Low-cost and clinically applicable copy number profiling using repeat DNA

BACKGROUND

Somatic copy number alterations (SCNAs) are an important class of genomic alteration in cancer. They are frequently observed in cancer samples, with studies showing that, on average, SCNAs affect 34% of a cancer cell's genome. Furthermore, SCNAs have been shown to be major drivers of tumour development and have been associated with response to therapy and prognosis. Large-scale cancer genome studies suggest that tumours are driven by somatic copy number alterations (SCNAs) or single-nucleotide variants (SNVs). Despite the frequency of SCNAs and their clinical relevance, the use of genomics assays in the clinic is biased towards targeted gene panels, which identify SNVs but provide limited scope to detect SCNAs throughout the genome. There is a need for a comparably low-cost and simple method for high-resolution SCNA profiling.

RESULTS

We present conliga, a fully probabilistic method that infers SCNA profiles from a low-cost, simple, and clinically-relevant assay (FAST-SeqS). When applied to 11 high-purity oesophageal adenocarcinoma samples, we obtain good agreement (Spearman's rank correlation coefficient, r_s=0.94) between conliga's inferred SCNA profiles using FAST-SeqS data (approximately £14 per sample) and those inferred by ASCAT using high-coverage WGS (gold-standard). We find that conliga outperforms CNVkit (r_s=0.89), also applied to FAST-SeqS data, and is comparable to QDNAseq (r_s=0.96) applied to low-coverage WGS, which is approximately four-fold more expensive, more laborious and less clinically-relevant. By performing an in silico dilution series experiment, we find that conliga is particularly suited to detecting SCNAs in low tumour purity samples. At two million reads per sample, conliga is able to detect SCNAs in all nine samples at 3% tumour purity and as low as 0.5% purity in one sample. Crucially, we show that conliga's hidden state information can be used to decide when a sample is abnormal or normal, whereas CNVkit and QDNAseq cannot provide this critical information.

CONCLUSIONS

We show that conliga provides high-resolution SCNA profiles using a convenient, low-cost assay. We believe conliga makes FAST-SeqS a more clinically valuable assay as well as a useful research tool, enabling inexpensive and fast copy number profiling of pre-malignant and cancer samples.

The Role of Microbiota in Gastrointestinal Cancer and Cancer Treatment: Chance or Curse?

The gastrointestinal (GI) tract is home to a complex and dynamic community of microorganisms, comprising bacteria, archaea, viruses, yeast, and fungi. It is widely accepted that human health is shaped by these microbes and their collective microbial genome. This so-called second genome plays an important role in normal functioning of the host, contributing to processes involved in metabolism and immune modulation. Furthermore, the gut microbiota also is capable of generating energy and nutrients (eg, short-chain fatty acids and vitamins) that are otherwise inaccessible to the host and are essential for mucosal barrier homeostasis. In recent years, numerous studies have pointed toward microbial dysbiosis as a key driver in many GI conditions, including cancers. However, comprehensive mechanistic insights on how collectively gut microbes influence carcinogenesis remain limited. In addition to their role in carcinogenesis, the gut microbiota now has been shown to play a key role in influencing clinical outcomes to cancer immunotherapy, making them valuable targets in the treatment of cancer. It also is becoming apparent that, besides the gut microbiota's impact on therapeutic outcomes, cancer treatment may in turn influence GI microbiota composition. This review provides a comprehensive overview of microbial dysbiosis in GI cancers, specifically esophageal, gastric, and colorectal cancers, potential mechanisms of microbiota in carcinogenesis, and their implications in diagnostics and cancer treatment.

EGF and BMPs Govern Differentiation and Patterning in Human Gastric Glands

BACKGROUND & AIMS

The homeostasis of the gastrointestinal epithelium relies on cell regeneration and differentiation into distinct lineages organized inside glands and crypts. Regeneration depends on Wnt/β-catenin pathway activation, but to understand homeostasis and its dysregulation in disease, we need to identify the signaling microenvironment governing cell differentiation. By using gastric glands as a model, we have identified the signals inducing differentiation of surface mucus-, zymogen-, and gastric acid-producing cells.

METHODS

We generated mucosoid cultures from the human stomach and exposed them to different growth factors to obtain cells with features of differentiated foveolar, chief, and parietal cells. We localized the source of the growth factors in the tissue of origin.

RESULTS

We show that epidermal growth factor is the major fate determinant distinguishing the surface and inner part of human gastric glands. In combination with bone morphogenetic factor/Noggin signals, epidermal growth factor controls the differentiation of foveolar cells vs parietal or chief cells. We also show that epidermal growth factor is likely to underlie alteration of the gastric mucosa in the precancerous condition atrophic gastritis.

CONCLUSIONS

Use of our recently established mucosoid cultures in combination with analysis of the tissue of origin provided a robust strategy to understand differentiation and patterning of human tissue and allowed us to draw a new, detailed map of the signaling microenvironment in the human gastric glands.

Cost-effectiveness modelling of use of urea breath test for the management of Helicobacter pylori-related dyspepsia and peptic ulcer in the UK

Objective

Clinical data comparing diagnostic strategies in the management of Helicobacter pylori-associated diseases are limited. Invasive and noninvasive diagnostic tests for detecting H. pylori infection are used in the clinical care of patients with dyspeptic symptoms. Modelling studies might help to identify the most cost-effective strategies. The objective of the study is to assess the cost-effectiveness of a ‘test-and-treat’ strategy with the urea breath test (UBT) compared with other strategies, in managing patients with H. pylori-associated dyspepsia and preventing peptic ulcer in the UK.

Design

Cost-effectiveness models compared four strategies: ‘test-and-treat’ with either UBT or faecal antigen test (FAT), ‘endoscopy-based strategy’ and ‘symptomatic treatment’. A probabilistic cost-effectiveness analysis was performed using a simulation model in order to identify probabilities and costs associated with relief of dyspepsia symptoms (over a 4-week time horizon) and with prevention of peptic ulcers (over a 10-year time horizon). Clinical and cost inputs to the model were derived from routine medical practice in the UK.

Results

For relief of dyspepsia symptoms, ‘test-and-treat’ strategies with either UBT (€526/success) and FAT (€518/success) were the most cost-effective strategies compared with ‘endoscopy-based strategy’ (€1317/success) and ‘symptomatic treatment’ (€1 029/success). For the prevention of peptic ulcers, ‘test-and-treat’ strategies with either UBT (€208/ulcer avoided/year) or FAT (€191/ulcer avoided/year) were the most cost-effective strategies compared with ‘endoscopy-based strategy’ (€717/ulcer avoided/year) and ‘symptomatic treatment’ (€651/ulcer avoided/year) (1 EUR=0,871487 GBP at the time of the study).

Conclusion

‘Test-and-treat’ strategies with either UBT or FAT are the most cost-effective medical approaches for the management of H. pylori-associated dyspepsia and the prevention of peptic ulcer in the UK. A ‘test-and-treat’ strategy with UBT has comparable cost-effectiveness outcomes to the current standard of care using FAT in the UK.

Myths and misconceptions in the management of Helicobacter pylori infection

The discovery of Helicobacter pylori infection in 1984 revolutionised the management of several common upper gastrointestinal diseases. However, some of the clinical practices that were adopted following discovery of this organism have become less appropriate over the intervening years. This article discusses five 'myths and misconceptions' that we believe have now emerged and which we argue need re-evaluation. Although the prevalence of H. pylori infection is decreasing in some developed countries, it remains a huge global problem and the most serious consequence of infection, gastric adenocarcinoma, is still a major cause of mortality. The epidemiology of H. pylori-related diseases is also changing and careful testing remains crucially important, especially in patients with peptic ulceration. Eradication of H. pylori infection has also become much more difficult over recent years as a result of the widespread acquisition of antibiotic resistance. Routine assessment of the success of eradication should therefore now be performed. Finally, there has been increased awareness about the role of H. pylori in the multistep pathway of gastric carcinogenesis, about the opportunities to prevent cancer development by eradicating this infection in some individuals and about detecting high-risk preneoplastic changes via endoscopic surveillance. The discovery of H. pylori was rightly honoured by the award of the Nobel prize for Physiology and Medicine in 2005. However, unless we re-evaluate and update the ways in which we manage H. pylori infection, much of the fantastic progress that has been made in this field of medicine may tragically be lost once again.

The complexity of cancer origins at the gastro-oesophageal junction

Chronic acid-biliary reflux and Helicobacter pylori infection are instrumental environmental drivers of cancer initiation and progression in the upper gastrointestinal tract. Remarkably, although these environmental carcinogens are quite dissimilar, the tumour progression cascade these carcinogens engender is highly comparable. For this reason, studies of malignant progression occurring at the anatomic borderland between the oesophagus and the stomach have traditionally lumped junctional adenocarcinomas with either oesophageal adenocarcinoma or gastric adenocarcinoma. Whilst studies have revealed remarkable epidemiological and genetic similarities of these cancers and their associated premalignant conditions, these works have also revealed some key differences. This highlights that further scientific effort demands a dedicated focus on the understanding of the cell-cell interaction between the epithelium and the local microenvironment in this anatomic region. We here review available evidence with regards to tumour progression occurring at the gastro-oesophageal junction and contrast it with available data on cancer evolution in the metaplastic oesophagus and distal stomach.

Biopsy Sampling in Upper Gastrointestinal Endoscopy: A Survey from 10 Tertiary Referral Centres Across Europe

BACKGROUND

Guidelines give robust recommendations on which biopsies should be taken when there is endoscopic suggestion of gastric inflammation. Adherence to these guidelines often seems arbitrary. This study aimed to give an overview on current practice in tertiary referral centres across Europe.

METHODS

Data were collected at 10 tertiary referral centres. Demographic data, the indication for each procedure, endoscopic findings, and the number and sampling site of biopsies were recorded. Findings were compared between centres, and factors influencing the decision to take biopsies were explored.

RESULTS

Biopsies were taken in 56.6% of 9,425 procedures, with significant variation between centres (p < 0.001). Gastric biopsies were taken in 43.8% of all procedures. Sampling location varied with the procedure indication (p < 0.001) without consistent pattern across the centres. Fewer biopsies were taken in centres which routinely applied the updated Sydney classification for gastritis assessment (46.0%), compared to centres where this was done only upon request (75.3%, p < 0.001). This was the same for centres stratifying patients according to the OLGA system (51.8 vs. 73.0%, p < 0.001). More biopsies were taken in centres following the MAPS guidelines on stomach surveillance (68.1 vs. 37.1%, p < 0.001). Biopsy sampling was more likely in younger patients in 8 centres (p < 0.05), but this was not true for the whole cohort (p = 0.537). The percentage of procedures with biopsies correlated directly with additional costs charged in case of biopsies (r = 0.709, p = 0.022).

CONCLUSION

Adherence to guideline recommendations for biopsy sampling at gastroscopy was inconsistent across the participating centres. Our data suggest that centre-specific policies are applied instead.

EpiCO (epirubicin, cyclophosphamide and vincristine) as treatment for extrapulmonary high-grade neuroendocrine neoplasms

High-grade neuroendocrine neoplasms (NEN) comprise a rare entity. Due to the lack of randomized controlled trials, therapy recommendations were mainly extrapolated from its pulmonary analogue, small cell lung cancer and mostly validated in small retrospective case series. The multicentric Nordic NEC Study of gastro-entero-pancreatic (GEP) and cancer of unknown primary (CUP) high-grade neuroendocrine neoplasms showed a significant disease control upon treatment with etoposide and platinum-based chemotherapies 1. Such a combination with etoposide and a platinum (CE) compound is currently considered standard first-line treatment for high-grade GEP/CUP NEN. High-grade mixed-neuroendocrine-non-neuroendocrine neoplasms (MiNEN) formerly termed mixed adeno-neuroendocrine carcinomas (MANEC) also have a poor prognosis and are generally treated like other high-grade NEN. The CE protocol has significant activity in high-grade NEN and MiNEN, but the response is short-lived in most cases with response rates around 50-60 %. Second-line treatment alternatives are not established so far. The need for additional treatment options is evident.Combination chemotherapy with doxorubicin, cyclophosphamide and vincristine (CAV) showed efficacy in small cell lung carcinoma (SCLC) and was considered standard first-line therapy before the era of etoposide and platinum combinations. Due to a better toxicity profile, doxorubicin was replaced by epirubicin, resulting in the combination of epirubicin, cyclophosphamide and vincristine (abbreviated as EpiCO or CEV).In analogy to SCLC, selected patients with high-grade NEN were treated with the EpiCO regimen in second line (or in one patient first line) at our center. In this report we present the retrospective series of 5 cases with metastatic high-grade GEP/CUP NEN/MiNEN who received chemotherapy according to this protocol.

Transcriptomic profiling reveals three molecular phenotypes of adenocarcinoma at the gastroesophageal junction

Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment-naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina-HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune-response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed.

Feasibility of combined screening for upper gastrointestinal adenocarcinoma risk by serology and Cytosponge testing: the SUGAR study

AIMS

Aim was to assess the feasibility of serum markers to identify individuals at risk for gastro-oesophageal adenocarcinoma to reduce the number of individuals requiring invasive assessment by endoscopy.

METHODS

Blood samples from 56 patients with Barrett's oesophagus and 202 non-Barrett controls who previously took part in a trial assessing the accuracy of the Cytosponge for Barrett's oesophagus were assessed for serum pepsinogen (PG) 1 and 2, gastrin-17, trefoil factor 3 (TFF3) and Helicobacter pylori infection.

RESULTS

PG1 was pathological (<50 ng/mL) in 26 patients (10.1%), none of whom had Barrett's oesophagus (p<0.001). Smoking and drinking had no influence on these results. Pathological PG1 was associated with stomach pain (p=0.029), disruption of sleep (p=0.027) and disruption of diet by symptoms (p=0.019). Serum TFF3 was not associated with any clinical parameter.

CONCLUSIONS

Assessment of serum PG1 could be combined with a test for Barrett's oesophagus to identify additional patients requiring endoscopy.

Immune activation by DNA damage predicts response to chemotherapy and survival in oesophageal adenocarcinoma

OBJECTIVE

Current strategies to guide selection of neoadjuvant therapy in oesophageal adenocarcinoma (OAC) are inadequate. We assessed the ability of a DNA damage immune response (DDIR) assay to predict response following neoadjuvant chemotherapy in OAC.

DESIGN

Transcriptional profiling of 273 formalin-fixed paraffin-embedded prechemotherapy endoscopic OAC biopsies was performed. All patients were treated with platinum-based neoadjuvant chemotherapy and resection between 2003 and 2014 at four centres in the Oesophageal Cancer Clinical and Molecular Stratification consortium. CD8 and programmed death ligand 1 (PD-L1) immunohistochemical staining was assessed in matched resection specimens from 126 cases. Kaplan-Meier and Cox proportional hazards regression analysis were applied according to DDIR status for recurrence-free survival (RFS) and overall survival (OS).

RESULTS

A total of 66 OAC samples (24%) were DDIR positive with the remaining 207 samples (76%) being DDIR negative. DDIR assay positivity was associated with improved RFS (HR: 0.61; 95% CI 0.38 to 0.98; p=0.042) and OS (HR: 0.52; 95% CI 0.31 to 0.88; p=0.015) following multivariate analysis. DDIR-positive patients had a higher pathological response rate (p=0.033), lower nodal burden (p=0.026) and reduced circumferential margin involvement (p=0.007). No difference in OS was observed according to DDIR status in an independent surgery-alone dataset.DDIR-positive OAC tumours were also associated with the presence of CD8+ lymphocytes (intratumoural: p<0.001; stromal: p=0.026) as well as PD-L1 expression (intratumoural: p=0.047; stromal: p=0.025).

CONCLUSION

The DDIR assay is strongly predictive of benefit from DNA-damaging neoadjuvant chemotherapy followed by surgical resection and is associated with a proinflammatory microenvironment in OAC.

The Rationale and Efficacy of Primary and Secondary Prevention in Adenocarcinomas of the Upper Gastrointestinal Tract

While the primary risk factor for oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO) is gastro-oesophageal reflux, the infection with Helicobacter pylori (H. pylori) is the dominant risk factor for gastric cancer. Reduction of reflux by dietary measures and proton pump inhibitors has some merits in OAC prevention, and the chemopreventive effect of Aspirin and statins is being widely investigated; however, improved outcome in OAC occurs primarily as the result of secondary prevention. Early detection of neoplastic lesions in Barrett's metaplasia can be achieved by surveillance endoscopies. Novel endoscopic imaging modalities carry similar importance as the endoscopic treatment techniques as without detection of early lesions, therapy cannot be applied. Minimally invasive approaches are currently being investigated to identify patients with BO who are at particular risk of neoplastic progression. While dietary factors also play an important role in the prevention of gastric cancer and chemoprevention seems to be promising, the most beneficial effect has been shown for the eradication of H. pylori infection, which results in at least a one third reduction of gastric cancer risk. This effect can be further improved if the eradication takes place prior to the development of pre-neoplastic gastric conditions such as mucosal atrophy or intestinal metaplasia (IM). The definition of the "point of no return", after which eradication is less effective, is of high importance, although H. pylori eradication can still be beneficial even at more advance stages of mucosal changes. For this reason, patients with advanced atrophy and IM should undergo endoscopic surveillance in the same way as patients with BO. There is also need for development of non-invasive tests to identify patients at high risk of progression to gastric cancer to improve outcome of these surveillance approaches.

Combined Gastric and Colorectal Cancer Screening-A New Strategy

Background: Our aim was to evaluate the feasibility of a serological assessment of gastric cancer risk in patients undergoing colonoscopy in countries with low-to-moderate incidence rates. Methods: Serum samples were prospectively collected from 453 patients (>50 years old) undergoing colonoscopies. Of these, 279 (61.6%) also underwent gastroscopy to correlate the results for serum pepsinogen I and II (sPG-I and sPG-II), sPG-I/II ratio, and anti-H. pylori antibodies with gastric histopathology findings (graded according to the updated Sydney classification and the Operative Link of Gastritis Assessment (OLGA) and the Operative Link for Gastric Intestinal Metaplasia assessment (OLGIM) systems). Results: H. pylori was found in 85 patients (30.5%). Chronic atrophic gastritis was diagnosed in 89 (31.9%) patients. High-risk OLGA (III–IV) stages were present in 24 patients, and high-risk OLGIM stages were present in 14 patients. There was an inverse correlation of sPG-I with the degree of atrophy and intestinal metaplasia (IM), as well as with the respective OLGA (r = −0.425; p < 0.001) and OLGIM (r = −0.303; p < 0.001) stages. A pathological sPG-I result was associated with a relative risk (RR) of 12.2 (95% confidence interval: 6.29–23.54; p < 0.001) for gastric preneoplastic changes. Conclusions: The assessment of serum pepsinogen allows the identification of patients at increased risk of gastric cancer. A prevention strategy of combining a screening colonoscopy with a serological screening for preneoplastic gastric changes should be considered in the general population.

Regulation of apoptosis is impaired in atrophic gastritis associated with gastric cancer

BACKGROUND

Gastric premalignant conditions, atrophic gastritis (AG) and intestinal metaplasia (IM) are characterized by an increase of proliferation and a reduction of apoptosis in epithelial cells. The epithelial cell kinetics in AG and IM in gastric mucosa adjacent to gastric cancer is still unclear. The aim of this study was to evaluate the epithelial cell turnover and expression of proliferation and apoptosis-related genes in gastric cancer (GC) and adjacent mucosa with atrophic gastritis or intestinal metaplasia (AG/IM GC+), as well as in atrophic gastritis or intestinal metaplasia mucosa of patients without GC (AG/IM GC-) and in control biopsy samples of non-transformed gastric mucosa (Control).

METHODS

We selected 58 patients (M: F = 34:24; age range 20-84 years, median 61.06 years) with 4 well defined histological conditions: 20 controls with histological finding of non-transformed gastric mucosa, 20 patients with AG or IM (AG/IM GC-), and 18 patients with intestinal type gastric adenocarcinoma (GC) and AG or IM in the adjacent mucosa (3 cm from the macroscopic tumour margin, AG/IM GC+). We performed an immunohistochemical staining of Ki67 and TUNEL and quantitative RT-PCR to determine the expression of PCNA and Bax/Bcl-2.

RESULTS

The immunohistochemical expression of Ki67 and TUNEL in AG/IM GC- was significantly increased compared to not transformed gastric mucosa (p < 0.0001) but not compared to AG/IM in gastric mucosa adjacent to GC. Levels of Bcl-2 were reduced in GC and AG/IM GC- compared to controls as well as in AG/IM GC- compared to AG/IM in mucosa adjacent to GC+ (p < 0.05). Proliferation and apoptosis markers did not correlate with H.pylori status in our study population.

CONCLUSIONS

In AG/IM associated with GC, no significant changes in the epithelial cell turnover were detected. Decreased Bcl-2 gene expression signified atrophic gastritis and IM in presence of cancer, as well as intestinal type gastric adenocarcinoma.

A comparative analysis of whole genome sequencing of esophageal adenocarcinoma pre- and post-chemotherapy

The scientific community has avoided using tissue samples from patients that have been exposed to systemic chemotherapy to infer the genomic landscape of a given cancer. Esophageal adenocarcinoma is a heterogeneous, chemoresistant tumor for which the availability and size of pretreatment endoscopic samples are limiting. This study compares whole-genome sequencing data obtained from chemo-naive and chemo-treated samples. The quality of whole-genomic sequencing data is comparable across all samples regardless of chemotherapy status. Inclusion of samples collected post-chemotherapy increased the proportion of late-stage tumors. When comparing matched pre- and post-chemotherapy samples from 10 cases, the mutational signatures, copy number, and SNV mutational profiles reflect the expected heterogeneity in this disease. Analysis of SNVs in relation to allele-specific copy-number changes pinpoints the common ancestor to a point prior to chemotherapy. For cases in which pre- and post-chemotherapy samples do show substantial differences, the timing of the divergence is near-synchronous with endoreduplication. Comparison across a large prospective cohort (62 treatment-naive, 58 chemotherapy-treated samples) reveals no significant differences in the overall mutation rate, mutation signatures, specific recurrent point mutations, or copy-number events in respect to chemotherapy status. In conclusion, whole-genome sequencing of samples obtained following neoadjuvant chemotherapy is representative of the genomic landscape of esophageal adenocarcinoma. Excluding these samples reduces the material available for cataloging and introduces a bias toward the earlier stages of cancer.

Association of a DNA damage response deficiency (DDRD) assay with prognosis in resected esophageal and gastric adenocarcinoma

4026

Background: Current strategies to guide the selection of neo-adjuvant or adjuvant therapy in esophageal and gastric adenocarcinomas (EAC/GAC) are inadequate. We assessed a clinically validated 44 gene DNA Damage Response Deficiency (DDRD) assay to predict prognosis following neo-adjuvant DNA damaging chemotherapy (CT) in EAC and adjuvant CT or chemo-radiotherapy (CRT) in GAC. Methods: Transcriptional profiling of 273 formalin fixed paraffin embedded pre-treatment endoscopic EAC biopsies was performed using the Almac Diagnostics Xcel array. All EAC patients were treated with cisplatin-based neo-adjuvant chemotherapy followed by surgical resection between 2003 and 2014 at four UK centers in the OCCAMS consortium. Further validation was performed using a publically available dataset of 270 resected gastric cancers treated with adjuvant platinum-based CT, CRT or surgery alone at the Samsung Medical Centre, Seoul, Korea. The association between the DDRD score and prognosis was assessed by Kaplan-Meier analysis and Cox Proportional Hazards regression. Results: A total of 66 EAC samples (24%) were characterized as DDRD positive with the remaining 207 samples (76%) being DDRD negative. DDRD assay positivity was associated with improved DFS (HR 0.58; 95% CI 0.36-0.93; p = 0.024) and OS (HR 0.56; 95% CI 0.34-0.92; p = 0.023) following multivariate analysis. DDRD positive patients had a higher pathological response rate (p = 0.033) and a higher rate of loco-regional versus distant relapse (30% vs 20%; p = 0.013). For GAC, 132 samples (49%) were characterized as DDRD positive with the remaining 138 (51%) being DDRD negative. DDRD positivity was associated with improved DFS (HR 0.48; 95% CI 0.25-0.96; p = 0.037) following D2 gastrectomy and adjuvant CT or CRT. DDRD status was not associated with DFS in the surgery alone cohort (HR 0.87; 95% CI 0.55-1.38; p = 0.562). Conclusions: The DDRD assay is strongly predictive of benefit from DNA damaging neo-adjuvant CT and esophagectomy in EAC and gastrectomy and CT/CRT in GAC and can be applied to routine diagnostic material.

Mutational signatures in esophageal adenocarcinoma define etiologically distinct subgroups with therapeutic relevance

Esophageal adenocarcinoma (EAC) has a poor outcome, and targeted therapy trials have thus far been disappointing owing to a lack of robust stratification methods. Whole-genome sequencing (WGS) analysis of 129 cases demonstrated that this is a heterogeneous cancer dominated by copy number alterations with frequent large-scale rearrangements. Co-amplification of receptor tyrosine kinases (RTKs) and/or downstream mitogenic activation is almost ubiquitous; thus tailored combination RTK inhibitor (RTKi) therapy might be required, as we demonstrate in vitro. However, mutational signatures showed three distinct molecular subtypes with potential therapeutic relevance, which we verified in an independent cohort (n = 87): (i) enrichment for BRCA signature with prevalent defects in the homologous recombination pathway; (ii) dominant T>G mutational pattern associated with a high mutational load and neoantigen burden; and (iii) C>A/T mutational pattern with evidence of an aging imprint. These subtypes could be ascertained using a clinically applicable sequencing strategy (low coverage) as a basis for therapy selection.

Genetic progression of Barrett's oesophagus to oesophageal adenocarcinoma

Barrett's oesophagus (BE) is the premalignant condition associated with the development of oesophageal adenocarcinoma (OAC). Diagnostically, p53 immunohistochemistry remains the only biomarker recommended clinically to aid histopathological diagnosis. The emerging mutational profile of BE is one of highly heterogeneous lesions at the genomic level with many mutations already occurring in non-dysplastic tissue. As well as point mutations, larger scale copy-number changes appear to have a key role in the progression to OAC and clinically applicable assays for the reliable detection of aneuploidy will be important to incorporate into future clinical management of patients. For some patients, the transition to malignancy may occur rapidly through a genome-doubling event or chromosomal catastrophe, termed chromothripsis, and detecting these patients may prove especially difficult. Given the heterogeneous nature of this disease, sampling methods to overcome inherent bias from endoscopic biopsies coupled with the development of more objective biomarkers than the current reliance on histopathology will be required for risk stratification. The aim of this approach will be to spare low-risk patients unnecessary procedures, as well as to provide endoscopic therapy to the patients at highest risk, thereby avoiding the burden of incurable metastatic disease.

[S2k-guideline Helicobacter pylori and gastroduodenal ulcer disease]

In the line "bismuth-containing quadruple therapy" of Table 7 (p 342), in the column "dosage" incorrectly at the three antibiotics respectively 1-1-1-1. The correct is: 3-3-3-3.

Expression of aurora kinase A correlates with the Wnt-modulator RACGAP1 in gastric cancer

Canonical Wnt signaling is involved in gastric carcinogenesis. The aim of this study was to identify the link between Wnt signaling and aurora kinase A (AURKA), a target for the treatment of gastrointestinal cancers. Publicly available microarray data were used to identify phenotype‐specific protein–protein interaction (PPI) subnetworks. The in silico analysis revealed a gastric cancer‐specific PPI subnetwork consisting of 2745 proteins and 50,935 interactions. We focused on the link of AURKA to a Wnt‐specific interaction module consisting of 92 proteins. There was a direct association of AURKA with Rac GTPase‐activating protein 1 (RACGAP1), as well as with CTNBB1 (β‐catenin) and CDKN1A as second‐order interactors. Differential expression analysis revealed a significant downregulation of both AURKA and RACGAP1 in gastric cancer compared to noncancer controls. Biopsies from a prospective cohort of 56 patients with gastric cancer (32 intestinal type, 24 diffuse type) and 20 noncancer controls were used for validation of the identified targets. The RT‐PCR data confirmed a strong correlation of AURKA and RACGAP1 gene expression both in the tumor, the tumor‐adjacent and the tumor‐distant mucosa. RACGAP1 in the tumor was also associated with CTNBB1 expression, and inversely associated with CDKN1A gene expression. Immunohistochemistry confirmed expression of the RACGAP1 protein in gastric cancer and the tumor‐adjacent mucosa. RACGAP1 expression was not associated with tumor stage, grading, Lauren type, Helicobacter pylori infection, or age. In conclusion, AURKA is directly associated with the expression of RACGAP1, a modulator of the canonical Wnt signaling pathway.

MMP2 and MMP7 at the invasive front of gastric cancer are not associated with mTOR expression

Background

Regulation of MMP expression by activation of mTOR signalling has been demonstrated for several tumor types, but has thus far not been confirmed in gastric cancer.

Findings

The study compromised 128 patients who underwent gastric resection for cancer (66.4 % male; 86 intestinal, 42 diffuse type). Immunohistochemical staining of MMPs was performed to analyse the topographical pattern of MMP expression at the tumor center and the invasive front, respectively. MMP2 showed higher expression at the invasive front compared to the tumor center, whereas MMP7 staining scores were higher in the tumor center, and there was no difference for MMP9. The expression of p-mTOR was higher in the tumor center than at the invasive front, with a similar trend for mTOR. For intestinal type gastric cancer there was a weak correlation of MMP9 with expression of mTOR in the tumor center. Otherwise, there was no correlation of the MMPs with mTOR. By treatment of MKN45 gastric cancer cells with rapamycin, a reduction of p-mTOR in the Western blot was achieved; however, expression of MMPs remained unaffected.

Conclusions

Expression of MMP2 and MMP7 in gastric cancer is not associated with mTOR, MMP9 expression might be related to mTOR signalling in a subset of tumors.

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-015-0449-z) contains supplementary material, which is available to authorized users.

Significance of a Single-Time-Point Somatostatin Receptor SPECT/Multiphase CT Protocol in the Diagnostic Work-up of Gastroenteropancreatic Neuroendocrine Neoplasms

This prospective study compared a 1-d SPECT/CT protocol with the commonly used 3-d protocol for somatostatin receptor scintigraphy in patients with gastroenteropancreatic neuroendocrine neoplasms. Additionally, the influence of SPECT/CT on patient management was evaluated.

METHODS

From October 2011 to October 2012, all gastroenteropancreatic neuroendocrine neoplasm patients undergoing restaging with somatostatin receptor scintigraphy on a modern SPECT/CT device were enrolled in this study. The protocol consisted of planar imaging at 4, 24, and 48 h; low-dose SPECT/CT at 24 and 48 h; diagnostic CT at 24 h using a triple-phase delay after administration of contrast; and diagnostic SPECT/CT at 24 h. All components of the imaging data were reassessed by 3 masked interpreters. The results were compared with a reference standard based on all clinical, imaging, and histopathology follow-up data available (follow-up range, 24-36 mo; mean, 29.9 mo). The reference standard was defined by a study-specific interdisciplinary tumor board that also reassessed treatment decisions.

RESULTS

Thirty-one patients were eligible for analysis (18 men and 13 women; mean age, 60.4 y). Ten had no imaging signs of disease and remained disease-free during follow-up. Twenty-one had persistent or recurrent disease (82 lesions: 24 in the liver, 21 in the lymph nodes, 16 in bone, 12 in the pancreas, and 9 in other locations). The respective lesion detection rates for interpreters 1, 2, and 3 were 51.9%, 49.4%, and 71.6% for low-dose SPECT/CT at 24 h; 51.9%, 55.6%, and 67.9% for low-dose SPECT/CT at 48 h; 63.0%, 70.4%, and 85.2% for diagnostic CT; and 77.8%, 84.0%, and 88.9% for diagnostic SPECT/CT. Interobserver agreement was moderate for diagnostic SPECT/CT (κ = 0.44), diagnostic CT (κ = 0.43), low-dose SPECT/CT at 48 h (κ = 0.61), and low-dose SPECT/CT at 24 h (κ = 0.55). For planar imaging, interobserver agreement was fair after 48 h (κ = 0.36) and 24 h (κ = 0.38) and moderate after 4 h (κ = 0.42). Every lesion detectable on planar imaging or low-dose SPECT/CT was also detectable on diagnostic SPECT/CT. The CT and SPECT components of diagnostic SPECT/CT strongly complemented each other, as 34 of 82 lesions (41.4%) were detected on only the CT component or only the SPECT component. Therapeutic management was influenced by the diagnostic SPECT/CT interpretation in 8 of 31 patients (25.8%).

CONCLUSION

The highest detection rates were achieved by diagnostic SPECT/CT. Thus, a more patient-friendly 1-d protocol is feasible. Furthermore, multiphase SPECT/CT affected management in about a quarter of patients.

Medial and lateral foot loading and its effect on knee joint loading

BACKGROUND

The medial knee contact force may be lowered by modified foot loading to prevent the progression of unilateral gonarthrosis but the real effects of such gait modifications are unknown. This study investigates how walking with a more medial or lateral rollover of the foot influences the in vivo measured knee contact forces.

METHODS

Five subjects with telemeterized knee implants walked on a treadmill with pronounced lateral or medial foot loading. Acoustic feedback of peak foot pressure was used to facilitate the weight bearing shift. The resultant contact force, Fres, the medial contact force, Fmed, and the force distribution Fmed/Fres across the tibial plateau were computed from the measured joint contact loads.

FINDINGS

During lateral foot loading, the two maxima of Fres during the stance phase, Peak 1 and Peak 2, increased by an average of 20% and 12%, respectively. The force distribution was changed by only -3%/+2%. As a result, Fmed increased by +16%/+17%. Medial foot loading, on the other hand, changed Fres only slightly, but decreased the distribution by -18%/-11%. This led to average reductions of Fmed by -18%/-18%. The reductions were realized by kinematic adaptations, such as increases of ankle eversion, step width and foot progression angle.

INTERPRETATION

Medial foot loading consistently reduced the medial knee compartment, and may be a helpful gait modification for patients with pronounced medial gonarthrosis. The increase of Fmed during lateral foot loading was most likely caused by muscular co-contractions. Long-term training may lead to more efficient gait and reduce co-contractions.

From Barrett metaplasia to esophageal adenocarcinoma: the molecular background

The molecular landscape of Barrett's esophagus and Barrett-related neoplastic lesions is still far from being completely elucidated. Both in vitro and in vivo studies pinpointed the pathogenetic role of different morphogenic pathways (the para-homeobox, the Notch and the Sonic Hedgehog families in particular) implicated in the acquisition of the metaplastic phenotype of the esophageal mucosa. On the other hand, the most common genetic alterations observed during Barrett's carcinogenesis include disorders of major regulators of the cell cycle, as well as deregulation of the TGF-β/Smad and receptor tyrosine kinases signalling pathways. Recent comprehensive mutational profiling studies identified that the inactivation of the TP53 and of the SMAD4 tumour suppressor genes occurred in a stage-specific manner, confined to (high grade) dysplastic and neoplastic lesions, respectively. The next step will be the correlation of these findings into multidisciplinary diagnostic approaches integrating endoscopy, histology, molecular profiling and liquid biopsies. This will allow the introduction of innovative strategies for secondary prevention of esophageal adenocarcinoma based on biological rationales, and the implementation of potential novel therapeutic targets.

From Barrett metaplasia to esophageal adenocarcinoma: the molecular background

The molecular landscape of Barrett's esophagus and Barrett-related neoplastic lesions is still far from being completely elucidated. Both in vitro and in vivo studies pinpointed the pathogenetic role of different morphogenic pathways (the para-homeobox, the Notch and the Sonic Hedgehog families in particular) implicated in the acquisition of the metaplastic phenotype of the esophageal mucosa. On the other hand, the most common genetic alterations observed during Barrett's carcinogenesis include disorders of major regulators of the cell cycle, as well as deregulation of the TGF-β/Smad and receptor tyrosine kinases signalling pathways. Recent comprehensive mutational profiling studies identified that the inactivation of the TP53 and of the SMAD4 tumour suppressor genes occurred in a stage-specific manner, confined to (high grade) dysplastic and neoplastic lesions, respectively. The next step will be the correlation of these findings into multidisciplinary diagnostic approaches integrating endoscopy, histology, molecular profiling and liquid biopsies. This will allow the introduction of innovative strategies for secondary prevention of esophageal adenocarcinoma based on biological rationales, and the implementation of potential novel therapeutic targets.

Adenocarcinomas at different positions at the gastro-oesophageal junction show distinct association with gastritis and gastric preneoplastic conditions

OBJECTIVE

Adenocarcinomas at the gastro-oesophageal junction (GOJ) are currently stratified by tumour location. This retrospective study examines the association of preneoplastic conditions and inflammation of the gastric mucosa with GOJ cancer at different locations and compares them with nonjunctional gastric cancers.

PATIENTS AND METHODS

A total of 520 patients with junctional and nonjunctional gastric cancer were assessed for the presence and degree of intestinal metaplasia, glandular atrophy and inflammation in the stomach. Histopathological data were complete for 428 patients (68.9% men, median age 67.7 years), including 172 patients with GOJ cancer (GOJ1: 1-5 cm proximal to the junction, GOJ2: 'true' junctional, GOJ3: 2-5 cm distal to the junction). Gastric inflammation and preneoplastic conditions were scored according to the updated Sydney classification and further stratified into respective operative link on gastritis assessment (OLGA) and operative link on gastritis assessment on intestinal metaplasia (OLGIM) stages.

RESULTS

The prevalence and degree of gastric atrophy and intestinal metaplasia were significantly lower in GOJ1 than GOJ3 (P<0.01). Preneoplastic conditions in the stomach were similar in GOJ3 compared with nonjunctional gastric cancer. GOJ1 were almost exclusively (98.4%) of the intestinal type, whereas GOJ2 and GOJ3 were the diffuse type in 22.6 and 22.4% of the patients (P<0.001). Of all patients, only 8.5 and 12.7% presented with stage III/IV according to OLGA and OLGIM, respectively. However, data for OLGA and OLGIM staging were only available in 61.2 and 67.9% of patients, respectively.

CONCLUSION

GOJ1 are less likely to be associated with gastric pathology compared with GOJ3 or nonjunctional gastric cancer. OLGA or OLGIM staging in patients with advanced gastro-oesophageal cancer seems to be of limited value.

Assessment and monitoring of liver function by ¹³C-aminopyrine breath test after selective transarterial chemoembolisation of hepatocellular carcinoma

BACKGROUND

Liver function and tumor staging are essential parameters for selection of treatment modalities in patients with hepatocellular carcinoma (HCC). Transarterial chemoembolization (TACE) is associated with a risk of deterioration of liver function. In clinical routine hepatic function in patients with liver cirrhosis is assessed by the Child-Pugh-classification. Dynamic breath tests allow the assessment of the hepatic functional mass and have the potential to give more accurate information on hepatic function periinterventionally.

PATIENTS AND METHODS

A prospective clinical study was performed in 13 patients receiving a total of 18 TACE sessions. (13)C-aminopyrine breath test was performed the day before TACE, 2 days and 30 days after TACE and correlated with standard laboratory work-up of the patients.

RESULTS

Fourteen TACE sessions were performed in Child A liver cirrhosis, 4 in Child B cirrhosis. All patients presented with impaired aminopyrine metabolism at baseline. No significant changes in the (13)C aminopyrine breath test following TACE were observed. Two patients treated in Child A cirrhosis decompensated to Child B, one of them recovered. No further decompensation was observed in patients treated in Child B cirrhosis.

DISCUSSION AND CONCLUSION

Liver function assessment with (13)C-aminopyrine breath test and Child-Pugh-classification following TACE was discordant in a large proportion of patients. Whether a quantification of mitochondrial liver function in patients planned to undergo locoregional treatment of HCC in liver cirrhosis is helpful in the prediction of postprocedural liver decompensation needs to be addressed in larger prospective clinical trials.

Different antibiotic susceptibility between antrum and corpus of the stomach, a possible reason for treatment failure of Helicobacter pylori infection

AIM: To assess whether antibiotic resistance varies between the antrum and corpus of the stomach of patients that are either Helicobacter pylori (H. pylori) therapy-naive or pre-treated.

METHODS: H. pylori strains were isolated from antrum and corpus biopsies from 66 patients that received a diagnostic gastroduodenoscopy for variant clinical indications. Antimicrobial susceptibility to amoxicillin, clarithromycin, tetracycline, metronidazole, levofloxacin and rifabutin was tested with the E-test method on Iso-Sensitest agar with 10 vol% defibrinated horse blood. In patients with a different antibiotic susceptibility pattern between the isolates from the antrum and corpus, DNA fingerprinting via random amplified polymorphic DNA analysis was performed to detect differences among DNA patterns of H. pylori isolates.

RESULTS: Primary, secondary and tertiary resistance to clarithromycin was 6.9%, 53.8% and 83.3%, retrospectively. Metronidazole and levofloxacin resistance also increased according to the number of previous treatments (17.2%, 69.2%, 83.3%; 13.8%, 23.1%, 33.3%). Tertiary resistance to rifabutin was detected in 12.5% of patients. In none of the 66 patients a resistance against amoxicillin or tetracycline was detectable. Discordant antibiotic susceptibility between antrum and corpus isolates for different antibiotics was seen in 15.2% (10/66) of the patients. Two out of those ten patients were naive to any H. pylori antibiotic treatment. The remaining eight patients previously received at least one eradication therapy. DNA fingerprinting analysis revealed no substantial differences among DNA patterns between antrum and corpus isolates in the majority of patients suggesting an infection with a single H. pylori strain.

CONCLUSION: Different antibiotic susceptibility between antrum and corpus biopsies is a common phenomenon and a possible explanation for treatment failure. Resistant H. pylori strains may be missed if just one biopsy from one anatomic site of the stomach is taken for H. pylori susceptibility testing.

Transcribed ultraconserved noncoding RNAs (T-UCR) are involved in Barrett's esophagus carcinogenesis

Barrett's esophagus (BE) involves a metaplastic replacement of native esophageal squamous epithelium (Sq) by columnar-intestinalized mucosa, and it is the main risk factor for Barrett-related adenocarcinoma (BAc). Ultra-conserved regions (UCRs) are a class non-coding sequences that are conserved in humans, mice and rats. More than 90% of UCRs are transcribed (T-UCRs) in normal tissues, and are altered at transcriptional level in tumorigenesis. To identify the T-UCR profiles that are dysregulated in Barrett's mucosa transformation, microarray analysis was performed on a discovery set of 51 macro-dissected samples obtained from 14 long-segment BE patients. Results were validated in an independent series of esophageal biopsy/surgery specimens and in two murine models of Barrett's esophagus (i.e. esophagogastric-duodenal anastomosis). Progression from normal to BE to adenocarcinoma was each associated with specific and mutually exclusive T-UCR signatures that included up-regulation of uc.58-, uc.202-, uc.207-, and uc.223- and down-regulation of uc.214+. A 9 T-UCR signature characterized BE versus Sq (with the down-regulation of uc.161-, uc.165-, and uc.327-, and the up-regulation of uc.153-, uc.158-, uc.206-, uc.274-, uc.472-, and uc.473-). Analogous BE-specific T-UCR profiles were shared by human and murine lesions. This study is the first demonstration of a role for T-UCRs in the transformation of Barrett's mucosa.

Helicobacter pylori and gastric cancer

Infection with Helicobacter pylori is established as the major risk factor for gastric cancer development. Damage of the mucosal barrier due to H. pylori-induced inflammation enhances the carcinogenic effect of other risk factors such as salt intake or tobacco smoking. The genetic disposition of both the bacterial strain and the host can increase the potential towards gastric cancer formation. Genetic variance of the bacterial proteins CagA and VacA is associated with a higher gastric cancer risk, as are polymorphisms and epigenetic changes in host gene coding for interleukins (IL1β, IL8), transcription factors (CDX2, RUNX3) and DNA repair enzymes. Application of high-throughput assays for genome-wide assessment of either genetic structural variance or gene expression patterns may lead to a better understanding of the pathobiological background of these processes, including the underlying signaling pathways. Understanding of the stepwise alterations that take place in the transition from chronic atrophic gastritis, via metaplastic changes, to invasive neoplasia is vital to define the 'point of no return' before which eradication of H. pylori has the potential to prevent gastric cancer. Currently, eradication as preventive strategy is only recommended for high-incidence regions in Asia; large population studies with an adequate follow-up are required to demonstrate the effectiveness of such an approach in Western populations.

Clinical characteristics and time trends in etiology of hepatocellular cancer in Germany

INTRODUCTION

The incidence of hepatocellular cancer (HCC) continues to rise in Europe with a shift of the primary cause towards alcoholic and non-alcoholic fatty liver disease. Metabolic factors like diabetes mellitus and overweight have been identified as significant risk factors for HCC development.

PATIENTS AND METHODS

A retrospective analysis in a large single-center cohort of 650 patients diagnosed with HCC was performed. Demographic characteristics, risk factors, tumor stage at diagnosis and survival were evaluated.

RESULTS

Among 650 patients (aged 17-87 years, with a male: female ratio of 4:1), 80.8% had underlying liver cirrhosis. Alcohol abuse was identified as the only risk factor for liver cirrhosis in 52.2% of patients. Viral infection with hepatitis C and hepatitis B was present in 13.7 and 3.6% of patients, respectively. 66.1% of patients with HCC were overweight with a body mass index exceeding 25, 25.5% even exceeding 30; 52% of patients had diabetes mellitus.

CONCLUSION

Strategies aiming at prevention and surveillance of patients at risk to develop HCC in the future need to widen the focus from patients with chronic viral hepatitis and a history of alcohol abuse to patients with metabolic risk factors.

Helicobacter pylori but not gastrin is associated with the development of colonic neoplasms

Recent studies have suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of colonic neoplasia. Hypergastrinemia can be induced by H. pylori infection, and gastrin can act as putative promoter of colorectal carcinogenesis. Aim of our study was to assess whether H. pylori infection and/or increased serum gastrin levels are associated with the occurrence of colonic neoplasms. For this, we reviewed prospectively collected data of 377 patients with a minimum age of 50 years who underwent colonoscopy. H. pylori and CagA status were determined by serology. Serum gastrin levels were measured in fasting state by commercially available assay. In H. pylori infected patients (n = 138; 36.6%), the overall prevalence of colonic neoplasms was more frequent compared to H. pylori negative patients (n = 239; 63.4%) (OR = 2.73, 95% CI: 1.76-4.24). H. pylori infection occurred more frequently in patients with hyperplastic polyps (OR = 2.66, 95% CI: 1.23-5.74) and adenomas presenting with low grade intraepithelial neoplasia (IEN) (OR = 1.85, 95% CI: 1.14-2.99). Attributable risk for adenomas with high grade IEN and colorectal adenocarcinoma (n = 14) was not assessed due to the low number of cases. The expression of CagA was also associated with an increased risk for colonic neoplasms (OR = 2.25, 95% CI: 1.29-3.94). Hypergastrinemia did not increase the risk for any colonic neoplasms and there was no difference in basal serum gastrin levels between H. pylori positive and negative patients. In conclusion, H. pylori infection, including CagA expression is associated with an increased risk for the development of colonic neoplasm.

Molecular diagnostics in gastric cancer

Despite recent advances in individualised targeted therapy, gastric cancer remains one of the most challenging diseases in gastrointestinal oncology. Modern imaging techniques using endoscopic filter devices and in vivo molecular imaging are designed to enable early detection of the cancer and surveillance of patients at risk. Molecular characterisation of the tumour itself as well as of the surrounding inflammatory environment is more sophisticated in the view of tailored therapies and individual prognostic assessment. The broad application of high throughput techniques for the description of genome wide patterns of structural (copy number aberrations, single nucleotide polymorphisms, methylation pattern) and functional (gene expression profiling, proteomics, miRNA) alterations in the cancer tissue lead not only to a better understanding of the tumour biology but also to a description of gastric cancer subtypes independent from classical stratification systems. Biostatistical means are required for the interpretation of the massive amount of data generated by these approaches. In this review we give an overview on the current knowledge of diagnostic methods for detection, description and understanding of gastric cancer disease.

Energy dependence of the transverse momentum distributions of charged particles in pp collisions measured by ALICE

Differential cross sections of charged particles in inelastic pp collisions as a function of p_T have been measured at [Formula: see text] at the LHC. The p_T spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual [Formula: see text] cannot be described by NLO-pQCD, the relative increase of cross section with [Formula: see text] is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at [Formula: see text] up to p_T=50 GeV/c as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus collisions.