Toll-like receptors 1-9 in small bowel neuroendocrine tumors-Clinical significance and prognosis.

Toll-like receptors (TLRs) are pattern recognition receptors of the innate immunity. TLRs are known to mediate both antitumor effects and tumorigenesis. TLRs are abundant in many cancers, but their expression in small bowel neuroendocrine tumors (SB-NETs) is unknown. We aimed to characterize the expression of TLRs 1-9 in SB-NETs and lymph node metastases and evaluate their prognostic relevance. The present study included 125 patients with SB-NETs, of whom 95 had lymph node metastases, from two Finnish hospitals. Tissue samples were stained immunohistochemically for TLR expression, assessed based on cytoplasmic and nucleic staining intensity and percentage of positively stained cells. Statistical methods for survival analysis included Kaplan-Meier method and Cox regression adjusted for confounding factors. Disease-specific survival (DSS) was the primary outcome. TLRs 1-2 and 4-9 were expressed in SB-NETs and lymph node metastases. TLR3 showed no positive staining. In primary SB-NETs, TLRs 1-9 were not associated with survival. For lymph node metastases, high cytoplasmic TLR7 intensity associated with worse DSS compared to low cytoplasmic intensity (26.4% vs. 84.9%, p = 0.028). Adjusted mortality hazard (HR) was 3.90 (95% CI 1.07-14.3). The expression of TLRs 1-6 and 8-9 in lymph node metastases were not associated with survival. SB-NETs and their lymph node metastases express cytoplasmic TLR 1-2 and 4-9 and nucleic TLR5. High TLR7 expression in SB-NET lymph node metastases was associated with worse prognosis. The current research has future perspective, as it can help create base for clinical drug trials to target specific TLRs with agonists or antagonists to treat neuroendocrine tumors.

Gastric cancer molecular classification based on immunohistochemistry and in-situ hybridisation and mortality.

BACKGROUND AND AIMS: Gastric cancers (GC) are divided into subtypes based on molecular profile: Epstein-Barr virus (EBV)-positive, microsatellite instability (MSI), chromosomal instability (CIN) and genomically stable (GS) tumours. The prognostic impact of this classification is unclear. The aim was to evaluate whether the molecular subtypes determined using in-situ hybridisation (ISH) and immunohistochemistry (IHC) are associated with clinicopathological parameters and prognosis. METHODS AND RESULTS: The study included 503 GC patients. Based on ISH (EBV) and IHC (MSI and TP53), tumours were divided into EBV-positive, MSI, CIN (EBVneg/MSS/TP53aberrant) and GS (EBVneg/MSS/TP53wild-type) subgroups. Survival analyses with intestinal- and diffuse-type tumours were examined separately. EBV-positive tumours associated with male sex. Both EBV-positive and MSI tumours associated with intestinal type. CIN tumours associated with intestinal-type and positive lymph node status. GS tumours associated with diffuse-type and negative lymph node status. In the total cohort, no significant differences in the 5-year survival were observed. In intestinal tumours, the 5-year survival was better in EBV-positive tumours compared with GS tumours [hazard ratio (HR) = 0.57, 95% confidence interval (CI) = 0.33-0.99]. In diffuse tumours, the 5-year survival was worse in CIN tumours compared with GS tumours (HR = 1.57, 95% CI = 1.14-2.18). In radically resected diffuse tumours, the 5-year survival was worse in MSI tumours compared with GS tumours (HR = 3.26, 95% CI = 1.20-8.82). CONCLUSIONS: The molecular classification is associated with histological type but not prognosis in GC. As the prognostic effects of molecular subtypes in intestinal- and diffuse-type cancers may differ, combining histological and molecular information is recommended for future studies.

Comparison of Postoperative Complications After Gastrectomy for Gastric Cancer with Antecolic Versus Retrocolic Reconstruction: A Population-Based Study.

BACKGROUND: The purpose of this study was to examine the rates of 90-day anastomotic complications and other postoperative complications after total or partial gastrectomy with antecolic versus retrocolic reconstruction in a population-based setting. METHODS: This population-based nationwide retrospective cohort study included all patients undergoing total or partial gastrectomy for gastric adenocarcinoma in Finland in 2005-2016, with follow-up until 31 December 2019. Logistic regression provided odds ratios (ORs) with 95% confidence intervals (CIs) of 90-day mortality. Results were adjusted for age, sex, year of the surgery, comorbidities, tumor locations, pathological stage, and neoadjuvant therapy. RESULTS: A total of 2063 patients having gastrectomy with antecolic (n = 814) or retrocolic (n = 1249) reconstruction were identified from the registries. The anastomotic complication rate was 3.8% with antecolic reconstruction and 5.0% with retrocolic reconstruction. Antecolic reconstruction was not associated with a higher risk of anastomotic complications compared with retrocolic reconstruction in the adjusted analysis (OR 0.69, 95% CI 0.44-1.09) of the whole cohort or in the predefined subgroups. The reoperation rate was 8.2% with antecolic reconstruction and 7.7% with retrocolic reconstruction, without statistical significance. In subgroup analysis of total gastrectomy patients, the risk of major complications was lower with antecolic reconstruction compared with retrocolic reconstruction (OR 0.62, 95% CI 0.45-0.86). CONCLUSIONS: The rate of anastomotic complications did not differ after antecolic versus retrocolic reconstruction after total or partial gastrectomy. In total gastrectomies, the risk of major complications was lower after antecolic compared with retrocolic reconstruction.

Postoperative delayed emptying after total, subtotal, or distal gastrectomy for gastric cancer: a population-based study.

BACKGROUND: This study aimed to examine the rate of delayed emptying and other 90-day postoperative complications after total, subtotal, and distal gastrectomies for gastric adenocarcinoma in a population-based setting. METHODS: This study included all patients who underwent total, subtotal, or distal gastrectomy for gastric cancer in Finland in 2005-2016, with follow-up until December 31, 2019. Logistic regression provided the odds ratios with 95% CIs of 90-day mortality. The results were adjusted for age, sex, year of surgery, comorbidities, pathologic stage, and neoadjuvant therapy. RESULTS: A total of 2058 patients underwent total (n = 1227), subtotal (n = 450), or distal (n = 381) gastrectomy. In the total, subtotal, and distal gastrectomy groups, the rates of 90-day delayed emptying were 1.7%, 1.3%, and 2.1% in the whole cohort and 1.6%, 1.8%, and 3.5% in the subgroup analysis of R0 resections, respectively. The resection type was not associated with the risk of delayed emptying. Subtotal gastrectomy was associated with a lower risk of major complications and reoperations, whereas distal gastrectomy was associated with a lower risk of anastomotic complications. CONCLUSION: The extent of resection did not affect delayed emptying, whereas fewer postoperative complications were observed after subtotal or distal gastrectomy than after total gastrectomy.

Stapled vs handsewn anastomosis and anastomotic leaks in gastric cancer surgery-a population-based nationwide study in Finland.

BACKGROUND: There is a lack of evidence regarding anastomotic technique and postoperative complications in gastric cancer surgery. This study aimed to evaluate whether there are differences between stapled and handsewn anastomosis and anastomotic leaks. METHODS: This was a population-based, retrospective, nationwide cohort study in Finland using the Finnish National Esophago-Gastric Cancer Cohort. Patients undergoing gastrectomy with available postoperative complication data were included. Logistic regression analysis was used to calculate the odds ratios with 95% CIs, adjusted for calendar period of surgery, age at surgery, sex, comorbidity, tumor stage, neoadjuvant therapy, minimally invasive surgery, type of gastrectomy, radical resection, and type of anastomosis. RESULTS: Of the 2164 patients, 472 of all patients (21.8%) had handsewn anastomosis and 1692 of all patients (78.2%) had stapled anastomosis. In the unadjusted analysis, anastomotic leaks were significantly lower in the handsewn group (hazard ratio [HR], 0.42; 95% CI, 0.22-0.79) than the stapled group, but after adjustment for known prognostic factors, this association was no longer significant (HR, 0.57; 95% CI, 0.27-1.21). In the analysis stratified by gastrectomy type (distal or total), no differences in anastomotic leaks were observed between anastomotic techniques. CONCLUSION: In this population-based nationwide study, anastomotic technique (stapled or handsewn) was not associated with anastomotic leaks in any, distal or total, gastrectomy.

Risk of Esophageal Adenocarcinoma After Helicobacter pylori Eradication Treatment in a Population-Based Multinational Cohort Study.

BACKGROUND & AIMS: Helicobacter pylori infection is associated with a decreased risk of esophageal adenocarcinoma, and the decreasing prevalence of such infection might contribute to the increasing incidence of this tumor. We examined the hypothesis that eradication treatment of H pylori increases the risk of esophageal adenocarcinoma. METHODS: This population-based multinational cohort, entitled "Nordic Helicobacter Pylori Eradication Project (NordHePEP)," included all adults (≥18 years) receiving H pylori eradication treatment from 1995-2018 in any of the 5 Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) with follow-up throughout 2019. Data came from national registers. We calculated standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) by dividing the cancer incidence in the exposed cohort by that of the entire Nordic background populations of the corresponding age, sex, calendar period, and country. Analyses were stratified by factors associated with esophageal adenocarcinoma (ie, education, comorbidity, gastroesophageal reflux, and certain medications). RESULTS: Among 661,987 participants who contributed 5,495,552 person-years after eradication treatment (median follow-up, 7.8 years; range, 1-24 years), 550 cases of esophageal adenocarcinoma developed. The overall SIR of esophageal adenocarcinoma was not increased (SIR = 0.89; 95% CI, 0.82-0.97). The SIR did not increase over time after eradication treatment, but rather decreased and was 0.73 (95% CI, 0.61-0.86) at 11-24 years after treatment. There were no major differences in the stratified analyses. The overall SIR of esophageal squamous cell carcinoma, calculated for comparison, showed no association (SIR = 0.99; 95% CI, 0.89-1.11). CONCLUSIONS: This absence on an increased risk of esophageal adenocarcinoma after eradication treatment of H pylori suggests eradication is safe from a cancer perspective.

Statin use in relation to long-term survival after gastrectomy for gastric adenocarcinoma: a Swedish population-based cohort study.

BACKGROUND: Studies have suggested that medication with statins improves survival in patients with gastric cancer, but methodological issues have limited the interpretability and prohibited conclusive results. We aimed to provide valid evidence as to whether statin use improves survival of gastric adenocarcinoma. METHODS: This nationwide and population-based cohort study included virtually all patients who underwent curatively intended surgery (gastrectomy) for gastric adenocarcinoma in Sweden between 2006 and 2015 with follow-up throughout 2019 for disease-specific mortality and 2020 for all-cause mortality. Data came from medical records and national healthcare registries. The exposure was statin use during the year prior to gastrectomy which was compared to no such use during the same period. The outcomes were 5-year disease-specific mortality (main) and 5-year all-cause mortality (secondary). Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, sex, education, calendar year, comorbidity, low-dose aspirin use, tumour sublocation, pathological tumour stage, neoadjuvant chemotherapy, annual surgeon volume, and surgical radicality. RESULTS: Among 1515 participating patients, the mean age was 69 years and 58.4% were men. Statin use, identified in 399 (26.3%) patients, was not associated with any statistically significantly decreased 5-year disease-specific mortality (HR 0.99, 95% CI 0.82-1.21) or 5-year all-cause mortality (HR 0.94, 95% CI 0.79-1.12). No risk reductions were found across subgroups of age, sex, aspirin user status, or tumour stage, or in patients with long-term preoperative of postoperative use of statins, all with point estimates close to 1. CONCLUSIONS: Perioperative use of statins does not seem to improve the 5-year survival in patients who undergo gastrectomy with curative intent for gastric adenocarcinoma in Sweden.

Optimal lymph node yield in oesophagectomy for oesophageal cancer: a nationwide population-based study.

OBJECTIVES: The desirable lymph node count was determined to maximize the survival time expectancy according to the lymph node count among patients who have undergone oesophagectomy for oesophageal cancer. METHODS: The data of national Finnish population-based cohort including all patients who have undergone oesophagectomy due to oesophageal cancer during 2002-2016 were used. Restricted mean survival time (RMST) estimates were determined by lymph node count, and the desirable count was determined using locally estimated scatterplot smoothing regression. RESULTS: A total of 883 patients with the median follow-up time of 3.73 (interquartile range 1.43-7.50) years were included. The lymph node count of 27 (95% confidence interval 25-28) was associated with the highest RMST estimates. Sensitivity analyses indicated that in pN0 patients, the highest RMST estimates was observed at 26 (95% confidence interval 24-28) lymph nodes and in pN+ patients, the RMST estimates peaked at 28 (95% confidence interval 25-33) lymph nodes. CONCLUSIONS: According to the findings of this study, at least 24 examined lymph nodes is the recommended target for the lymph node count after oesophagectomy for oesophageal cancer. The beneficial effect of this count on survival may be achieved regardless of nodal metastases.

Randomized controlled trial of nasogastric tube use after esophagectomy: study protocol for the kinetic trial.

Esophagectomy is a complex and complication laden procedure. Despite centralization, variations in perioparative strategies reflect a paucity of evidence regarding optimal routines. The use of nasogastric (NG) tubes post esophagectomy is typically associated with significant discomfort for the patients. We hypothesize that immediate postoperative removal of the NG tube is non-inferior to current routines. All Nordic Upper Gastrointestinal Cancer centers were invited to participate in this open-label pragmatic randomized controlled trial (RCT). Inclusion criteria include resection for locally advanced esophageal cancer with gastric tube reconstruction. A pretrial survey was undertaken and was the foundation for a consensus process resulting in the Kinetic trial, an RCT allocating patients to either no use of a NG tube (intervention) or 5 days of postoperative NG tube use (control) with anastomotic leakage as primary endpoint. Secondary endpoints include pulmonary complications, overall complications, length of stay, health related quality of life. A sample size of 450 patients is planned (Kinetic trial: https://www.isrctn.com/ISRCTN39935085). Thirteen Nordic centers with a combined catchment area of 17 million inhabitants have entered the trial and ethical approval was granted in Sweden, Norway, Finland, and Denmark. All centers routinely use NG tube and all but one center use total or hybrid minimally invasive-surgical approach. Inclusion began in January 2022 and the first annual safety board assessment has deemed the trial safe and recommended continuation. We have launched the first adequately powered multi-center pragmatic controlled randomized clinical trial regarding NG tube use after esophagectomy with gastric conduit reconstruction.

Antireflux Surgery Versus Antireflux Medication and Risk of Esophageal Adenocarcinoma in Patients With Barrett's Esophagus.

BACKGROUND & AIMS: Antireflux treatment is recommended to reduce esophageal adenocarcinoma in patients with Barrett's esophagus. Antireflux surgery (fundoplication) counteracts gastroesophageal reflux of all types of carcinogenic gastric content and reduces esophageal acid exposure to a greater extent than antireflux medication (eg, proton pump inhibitors). We examined the hypothesis that antireflux surgery prevents esophageal adenocarcinoma to a larger degree than antireflux medication in patients with Barrett's esophagus. METHODS: This multinational and population-based cohort study included all patients with a diagnosis of Barrett's esophagus in any of the national patient registries in Denmark (2012-2020), Finland (1987-1996 and 2010-2020), Norway (2008-2020), or Sweden (2006-2020). Patients who underwent antireflux surgery were compared with nonoperated patients using antireflux medication. The risk of esophageal adenocarcinoma was calculated using multivariable Cox regression, providing hazard ratios (HRs) and 95% CIs adjusted for age, sex, country, calendar year, and comorbidity. RESULTS: The cohort consisted of 33,939 patients with Barrett's esophagus. Of these, 542 (1.6%) had undergone antireflux surgery. During up to 32 years of follow-up, the overall HR was not decreased in patients having undergone antireflux surgery compared with nonoperated patients using antireflux medication, but rather increased (adjusted HR, 1.9; 95% CI, 1.1-3.5). In addition, HRs did not decrease with longer follow-up, but instead increased for each follow-up category, from 1.8 (95% CI, 0.6-5.0) within 1-4 years of follow-up to 4.4 (95% CI, 1.4-13.5) after 10-32 years of follow-up. CONCLUSIONS: Patients with Barrett's esophagus who undergo antireflux surgery do not seem to have a lower risk of esophageal adenocarcinoma than those using antireflux medication.

Postoperative Complications After Neoadjuvant Chemotherapy Versus Upfront Surgery in Gastric Adenocarcinoma: A Population-Based Nationwide Study in Finland.

BACKGROUND: To date, no large population-based studies have compared complications and short-term outcomes between neoadjuvant chemotherapy and upfront surgery in gastric cancer. More nationwide studies with standardized reporting on complications are needed to enable international comparison between studies. This study aimed to compare postoperative complications between neoadjuvant therapy and upfront surgery after gastrectomy for gastric adenocarcinoma in a population-based setting. METHODS: This population-based study based on the Finnish National Esophago-Gastric Cancer Cohort included all patients 18 years of age or older undergoing gastrectomy for gastric adenocarcinoma in Finland during 2005-2016. Logistic regression provided odds ratios (ORs) with 95% confidence intervals (CIs), both crude and adjusted for key confounders. Different types of complications were graded based on the Esophagectomy Complications Consensus Group definitions, and major complications were assessed by the Clavien-Dindo scale. RESULTS: This study analyzed 769 patients. Neoadjuvant chemotherapy did not increase major postoperative complications after gastrectomy for gastric cancer compared with upfront surgery (OR, 1.12; 95% CI 0.81-1.56). Furthermore, it did not increase pneumonia, anastomotic complications, wound complications, or other complications. CONCLUSIONS: Neoadjuvant therapy is not associated with increased postoperative complications, reoperations, or short-term mortality compared with upfront surgery in gastric adenocarcinoma.

Population-based nationwide incidence of complications after gastrectomy for gastric adenocarcinoma in Finland.

BACKGROUND: The incidence of postoperative complications after gastrectomy for gastric cancer is not well known. More population-based studies using established complication classifications are needed for international comparison. The aim of this study was to evaluate the population-based incidence of postoperative complications after gastrectomy for gastric cancer. METHODS: This population-based study based on the Finnish National Esophago-Gastric Cancer Cohort included all patients at least 18 years of age undergoing gastrectomy for gastric adenocarcinoma in Finland during 2005-2016. The occurrence of complications 30 and 90 days after surgery was graded based on the Esophagectomy Complications Consensus Group definitions and the severity of complications was assessed using the Clavien-Dindo scale. RESULTS: This study included a total of 2196 patients. Postoperative complications occurred in 906 (41.3 per cent) of patients during 30 days after surgery and in 946 (43.1 per cent) during 90 days after surgery. Clavien-Dindo grade III or higher complications occurred in 375 (17.1 per cent) of patients. The most common complications 90 days after surgery by Esophagectomy Complications Consensus Group upper-level categories were gastrointestinal (n = 438; 19.9 per cent), including anastomotic leak, infectious (n = 377; 17.2 per cent) and pulmonary (n = 335; 15.3 per cent) complications. Postoperative mortality rate was occurred in 72 (3.3 per cent) patients within 30 days and in 161 (7.3 per cent) patients within 90 days after surgery. The median duration of postoperative hospital stay was 9 days (interquartile range 4-14). CONCLUSIONS: Postoperative complications are common across all types of gastrectomy and the majority occur during the first 30 postoperative days. This study informs the patients and caregivers of the expected outcomes of gastrectomy.

Non-erosive gastro-oesophageal reflux disease and incidence of oesophageal adenocarcinoma in three Nordic countries: population based cohort study.

OBJECTIVE: To assess the incidence rate of oesophageal adenocarcinoma among patients with non-erosive gastro-oesophageal reflux disease compared with the general population. DESIGN: Population based cohort study. SETTING: All patients in hospital and specialised outpatient healthcare in Denmark, Finland, and Sweden from 1 January 1987 to 31 December 2019. PARTICIPANTS: 486 556 adults (>18 years) who underwent endoscopy were eligible for inclusion: 285 811 patients were included in the non-erosive gastro-oesophageal reflux disease cohort and 200 745 patients in the validation cohort with erosive gastro-oesophageal reflux disease. EXPOSURES: Non-erosive gastro-oesophageal reflux disease was defined by an absence of oesophagitis and any other oesophageal diagnosis at endoscopy. Erosive gastro-oesophageal reflux disease was examined for comparison reasons and was defined by the presence of oesophagitis at endoscopy. MAIN OUTCOME MEASURES: The incidence rate of oesophageal adenocarcinoma was assessed for up to 31 years of follow-up. Standardised incidence ratios with 95% confidence intervals were calculated by dividing the observed number of oesophageal adenocarcinomas in each of the gastro-oesophageal reflux disease cohorts by the expected number, derived from the general populations in Denmark, Finland, and Sweden of the corresponding age, sex, and calendar period. RESULTS: Among 285 811 patients with non-erosive gastro-oesophageal reflux disease, 228 developed oesophageal adenocarcinomas during 2 081 051 person-years of follow-up. The incidence rate of oesophageal adenocarcinoma in patients with non-erosive gastro-oesophageal reflux disease was 11.0/100 000 person-years. The incidence was similar to that of the general population (standardised incidence ratio 1.04 (95% confidence interval 0.91 to 1.18)), and did not increase with longer follow-up (1.07 (0.65 to 1.65) for 15-31 years of follow-up). For validity reasons, we also analysed people with erosive oesophagitis at endoscopy (200 745 patients, 1 750 249 person-years, and 542 oesophageal adenocarcinomas, corresponding to an incidence rate of 31.0/100 000 person-years) showing an increased overall standardised incidence ratio of oesophageal adenocarcinoma (2.36 (2.17 to 2.57)), which became more pronounced with longer follow-up. CONCLUSIONS: Patients with non-erosive gastro-oesophageal reflux disease seem to have a similar incidence of oesophageal adenocarcinoma as the general population. This finding suggests that endoscopically confirmed non-erosive gastro-oesophageal reflux disease does not require additional endoscopic monitoring for oesophageal adenocarcinoma.

Toll-like receptors 1, 2, 4, 5, and 6 in gastric cancer.

Toll-like receptors (TLRs) are expressed on both immune cells and tumor cells, triggering both anti-tumor and pro-tumor responses. Therefore, TLRs have potential as prognostic biomarkers and immunotherapeutic targets. The aim of this study was to investigate TLR1, TLR2, TLR4, TLR5, and TLR6 expression and association with clinicopathological variables and survival in gastric cancer. Immunohistochemical study on cancer specimens from 564 resected gastric cancer patients was performed using tissue microarrays. The association between patient survival and TLR expression was calculated with Cox regression adjusted for confounding factors. Patients with high cytoplasmic TLR2 expression had significantly poorer 5-year survival than the low cytoplasmic TLR2 expression group in multivariate analysis (adjusted HR 1.38, 95% CI 1.11-1.71), and this estimate was similar in intestinal type (adjusted HR 1.33, 95% CI 0.98-1.80) and diffuse type (adjusted HR 1.48, 95% CI 1.06-2.05) histology subgroups. Patients with high cytoplasmic TLR6 expression group had significantly better 5-year survival compared with low cytoplasmic TLR6 expression group in multivariate analysis (adjusted HR 0.74, 95% CI 0.60-0.91). In the subgroup analysis of diffuse type of histology, the 5-year survival was better in high cytoplasmic TLR6 expression group in multivariable analysis (HR 0.62, 95% CI 0.46-0.83). In the intestinal type of histology subgroup, no significant differences between the groups were present. TLR1, TLR4, and TLR5 expression were not associated with 5-year survival. In conclusion, cytoplasmic TLR2 and TLR6 expression seem to have independent prognostic impact in gastric cancer, while TLR1, TLR4, and TLR5 do not.

Decreased Risk of Esophageal Adenocarcinoma After Gastric Bypass Surgery in a Cohort Study From 3 Nordic Countries.

OBJECTIVE: The objective of this study was to test the hypothesis that bariatric surgery decreases the risk of esophageal and cardia adenocarcinoma. BACKGROUND: Obesity is strongly associated with esophageal adenocarcinoma and moderately with cardia adenocarcinoma, but whether weight loss prevents these tumors is unknown. METHODS: This population-based cohort study included patients with an obesity diagnosis in Sweden, Finland, or Denmark. Participants were divided into a bariatric surgery group and a nonoperated group. The incidence of esophageal and cardia adenocarcinoma (ECA) was first compared with the corresponding background population by calculating standardized incidence ratios (SIR) with 95% CIs. Second, the bariatric surgery group and the nonoperated group were compared using multivariable Cox regression, providing hazard ratios (HR) with 95% CI, adjusted for sex, age, comorbidity, calendar year, and country. RESULTS: Among 748,932 participants with an obesity diagnosis, 91,731 underwent bariatric surgery, predominantly gastric bypass (n=70,176; 76.5%). The SIRs of ECA decreased over time after gastric bypass, from SIR=2.2 (95% CI, 0.9-4.3) after 2 to 5 years to SIR=0.6 (95% CI, <0.1-3.6) after 10 to 40 years. Gastric bypass patients were also at a decreased risk of ECA compared with nonoperated patients with obesity [adjusted HR=0.6, 95% CI, 0.4-1.0 (0.98)], with decreasing point estimates over time. Gastric bypass was followed by a strongly decreased adjusted risk of esophageal adenocarcinoma (HR=0.3, 95% CI, 0.1-0.8) but not of cardia adenocarcinoma (HR=0.9, 95% CI, 0.5-1.6), when analyzed separately. There were no consistent associations between other bariatric procedures (mainly gastroplasty, gastric banding, sleeve gastrectomy, and biliopancreatic diversion) and ECA. CONCLUSIONS: Gastric bypass surgery may counteract the development of esophageal adenocarcinoma in morbidly obese individuals.

Optimized detection and segmentation of nuclei in gastric cancer images using stain normalization and blurred artifact removal.

Histological analysis with microscopy is the gold standard to diagnose and stage cancer, where slides or whole slide images are analyzed for cell morphological and spatial features by pathologists. The nuclei of cancerous cells are characterized by nonuniform chromatin distribution, irregular shapes, and varying size. As nucleus area and shape alone carry prognostic value, detection and segmentation of nuclei are among the most important steps in disease grading. However, evaluation of nuclei is a laborious, time-consuming, and subjective process with large variation among pathologists. Recent advances in digital pathology have allowed significant applications in nuclei detection, segmentation, and classification, but automated image analysis is greatly affected by staining factors, scanner variability, and imaging artifacts, requiring robust image preprocessing, normalization, and segmentation methods for clinically satisfactory results. In this paper, we aimed to evaluate and compare the digital image analysis techniques used in clinical pathology and research in the setting of gastric cancer. A literature review was conducted to evaluate potential methods of improving nuclei detection. Digitized images of 35 patients from a retrospective cohort of gastric adenocarcinoma at Oulu University Hospital in 1987-2016 were annotated for nuclei (n = 9085) by expert pathologists and 14 images of different cancer types from public TCGA dataset with annotated nuclei (n = 7000) were used as a comparison to evaluate applicability in other cancer types. The detection and segmentation accuracy with the selected color normalization and stain separation techniques were compared between the methods. The extracted information can be supplemented by patient's medical data and fed to the existing statistical clinical tools or subjected to subsequent AI-assisted classification and prediction models. The performance of each method is evaluated by several metrics against the annotations done by expert pathologists. The F1-measure of 0.854 ± 0.068 is achieved with color normalization for the gastric cancer dataset, and 0.907 ± 0.044 with color deconvolution for the public dataset, showing comparable results to the earlier state-of-the-art works. The developed techniques serve as a basis for further research on application and interpretability of AI-assisted tools for gastric cancer diagnosis.

Magnitude and Time-Trends of Post-Endoscopy Esophageal Adenocarcinoma and Post-Endoscopy Esophageal Neoplasia in a Population-Based Cohort Study: The Nordic Barrett's Esophagus Study.

BACKGROUND & AIMS: Post-endoscopy esophageal adenocarcinoma (PEEC) and post-endoscopy esophageal neoplasia (PEEN) undermine early cancer detection in Barrett's esophagus (BE). We aimed to assess the magnitude and conduct time-trend analysis of PEEC and PEEN among patients with newly diagnosed BE. METHODS: This population-based cohort study was conducted in Denmark, Finland, and Sweden between 2006 and 2020 and included 20,588 patients with newly diagnosed BE. PEEC and PEEN were defined as esophageal adenocarcinoma (EAC) or high-grade dysplasia (HGD)/EAC, respectively, diagnosed 30-365 days from BE diagnosis (index endoscopy). HGD/EAC diagnosed from 0-29 days and HGD/EAC diagnosed >365 days from BE diagnosis (incident HGD/EAC) were assessed. Patients were followed up until HGD/EAC, death, or end of study period. Incidence rates (IR) per 100,000 person-years with 95% confidence interval (95% CI) were calculated using Poisson regression. RESULTS: Among 293 patients diagnosed with EAC, 69 (23.5%) were categorized as PEEC, 43 (14.7%) as index EAC, and 181 (61.8%) as incident EAC. The IRs/100,000 person-years for PEEC and incident EAC were 392 (95% CI, 309-496), and 208 (95% CI, 180-241), respectively. Among 279 patients diagnosed with HGD/EAC (Sweden only), 17.2% were categorized as PEEN, 14.6% as index HGD/EAC, and 68.1% as incident HGD/EAC. IRs/100,000 person-years for PEEN, and incident HGD/EAC were 421 (95% CI, 317-558), and 285 (95% CI, 247-328), respectively. Sensitivity analyses that varied time interval for occurrence of PEEC/PEEN demonstrated similar results. A time-trend analysis for IRs demonstrated rising incidence rates of PEEC/PEEN. CONCLUSIONS: Almost a quarter of all EACs are detected within a year after an ostensibly negative upper endoscopy in patients with newly diagnosed BE. Interventions to improve detection may reduce PEEC/PEEN rates.