating Scale (GSRS). Biopsies were taken from antrum and corpus. Results: H. pylori infection was present in 22%. Non-Caucasian subjects had a significantly higher H. pylori prevalence (p < 0.001). AG, IM and DYS were together found in 9.3% of subjects. Subjects with AG, IM or DYS were significantly older (p < 0.001). No differences were found with respect to gender, presence of GI symptoms as scored by GSRS, lifestyle and medication use. Conclusions: The prevalence of premalignant gastric lesions is considerable in general Western population with increasing age as the main risk factor. One time screening for premalignant lesions at the age of 60 years is a reasonable strategy since the numbers found imply that gastric cancer will remain a prevalent disease. http://repub.eur.nl/res/pub/23899/ 2011-04-01T00:00:00Z Background & Aims: The fecal immunochemical test (FIT) is superior to the guaiac-based fecal occult blood test in detecting neoplasia. There are not much data on the optimal number of FITs to perform. We conducted a population-based trial to determine attendance and diagnostic yield of 1- and 2-sample FIT screening. Methods: The study included 2 randomly selected groups of subjects aged 50-74 years (1-sample FIT, n = 5007; 2-sample FIT, n = 3197). The 2-sample group was instructed to collect fecal samples on 2 consecutive days. Subjects were referred for colonoscopy when at least 1 sample tested positive (≥50 ng hemoglobin/mL). Results: Attendance was 61.5% in the 1-sample group (2979 of 4845; 95% confidence interval, 60.1%-62.9%) and 61.3% in the 2-sample group (1875 of 3061; 95% confidence interval, 59.6%-63.0%; P = .84). In the 1-sample group 8.1% tested positive, and in the 2-sample group 12.8% had at least 1 positive test outcome and 5.0% had 2 positive test outcomes (P < .05). When the mean from both test results in the 2-sample group was used, 10.1% had a positive test outcome (P < .05). The detection rates for advanced neoplasia were 3.1% in the 1-sample group, 4.1% in the 2-sample group with at least 1 positive test outcome, 2.5% when both test results were positive, and 3.7% among subjects with the mean from both test results being positive. Conclusions: There is no difference in attendance for subjects offered 1- or 2-sample FIT screening. The results allow for the development of efficient FIT screening strategies that can be adapted for local colonoscopy capacities, rather than varying the cut-off value in a 1-sample strategy. http://repub.eur.nl/res/pub/23886/ 2011-02-01T00:00:00Z Aims: Testis-sparing surgery might benefit quality of life, but can only be applied with histological examination for the presence of invasive germ cell tumour components, and the precursor carcinoma in situ (CIS). Currently, diagnosis is based on paraffin-embedded tissue, therefore a delay in further surgery is mainly unavoidable. The aim was to develop an intraoperative assessment technique using alkaline phosphatase as a marker. Methods and results: A total of 4093 snap-frozen samples and matched paraffin-embedded tissue of 1500 patients were included. Besides standard haematoxylin and eosin (H&E) staining, the direct enzymatic alkaline phosphatase reactivity (dAP) test (duration 15min) was applied on frozen sections, while H&E and immunohistochemistry for detection of OCT3/4, α-fetoprotein, human chorionic gonadotrophin (hCG) and cytokeratin was performed on the paraffin-embedded slides. Endothelial cells served as control for the dAP test. Positive staining was found in all CIS (n=965), seminoma (n=1035) and embryonal carcinoma (n=584), either intratubular, microinvasive or invasive. Differentiated non-seminomas (n=1238) showed variable staining. No staining was identified in spermatocytic seminomas (n=5), testicular lymphomas (n=42), testicular rhabdomyosarcomas (n=7), Leydig cell tumours (n=31), Sertoli-cell-only nodules (n=4), (epi) dermoid cyst (n=16), normal testicular parenchyma (n=116), testicular torsion (n=32) and inflammation of the epididymis (n=19). The dAP test results matched H&E-stained parallel sections, as well paraffin-embedded tissue analysis, including immunohistochemistry. Conclusions: The dAP test is an informative, reproducible and easy tool to diagnose CIS, (intratubular and microinvasive) seminoma and embryonal carcinoma on frozen tissue sections, being of great value in the context of sparing surgery. http://repub.eur.nl/res/pub/21928/ 2010-12-01T00:00:00Z Background: Surveillance of premalignant gastric lesions relies mainly on random biopsy sampling. Narrow band imaging (NBI) may enhance the accuracy of endoscopic surveillance of intestinal metaplasia (IM) and dysplasia. We aimed to compare the yield of NBI to white light endoscopy (WLE) in the surveillance of patients with IM and dysplasia. Methods: Patients with previously identified gastric IM or dysplasia underwent a surveillance endoscopy. Both WLE and NBI were performed in all patients during a single procedure. The sensitivity of WLE and NBI for the detection of premalignant lesions was calculated by correlating endoscopic findings to histological diagnosis. Results: Forty-three patients (28 males and 15 females, mean age 59 years) were included. IM was diagnosed in 27 patients; 20 were detected by NBI and WLE, four solely by NBI and three by random biopsies only. Dysplasia was detected in seven patients by WLE and NBI and in two patients by random biopsies only. Sixty-eight endoscopically detected lesions contained IM: 47 were detected by WLE and NBI, 21 by NBI only. Nine endoscopically detected lesions demonstrated dysplasia: eight were detected by WLE and NBI, one was detected by NBI only. The sensitivity, specificity, positive and negative predictive values for detection of premalignant lesions were 71, 58, 65 and 65% for NBI and 51, 67, 62 and 55% for WLE, respectively. Conclusions: NBI increases the diagnostic yield for detection of advanced premalignant gastric lesions compared to routine WLE. http://repub.eur.nl/res/pub/21957/ 2010-12-01T00:00:00Z Background: Inflammation is a known pitfall of surveillance colonoscopy for inflammatory bowel disease (IBD) as it is difficult to differentiate between inflammation and true dysplasia. This randomized controlled trial assessed the effectiveness of a low dose of corticosteroids prior to surveillance colonoscopy to decrease mucosal inflammation. Methods: IBD-patients scheduled for surveillance colonoscopy between July 2008-January 2010 were eligible to participate. Patients were randomized to either two weeks daily 20. mg prednisone and calcium plus vitamin D prior to surveillance colonoscopy or no treatment. All biopsies were reviewed by an expert gastrointestinal pathologist who was blinded for medication-use. Statistics were performed using chi-square tests, non-parametric tests and binary logistic regression. Results: Sixty patients (M/F 30/30, UC/CD 31/29) participated: 31 (52%) in the treatment arm and 29 (48%) in the control group. In the treatment arm, 247 biopsies were scored against 262 in the control group. In the treatment arm 27 out of 247 biopsies (10.9%) had a score > 1 on the Geboes scale, against 50 out of 262 biopsies (19.1%) in the control group, p = 0.013. In total, 58% of the treatment arm against 66% of the control group had endoscopic or histological mucosal inflammation (p = 0.6). There was a trend for patients in the treatment arm to have less severe inflammation compared with the control group, however this was not significant (p = 0.12). Conclusions: In our cohort, a short course of corticosteroids decreases the overall histological disease activity in individual biopsies without major side-effects. Moreover, there is a trend for corticosteroids to decrease the maximum severity of both endoscopic and histological disease activity per patient. http://repub.eur.nl/res/pub/27421/ 2010-12-01T00:00:00Z Background: Both endoscopic and surgical treatments are recommended for m3- or sm1-adenocarcinomas of the esophagus, depending on patients' lymph nodal status. Lymphatic dissemination is related to tumor infiltration depth, but varying incidences have been reported in m3- and sm1-adenocarcinomas. The study aim was to investigate whether the presence of occult tumor cells in lymph nodes could explain this variation. Methods Sixty-three node-negative (N0) patients with early esophageal adenocarcinoma (m2/m3/sm1-tumors) were included. Multilevel-sectioning of lymph nodes was performed; sections were stained by means of immunohistochemistry with cytokeratin marker CAM5.2. Two pathologists searched for micrometastases (0.2-2.0 mm) and isolated tumor cells (ITCs, <0.2 mm). Results Positive CAM5.2 staining in lymph nodes was not seen in any of the 18 m2-patients. In 2/25 m3-tumors (8.0%) an ITC was found, but no micrometastases. Tumor cells were identified in 4/20 sm1-tumors (20.0%): three micrometastases and one ITC. Median follow-up was 121 months. Two m3-patients (3.2%) died due to disease recurrence, including one patient in whom an ITC was detected. Conclusions Lymphatic migration of tumor cells was found in node-negative m3- and sm1-adenocarcinomas of the esophagus (8.0% and 20.0%, respectively). However, the clinical relevance of these occult tumor cells should become apparent from large series of endoscopically treated patients. http://repub.eur.nl/res/pub/27592/ 2010-11-01T00:00:00Z Aims: According to the classification established by the Japanese Society for Oesophageal Disease, early oesophageal cancer can be subdivided into six successive layers of the mucosa or submucosa, which influences the treatment strategy and prognosis of the individual patient. However, the reproducibility of this classification in terms of inter- and intraobserver variability is unclear. Methods: Histological slides from 105 surgical resection specimens of patients who had undergone oesophagectomy for early oesophageal adenocarcinoma were reviewed independently by three gastrointestinal pathologists, andwere classified according to the Japanese criteria (m1/m2/m3/sm1/sm2/sm3 tumours). Inter- and intraobserver variation was determined by κ-statistics. Results: The interobserver reproducibility was good between pathologist 1 and 2 (κ=0.61, 95% CI 0.55 to 0.67), and moderate between pathologist 1 and 3 (κ=0.51, 95% CI 0.45 to 0.57) and between pathologist 2 and 3 (κ=0.50, 95% CI 0.38 to 0.61). The intraobserver agreement as assessed by the expert pathologist was good (κ=0.76), with a 95% CI that was interpreted as good to very good (0.67 to 0.85). Most agreement was achieved at the lower (m1) and upper site (sm2, sm3) of the spectrum, whereas the m2 tumours reflected the most discrepant stage. The majority of the observed discrepancy included the variation in one substage only. Conclusions: The reproducibility of the Japanese classification is good in terms of inter- and intraobserver variability when grading early oesophageal adenocarcinoma on surgical resection specimens. The present data confirm that dedicated gastrointestinal pathologists with broad experience are preferred when grading the resection specimens of patients with early oesophageal adenocarcinoma. http://repub.eur.nl/res/pub/26019/ 2010-10-01T00:00:00Z Aims: Diagnosing chronic upper gastrointestinal ischaemia (CUGI) remains a challenge in clinical practice. Histological examination of biopsy material currently plays no role in the diagnosis of transient CUGI, as little is known about gastrointestinal histology in these patients. The aim of this study was to investigate upper gastrointestinal histology in patients with well-defined CUGI.Methods and results: Consecutive patients suspected of CUGI were included prospectively and underwent a diagnostic work-up existing of upper endoscopy, gastrointestinal tonometry and computed tomography (CT) or magnetic resonance (MR) angiography. Results were discussed in a multidisciplinary team and a consensus diagnosis was made. Endoscopic biopsy samples were taken from the descending duodenum, gastric antrum and corpus, and scored using the Sydney, Vienna, Chiu, Marsh and Operative Link for Gastritis Assessment (OLGA) classifications. Gastropathy was scored present or absent. Seventy-nine patients were analysed in 8 months. CUGI was diagnosed in 41 patients (52%): 36 males, mean age 60 (17-86) years. Prevalence of gastropathy was significantly higher in patients with ischaemia (P = 0.025). No other differences were found between patients with and without ischaemia.Conclusions: Histological examination of biopsy samples plays no definitive role in diagnosing CUGI, but the presence of histological signs of reactive gastropathy can be used to support the clinical diagnosis of ischaemia. http://repub.eur.nl/res/pub/20916/ 2010-09-01T00:00:00Z http://repub.eur.nl/res/pub/19931/ 2010-05-18T00:00:00Z Formation of the germ cell lineage involves multiple processes, including repression of somatic differentiation and reacquisition of pluripotency as well as a unique epigenetic constitution. The transcriptional regulator Prdm1 has been identified as a main coordinator of this process, controlling epigenetic modification and gene expression. Here we report on the expression pattern of the transcription factor Tcfap2c, a putative downstream target of Prdm1, during normal mouse embryogenesis and the consequences of its specific loss in primordial germ cells (PGCs) and their derivatives. Tcfap2c is expressed in PGCs from Embryonic Day 7.25 (E 7.25) up to E 12.5, and targeted disruption resulted in sterile animals, both male and female. In the mutant animals, PGCs were specified but were lost around E 8.0. PGCs generated in vitro from embryonic stem cells lacking TCFAP2C displayed induction of Prdm1 and Dppa3. Upregulation of Hoxa1, Hoxb1, and T together with lack of expression of germ cell markers such Nanos3, Dazl, and Mutyh suggested that the somatic gene program is induced in TCFAP2C-deficient PGCs. Repression of TCFAP2C in TCam-2, a human PGC-resembling seminoma cell line, resulted in specific upregulation of HOXA1, HOXB1, MYOD1, and HAND1, indicative of mesodermal differentiation. Expression of genes indicative of ectodermal, endodermal, or extraembryonic differentiation, as well as the finding of no change to epigenetic modifications, suggested control by other factors. Our results implicate Tcfap2c as an important effector of Prdml activity that is required for PGC maintenance, most likely mediating Prdm1-induced suppression of mesodermal differentiation. http://repub.eur.nl/res/pub/18384/ 2010-03-05T00:00:00Z Current classification systems of human germ cell tumors (GCTs) are based on histological composition. In the group of nonseminomas, different variants of teratoma (somatic differentiation), yolk sac tumor and choriocarcinoma (extra-embryonic differentiation), are recognized, as well as their stem cell component embryonal carcinoma. In addition, the seminomatous tumors are distinguished, subdivided into classic - and spermatocytic variants. The morphologically similar classic seminomas of the ovary are called dysgerminomas, and those of the brain germinomas. Tumors containing both a (classic) seminoma and a nonseminoma component are referred to as combined tumor according to the British classification , and as nonseminoma in the World Health Organisation (WHO) Classification. This traditional histological description obscures the biological diversity of this type of cancer, which hampers identification of pathogenetic mechanisms and proper comparison of the neoplastic cells to their normal counterparts. Therefore, an alternative classification was proposed, recognizing five categories (I-V) of GCTs (see Table 1), based on site of presentation, age of the patient at diagnosis, histological composition, as well as pattern of genomic imprinting, and chromosomal constitution. This thesis will deal only with the type II GCTs, predominantly of the testis, and therefore the other types will not be discussed here. The testicular type II GCTs will be referred as TGCTs. http://repub.eur.nl/res/pub/19809/ 2010-01-01T00:00:00Z Lynch syndrome (LS) is caused by mutations in mismatch repair genes and is characterized by a high cumulative risk for the development of mainly colorectal carcinoma and endometrial carcinoma. Early detection of LS is important since surveillance can reduce morbidity and mortality. However, the diagnosis of LS is complicated by the absence of a pre-morbid phenotype and germline mutation analysis is expensive and time consuming. Therefore it is standard practice to precede germline mutation analysis by a molecular diagnostic work-up of tumours, guided by clinical and pathological criteria, to select patients for germline mutation analysis. In this review we address these molecular analyses, the central role for the pathologist in the selection of patients for germline diagnostics of LS, as well as the molecular basis of LS. http://repub.eur.nl/res/pub/15203/ 2008-09-01T00:00:00Z Germ cell tumors (GCT) comprise a heterogeneous group of benign and malignant tumors. Based on their different biological characteristics and their origin, five types of GCT are classified. Among these, malignant seminomatous and non-seminomatous GCT in males and females are designated as type II GCT. They occur most frequently as malignant testicular GCTs. Many characteristics of type II GCT can be linked to embryonic stem cells. Intratubular germ cell neoplasia, unclassified (IGCNU) is the precursor of type II GCT and derives from undifferentiated germ cells, gonocytes, which persist in the newborn testis and escape the normal differentiation process. It is suggested that Exon-17-activated mutations of the receptor tyrosine kinase, c-KIT, occur early in germ cell development and that gonocytes with an activated c-KIT receptor are restricted in their differentiation, thereby escaping normal development. New diagnostic markers for neoplastic germ cells, including OCT3/4 and AP-2γ, are specifically detected in IGCNU, seminomas and embryonal carcinomas and are helpful in the differentiation of type II GCT from other malignant tumors.