Arne Skarstein

Smoking and ulcer perforation

Background—The use of ulcerogenic drugs is the only well documented risk factor for peptic ulcer perforation, but accounts for only a quarter of the events. Smoking is a well known risk factor for uncomplicated ulcer disease, and patients with ulcer bleeding have increased death rates from smoking related disorders. Aim—To assess the role of smoking in ulcer perforation. Subjects—A total of 168 consecutive patients with gastroduodenal ulcer perforation and 4469 control subjects from a population based health survey. Methods—The association between ulcer perforation and smoking habits was analysed by logistic regression while adjusting for age and sex. Results—Current smoking increased the risk for ulcer perforation 10-fold in the age group 15–74 years (OR 9.7, 95% CI 5.9 to 15.8) and there was a highly significant dose-response relationship (p<0.001). The results were similar in men (OR 9.3, 95% CI 4.9 to 17) and women (OR 11.6, 95% CI 5.3 to 25), and for gastric (OR 10.5, 95% CI 4.5 to 25) and duodenal (OR 8.6, 95% CI 4.9 to 15.4) ulcer perforation. No increase in risk was found in previous smokers (OR 0.8, 95% CI 0.2 to 2.2). Conclusion—Our findings suggest that smoking is a causal factor for ulcer perforation and accounts for a major part of ulcer perforations in the population aged less than 75 years.

MicroRNA-15b is induced with E2F-controlled genes in HPV-related cancer.

Background:MicroRNAs (miRNAs) are important regulators of cellular processes and are found to be deregulated in many cancers. We here analysed the miRNA expression in anal carcinomas. In a previous study, we found that our anal carcinoma tumours were divided into two groups based on the expression of E2F-regulated genes. Therefore, we searched for miRNAs that could reproduce this grouping.Methods:A global screen of the miRNA population was performed using real-time quantitative PCR (RT–qPCR) array methods and differentially expressed miRNAs were identified. Real-time–qPCR was used to verify the expression levels of selected miRNAs and genes in a larger collection of biopsies. A siRNA-mediated knockdown of human papilloma virus (HPV)16 E7 in a cervical cell line was performed to assess the effect of E7 on miR-15b.Results:The grouping of tumours into two groups based on the expression of E2F-controlled genes was confirmed in a larger collection of anal carcinoma tumours. The expression of miR-15b was shown to be highly correlated with that of five selected E2F-induced genes (CCNA2, CCNB1, CCNB2, MSH6 and MCM7). A knockdown of HPV16 E7 resulted in decreased levels of miR-15b in Ca Ski cells.Conclusion:MiR-15b expression correlates with E2F-regulated genes in anal carcinoma and appears to be part of the E2F-regulatory network.

Urokinase plasminogen activator receptor on invasive cancer cells: a prognostic factor in distal gastric adenocarcinoma.

Gastric cancer is the second cancer causing death worldwide. The five‐year survival for this malignancy is below 25% and few parameters have shown an impact on the prognosis of the disease. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micrometastasis and poor prognosis. Using immunohistochemistry, the prognostic significance of uPAR was evaluated in tissue samples from a retrospective series of 95 gastric cancer patients. uPAR was expressed by neoplastic cells, macrophages, myofibroblasts and neutrophils in both intestinal and diffuse subtypes. No association was demonstrated between the expression of uPAR on cancer cells and histological subtype (p = 0.64) or TNM stage (p = 0.75). Univariate analysis revealed a significant association between the expression of uPAR on tumor cells in the peripheral invasion zone and overall survival of gastric cancer patients (HR = 2.16; 95% CI: 1.13–4.14; p = 0.02). Multivariate analysis showed that uPAR immunoreactivity in cancer cells at the invasive front is an independent prognostic factor for overall survival in gastric cancer (HR = 2.39; 95% CI: 1.22–4.69; p = 0.011). In consequence, scoring of uPAR‐positive cancer cells may be a direct measure for the invasive potential of gastric adenocarcinomas.

Gene expression reveals two distinct groups of anal carcinomas with clinical implications

Human papillomavirus (HPV) is a major aetiological agent in anal carcinomas. We here present a study of global gene expression using microarray hybridisation in a collection of anal carcinoma biopsies. Quantitative PCR was used to verify expression of selected genes. All biopsies contained integrated DNA of human papillomavirus subtype 16 (HPV16) and expressed HPV16 E7 mRNA. No other subspecies of HPV were detected in these 13 biopsies as assessed by PCR amplification and DNA sequencing. Unsupervised cluster analysis, based on global mRNA expression, divided the tumour biopsies into two distinct groups. Cluster analysis based on a number of high-risk HPV and/or E2F-regulated genes reproduced this biopsy grouping, suggesting that integrated HPV16 substantially influenced global gene expression in approximately half the biopsies studied. The levels of HPV16 E7 mRNA were significantly different between the two groups, but with considerable overlap. Thus, influence on global gene expression could not be absolutely ascribed to the expression level of HPV16. To investigate whether this distinction in gene expression had prognostic impact, we studied protein expression in an independent cohort of 55 anal carcinomas not included in the microarray study of two differentially expressed candidate genes, minichromosome maintenance complex component 7 (MCM7) and cyclin-dependent kinase inhibitor 2A (CDKN2A or p16). HPV status was assessed by in situ hybridisation. There was a significant association between in situ staining for HPV E7 mRNA and immunostaining for CDKN2A (p16) and MCM7 protein. CDKN2A (p16) mRNA was found significantly differentially expressed between the two tumour groups. However, cluster analysis on genes directly regulated by CDKN2A (p16) could not reproduce this split of biopsies into two groups, suggesting that the transcriptional regulatory activity of CDKN2A in these biopsies is inhibited. Furthermore, protein expression of CDKN2A (p16) could not be associated with survival. MCM7 is directly regulated by E2F and induced by HPV, and its mRNA was found differentially expressed between the two tumour groups. High level of MCM7 protein was found to be associated with both improved relapse-free survival (RFS, P=0.02) and cancer-specific survival (CSS, P=0.03) in anal cancer patients treated with radiation with or without additional chemotherapy.

Urokinase plasminogen activator receptor is expressed in invasive cells in gastric carcinomas from high- and low-risk countries

Gastric cancer is the second cancer causing death worldwide. Both incidence and mortality rates vary according to geographical regions. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micro‐metastasis and poor prognosis. Immunohistochemical analyses of a set of 44 gastric cancer lesions from Costa Rica showed expression of uPAR in cancer cells in both intestinal subtype (14 of 27) and diffuse subtype (10 of 17). We compared the expression pattern of uPAR in gastric cancers from a high‐risk country (Costa Rica) with a low‐risk country (Norway). We found uPAR on gastric cancer cells in 24 of 44 cases (54%) from Costa Rica and in 13 of 23 cases (56%) from Norway. uPAR was seen in macrophages and neutrophils in all cases. We also examined the nonneoplastic mucosa and found that uPAR was more frequently seen in epithelial cells located at the luminal edge of the crypts in cases with Helicobacter pylori infection than in similar epithelial cells in noninfected mucosa (p = 0.033; χ2 = 4.54). In conclusion, the expression of uPAR in cancer cells in more than half of the gastric cancer cases suggests that their uPAR‐positivity do not contribute to explain the different mortality rates between the 2 countries, however, the actual prevalence of uPAR‐positive cancer cells in the gastric cancers may still provide prognostic information.

Crohn's disease: Comparison of in vitro ultrasonographic images and histology

Objective. To examine some typical histological findings in Crohns disease using high-frequency ultrasound and to define the echo properties of these findings. Material and methods. Bowel resection specimens from 14 patients operated on for Crohns disease were examined with a 10 MHz linear array ultrasound transducer in a saline reservoir. Needles were placed in the specimen corresponding to the ultrasound plane. After formalin fixation, histological sections were taken according to these markings. Fifty-eight ultrasonographic images with 123 regions of interest were compared with corresponding histology. Results. A thickened muscularis mucosae (>0.3 mm) was found in 48 of 69 regions of interest on histology. Submucosa with slight to moderate fibrosis was imaged as an echo-rich layer with sporadic, echo-poor elements (36/56), while severe fibrosis was seen as an echo-rich layer with diffuse, echo-poor elements (40/55). Muscularis propria with slight to moderate fibrosis was seen as an echo-poor layer with sporadic, echo-rich elements (49/66) while severe fibrosis was seen as an echo-poor layer with diffuse, echo-rich elements (17/22). Crohns rosary was seen as echo-poor extensions of the 4th echo layer (31/50). Conclusions. Typical histological findings in Crohns disease such as a thickened muscularis mucosae and Crohns rosary can be imaged with high-frequency ultrasound in vitro. Fibrosis in the submucosa and muscularis propria is associated with decreasing and increasing echogenicity, respectively.

Dieulafoy's Vascular Malformation: Role of Endoscopic Ultrasonography in Therapeutic Decision-Making

BACKGROUND Dieulafoys vascular malformation may cause severe, potentially life-threatening gastrointestinal bleeding. Endoscopic diagnosis may be difficult because of minute mucosal lesions, and additional intramural abnormalities are usually not encountered. Endoluminal high-frequency ultrasonography is a new modality for imaging intramural and perivisceral structures. METHODS We report two cases of recurrent severe gastric bleeding in which different endosonographic modalities were used in the diagnosis of Dieulafoys malformation, and the impact of endosonography on therapeutic strategy is discussed. In the first case a radial-scanning 7.5/12-MHz echoendoscope and a linear 20-MHz miniature probe were applied for B-mode imaging in a stable-state patient who had undergone previous endoscopic sclerotherapy, and arterial flow signals from the small intramural lesion were recorded using a 10-MHz transendoscopic pulsed Doppler probe. In the other case urgent endosonography was performed shortly after a bleeding episode, disclosing an aberrant large-calibre artery entering the gastric wall with a long submucosal branch. RESULTS Both patients were successfully operated on with a transabdominal approach. CONCLUSION Endosonography is a quick and safe diagnostic method and should be considered when vascular malformations are suspected as the cause of gastric bleeding.

Treatment of Rectal Cancer: Reduction of Local Recurrence after the Introduction of TME – Experience from One University Hospital

Background: Local recurrence (LR) of cancer after rectal surgery is followed by significant morbidity and mortality. Since the introduction of total mesorectal excision (TME) the rates of LR have decreased in many centres. The aim of this retrospective study was to investigate the effect of TME on the recurrence rates of rectal cancer and the impact of the surgeons. Methods: All patients resected for invasive rectal cancer from 1990 until 2000 were initially included in the study. From February 1994, TME was adopted as the standard treatment (TME group). Before this period, rectal surgery was performed by the non-TME technique (non-TME group). To obtain homogeneity, patients who underwent preoperative irradiation, emergency operations, pre- or intraoperative bowel perforation, residual tumour stage (R1,2) including Dukes’ D stage and postoperative mortality within 31 days, were excluded. 139 patients in the non-TME group and 181 patients in the TME group were found eligible for analyses. Results: The estimated LR rate at 1, 3 and 5 years was 7, 15 and 17% (non-TME) versus 4, 9 and 9% (TME) (p = 0.046, log-rank test). The anastomotic leakage rate was 6% (non-TME) versus 4% (TME) (not significant). Perioperative blood loss >500 ml, reoperations during the hospital stay and lymph node (N) stage were the independent risk factors for LR in the multivariate analysis. The case volume did not significantly influence LR rates. However, the variability of individual surgical results was reduced after the introduction of TME. Conclusions: TME yields significantly lower LR rates compared with traditional surgery. Since the introduction of TME, experience with rectal surgery has been gathered by a limited number of surgeons. The results of individual surgeons have consistently improved and the variability of individual surgical results is now at a lower level.

Prognosis in adenocarcinomas of lower oesophagus, gastro-oesophageal junction and cardia evaluated by uPAR-immunohistochemistry.

Adenocarcinomas of lower oesophagus, gastro‐oesophageal junction and cardia in humans are highly invasive tumours with poor prognosis. The localisation of urokinase‐type plasminogen activator receptor (uPAR) was determined in 66 patients; 60 with adenocarcinomas and six cases with Barretts oesophagus. uPAR was expressed in nearly all cases of invasive adenocarcinomas by populations of cancer cells, macrophages and myofibroblasts at both the invasion front and the tumour core. In areas with high‐grade dysplasia or with Barretts metaplasia adjacent to the tumour tissue, no uPAR‐immunoreactivity was found. High local expression of uPAR, therefore, appears to be a characteristic marker for invasive behaviour in this tumour, suggesting that uPARs contribution to matrix degradation during invasive growth is a late event in carcinogenesis. Using a scoring system for semiquantitative estimation of uPAR‐positivity on immmunohistochemically stained specimens, a significant association was found between poor overall survival and high uPAR‐score for cancer cells in the tumour core and for macrophages peripherally at the tumour invasion zone. In multivariate analysis, these two uPAR‐scores were confirmed as highly significant prognostic parameters independent of Tumour, Node, Metastasis (TNM)‐stage and World Health Organization (WHO) classification. The proteolytic action of these malignant and nonmalignant accessory cells thus seemed to follow two main patterns: one dominated by uPAR positive cancer cells and one by uPAR‐positive macrophages. Scoring of uPAR‐positivity might be a useful parameter for onset of invasion and prognosis in these adenocarcinomas.

Expression of DSG1 and DSC1 are prognostic markers in anal carcinoma patients

Background:Our purpose was to investigate if dysregulation of cell adhesion molecules could be linked to prognosis in squamous cell carcinomas (SCCs) of the anal region.Methods:Protein expression of desmoglein-1 (DSG1), desmocollin-1 (DSC1) and E-cadherin was studied by immunohistochemistry in a cohort of 53 anal carcinoma patients treated by radiation alone or combined with 5-fluorouracil and mitomycin C.Results:Univariate analyses identified, among others, negative membranous DSG1 staining (P=0.009), negative cytoplasmic DSC1 staining (P=0.012) and negative DSG1 (membranous)+negative DSC1 (cytoplasmic) staining (P=0.004) to be associated with improved cancer-specific survival (CSS). On multivariate analyses positive DSG1 (membranous)+DSC1 (cytoplasmic) staining (HR 6.95, P=0.044), large tumour size and lymph node metastases (HR 6.44, P=0.004) and radiation without chemotherapy (HR 6.73 P=0.004) were associated with worse CSS. On univariate analysis, improved disease-free survival was associated with negative membranous staining of DSG1 (P=0.047), and negative DSG1 (membranous)+negative DSC1 (cytoplasmic) staining (P=0.025), among others.Conclusion:Membrane negativity for DSG1 and cytoplasmic negativity for DSC1 are favourable markers for CSS in SCCs of the anal region.