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The macroscopic and microscopic assessments of pancreatic cancer resection specimens belong to the standard repertoire of any department of pathology. In recent years standards have been developed regarding both macroscopic and microscopic assessments, which are laid down in international and national guidelines and classifications and are regularly updated. In this way the reporting of results and interdisciplinary communication are facilitated. These classifications and guidelines are influenced by current studies and the data from them provide information on which histopathological factors are particularly relevant for the prognosis and treatment. Due to the increasing use of neoadjuvant therapy the assessment of tumor regression in histopathological specimens is also gaining in importance. Finally, individual targeted treatments are also now available for pancreatic cancer, which require extended molecular pathological diagnostics.Die makroskopische und mikroskopische Begutachtung onkologischer Resektate von Pankreaskarzinomen gehört zum Standardrepertoire eines pathologischen Instituts. In den letzten Jahren wurden sowohl bezüglich der makroskopischen als auch der mikroskopischen Beurteilung Standards erarbeitet, die in internationalen und nationalen Leitlinien und Klassifikationen festgelegt sind und regelmäßig aktualisiert werden. Dadurch werden die Befunderstellung und auch die interdisziplinäre Kommunikation erleichtert. Beeinflusst werden diese Klassifikationen und Leitlinien durch aktuelle Studien, die Daten dazu liefern, welche pathohistologischen Faktoren besonders prognose- und therapierelevant sind. Durch den zunehmenden Einsatz einer neoadjuvanten Therapie gewinnt auch die Beurteilung der Tumorregression im pathohistologischen Präparat an Bedeutung. Zuletzt sind auch mittlerweile für das Pankreaskarzinom einzelne zielgerichtete Therapien verfügbar, die eine weiterführende molekularpathologische Diagnostik erfordern.

We previously reported 2 cases of pathologic complete response (pCR) of a pancreatic cancer (PC) following neoadjuvant FOLFIRINOX treatment. We now complete our report by a follow-up on both patients. Patient 1 achieved a disease-free survival of 12 months after initial resection until she developed a singular hepatic metastasis. Treatment by FOLFIRINOX and complete removal of the metastasis by atypical liver resection after 6 months allowed for another 12 months of disease control. After intra-abdominal tumor recurrence and development of intracerebral metastases, the patient died 34 months after primary diagnosis. Patient 2 developed hepatic tumor recurrence only 3 months after initial resection. However, treatment by FOLFIRINOX led to a stable disease for 27 months after resection and was followed by atypical liver resection of multiple segments. Six months later, another hepatic recurrence was suspected. Via next-generation sequencing (NGS) of the tumor genome, a deleterious mutation in the ataxia telangiectasia-mutated (ATM) gene, causing a BRCAness, was detected. After initial treatment by FOLFOX, maintenance therapy with the poly-ADP-ribose-polymerase (PARP) inhibitor olaparib was initiated. The patient is now alive for 54 months after initial diagnosis of metastasized pancreatic adenocarcinoma. Tumor recurrence is possible even after pCR of PC and remains challenging. In case of multifocal tumor recurrence, chemotherapy remains the standard treatment. Recently, genetic sequencing allows individualized treatments. In selected cases, highly specialized teams can offer a variety of therapeutic options leading to previously unseen clinical courses.

Intraductal papillary neoplasms of the biliary tract (IPNB) are rare tumors originating from the bile duct epithelium. Metastatic disease of IPNB is extremely rare and only reported in a small number of cases worldwide. Due to this limitation in number, the treatment of IPNB mainly relies on retrospective case series. We reported three cases of IPNB, one benign, one carcinoma with lymph node metastasis, and one case with histologically proven metachronous pulmonary metastasis. We correlated our findings with the existing data found in the literature. All patients underwent hemihepatectomy and complete tumor resection was achieved. Diagnosis of IPNB can be challenging due to varying presentation. The treatment of choice is surgical oncological resection in an early tumor stage. Long-term outcome highly depends on the underlying grade of dysplasia, multiplicity, and tumor-free margins. Aggressive tumor invasion is reported in up to 72% of cases in IPNB. Furthermore, the recurrence rate of IPNB is high with up to 22%. Further factors associated with an impaired survival are incomplete resection, lymph node involvement, and MUC1 expression. High potential for dysplasia and proof of invasive carcinoma upon diagnosis are hallmarks of IPNB. Metastatic disease in IPNB is reported only in small numbers. IPNB is an aggressive tumor entity with impaired long-term outcomes. A drawback for interpretation of current data is the fact that they rely on case series and reports and are not validated through more powerful randomized multicentric trials.

ZusammenfassungDank flächendeckender Vorsorgeuntersuchungen werden immer mehr Tumore im Gastrointestinaltrakt so früh diagnostiziert, dass sie endoskopisch resezierbar sind. Doch nicht alle Läsionen eignen sich für eine kurative endoskopische Therapie. Abhängig ist dies vom lymphogenen Metastasierungsrisiko, das sich anhand histopathologischer Charakteristika abschätzen lässt.

Acinar cell carcinomas (ACC) and adenomas (ACA) of the pancreas are rare entities. Sufficient knowledge about occurrence and prognosis is scarce. A retrospective chart review of our database was performed for all patients who had undergone pancreatic surgery between 2006 and 2018. Results were compared to recent literature findings. Nine patients were diagnosed with ACC and four patients with ACA of the pancreas in the study period. ACC patients were older and more often male than patients of the ACA group. ACC were mainly localized in the pancreatic head, whereas ACA were more often found in the distal pancreas. Tumor markers are not necessarily elevated, even in case of malignancy. ACC and ACA are very rare pancreatic tumors. Both entities account for less than 1% of all pancreatic neoplasms. Diagnosis is challenging due to unspecific radiologic features and clinical symptoms. Nevertheless, a patient complaining of abdominal discomfort and an unclear hypodense pancreatic lesion should undergo surgical exploration.

Introduction: Pancreatic cancer is a lethal disease and often asymptomatic. Therefore, it is most often diagnosed at an advanced stage. The standard approach in a metastasized tumor stage is palliative chemotherapy. However, the prognosis remains extremely poor. Case Report: We present the case of a patient who was diagnosed with a cancer of the head of the pancreas with hepatic metastases. After receiving palliative intended chemotherapy with the FOLFIRINOX regimen, staging computed tomography revealed the disappearance of the liver metastases and local resectability of the pancreatic head tumor. The patient underwent an uneventful Whipple’s procedure. Surprisingly, pathohistological investigation revealed a complete pathological response. Conclusion: Pathological complete response after FOLFIRINOX treatment in hepatic metastasized pancreatic cancer is extremely rare. It enables surgical resection and increases the survival rate significantly.

Background: Pancreatic cancer is a fatal disease most often diagnosed at an advanced stage. Most patients already suffer from irresectable tumor or distant metastases being most commonly found in the liver or the lung. However, cerebral metastases occur extremely rare.Methods: We performed a retrospective analysis of our database to identify all patients diagnosed with pancreatic cancer and cerebral metastases who underwent surgical treatment in our department from January 2004 to November 2016.Results: Only 0.2% (4 of 2492) were diagnosed with cerebral metastases. Two patients had surgical resection of the cerebral metastases. One patient underwent palliative radiation therapy and the fourth patient received only palliative therapy. Mean interval between initial diagnosis and development of brain metastases was 8.5 months (range 1-20). Mean survival period after diagnosis of brain metastases was 4.75 months (range 1-10).Conclusions: Cerebral metastases of pancreatic cancer occur extremely rare. They are associated with an advanced tumor stage, commonly liver and lung metastases. All patients presenting with neurological symptoms, multifocal metastases, and significantly elevated CA 19-9 levels are suspicious of sustaining cerebral metastases and should undergo brain imaging.

Pancreatic cancer (PC) is a lethal disease with a poor prognosis. It is typically asymptomatic and therefore most often diagnosed at an advanced stage. A primary unresectable PC can become resectable in case of tumor regression turning palliative into neoadjuvant therapy. We present a 67-year old female patient who was diagnosed with a locally advanced adenocarcinoma of the pancreatic head. After receiving palliative intended chemotherapy with the FOLFIRINOX regimen, staging computed tomography revealed local resectability of the pancreatic head tumor. The patient underwent an uneventful total pancreatectomy. Pathohistological investigation revealed a pathologic complete response (pCR). pCR after FOLFIRINOX treatment in primary unresectable PC is extremely rare. It might enable surgical resection and can increase the survival rate.

Die Autoimmunpankreatitis (AIP) ist eine seltene Form der Pankreatitis und betrifft etwa 5% der Patienten mit chronischer Pankreatitis. Die Grundzuge der Entitat wurden erstmals 1961 durch Sarles et al. beschrieben, die bei mehreren Patienten eine idiopathische chronische Pankreatitis mit Hypergammaglobulinamie nachweisen konnten und eine autoimmune Genese dieser Entzundung postulierten [1]. Ab 1995–34 Jahre spater–wurde die Autoimmunpankreatitis als eigene Krankheitsentitat etabliert [2].

Background & Aims Endoscopic ultrasound–guided fine-needle aspiration (EUS-FNA) in combination with cytopathology is the optimal method for diagnosis and staging of pancreatic ductal adenocarcinoma (PDAC) and other pancreatic lesions. Its clinical utility, however, can be limited by high rates of indeterminate or false-negative results. We aimed to develop and validate a microRNA (miRNA)-based test to improve preoperative detection of PDAC. Methods Levels of miRNAs were analyzed in a centralized clinical laboratory by relative quantitative polymerase chain reaction in 95 formalin-fixed paraffin-embedded specimens and 228 samples collected by EUS-FNA during routine evaluations of patients with solid pancreatic masses at 4 institutions in the United States, 1 in Canada, and 1 in Poland. Results We developed a 5-miRNA expression classifier, consisting of MIR24, MIR130B, MIR135B, MIR148A, and MIR196, that could identify PDAC in well-characterized, formalin-fixed, paraffin-embedded specimens. Detection of PDAC in EUS-FNA samples increased from 78.8% by cytology analysis alone (95% confidence interval, 72.2%–84.5%) to 90.8% when combined with miRNA analysis (95% confidence interval, 85.6%–94.5%). The miRNA classifier correctly identified 22 additional true PDAC cases among 39 samples initially classified as benign, indeterminate, or nondiagnostic by cytology. Cytology and miRNA test results each were associated significantly with PDAC ( P Conclusions We developed and validated a 5-miRNA classifier that can accurately predict which preoperative pancreatic EUS-FNA specimens contain PDAC. This test might aid in the diagnosis of pancreatic cancer by reducing the number of FNAs without a definitive adenocarcinoma diagnosis, thereby reducing the number of repeat EUS-FNA procedures.

Die S3-Pankreaskarzinomleitlinie wurde im letzten Jahr aktualisiert. Neben der internistisch-onkologischen und Palliativtherapie standen die chirurgische Therapie und insbesondere die Pathologie im sog. Themenkomplex 3 zur Aktualisierung an. Die Neuerungen betreffen im Wesentlichen die histopathologische Aufarbeitung, die besonders im Hinblick auf den zirkumferenziellen Resektionsrand und die R-Klassifikation uberarbeitet wurde. Weiterhin wird in den Empfehlungen festgelegt, welche Angaben ein vollstandiger pathohistologischer Befund enthalten sollte. Insbesondere auf die Angabe der Lymphknotenratio wird abgehoben.

The ductal adenocarcinoma of the pancreas is characterised by a very poor prognosis due to an early inoperability of the tumours. Even if operated under curative aspects, local recurrence of the disease is quite frequent with corresponding poorer prognosis. For a better assessment, standardised protocols for the pathohistological processing of resection specimens of the pancreas are needed urgently as well as a strict adherence to the R classification. In order to establish a reliable marker for the risk of recurrence, the smallest distance to the circumferential resection margin should be indicated in comparison to the circumferential resection margin (CRM) concept in colorectal carcinoma.

Osteonecrosis of the jaw (ONJ) is defined by areas of tissue breakdown and exposure of bone in the maxillofacial region that fail to heal within 8 weeks after identification by a health provider in a patient who has not received radiation of the jaws. The disease affects the quality of life and produces significant morbidity in afflicted patients. ONJ is correlated with such risk factors as treatment with bisphosphonates, dental extraction-related trauma, chemotherapy, corticosteroids, renal osteodystrophy and infections. Although the use of bisphosphonates is associated with osteonecrosis of the jaw, the pathophysiology of bisphosphonate-associated ONJ is still unknown. It has been assumed that bisphosphonates lead to the inhibition of capillary angiogenesis and disturbances in the activities of both osteoblasts and osteoclasts, thereby impairing bone remodelling. Currently, inhibitors of angiogenesis used in the treatment of cancer patients are implicated in isolated cases of ONJ. This manuscript reports a case of ONJ in a female patient who received bevacizumab (Avastin®, Roche), a humanised monoclonal antibody that recognises and blocks vascular endothelial growth factor (VEGF)-A. The anti-angiogenic agent, bevacizumab, may increase the risk of osteonecrosis of the jaw. This agent inhibits VEGF and, therefore, also presumably represses the vascularisation of the jaw, which leads to healing complications. Due to increasing use of bevacizumab, patients receiving this agent should be closely monitored for possible side effects.

Since the implementation of a nationwide screening colonoscopy the incidence of colorectal adenocarcinoma is decreasing, while the amount of early endoscopically resectable tumours is increasing. Similarly malignant tumors of the upper gastrointestinal tract are diagnosed and resected endoscopically more often. In part, this also depends on improvements in technology.The current guidelines of diagnosis and treatment of squamous carcinoma and adenocarcinoma of the esophagus, gastric cancer and colorectal cancer exactly define, which lesions can be endoscopically resected curatively. This mostly depends on the risc of metastases in regional lymph nodes. The risc of a lymphatic spread can be asessed by histopathological characteristics depending on the localisation of the lesion. Substantially, these characteristics comprise the depth of invasion in the resection specimen and the status at the resection margins after the endoscopic resection as well as the tumor subtype and the histological grading of the tumor. In addition, an infiltration in lymphatic or blood vessels has to be taken into account.

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in different biological processes by suppressing target gene expression. Altered expression of miR-30a-5p has been reported in colon carcinoma. To elucidate its potential biological role in colon cancer, miR-30a-5p was overexpressed via a lentiviral vector system in two different colon cancer cell lines. This induced in both lines miR-30a-5p-mediated growth inhibition, attributable to a cell cycle arrest at the G(1) phase and an induction of apoptosis. Combining global gene expression analyses of miR-30a-5p transgenic line HCT116 with in silico miRNA target prediction, we identified the denticleless protein homolog (DTL) as a potential miRNA-30a-5p target. Subsequent reporter gene assays confirmed the predicted miR-30a-5p binding site in the 3'untranslated region of DTL. Importantly, overexpression of DTL in HCT116 cells partially rescued these cells from miR-30a-5p-mediated growth suppression. In addition, TP53 and CDKN1A expression were increased in miR-30a-5p-overexpressing HCT116 cells, suggesting that miR-30a-5p is able to modulate the cell cycle via a DTL-TP53-CDKN1A regulatory circuit. Finally, 379 colorectal cancer tissues were screened for DTL expression and DTL was found to be overexpressed in 95.8% of human colorectal cancers compared with normal colon mucosa. In conclusion, our data identified miR-30a-5p as a tumor-suppressing miRNA in colon cancer cells exerting its function via modulation of DTL expression, which is frequently overexpressed in colorectal cancer. Thus, our data suggest that restoring miR-30a-5p function may prove useful as therapeutic strategy for tumors with reduced miR-30a-5p expression. MicroRNAs (miRNAs) are small non-coding RNAs that are involved in different biological processes by suppressing target gene expression. Altered expression of miR-30a-5p has been reported in colon carcinoma. To elucidate its potential biological role in colon cancer, miR-30a-5p was overexpressed via a lentiviral vector system in two different colon cancer cell lines. This induced in both lines miR-30a-5p-mediated growth inhibition, attributable to a cell cycle arrest at the G(1) phase and an induction of apoptosis. Combining global gene expression analyses of miR-30a-5p transgenic line HCT116 with in silico miRNA target prediction, we identified the denticleless protein homolog (DTL) as a potential miRNA-30a-5p target. Subsequent reporter gene assays confirmed the predicted miR-30a-5p binding site in the 3'untranslated region of DTL. Importantly, overexpression of DTL in HCT116 cells partially rescued these cells from miR-30a-5p-mediated growth suppression. In addition, TP53 and CDKN1A expression were increased in miR-30a-5p-overexpressing HCT116 cells, suggesting that miR-30a-5p is able to modulate the cell cycle via a DTL-TP53-CDKN1A regulatory circuit. Finally, 379 colorectal cancer tissues were screened for DTL expression and DTL was found to be overexpressed in 95.8% of human colorectal cancers compared with normal colon mucosa. In conclusion, our data identified miR-30a-5p as a tumor-suppressing miRNA in colon cancer cells exerting its function via modulation of DTL expression, which is frequently overexpressed in colorectal cancer. Thus, our data suggest that restoring miR-30a-5p function may prove useful as therapeutic strategy for tumors with reduced miR-30a-5p expression.

CCR7 expression on tumor cells promotes lymphatic spread in several malignant tumors. However, a comprehensive characterization of the CCL19/CCL21-CCR7 axis in pancreatic ductal adenocarcinoma (PDAC), which is known for its high rates of lymph-node metastases, is still lacking. CCR7 mRNA and CCR7 protein were found to be expressed in spheroid cultures of all six examined PDAC cell lines. In migration assays, CCR7 expressing PDAC cells showed enhanced migration toward CCL19 and CCL21, the two ligands of CCR7. In an orthotopic nude mouse model, CCR7-transfected PT45P1 cells gave rise to significantly larger tumors and showed a higher frequency of lymph vessel invasion and lymph-node metastases than mock-transfected cells. In an analysis using quantitative real-time PCR, CCR7 showed fourfold overexpression in microdissected PDAC cells compared to normal duct cells. Moderate-to-strong immunohistochemical CCR7 expression, found in 58 of 121 well-characterized human PDACs, correlated with high rates of lymph vessel invasion. Conversely, PDACs completely lacking CCR7 expression showed only low rates of lymph vessel invasion and lymph-node metastases. The evaluation of CCL21 expression by immunofluorescence staining revealed a significant upregulation of CCL21 in peritumoral and intratumoral lymph vessels compared to lymph vessels in disease-free pancreata. In conclusion, our study revealed strong evidence that lack of CCR7 impairs the metastatic potential of PDAC. Lymph vessel invasion by CCR7 expressing PDAC cells may be additionally enhanced by upregulation of CCL21 in tumor-associated lymph vessels, representing a previously unknown factor of lymphatic spread.

Improved non-invasive strategies for early cancer detection are urgently needed to reduce morbidity and mortality. Non-coding RNAs, such as microRNAs and small nucleolar RNAs, have been proposed as biomarkers for non-invasive cancer diagnosis. Analyzing serum derived from nude mice implanted with primary human pancreatic ductal adenocarcinoma (PDAC), we identified 15 diagnostic microRNA candidates. Of those miR-1246 was selected based on its high abundance in serum of tumor carrying mice. Subsequently, we noted a cross reactivity of the established miR-1246 assays with RNA fragments derived from U2 small nuclear RNA (RNU2-1). Importantly, we found that the assay signal discriminating tumor from controls was derived from U2 small nuclear RNA (snRNA) fragments (RNU2-1f) and not from miR-1246. In addition, we observed a remarkable stability of RNU2-1f in serum and provide experimental evidence that hsa-miR-1246 is likely a pseudo microRNA. In a next step, RNU2-1f was measured by qRT-PCR and normalized to cel-54 in 191 serum/plasma samples from PDAC and colorectal carcinoma (CRC) patients. In comparison to 129 controls, we were able to classify samples as cancerous with a sensitivity and specificity of 97.7% [95% CI = (87.7, 99.9)] and 90.6% [95% CI = (80.7, 96.5)], respectively [area under the ROC curve 0.972]. Of note, patients with CRC were detected with our assay as early as UICC Stage II with a sensitivity of 81%. In conclusion, this is the first report showing that fragments of U2 snRNA are highly stable in serum and plasma and may serve as novel diagnostic biomarker for PDAC and CRC for future prospective screening studies. Improved non-invasive strategies for early cancer detection are urgently needed to reduce morbidity and mortality. Non-coding RNAs, such as microRNAs and small nucleolar RNAs, have been proposed as biomarkers for non-invasive cancer diagnosis. Analyzing serum derived from nude mice implanted with primary human pancreatic ductal adenocarcinoma (PDAC), we identified 15 diagnostic microRNA candidates. Of those miR-1246 was selected based on its high abundance in serum of tumor carrying mice. Subsequently, we noted a cross reactivity of the established miR-1246 assays with RNA fragments derived from U2 small nuclear RNA (RNU2-1). Importantly, we found that the assay signal discriminating tumor from controls was derived from U2 small nuclear RNA (snRNA) fragments (RNU2-1f) and not from miR-1246. In addition, we observed a remarkable stability of RNU2-1f in serum and provide experimental evidence that hsa-miR-1246 is likely a pseudo microRNA. In a next step, RNU2-1f was measured by qRT-PCR and normalized to cel-54 in 191 serum/plasma samples from PDAC and colorectal carcinoma (CRC) patients. In comparison to 129 controls, we were able to classify samples as cancerous with a sensitivity and specificity of 97.7% [95% CI = (87.7, 99.9)] and 90.6% [95% CI = (80.7, 96.5)], respectively [area under the ROC curve 0.972]. Of note, patients with CRC were detected with our assay as early as UICC Stage II with a sensitivity of 81%. In conclusion, this is the first report showing that fragments of U2 snRNA are highly stable in serum and plasma and may serve as novel diagnostic biomarker for PDAC and CRC for future prospective screening studies.

Pancreatic ductal adenocarcinoma (PDAC) is known for its poor prognosis resulting from being diagnosed at an advanced stage. Accurate early diagnosis and new therapeutic modalities are therefore urgently needed. MicroRNAs (miRNAs), considered a new class of biomarkers and therapeutic targets, may be able to fulfill those needs. Combining tissue microdissection with global miRNA array analyses, cell type-specific miRNA expression profiles were generated for normal pancreatic ductal cells, acinar cells, PDAC cells derived from xenografts and also from macrodissected chronic pancreatitis (CP) tissues. We identified 78 miRNAs differentially expressed between ND and PDAC cells providing new insights into the miRNA-driven pathophysiological mechanisms involved in PDAC development. Having filtered miRNAs which are upregulated in the three pairwise comparisons of PDAC vs. ND, PDAC vs. AZ and PDAC vs. CP, we identified 15 miRNA biomarker candidates including miR-135b. Using relative qRT-PCR to measure miR-135b normalized to miR-24 in 75 FFPE specimens (42 PDAC and 33 CP) covering a broad range of tumor content, we discriminated CP from PDAC with a sensitivity and specificity of 92.9% [95% CI=(80.5, 98.5)] and 93.4% [95% CI=(79.8, 99.3)], respectively. Furthermore, the area under the curve (AUC) value reached of 0.97 was accompanied by positive and negative predictive values of 95% and 91%, respectively. In conclusion, we report pancreatic cell-specific global miRNA profiles, which offer new candidate miRNAs to be exploited for functional studies in PDAC. Furthermore, we provide evidence that miRNAs are well-suited analytes for development of sensitive and specific aid-in-diagnosis tests for PDAC.

Die zunehmende Uberwachung von Patienten mit Barrettschleimhaut fuhrt zu einer zuneh­menden Diagnostik fruher Karzinomformen mit nur geringer Invasionstiefe. Vergleichbar zu asiatischen Landern, in denen aufgrund der hoheren Inzidenz von Magenkarzinomen eine engmaschige Uberwachung von Risikopatienten durchgefuhrt wird, werden auch zunehmend in europaischen Landern endoskopische Resektionen von sogenannten Fruhkarzinomen des Magens oder fruhen Karzinomen des Osophagus vorgenommen. Neben der Kenntnis der endoskopischen Techniken mussen auch bestimmte Anforderungen an das zu gewinnende Resektat gestellt werden, die eine gute pathohistologische Aufarbeitung ermoglichen. Nur so kann die genaue Tie­feninfiltration ermittelt und die Entfernung im Gesunden korrekt bestimmt werden, was fur den weiteren Therapieverlauf und die Prognose entscheidend ist. Fortgeschrittene Karzinome des Osophagus und des Magens werden multi­modal behandelt, sodass vor der endgultigen Therapie zumeist eine neoadjuvante Radio- und / oder Chemotherapie durchgefuhrt wird. Dies fuhrt zu bestimmten, pathohistologisch nachweisbaren Veranderungen im Karzinomgewebe, denen mit einem Regressionsgrading Rechnung getragen wird.

MicroRNAs (miRNAs: short non-coding RNAs) are emerging as a class of potential novel tumor markers, as their dysregulation is being increasingly reported in various types of cancers. In the present study, we investigated the transcription status of miRNA-148a (miR-148a) in human pancreatic ductal adenocarcinoma (PDAC) and its role in the regulation of the dual specificity protein phosphatase CDC25B. We observed that miR-148a exhibited a significant 4-fold down-regulation in PDAC as opposed to normal pancreatic ductal cells. In addition, we observed that stable lentiviral-mediated overexpression of miR-148a in the pancreatic cancer cell line IMIM-PC2, inhibited tumor cell growth and colony formation. Furthermore, CDC25B was identified as a potential target of miR-148a by in silico analysis using PicTar, Targetscan and miRanda in conjunction with gene ontology analysis. The proposed interaction between miR-148a and the 3' untranslated region (UTR) of CDC25B was verified by in-vitro luciferase assays. We demonstrate that the activity of a luciferase reporter containing the 3'UTR of CDC25B was repressed in the presence of miR-148a mimics, confirming that miR-148a targets the 3'UTR of CDC25B. Finally, CDC25B was down-regulated at the protein level in miR-148a overexpressing IMIM-PC2-cells, and in transiently transfected pancreatic cell lines (as detected by Western blot analysis), as well as in patient tumor samples (as detected by immunohistochemistry). In summary, we identified CDC25B as a novel miR-148a target which may confer a proliferative advantage in PDAC.

INTRODUCTION Tumour angiogenesis via vascular endothelial growth factor (VEGF) is essential for promoting tumour progression and is overexpressed in colorectal cancer. The humanised monoclonal anti-VEGF antibody bevacizumab (Avastin®, Genentech Inc., South San Francisco, CA) has shown activity in metastatic colorectal cancer (mCRC) combined with conventional chemotherapy. The search for biomarkers to predict response to anti-angiogenic therapy in mCRC is of great interest. We investigated several potential predictive anti-angiogenic markers including circulating endothelial progenitor cells (EPC) in patients with mCRC receiving bevacizumab containing treatment within a randomised multicenter phase 2 study of the German AIO GI tumour study group. METHODS We collected sequential blood samples and tumour tissues from patients participating in a clinical trial for patients with mCRC. We performed flow cytometry of mononuclear cells isolated from peripheral blood to assess CD 133 + or CD 34 + /KDR + EPC before the first bevacizumab containing chemotherapy and after 21 days. Circulating VEGF blood levels before a bevacizumab containing chemotherapy regimen and after 21 days and VEGF expression in tumour tissue were examined. RESULTS Patients with mCRC and a partial remission after six months of immuno-chemotherapy containing bevacizumab showed a reduction of CD 34 negative KDR positive cells as early as 3 weeks after start of therapy. In contrast, no remarkable change in the number of CD 34 /KDR positive or CD 34 /CD133 positive cells was seen. Furthermore, there was no correlation between treatment response and VEGF expression within the tumour tissue. The mAb bevacizumab reduced serum-VEGF levels in patients independent of their treatment response to bevacizumab. DISCUSSION We examined circulating endothelial progenitor cells (EPC), serum-VEGF levels and the tumour tissue VEGF expression of patients with mCRC under a bevacizumab containing chemotherapy. The patients with a partial remission after six months of immuno-chemotherapy showed a reduction of CD 34 negative KDR positive cells as early as 3 weeks after start of therapy. Neither serum nor tissue markers were of significant predictive value in our pilot study. Furthermore, we review the current data on biomarkers for anti-angiogenic therapy of mCRC.

The microRNA encoding genes miR-34a and miR-34b/c represent direct p53 target genes and possess tumor suppressive properties as they mediate apoptosis, cell cycle arrest, and senescence. We previously reported that the miR-34a gene is subject to epigenetic inactivation by CpG methylation of its promoter region in primary prostate cancer and melanomas, and in 110 different cancer cell lines of diverse origin. Here we analyzed the methylation status of miR-34a and miR-34b/c in additional primary tumors of divergent sites. We found methylation of miR-34a or miR-34b/c in formalin-fixed, paraffin-embedded (FFPE) tumor samples from 178 patients with the following frequencies: colorectal cancer (74% miR-34a, 99% miR-34b/c; n = 114), pancreatic cancer (64%, 100%; n = 11), mammary cancer (60%, 90%; n = 10), ovarian cancer (62%, 69%; n = 13), urothelial cancer (71%, 57%; n = 7), and renal cell cancer (58%, 100%; n = 12). Furthermore, soft tissue sarcomas showed methylation of miR-34 gene promoters in FFPE samples (64%, 45%; n = 11), in explanted, cultured cells (53%, 40%; n = 40), and in frozen tissue samples (75%, 75%, n = 8). In the colorectal cancer samples a statistically significant correlation of miR-34a methylation and the absence of p53 mutation was detected. With the exception of sarcoma cell lines, the inactivation of miR-34a and miR-34b/c was concomitant in most cases. These results show that miR-34 inactivation is a common event in tumor formation, and suggest that CpG methylation of miR-34a and miR-34-b/c may have diagnostic value. The mutual exclusiveness of miR-34a methylation and p53 mutation indicates that miR-34a inactivation may substitute for loss of p53 function in cancer.

Melatonin plays a protective role in experimental acute pancreatitis (AP) because of its antioxidative, antiinflammatory, and immunomodulatory effects. This study presents the first data on the dynamic changes of endogenous melatonin in the early phase of human AP. Morning (08:00 hr) serum melatonin concentrations were measured by ELISA in 75 patients with AP for the first 5 days after the onset of pain. According to the Atlanta classification, 26 patients suffered a mild AP (MAP). The other 49 developed a severe AP (SAP). Median melatonin concentrations of healthy volunteers were used as a control. Median melatonin level in healthy controls was 18.5 pg/mL. Levels of melatonin were significantly higher in the first 24 hr after onset of disease in patients with MAP compared to those with SAP, 51.2 versus 8.7 pg/mL (P = 0.01). Melatonin values were the same in MAP and SAP during the remainder of the study period. Melatonin concentrations during the first 24 hr after the onset of pain in younger patients ( 35 yrs): 73 versus 8.7 pg/mL (P = 0.01). No correlation existed between melatonin levels and the following parameters: gender, etiology (biliary versus alcohol induced), and histological findings (edematous versus necrotizing versus infected necrosis). High endogenous melatonin serum levels in the first 24 hr after the onset of AP played a protective role and favoured a mild course of the disease in humans, especially in young patients.

Although laparoscopic cholecystectomy is recommended as standard treatment for acute cholecystitis, in 10–30 % a conversion to open cholecystectomy is required. Among some surgeons, this is still perceived as a “complication.” The aim of our study was to define characteristics and outcome of patients with acute cholecystitis undergoing conversion cholecystectomy. Over a 9-year period, 464 consecutive patients undergoing cholecystectomy for acute cholecystitis were analyzed for demographic, preoperative, intraoperative, histopathological, and laboratory findings and surgical outcome parameters. Patients with conversion cholecystectomy were characterized by younger age, lower American Society of Anesthesiologists (ASA) score, and less cardiac comorbidities compared to patients with primary open cholecystectomy. Severity of inflammation on the clinical and histopathological level was similar and comparable. Overall complication rate, mortality, and median hospital stay were significantly lower compared to those of primary open cholecystectomy group. There are no disadvantages for patients undergoing conversion cholecystectomy compared to primary open cholecystectomy. The outcome is influenced by general condition and comorbidities rather than by the surgical approach. Underlying fear of conversion should not avoid a laparoscopic approach in patients with acute cholecystitis.

Colorectal cancer is one of the most frequently observed neoplasms in the world. It develops from intraepithelial neoplasia of the colorectal mucosa, and these precursor lesions are also known as adenoma. As the precursor lesion is known and can be detected easily, efficient screening strategies are available for a reliable prevention of colorectal adenocarcinoma, e.g. by colonoscopy.Literature databases (PubMed) were searched selectively for the keywords 'colorectal adenoma', 'epidemiology', and 'resection techniques'. The results are presented in the following text, also taking into account our own experience and the current S3 guidelines.Endoscopic resection samples are one of the specimens most frequently assessed by pathologists. Therefore, gastroenterologists expect standardized and well-structured pathology reports, stating relevant information concerning the removed lesions and recommendations for clinical management. These aspects are summarized in the evidence-based S3 guideline.As a consequence of colorectal adenoma resection during screening procedures, the carcinoma incidence is decreasing. For further advancements in successful prevention, knowledge of different precursor lesions (conventional adenoma, serrated adenoma) is important, but also structured communication between the different disciplines engaged in colorectal cancer screening.Das kolorektale Adenokarzinom ist eines der weltweit am häufigsten auftretenden Karzinome. Es entwickelt sich aus Vorläuferläsionen, den intraepithelialen Neoplasien der kolorektalen Schleimhaut, die auch als Adenome bezeichnet werden. Dadurch, dass die Vorläuferläsionen bekannt sind und leicht detektiert werden können, ist es möglich, ein effizientes Screening durchzuführen. Der Goldstandard der kolorektalen Krebsvorsorge ist die Koloskopie und die Abtragung der Vorläuferläsionen.Eine Literaturdatenbankrecherche (PubMed) wurde durchgeführt und Artikel mit Bezug zu Epidemiologie und Resektion/Aufarbeitung kolorektaler Adenome wurden selektiv ausgewählt. Diese wurden auch unter Berücksichtigung eigener Erfahrungen und der aktuell gültigen S3-Leitlinie ausgewertet.Endoskopisch resezierte Polypen und kolorektale Biopsien sind mit das häufigste Untersuchungsgut der Pathologen. Im Gegenzug erwarten Gastroenterologen eine standardisierte und strukturierte Aufarbeitung und Befundung mit einer genauen Diagnose, aus der sich das weitere klinische Management ableiten lässt. Diese Anforderungen werden in der aktuellen Version der evidenzbasierten S3-Leitlinie zusammengefasst.Als Folge des Screenings nimmt die kolorektale Karzinominzidenz ab. Um diese Erfolge der Vorsorgeuntersuchungen weiter zu verbessern, ist die Kenntnis der verschiedenen Vorläuferläsionen (klassisches Adenom, serratierte Adenome) von wesentlicher Bedeutung, genauso wie eine gute und strukturierte interdisziplinäre Zusammenarbeit.

Background: Hard pancreas is welcome by surgeons performing resective pancreatic surgery, because it is believed to offer better suture holding capacity (SHC), thus decreasing the risk for a postoperative leak. However, neither the actual SHC of pancreatic tissue in humans nor its determinants have been studied. Methods: We directly measured SHC for polydioxanone 5e0 suture and tissue hardness at the pancreatic isthmus in 53 human pancreata using a dynamometer and a durometer. A histologic score based on fibrosis grade, fat content, pancreatic duct size, and signs of chronic pancreatitis was calculated for every sample. We tested the hypothesis that SHC of the pancreas was proportional to tissue hardness, and evaluated the role of different possible histomorphologic determinants of SHC. Results: Suture-holding capacity correlated perfectly with tissue hardness (r ¼ 0.98; P < 0.001; 95% confidence interval, 0.96e0.99). The histologic score showed a stronger correlation with both parameters than any single histologic parameter. The SHC of transductal sutures was significantly higher than that of pure transparenchymal sutures. The SHC and hardness were significantly lower in patients who developed a clinically relevant pancreatic fistula postoperatively. Conclusions: A mixture of histomorphologic features of human pancreas determines its tissue hardness and SHC. Involvement of the main pancreatic duct in the suture line appears to increase the mechanical strength of the pancreatic anastomosis.

Endoscopic polypectomy significantly reduces the incidence of colorectal cancer, but recurrence rates are high, especially for adenomas with advanced histology. The present guidelines recommend re-colonoscopy 3 to 5 years later. Due to limited resources, more precise predictions of adenoma recurrence are required.Lesions from 109 patients with colorectal adenomas recruited into a randomized, placebo-controlled chemoprevention trial with mesalazine were included. Formalin-fixed paraffin-embedded tissue sections were stained for ß-catenin, cyclooxygenase-2 (Cox-2), and p53 and scored. Adenoma recurrence rates were recorded after 3 years and associated with clinical and immunohistochemical parameters by contingency table analysis.After 3 years, adenomas recurred in 51.4% of patients. Out of 109 adenomas, 95 met at least one criterion of advanced adenoma (size1 cm, villous histology, high-grade intraepithelial neoplasia). There was no influence of age, sex, size or villous histology on adenoma reappearance, whilst the number of adenomas at baseline was positively associated with recurrence (p = 0.003). In contrast, ß-catenin nuclear localisation, Cox-2 expression and p53 nuclear expression were significantly associated with adenoma recurrence after 3 years (ß-catenin: p = 0.002; Cox-2: p = 0.001; p53: p = 0.001). Combining these three markers led to a negative predictive value of 88.5% and a sensitivity of 94.6%. (OR = 13.54) CONCLUSIONS: Scoring each single parameter and, more strongly, the combination of all three parameters of the expression of ß-catenin, Cox-2 and p53 in colorectal adenoma tissue may be a useful negative predictor for adenoma recurrence in patients with advanced colorectal adenomas.

Rare solid tumors of the pancreas can be misinterpreted as primary pancreatic cancer.The aim of this study was to report our experience in the treatment of patients with rare tumor lesions of the pancreas and to discuss clinical and pathological characteristics in the context of the role of surgery.Data from patients of our prospective data-base with rare benign and malignant tumors of the pancreas, treated in our division from January 2004 to August 2010, were analyzed retrospectively.One-thousand and ninety-eight patients with solid tumors of the pancreas underwent pancreatic surgery. In 19 patients (10 women, 9 men) with a mean age of 57 years (range: 20-74 years) rare pancreatic tumors (metastasis, solid pseudopapillary tumor, teratoma, hemangioma, accessory spleen, lymphoepithelial cyst, hamartoma, sarcoidosis, yolk sac tumor) were the reason for surgical intervention.If rare benign and malignant pancreatic tumors, intrapancreatic metastasis, as well as pancreatic malformations or other abnormalities, present themselves as solid masses of the pancreas, they constitute an important differential diagnosis to primary pancreatic neoplasia, e.g. pancreatic ductal adenocarcinoma. Clinical imaging techniques cannot always rule out malignancy, thus operative exploration often remains the treatment of choice to provide the correct diagnosis and initiate adequate surgical therapy.

Objectives This study aimed at T-cell inhibition by immunosuppressants to reduce cell damage and improve the course of severe acute pancreatitis (SAP). Methods A taurocholate-induced SAP was used and 5 groups were compared: (1) rapamycin + FTY720, (2) rapamycin, (3) FTY720, (4) cortisol, and (5) control: sodium chloride. Drugs were applied intravenously at SAP induction; 6 hours later, rats were killed. Interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor α, platelet-activating factor, amylase, and lipase were measured in serum and myeloperoxidase tissue activity in pancreas, kidney, lung, liver, and spleen. Edema, inflammation, and necrosis were histologically determined in pancreas. CD4/CD8 immunohistochemistry was performed. Results Inflammation was ameliorated in all 4 treated groups. Necrosis development was suppressed by FTY720, FTY720 + rapamycin, and cortisol. IL-6 and IL-10 were significantly lower in these groups. Amylase was higher in all treatment groups compared to the controls except for the cortisol group. Tumor necrosis factor α, lipase, and myeloperoxidase activity were not affected by therapy. CD4+/CD8+ cells were significantly less in FTY720-treated pancreata. Conclusion Rapamycin and FTY720 ameliorated the severity of SAP, which may be due to early suppression of helper T cells. FTY720 reduced the development of pancreatic necrosis. The combination of both immunosuppressants did not show advantage to treatment with FTY720 alone.

Surveillance colonoscopy is an important strategy for prevention of colorectal cancer. 5-aminosalicylate (ASA) (mesalazine) is discussed as a chemopreventive agent as it reduces the cancer risk in ulcerative colitis patients. The current study analyses the effect of 5-ASA on Wnt/β-catenin signaling in vitro and in vivo in colon epithelial cells. The effect of 5-ASA was determined using a β-catenin/T-cell factor (TCF)-reporter assay and by western blotting in cultured colon cancer cells. Formalin fixed paraffin embedded material from 227 polyps removed from a subgroup of 56 patients, who participated in a randomized placebo-controlled 3-year prevention trial with 5-ASA was evaluated according to histomorphological characteristics and expression of β-catenin and target genes Cox2, cyclin D1 and E-cadherin as well as ornithine decarboxylase (ODC). Patients were grouped into a low-risk and a high-risk group according to the number of adenomas at initial colonoscopy. ss-catenin/TCF signaling activity was significantly reduced by 5-ASA treatment possibly through a reduction in ss-catenin levels. Moreover, 5-ASA significantly reduced ss-catenin levels and nuclear localization in patients' adenomas. In addition, 5-ASA also significantly changed expression of the downstream targets Cox2, cyclin D1 and E-cadherin, correlating with ss-catenin status. Moreover, 5-ASA significantly reduced levels of ODC in vivo. Expression of p53 was unaltered by the 5-ASA treatment. Our study shows a significant in vitro and long-term in vivo effect of 5-ASA on ss-catenin signaling as a key signaling pathway in the development of colorectal adenoma. Therefore, we suggest the use of 5-ASA as a promising drug for prevention of sporadic colorectal carcinoma.

Solid pseudopapillary neoplasms (SPNs) are rare pancreatic tumors. They occur most frequently in young females and are often diagnosed accidentally. SPNs are characterized by an excellent clinical outcome. In our case series the clinical course, pathohistological data and clinical outcome of eight patients (7 female patients, 1 male patient) with SPN are described. Histological examination as well as immunohistochemical analysis shows similar results in all eight cases. Although in the literature a few cases of SPNs with bad prognosis have been reported, up to now none of our patients shows any signs of recurrence or metastasis. Moreover, we give in this case series a summary of SPNs in the literature, important clinical and pathological differential diagnosis, and additionally discuss relevant differential diagnosis occurring in daily routine work.

Background/Aims: Postoperative pancreatic fistula (POPF) is a major complication after resective pancreatic surgery. This study aimed to identify histomorphological features of the pancreatic remnant as independent determinants for the development of POPF. Methods: Twenty-five patients, 3.6% of 696 resections over a period of 5 years, who developed POPF were matched for age, gender, diagnosis, comorbidities, surgeon and procedure with 25 controls without POPF. Pancreatic duct size and index, fibrosis grade, fat content, edema, and signs of chronic and acute inflammation were measured in frozen sections of the resection margin and were then compared. Results: The POPF rate was 12.2 and 2.6% after distal pancreatectomy and pancreatoduodenectomy, respectively. The POPF group was characterized by a longer ICU and total postoperative stay, higher rate of reoperations and complications. Their pancreata were softer at palpation (88 vs. 56%). Their pancreatic duct was smaller (2.5 vs. 3.2 mm) and their pancreatic fat content higher (16 vs. 8%). High inter- and intralobular fat content, small duct size, low interlobular fibrosis grade and lack of signs of chronic pancreatitis were predictors of POPF development. A score including these parameters identified high-risk patients with a sensitivity of 92% and a specificity of 84%. Conclusion: Histomorphological features of the pancreatic remnant play an independent role as risk factors for the development of POPF. A simple histological score based on the frozen sections may already intraoperatively predict the risk of POPF development.

Background: SMAD4 is a polypeptide with tumor suppressor function being investigated as a prognostic biomarker in Union Internationale Contre le Cancer stages II and III in previous studies, but its role as a prognostic marker in stage IV colorectal cancer (CRC) is still undefined. We investigated the prognostic value of reduced SMAD4 expression in patients with metastatic (mCRC) under first-line oxaliplatin-containing combination chemotherapy. Patients and Methods: Tumor samples were obtained from patients who took part in a prospective randomized phase III chemotherapy trial of the Arbeitsgemeinschaft Internistische Onkologie of the German Cancer Society colorectal study group, comparing the use of capecitabine plus oxaliplatin with infusional 5-fluorouracil (5-FU) plus oxaliplatin as first-line therapy in mCRC. SMAD4 expression was determined by immunohistochemistry. Results: Tumor tissues from 230 patients were obtained. Reduced SMAD4 expression was identified in 34% of samples. Patients with reduced nuclear SMAD4 expression in tumor tissue showed a shorter progression-free survival (PFS; 7.0 months vs. 8.9 months; P = .024) and overall survival (OS; 13.9 months vs. 17.8 months; P = .044) compared with patients retaining SMAD4 expression. The effect of SMAD4 expression on PFS and OS could be demonstrated in univariate and multivariate analyses. Conclusion: Our data demonstrate the importance of reduced SMAD4 expression in patients with mCRC receiving chemotherapy with oxaliplatin and 5-FU.

Background Inactivating mutations of SMAD4 are frequent in metastatic colorectal carcinomas. In previous analyses, we were able to show that restoration of Smad4 expression in Smad4-deficient SW480 human colon carcinoma cells was adequate to suppress tumorigenicity and invasive potential, whereas in vitro cell growth was not affected. Using this cellular model system, we searched for new Smad4 targets comparing nuclear subproteomes derived from Smad4 re-expressing and Smad4 negative SW480 cells. Methods High resolution two-dimensional (2D) gel electrophoresis was applied to identify novel Smad4 targets in the nuclear subproteome of Smad4 re-expressing SW480 cells. The identified candidate protein Keratin 23 was further characterized by tandem affinity purification. Immunoprecipitation, subfractionation and immunolocalization studies in combination with RNAi were used to validate the Keratin 23-14-3-3ε interaction. Results We identified keratins 8 and 18, heat shock proteins 60 and 70, plectin 1, as well as 14-3-3ε and γ as novel proteins present in the KRT23-interacting complex. Co-immunoprecipitation and subfractionation analyses as well as immunolocalization studies in our Smad4-SW480 model cells provided further evidence that KRT23 associates with 14-3-3ε and that Smad4 dependent KRT23 up-regulation induces a shift of the 14-3-3ε protein from a nuclear to a cytoplasmic localization. Conclusion Based on our findings we propose a new regulatory circuitry involving Smad4 dependent up-regulation of KRT23 (directly or indirectly) which in turn modulates the interaction between KRT23 and 14-3-3ε leading to a cytoplasmic sequestration of 14-3-3ε. This cytoplasmic KRT23-14-3-3 interaction may alter the functional status of the well described 14-3-3 scaffold protein, known to regulate key cellular processes, such as signal transduction, cell cycle control, and apoptosis and may thus be a previously unappreciated facet of the Smad4 tumor suppressive circuitry.

Melatonin plays a protective role in experimental acute pancreatitis (AP) because of its antioxidative, antiinflammatory, and immunomodulatory effects. This study presents the first data on the dynamic changes of endogenous melatonin in the early phase of human AP. Morning (08:00 hr) serum melatonin concentrations were measured by ELISA in 75 patients with AP for the first 5 days after the onset of pain. According to the Atlanta classification, 26 patients suffered a mild AP (MAP). The other 49 developed a severe AP (SAP). Median melatonin concentrations of healthy volunteers were used as a control. Median melatonin level in healthy controls was 18.5 pg/mL. Levels of melatonin were significantly higher in the first 24 hr after onset of disease in patients with MAP compared to those with SAP, 51.2 versus 8.7 pg/mL (P = 0.01). Melatonin values were the same in MAP and SAP during the remainder of the study period. Melatonin concentrations during the first 24 hr after the onset of pain in younger patients (35 yrs old) were significantly higher than levels in older patients (35 yrs): 73 versus 8.7 pg/mL (P = 0.01). No correlation existed between melatonin levels and the following parameters: gender, etiology (biliary versus alcohol induced), and histological findings (edematous versus necrotizing versus infected necrosis). High endogenous melatonin serum levels in the first 24 hr after the onset of AP played a protective role and favoured a mild course of the disease in humans, especially in young patients.

Background The concept of total mesorectal excision has revolutionised rectal cancer surgery. TME reduces the rate of local recurrence and tumour associated mortality. However, in clinical trials only 50% of the removed rectal tumours have an optimal TME quality. Patients: During a period of 36 months we performed 103 rectal resections. The majority of patients (76%; 78/103) received an anterior resection. The remaining patients underwent either abdominoperineal resection (16%; 17/103), Hartmann's procedure (6%; 6/103) or colectomy (2%; 2/103). Results In 90% (93/103) TME quality control could be performed. 99% (92/93) of resected tumours had optimal TME quality. In 1% (1/93) the mesorectum was nearly complete. None of the removed tumours had an incomplete mesorectum. In 98% (91/93) the circumferential resection margin was negative. Major surgical complications occurred in 17% (18/103). 5% (4/78) of patients with anterior resection had anastomotic leakage. 17% (17/103) developed wound infections. Mortality after elective surgery was 4% (4/95). Conclusion Optimal TME quality results can be achieved in all stages of rectal cancer with a rate of morbidity and mortality comparable to the results from the literature. Future studies should evaluate outcome and local recurrence in accordance to the degree of TME quality.

Inactivation of the tumour suppressor gene SMAD4 is a genetically late event in gastrointestinal carcinogenesis. SMAD4 is a transmitter of growth-inhibitory effects of transforming growth factor-beta (TGF-beta), an important tumour promoter capable of inducing an epithelial to mesenchymal transition (EMT). The role of SMAD proteins in late, tumour-promoting effects of TGF-beta is not well understood.The change of molecular differentiation markers typical for EMT upon SMAD4 re-expression in SW480 cells was determined using Western blotting, immunohistochemistry and confocal laser microscopy. The influence of SMAD4 on the migration of SW480 cells was assessed in wound healing and pore migration assays.SMAD4 suppresses invasiveness and mediates reversion of SW480 cells from a mesenchymal-like to a polarized epithelial phenotype, with features of enterocyte-like differentiation. Moreover, SMAD4 reconstitution was associated with down-regulation of endogenous TGF-beta cytokines, suggesting that autocrine TGF-beta signaling may be involved in the EMT.These results provide further evidence for a role of SMAD4 as a regulator of invasion, a process of prime importance in carcinogenesis but hitherto poorly understood in molecular terms.