One Step Nucleic Acid Amplification (OSNA) - a new method for lymph node staging in colorectal carcinomas

<p>Abstract</p> <p>Background</p> <p>Accurate histopathological evaluation of resected lymph nodes (LN) is essential for the reliable staging of colorectal carcinomas (CRC). With conventional sectioning and staining techniques usually only parts of the LN are examined which might lead to incorrect tumor staging. A molecular method called OSNA (One Step Nucleic Acid Amplification) may be suitable to determine the metastatic status of the complete LN and therefore improve staging.</p> <p>Methods</p> <p>OSNA is based on a short homogenisation step and subsequent automated amplification of cytokeratin 19 (CK19) mRNA directly from the sample lysate, with result available in 30-40 minutes. In this study 184 frozen LN from 184 patients with CRC were investigated by both OSNA and histology (Haematoxylin & Eosin staining and CK19 immunohistochemistry), with half of the LN used for each method. Samples with discordant results were further analysed by RT-PCR for CK19 and carcinoembryonic antigen (CEA).</p> <p>Results</p> <p>The concordance rate between histology and OSNA was 95.7%. Three LN were histology+/OSNA- and 5 LN histology-/OSNA+. RT-PCR supported the OSNA result in 3 discordant cases, suggesting that metastases were exclusively located in either the tissue analysed by OSNA or the tissue used for histology. If these samples were excluded the concordance was 97.2%, the sensitivity 94.9%, and the specificity 97.9%. Three patients (3%) staged as UICC I or II by routine histopathology were upstaged as LN positive by OSNA. One of these patients developed distant metastases (DMS) during follow up.</p> <p>Conclusion</p> <p>OSNA is a new and reliable method for molecular staging of lymphatic metastases in CRC and enables the examination of whole LN. It can be applied as a rapid diagnostic tool to estimate tumour involvement in LN during the staging of CRC.</p

Optimal timing for antimicrobial prophylaxis to reduce surgical site infections: a retrospective analysis of 531 patients

Abstract It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30–60 min prior to colorectal surgery does not impact the SSI rate

Different Prevalence of Alarm, Dyspeptic and Reflux Symptoms in Patients with Cardia and Non-cardia Gastric Cancer

Background & Aims: Symptoms of patients with gastric cancer (GC) are often unspecific and differences in symptoms between patients with cardia and non-cardia GC have been poorly investigated. We aimed to characterize symptoms of patients with cardia and non-cardia GC. Methods: Patients with cardia (Siewert type II and III) and non-cardia GC were recruited in the German multicenter cohort of the Gastric Cancer Research (staR) study between 2013 and 2017. Alarm, dyspeptic and reflux symptoms at the time of presentation were documented using a self-administered questionnaire. Results: A completed self-administered questionnaire was available for 568/759 recruited patients (132 cardia GC, 436 non-cardia GC, male 61%, mean age 64 years). Dyspeptic symptoms were more common in patients with non-cardia GC (69.0 vs. 54.5%, p=0.0024). Cardia GC patients reported more frequently alarm symptoms (69.7 vs. 44.7%, p<0.0001), and were more likely to have Union for International Cancer Control (UICC) stage III-IV (54.1vs. 38.9%, p=0.0034). Especially, dysphagia and weight loss were more common in patients with cardia GC (49.2 vs. 6.4 %, p<0.0001 and 37.1 vs. 25.7%, p=0.02, respectively). No differences between the two groups were observed with respect to reflux symptoms. Patients with alarm symptoms were more likely to have UICC stage III-IV at presentation (69.4 vs. 42.9%, p<0.0001). Conclusions: In clinical practice the symptom pattern at presentation may serve as a hint for tumor localization. Despite the fact that they are common in the general population, dyspeptic symptoms offer a chance for earlier GC detection. Thus, in patients with dyspeptic symptoms who fail empiric approaches, endoscopy should not be delayed

Gastric cancer in autoimmune gastritis: A case-control study from the German centers of the staR project on gastric cancer research

Objectives Patients with autoimmune gastritis (AIG) are reported to have an increased risk of developing gastric cancer (GC). In this study, we assess the characteristics and outcomes of GC patients with AIG in a multicenter case-control study. Methods Between April 2013 and May 2017, patients with GC, including cancers of the esophagogastric junction (EGJ) Siewert type II and III, were recruited. Patients with histological characteristics of AIG were identified and matched in a 1:2 fashion for age and gender to GC patients with no AIG. Presenting symptoms were documented using a self-administered questionnaire. Results Histological assessment of gastric mucosa was available for 572/759 GC patients. Overall, 28 (4.9%) of GC patients had AIG (67 +/- 9 years, female-to-male ratio 1.3:1). In patients with AIG, GC was more likely to be localized in the proximal (i.e. EGJ, fundus, corpus) stomach (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.0-7.1). In GC patients with AIG, pernicious anemia was the leading clinical sign (OR 22.0, 95% CI 2.6-187.2), and the most common indication for esophagogastroduodenoscopy (OR 29.0, 95% CI 7.2-116.4). GC patients with AIG were more likely to present without distant metastases (OR 6.2, 95% CI 1.3-28.8) and to be treated with curative intention (OR 3.0, 95% CI 1.0-9.0). The five-year survival rates with 95% CI in GC patients with and with no AIG were 84.7% (83.8-85.6) and 53.5% (50.9-56.1), respectively (OR 0.25, 95% CI 0.08-0.75, p = 0.001). Conclusions Pernicious anemia leads to earlier diagnosis of GC in AIG patients and contributes significantly to a better clinical outcome

Evidence for PTGER4 ,PSCA, and MBOAT7 as risk genes for gastric cancer on the genome and transcriptome level

Genetic associations between variants on chromosome 5p13 and 8q24 and gastric cancer (GC) have been previously reported in the Asian population. We aimed to replicate these findings and to characterize the associations at the genome and transcriptome level. We performed a fine-mapping association study in 1926 GC patients and 2012 controls of European descent using high dense SNP marker sets on both chromosomal regions. Next, we performed expression quantitative trait locus (eQTL) analyses using gastric transcriptome data from 143 individuals focusing on the GC associated variants. On chromosome 5p13 the strongest association was observed at rs6872282 (P = 2.53 x 10(-04)) and on chromosome 8q24 at rs2585176 (P = 1.09 x 10(-09)). On chromosome 5p13 we found cis-eQTL effects with an up-regulation of PTGER4 expression in GC risk allele carrier (P = 9.27 x 10(-11)). On chromosome 8q24 we observed cis-eQTL effects with an upregulation of PSCA expression in GC risk allele carrier (P = 2.17 x 10(-47)). In addition, we found trans-eQTL effects for the same variants on 8q24 with a downregulation of MBOAT7 expression in GC risk allele carrier (P = 3.11 x 10(-09)). In summary, we confirmed and refined the previously reported GC associations at both chromosomal regions. Our data point to shared etiological factors between Asians and Europeans. Furthermore, our data imply an upregulated expression of PTGER4 and PSCA as well as a downregulated expression of MBOAT7 in gastric tissue as risk-conferring GC pathomechanisms

Dissecting the genetic heterogeneity of gastric cancer

Background: Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture. Methods: We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO. Findings: Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level. Interpretation: Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO. Errata: Hess, T., Maj, C., Gehlen, J. et. al. Corrigendum to “Dissecting the genetic heterogeneity of gastric cancer”. eBioMedicine. 2023:94:104709. DOI: 10.1016/j.ebiom.2023.104709</p