Cumulative exposure to impaired fasting glucose and gastrointestinal cancer risk: A nationwide cohort study

BACKGROUND

Impaired fasting glucose (IFG) is associated with the risk of various cancers, but the cumulative effect of IFG on gastrointestinal cancer risk remains unclear. This study evaluated the association between the cumulative exposure to IFG and gastrointestinal cancer risk.

METHODS

The authors extracted data from the Korean National Health Insurance Service and health examination data sets. Among individuals ≥40 years old who were free of diabetes or cancer, 1,430,054 who underwent national health examinations over 4 consecutive years from 2009 to 2012 were selected and followed up until gastrointestinal cancer diagnosis, death, or December 31, 2019. The IFG exposure score (range, 0-4) was based on the number of IFG diagnoses over 4 years.

RESULTS

The median follow-up duration was 6.4 years. Consistent normoglycemia for 4 years was found in 44.3% of the population, whereas 5.0% had persistent IFG and 50.7% had intermittent IFG. Compared to the group with an IFG exposure score of 0, groups with IFG exposure scores of 1, 2, 3, and 4 had a 5%, 8%, 9%, and 12% increased risk of gastrointestinal cancer, respectively (score 1: adjusted hazard ratio [aHR], 1.05; 95% confidence interval [CI], 1.01-1.08; score 2: aHR, 1.08; 95% CI, 1.04-1.12; score 3: aHR, 1.09; 95% CI, 1.05-1.14; score 4: aHR, 1.12; 95% CI, 1.06-1.19). Persistent IFG exposure was also associated with higher risks of individual cancer types (colorectum, stomach, pancreas, biliary tract, and esophagus).

CONCLUSIONS

Cumulative exposure to IFG is associated with an increased risk of developing gastrointestinal cancer, in a dose-dependent manner.

PLAIN LANGUAGE SUMMARY

Hyperglycemia, including both diabetes and prediabetes, has been associated with an increased risk of various cancers. However, the cumulative effect of impaired fasting glucose on the risk of developing gastrointestinal cancer remains unclear. A frequent diagnosis of impaired fasting glucose was dose-dependently associated with a higher risk of developing overall gastrointestinal cancer. Furthermore, risks of individual cancer types increased with persistent impaired fasting glucose. Early detection of hyperglycemia and strict glycemic control can lower the risk of gastrointestinal cancer by reducing hyperglycemic burden. Additionally, for some individuals, lifestyle changes such as managing metabolic syndrome or abstaining from alcohol may also be helpful.

Long-term Outcomes of Patients With Early Gastric Cancer Who Had Lateral Resection Margin-Positive Tumors Based on Pathology Following Endoscopic Submucosal Dissection

PURPOSE

Long-term outcomes of patients with positive lateral margins (pLMs) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study aimed to evaluate the remnant cancer and survival rates of patients with pLMs compared with those who underwent curative resection.

MATERIALS AND METHODS

A retrospective analysis was performed on consecutive patients with pLMs as the only non-curative factor of expanded indication who underwent ESD for EGC with a follow-up duration of 5 years or more. The rates of remnant cancer, recurrence, and survival were analyzed and compared to those of control patients who underwent curative resection by propensity score matching.

RESULTS

Among 3,515 patients treated with ESD between 2005 and 2018, 123 non-curative EGCs were retrospectively analyzed. A total of 108 patients were followed up without endoscopic or surgical resection for 8.2 years. The control group was matched in a 1:1 ratio with patients with EGC who underwent curative resection after ESD. The observation group with pLMs had a higher incidence of remnant cancer (25.9%; 28/108) compared to that in the curative resection group (0/108; P=0.000). The remaining tumors were treated with surgical or endoscopic resection, and no additional recurrences were observed. The overall survival analysis demonstrated no significant difference between the observation and curative resection groups (P=0.577).

CONCLUSIONS

No difference was observed in the overall survival rate between observation and curative resection groups. Therefore, observation may be a possible option for incomplete ESD with pLMs if continuous follow-up is performed.

Risk Assessment of Metachronous Gastric Neoplasm after Endoscopic Resection for Early Gastric Cancer According to Age at Helicobacter pylori Eradication

Background/Aims

Helicobacter pylori eradication can reduce the incidence of metachronous gastric neoplasm (MGN) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study evaluated the risk of developing MGN after ESD for EGC based on age at H. pylori eradication.

Methods

Data of patients who underwent curative ESD for EGC with H. pylori infection between 2005 and 2018 were retrospectively analyzed. The patients were allocated to four groups according to age at H. pylori eradication: group 1 (<50 years), group 2 (50-59 years), group 3 (60-69 years), and group 4 (≥70 years).

Results

All patients were followed up for at least 5 years after ESD. The 5-year cumulative incidence of MGN was 2.1%, 7.0%, 8.7%, and 16.7% in groups 1, 2, 3, and 4, respectively (p<0.001), and groups 3 and 4 showed a significant increase in the risk of MGN (hazard ratio [HR], 4.66; 95% confidence interval [CI], 1.09 to 19.92 and HR, 10.75; 95% CI, 2.45 to 47.12). After adjustments for moderate to severe intestinal metaplasia based on the updated Sydney system, groups 3 and 4 remained significantly associated with MGN (HR, 4.40; 95% CI, 1.03 to 18.84 and HR, 10.14; 95% CI, 2.31 to 44.57).

Conclusions

The incidence of MGN after ESD for EGC increased with age at H. pylori eradication. Age at H. pylori eradication ≥60 years was an independent risk factor for MGN, even after adjusting for the presence of advanced intestinal metaplasia.

Risk of gastric cancer in relation with serum cholesterol profiles: A nationwide population-based cohort study

Obesity is a known risk factor for gastric cancer. However, the relationship between serum lipids and gastric cancer risk has not been fully established. We investigated the relationship between serum cholesterol levels and gastric cancer risk using a nationwide population cohort. Adults who received health care screening in 2009 from the Korean National Health Insurance Service were enrolled. Gastric cancer risk in relation to quartiles of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) were compared according to sex, using adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs). Among 9690,168 subjects enrolled, 92,403 gastric cancer cases were diagnosed. Higher HDL-C levels were associated with lower gastric cancer risk in the total population, men, and women (aHR [for the highest quartile] = 0.98 [0.96-0.99, P < .0001], aHR = 0.98 [0.96-1.004, P = .0004], and aHR = 0.91 [0.88-0.94, P < .0001], respectively). HDL-C showed consistent trends regardless of age or statin use. Higher LDL-C levels were also associated with lower gastric cancer risk in the total population (aHR = 0.92 [0.91-0.94], P < .0001) and men (aHR = 0.94 [0.91-0.96], P < .0001), but not in women (P = .4073). A subgroup analysis of LDL-C showed significant interactions with age and statin use (Pinteraction < .0001 and Pinteraction = .0497, respectively). The risk of gastric cancer was higher in subjects with elevated LDL-C levels in the younger group (age < 55, HR [for the highest quartile] = 1.02 [0.99-1.04] in the total population; HR = 1.03 [1.003-1.06] in men), the risk was lower in subjects with elevated LDL-C in the elderly (age ≥ 55, HR = 0.93 [0.91-0.95] in the total population; HR = 0.94 [0.92-0.96] in men). Elevated TC was associated with lower gastric cancer risk in the total population (aHR = 0.95 [0.94-0.97], P < .0001), but not in each sex separately (P = .3922 in men; P = .1046 in women). Overall, higher HDL-C levels may play a protective role in gastric cancer pathogenesis. The association between LDL-C/TC and gastric cancer seems to vary according to sex, age, and statin use. Especially in young males under age 55, high LDL-C and TC levels were associated with higher risk of gastric cancer.

Optimal treatment duration of bismuth-containing quadruple therapy in Helicobacter pylori infection: A retrospective study

The use of bismuth-containing quadruple therapy (BQT) in Helicobacter pylori eradication has been increasing. Although the recommended treatment length for BQT is 14 days, longer durations may be associated with higher rates of adverse events. The aim of this study was to evaluate the optimal duration of BQT by comparing eradication rates and adverse events among 7, 10, and 14-day regimens. A total of 328 patients treated with BQT at Seoul National University Hospital from January 2010 to May 2022 were retrospectively evaluated. The eradication rates of different treatment groups were compared using intention-to-treat (ITT) and per-protocol (PP) analyses. Baseline characteristics of the enrolled patients and adverse events were also analyzed. A total of 74, 177, and 77 patients were included in the 7-, 10-, and 14-day groups, respectively. Forty-one patients were lost during the follow-up. The eradication rates were 71.6%, 84.2%, and 80.5% (P = .106) by ITT, and 84.1%, 94.9%, and 92.5% (P = .028) by PP analysis in the 7-, 10-, and 14-day groups, respectively. The 10-day regimen showed significantly higher eradication rates than the 7-day regimen in both ITT (P = .024) and PP (P = .018) analyses. However, there were no significant differences in eradication rates between the 10- and 14-day groups in either ITT (P = .667) or PP (P = .537) analysis. Adverse event incidence was comparable among the groups (P = .835). Treatment with BQT for 10 days was as effective as 14 days without increasing the adverse events.

Decision to perform additional surgery after non-curative endoscopic submucosal dissection for gastric cancer based on the risk of lymph node metastasis: a long-term follow-up study

BACKGROUND

Radical surgery after non-curative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) may be excessive, since only 5-10% of patients have lymph node metastasis (LNM). This study investigated the suitability of the eCura system for determining the need for radical surgery after non-curative ESD.

METHODS

We retrospectively investigated 343 patients who underwent non-curative ESD for EGC from 2006 to 2021 at a tertiary hospital in Korea. These patients were divided into surgery (n = 191) and observation (n = 152) groups based on whether they underwent additional surgery post-ESD. Each group was further classified into low-risk (eCura score 0-1), intermediate-risk (eCura score 2-4) and high-risk (eCura score 5-7). All patients were regularly followed-up at least annually after the initial treatment. The cumulative overall and recurrence-free survival rates were calculated for each category and compared between the surgery and observation groups.

RESULTS

No significant differences in overall survival were found between the surgery and observation groups in low-risk (p = 0.168) and intermediate-risk patients (p = 0.306); however, high-risk patients had better 5-year overall survival rate in the surgery group than in the follow-up group (95.2% vs. 71.4%, p < 0.001). The 5-year recurrence-free survival rate was higher in the surgery group than in the observation group for low-risk (100% vs. 84.3%; p = 0.034), intermediate-risk (96.1% vs. 88.4%; p = 0.081) and high-risk patients (100% vs. 83.3%; p = 0.023).

CONCLUSIONS

Follow-up without additional surgery after non-curative ESD can be a reasonable option for low-risk and even intermediate-risk patients according to the eCura system. However, surgery is warranted for eCura high-risk patients.

Helicobacter pylori Eradication Can Reverse Rho GTPase Expression in Gastric Carcinogenesis

Background/Aims

Altered DNA methylation is a key mechanism of epigenetic modification in gastric cancer (GC). This study aimed to evaluate the changes in epigenetic and genetic expression of multiple Rho GTPases in Helicobacter pylori-related gastric carcinogenesis by comparing H. pylori-positive GCs and negative controls.

Methods

The messenger RNA expression and methylation of Rho GTPases (RhoA, Rac1, DOCK180, ELMO1, and CDC42) were evaluated in H. pylori-negative (control) human gastric tissues and H. pylori-positive GCs by using real-time reverse transcription-polymerase chain reaction and the quantitative MethyLight assay, respectively. Changes in expression and methylation levels of the genes were also compared between H. pylori-eradicated and -persistent GCs at 1-year follow-up.

Results

In GCs, the methylation and expression levels of DOCK180 and ELMO1 were higher than in controls, while RhoA and Rac1 had lower levels than controls. CDC42 had the same expression pattern as DOCK180 and ELMO1 without DNA methylation. Although methylation levels of DOCK180 and ELMO1 had no difference between H. pylori-eradicated and -persistent GCs at the index endoscopic resection, those of H. pylori-persistent GCs increased and H. pylori-eradicated GCs decreased for 1 year. The expression levels of DOCK180, ELMO1, and CDC42 in H. pylori-persistent GCs were higher than those in H. pylori-eradicated GCs over 1 year, unlike those of RhoA and Rac1. The methylation levels at index and the degrees of change over time of RhoA and Rac1 had no difference between H. pylori-persistent and -eradicated GCs.

Conclusions

Epigenetic alterations of DOCK180 and ELMO1 are involved in H. pylori-related gastric carcinogenesis. This epigenetic field could be improved by H. pylori eradication.

Lower risk of depression after smoking cessation and alcohol abstinence in patients with gastric cancer who underwent gastrectomy: A population-based, nationwide cohort study

BACKGROUND

Although depression is associated with poor treatment outcomes in patients with cancer, little is known about whether lifestyle modifications could help prevent depression. The authors aimed to identify the effect of lifestyle modifications, including smoking cessation, alcohol abstinence, and starting regular physical activity, on new-onset depression in patients with gastric cancer who underwent surgery.

METHODS

By using the Korean National Health Insurance Service database, patients with gastric cancer who underwent surgery between 2010 and 2017 were identified. Self-reported lifestyle behaviors within 2 years before and after surgery were analyzed using the health examination database. Patients were classified according to changes in lifestyle behaviors, and their risk of new-onset depression was compared.

RESULTS

Among 18,902 patients, 2302 (12.19%) developed depression (26.00 per 1000 person-years). Smoking cessation (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.66-0.91) and alcohol abstinence (HR, 0.79; 95% CI, 0.69-0.90) were associated with reduced risk of depression development compared with persistent smoking and persistent drinking, respectively. Starting regular physical activity was not associated with risk of depression. When lifestyle behaviors after gastrectomy were scored from 0 to 3 points (1 point each for not smoking, not drinking, and being physically active), the risk of depression tended to decrease as lifestyle scores increased from 0 points (reference) to 1 point (HR, 0.69; 95% CI, 0.55-0.83), 2 points (HR, 0.60; 95% CI, 0.50-0.76), and 3 points (HR, 0.55; 95% CI, 0.45-0.68).

CONCLUSIONS

Smoking cessation and alcohol abstinence are associated with reduced risk of developing depression in patients with gastric cancer who undergo surgery.

A prospective randomized noninferiority trial comparing conventional smears and SurePathTM liquid-based cytology in endoscopic ultrasound-guided sampling of esophageal, gastric, and duodenal lesions

BACKGROUND

Several liquid-based cytology (LBC) methods are currently used, but the diagnostic accuracy of each method is not well known. We aimed to compare the diagnostic performance of SurePathTM LBC and conventional smear (CS) cytology in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of esophageal, gastric, and duodenal lesions.

METHODS

As a prospective randomized noninferiority study, patients who needed EUS-FNA due to subepithelial mass in the upper gastrointestinal tract were randomly assigned 1:1 to the LBC and CS groups. Cytologic preparation was carried out using a crossover design where 1 method was used for the first needle-pass sample and another method was used for the second needle-pass sample. The primary outcome was to compare the diagnostic performance between LBC and CS using the final diagnosis as the gold standard.

RESULTS

A total of 87 patients were randomized and 60 patients were analyzed. There were no differences between LBC and CS in diagnostic accuracy (91.7% vs 86.7%, P = .380), sensitivity (97.7% vs 90.7%, P = .169), specificity (76.5% vs 76.5%, P > .99), negative predictive value (92.9% vs 76.5%, P = .225), or positive predictive value (91.3% vs 90.7%, P = .921). The background of LBC was less bloody than that of CSs (5.0% vs 53.3%, P < .001) and the sample preparation time of LBC was shorter than that of CSs (29 ± 7 seconds vs 90 ± 17 seconds, P < .001).

CONCLUSION

In the EUS-FNA of a subepithelial mass in the upper gastrointestinal tract, the diagnostic performance of LBC was not inferior to that of CS. The field of view was better in LBC, because the background was less bloody and necrotic. As LBC is more convenient to perform and takes shorter time, it is expected that it can replace the CS method for EUS-FNA samples.

Gastric mucosal swab as an alternative to biopsy for Helicobacter pylori detection

BACKGROUND AND AIMS

Gastric mucosal swab may be a more sensitive sampling method than a biopsy since Helicobacter pylori (H. pylori) resides within the mucus layer. We compared the diagnostic performance of the rapid urease test (RUT) and bacterial load of H. pylori between swabs and tissue biopsy.

METHODS

Overall, 276 RUTs (138 swab-RUTs (S-RUT) and 138 tissue-RUTs (T-RUT)) were performed. To diagnose H. pylori infection, RUT, H. pylori PCR, and 16S ribosomal RNA gene sequencing of tissue and swab were used, and its infection was defined as at least two positives of the six test results. The diagnostic performances of RUTs and the H. pylori bacterial load using qPCR were compared between swab and biopsy.

RESULTS

The positivity rates of S-RUT and T-RUT were 35.5% (49/138) and 25.4% (35/138), respectively. The sensitivity, specificity, and accuracy of S-RUT were 98.0%, 100.0%, and 99.2%, while those of T-RUT were 70.0%, 100%, and 89.1%, respectively. The sensitivity and accuracy were significantly higher for S-RUT than for T-RUT (p < 0.05). In the patients with atrophic gastritis and intestinal metaplasia, S-RUT showed significantly higher sensitivity than T-RUT. qPCR showed that the swab contained a significantly higher H. pylori bacterial load than tissue biopsy (22.92-fold and 31.61-fold in the antrum and body (p < 0.05), respectively).

CONCLUSIONS

Gastric mucosal swabs showed higher RUT accuracy and H. pylori bacterial load than a tissue biopsy. This may be an alternative to a biopsy when diagnosing H. pylori infection during endoscopy is necessary. (ClinicalTrials.gov, NCT05349578).

Histamine-2 Receptor Antagonists and Proton Pump Inhibitors Are Associated With Reduced Risk of SARS-CoV-2 Infection Without Comorbidities Including Diabetes, Hypertension, and Dyslipidemia: A Propensity Score-Matched Nationwide Cohort Study

BACKGROUND

This study aimed to identify the effect of histamine-2 receptor antagonist (H2RA) and proton pump inhibitor (PPI) use on the positivity rate and clinical outcomes of coronavirus disease 2019 (COVID-19).

METHODS

We performed a nationwide cohort study with propensity score matching using medical claims data and general health examination results from the Korean National Health Insurance Service. Individuals aged ≥ 20 years who were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between 1 January and 4 June 2020 were included. Patients who were prescribed H2RA or PPI within 1 year of the test date were defined as H2RA and PPI users, respectively. The primary outcome was SARS-CoV-2 test positivity, and the secondary outcome was the instance of severe clinical outcomes of COVID-19, including death, intensive care unit admission, and mechanical ventilation administration.

RESULTS

Among 59,094 patients tested for SARS-CoV-2, 21,711 were H2RA users, 12,426 were PPI users, and 24,957 were non-users. After propensity score matching, risk of SARS-CoV-2 infection was significantly lower in H2RA users (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.74-0.98) and PPI users (OR, 0.62; 95% CI, 0.52-0.74) compared to non-users. In patients with comorbidities including diabetes, dyslipidemia, and hypertension, the effect of H2RA and PPI against SARS-CoV-2 infection was not significant, whereas the protective effect was maintained in patients without such comorbidities. Risk of severe clinical outcomes in COVID-19 patients showed no difference between users and non-users after propensity score matching either in H2RA users (OR, 0.89; 95% CI, 0.52-1.54) or PPI users (OR, 1.22; 95% CI, 0.60-2.51).

CONCLUSION

H2RA and PPI use is associated with a decreased risk for SARS-CoV-2 infection but does not affect clinical outcome. Comorbidities including diabetes, hypertension, and dyslipidemia seem to offset the protective effect of H2RA and PPI.

Lower risk of depression after smoking cessation and alcohol abstinence in patients with gastric cancer who underwent gastrectomy: A population-based nationwide cohort study

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Background: Although depression is associated with poor treatment outcomes and lower quality of life in cancer patients, little is known about whether lifestyle modifications could help prevent depression in these patients. This study aimed to identify the effect of lifestyle modifications such as smoking cessation, alcohol abstinence, and starting exercise on depression development in gastric cancer patients who underwent gastrectomy. Methods: Using the Korean National Health Insurance Service database, we identified gastric cancer patients who underwent gastrectomy between 2010 and 2017. Self-reported lifestyle behaviors within two years before and after gastrectomy were analyzed using health examination database. We classified the patients according to changes in lifestyle behaviors and compared their risk of developing depression. Results: Among 18,902 patients who underwent gastrectomy, 2,302 (12.19%) developed depression (26.00 per 1000 person-years). Smoking cessation (Hazard ratio (HR) = 0.77, 95% confidence interval (CI): 0.66-0.91) and alcohol abstinence (HR = 0.79, 95% CI: 0.69-0.90) were associated with reduced risk of depression development compared to persistent smoking and persistent drinking, respectively. Starting exercise was not associated with risk of depression. When lifestyle behaviors after gastrectomy were scored from 0 to 3 points (one point each for not smoking, not drinking, and being physically active), the risk of depression showed a decreasing tendency as lifestyle scores increased from 0 (reference) to 1 (HR = 0.69, 95% CI: 0.55-0.83), 2 (HR = 0.60, 95% CI: 0.50-0.76), and 3 (HR = 0.55, 95% CI: 0.45-0.68) points. Conclusions: Smoking cessation and alcohol abstinence can reduce the risk of depression in gastric cancer patients who undergo gastrectomy. [Table: see text]

Patient-Derived Organoids from Locally Advanced Gastric Adenocarcinomas Can Predict Resistance to Neoadjuvant Chemotherapy

BACKGROUND

Patients (pts) with locally advanced gastric adenocarcinoma (LAGA) often receive neoadjuvant chemotherapy. A minority of patients do not respond to chemotherapy and thus may benefit from upfront surgery. Patient-derived organoids (PDOs) are an in vitro model that may mimic the chemotherapy response of the original tumors.

METHODS

PDOs were generated from endoscopic biopsies of LAGAs prior to the initiation of chemotherapy and treated with the two chemotherapy regimens: FLOT and FOLFOX. Cell proliferation was assayed after 3-6 days. Following chemotherapy, pts underwent surgical resection, and percent pathological necrosis was determined.

RESULTS

Successful PDOs were obtained from 13 of 24 (54%) LAGAs. Failure to generate PDOs were due to contamination (n = 3, 13%), early senescence (n = 3, 13%), and late senescence (n = 5, 21%). By H&E staining, there were significant similarities in tumor morphology and high concordance in immunohistochemical expression of 6 markers between tumors and derived PDOs. Four of 13 pts with successful PDOs did not undergo chemotherapy and surgery. For the remaining 9 pts, percent necrosis in resected tumors was ≤ 50% in 2 pts. The corresponding PDOs from these 2 pts were clearly chemoresistant outliers. The Pearson correlation coefficient between chemosensitivity of PDOs to FOLFOX (n = 2) or FLOT (n = 7) and percent tumor necrosis in resected tumors was 0.87 (p = 0.003).

CONCLUSIONS

PDOs from pts with LAGAs in many respects mimic the original tumors from which they are derived and may be used to predict resistance to neoadjuvant chemotherapy.

SYNOPSIS

Patient-derived organoids (PDOs) can serve as personalized in vitro models of patient tumors. In this study, PDOs from locally advanced gastric cancers were able to reliably predict resistance to neoadjuvant chemotherapy.

Endoscopic submucosal dissection for papillary early gastric carcinoma: Insights from a large-scale analysis of post-gastrectomy pathology specimens

Gastric papillary adenocarcinoma is considered a differentiated adenocarcinoma in the current endoscopic submucosal dissection indication guidelines. However, the safety of endoscopic submucosal dissection remains controversial. Currently, data regarding which papillary early gastric cancer should be considered for endoscopic submucosal dissection are unavailable. Thus, the aim of this study was to investigate lymph node metastasis and the safety of endoscopic submucosal dissection in patients with papillary early gastric cancer. This observational study recruited 4264 consecutive patients with early gastric cancer who underwent curative gastrectomy between October 2000 and December 2017 at the National Cancer Center, Korea. Of these, 45 had pathologically confirmed papillary early gastric cancer, 2106 had differentiated non-papillary early gastric cancer, and 2113 had undifferentiated early gastric cancer. Logistic regression analysis was performed to identify risk factors for lymph node metastasis. Mucosal tumors were less common in papillary early gastric cancer (37.9%) than in differentiated non-papillary early gastric cancer (48.8%) and undifferentiated early gastric cancer (60.4%) (both P < .001). Lymph node metastasis was more common in papillary early gastric cancer (20.0%) than in differentiated non-papillary early gastric cancer (9.2%) and undifferentiated early gastric cancer (11.7%; both P < .001). In multivariate analysis, non-mixed-type papillary early gastric cancer showed marginally increased odds of lymph node metastasis than differentiated early gastric cancer (odds ratio [OR]: 2.5, 95% confidence interval [CI]: 1.0-6.3). Rates of lymph node metastasis (1/10, 10%) and angiolymphatic invasion (2/10, 20%) for papillary early gastric cancer meeting expanded criteria were higher than those for other histology types meeting endoscopic submucosal dissection absolute or expanded criteria (P = .03 and P < .001, respectively). Endoscopic submucosal dissection should be considered carefully for papillary early gastric cancer, especially if it meets expanded endoscopic submucosal dissection indications since it is associated with high rates of submucosal invasion and lymph node metastasis.

Safety of pylorus-preserving gastrectomy for gastric cancer combined with antral high-risk lesions: a comparison with endoscopic submucosal dissection

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is a surgical treatment option for cT1N0M0 gastric cancer located in the middle third of the stomach. However, data for the long-term post-PPG clinical outcomes related to metachronous gastric neoplasms (mGNs) in the residual stomach are currently lacking. Therefore, we aimed to evaluate the safety of PPG by focusing on mGNs.

METHODS

In this single-center, retrospective study, we reviewed the data for 362 patients who underwent PPG with a 3-cm antral cuff and 139 who underwent endoscopic submucosal dissection (ESD) for middle-third gastric cancer between January 2013 and December 2015. The histopathologic features of the antrum in the ESD group, which could not be determined in the PPG group, were analyzed to investigate the risk factors for mGNs. The estimated and actual incidence of mGNs in the antrum were compared in the PPG group.

RESULTS

The incidence of mGNs was 6.5% (9/139) in the ESD group. The presence of a synchronous adenoma (odds ratio [OR], 8.46; 95% confidence interval [CI], 1.55-46.34), carcinoma (OR, 15.71; 95% CI, 2.67-92.56) and moderate-to-severe intestinal metaplasia (OR, 9.77; 95% CI, 1.14-83.92) were associated with a higher risk of overall mGNs. However, when confined to the antrum, no significant association was observed between these factors and mGNs. In the ESD group, 2 of 9 mGNs (1.4%) were located at the 3-cm antral cuff. In the PPG group, both mGNs (0.6%) were located in the proximal remnant stomach.

CONCLUSION

Pylorus-preserving gastrectomy was a safe therapeutic option with regard to the occurrence of metachronous adenomas or carcinomas in our series. Despite the low mGN incidence in the 3-cm antral cuff after PPG, the presence of synchronous neoplasms or moderate-to-severe intestinal metaplasia was a risk factor for mGNs in the ESD group; thus, further studies on longer antral cuffs with long-term follow-up are needed.

Tumorigenic mechanisms of estrogen and Helicobacter pylori cytotoxin-associated gene A in estrogen receptor α-positive diffuse-type gastric adenocarcinoma

BACKGROUND

Diffuse-type gastric cancer (DGC), for which Helicobacter pylori infection is a causal factor, is associated with poor prognosis among young women, possibly due to female hormones such as estrogen. We aimed to identify the carcinogenesis induced by estrogen and H. pylori in DGC.

METHODS

We screened and selected estrogen receptor alpha (ERα)-positive (MKN45) and ERα-negative (SNU5) DGC cell lines. H. pylori strain 60190 and its isogenic mutant strain lacking cytotoxin-associated gene A (60190ΔCagA) were used to infect MKN45 cells. And the cytotoxin-related gene A (CagA) cDNA which was cloned into pSP65-SR-HA (cagA-pSP65SRa) vector was used to transfect MKN45 cells. Tumor samples were used for DGC organoid culture.

RESULTS

In MKN45 cells, we found that estradiol promotes epithelial-mesenchymal transition (EMT) and stemness phenotypes via HOTAIR expression. These effects were further enhanced by the addition of CagA secreted by H. pylori but were reversed by co-treatment with fulvestrant (ICI 182,780), a selective ER degrader. We also validated the effect of estrogen on DGC organoids. ERα expression was associated with tumor invasion and HOTAIR expression in DGC patients with overt H. pylori infection.

CONCLUSIONS

These findings may explain the rapid DGC progression in young women with physiologically high levels of estrogen and suggest that fulvestrant with ovarian function suppression could serve as a tumor-suppressive agent in premenopausal patients with DGC.

Gastric subepithelial tumor: long-term natural history and risk factors for progression

BACKGROUND

Subepithelial tumors are often detected incidentally during upper gastrointestinal endoscopy. However, their natural history and clinical management have yet to be clearly established. The aim of this study was to evaluate the natural history and risk factors for progression of gastric SETs.

METHODS

The study retrospectively reviewed the medical records of patients who were diagnosed with gastric SET using upper gastrointestinal endoscopy between January 2005 and December 2017. Tumor progression was defined by a ≥ 25% increase in diameter.

RESULTS

Among 3237 patients, 1859 underwent serial upper gastrointestinal endoscopy for more than six months. Endoscopic ultrasonography was further performed in 733 (39.43%) patients. Resection was performed in 73 (3.93%) patients. Tumor progressed in 138 (7.42%) patients over a mean follow-up period of 59.41 months (range, 5-215 months). In progressed tumors, the mean initial size was 15.01 mm (range, 2-50 mm) and the mean size increment was 12.86 mm (range, 3-50 mm). Large initial tumor size (OR: 1.03, 95% CI: 1.01-1.05), surface ulcer or erosion (OR: 2.47, 95% CI: 1.21-5.06), lobulated shape (OR: 3.76, 95% CI: 2.00-7.06), and middle-third location (OR: 1.65, 95% CI: 1.08-2.52) were significant risk factors for tumor progression. Large SETs had higher rates of progression and tended to grow faster than smaller tumors (r = 0.44, p < 0.001).

CONCLUSIONS

The majority of gastric SETs did not increase in size during the long-term follow-up. Serial endoscopy may be sufficient as a follow-up tool for small SETs with intact overlying mucosa without lobulated shape.

Deep learning model for diagnosing gastric mucosal lesions using endoscopic images: development, validation, and method comparison

BACKGROUND AND AIMS

Endoscopic differential diagnoses of gastric mucosal lesions (benign gastric ulcer, early gastric cancer [EGC], and advanced gastric cancer) remain challenging. We aimed to develop and validate convolutional neural network-based artificial intelligence (AI) models: lesion detection, differential diagnosis (AI-DDx), and invasion depth (AI-ID; pT1a vs pT1b among EGC) models.

METHODS

This study included 1366 consecutive patients with gastric mucosal lesions from 2 referral centers in Korea. One representative endoscopic image from each patient was used. Histologic diagnoses were set as the criterion standard. Performance of the AI-DDx (training/internal/external validation set, 1009/112/245) and AI-ID (training/internal/external validation set, 620/68/155) was compared with visual diagnoses by independent endoscopists (stratified by novice [<1 year of experience], intermediate [2-3 years of experience], and expert [>5 years of experience]) and EUS results, respectively.

RESULTS

The AI-DDx showed good diagnostic performance for both internal (area under the receiver operating characteristic curve [AUROC] = .86) and external validation (AUROC = .86). The performance of the AI-DDx was better than that of novice (AUROC = .82, P = .01) and intermediate endoscopists (AUROC = .84, P = .02) but was comparable with experts (AUROC = .89, P = .12) in the external validation set. The AI-ID showed a fair performance in both internal (AUROC = .78) and external validation sets (AUROC = .73), which were significantly better than EUS results performed by experts (internal validation, AUROC = .62; external validation, AUROC = .56; both P < .001).

CONCLUSIONS

The AI-DDx was comparable with experts and outperformed novice and intermediate endoscopists for the differential diagnosis of gastric mucosal lesions. The AI-ID performed better than EUS for evaluation of invasion depth.

Extragastric Metastasis of Early Gastric Cancer After Endoscopic Submucosal Dissection With Lymphovascular Invasion and Negative Resected Margins

Purpose

Lymphovascular invasion is a criterion for non-curative resection in patients who have undergone endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to determine the rate of extragastric metastasis (EGM) and identify the predictors of EGM in patients with negative resection margins (R0 resection) and lymphovascular invasion in post-ESD pathology.

Materials and Methods

A total of 2,983 patients underwent ESD for EGC. Among them, 110 had a pathology of R0 resection and positive lymphovascular invasion. Patients underwent additional gastrectomy (n=63) or further follow-up without gastrectomy (n=47).

Results

The 110 patients were assigned to one of the 3 groups according to ESD indications based on post-ESD pathology. The first group satisfied the absolute indication for ESD (n=18), the second group satisfied the expanded indications for ESD (n=34), and the last group satisfied the beyond indication (n=58). The number of occurrences of EGM in each group was 1 (5.6%), 3 (8.8%), and 3 (5.2%), respectively. The logistic regression analysis adjusted for age, sex, tumor size, and indication for ESD, showed that larger tumor size was associated with EGM (odds ratio, 1.76; 95% confidence interval, 1.00–3.10; P=0.048). In contrast, ESD indication criteria did not affect EGM (P=0.349).

Conclusions

Tumor size was the only predictive indicator for EGM in patients who underwent R0 resection and lymphovascular invasion on post-ESD pathology. Even patients with pathology corresponding to the absolute indication criteria of ESD had lymphovascular invasion, which means that they require additional gastrectomy due to the risk of EGM.

Clinical Outcomes of Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients with Comorbidities

Purpose

As the rate of endoscopic resection for early gastric cancer (EGC) has increased in patients with comorbid diseases, it is necessary to elucidate the efficacy of endoscopic submucosal dissection (ESD) for EGC in patients with comorbidities. This study aimed to analyze the clinical outcomes of ESD for EGC in patients with comorbidities.

Materials and Methods

A total of 969 patients with 1,015 lesions who underwent ESD for EGC at Seoul National University Hospital between 2010 and 2014 were analyzed. The short- and long-term clinical outcomes were evaluated according to the comorbidity status.

Results

Comorbidities were observed in 558 patients (57.6%). The comorbidity group had a higher proportion of patients using antithrombotic agents (29.5% vs. 0.9%; P<0.0001). Although procedure-related complications (bleeding and perforation) were not significantly different between the two groups, the length of hospital stay was significantly longer (1.8 vs. 1.4 days, P=0.023), while survival was significantly shorter in the comorbidity group (5-year overall survival rate: 90.5% vs. 97.2%, P<0.0001; 5-year disease-specific survival rate: 97.9% vs. 100%, P=0.018; 5-year disease-free survival rate: 83.4% vs. 89.2%, P=0.007).

Conclusions

Gastric ESD can be performed in patients with comorbidities without increasing the risk of complications.

WITHDRAWN: FOXC1 modulates stem-like cell properties and chemoresistance through hedgehog and EMT signaling in gastric adenocarcinoma

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Proton Pump Inhibitors and Gastric Cancer

Concerns have been raised regarding the long-term use of proton pump inhibitors (PPIs) as an important risk factor for gastric cancer in clinical practice. PPIs can cause hypergastrinemia at clinical doses, and hypergastrinemia has been reported to induce malignant neoplasms in the stomach in previous animal studies. In humans, the proliferation of enterochromaffin-like (ECL) cells induced by hypergastrinemia is suspected as a potential mechanism of gastric cancer. Meanwhile, persistent Helicobacter pylori (H. pylori) infection causes gastric atrophic change, which itself is a major cause of gastric cancer, and it can further increase the risk of gastric cancer by strengthening corpus atrophy through interaction with PPIs. Recent epidemiologic studies have reported an important link between long-term PPI intake and gastric cancer risk even after successful eradication of H. pylori. However, due to the methodological limitations of observational clinical studies, the causal relationship is still not clear, and a recent big data-based study reported that long-term PPI use was not related to gastric cancer incidence. Taken together, despite the potential detrimental effects of PPIs, it is currently difficult to draw a definite conclusion about its association with gastric cancer. To minimize the possibility of gastric cancer in H. pylori-infected patients or precancerous lesions in long-term PPI users, long-term PPI administration should be limited to the minimum effective dose, and antibacterial treatment for H. pylori should be considered.

Endoscopic Screening and Surveillance for Gastric Cancer

Gastric cancer is one of the most common cancers worldwide. Gastric cancer is a multifactorial disease, and the incidence varies widely by geographic region, with half of new cases occurring in East Asia. Population-based nationwide screening for gastric cancer has been implemented in some Eastern Asian countries such as South Korea and Japan. In these countries, endoscopic screening decreased gastric cancer mortality. Endoscopic screening seems to be a cost-effective modality in countries with high incidence of gastric cancer. However, the usefulness of population-based screening has not yet been proved in countries with low incidence of gastric cancer.

Impact of the Interval between Previous Endoscopic Exam and Diagnosis on the Mortality and Treatment Modality of Undifferentiated-Type Gastric Cancer

Purpose

The impact of the interval between previous endoscopy and diagnosis on the treatment modality or mortality of undifferentiated (UD)-type gastric cancer is unclear. This study aimed to investigate the effect of endoscopic screening interval on the stage, cancer-related mortality, and treatment methods of UD-type gastric cancer.

Materials and Methods

We reviewed the medical records of newly diagnosed patients with UD gastric cancer in 2013, in whom the interval between previous endoscopy and diagnosis could be determined. The patients were classified into different groups according to the period from the previous endoscopy to diagnosis (<12 months, 12–23 months, 24–35 months, ≥36 months, and no history of endoscopy), and the outcomes were compared between the groups. In addition, patients who underwent endoscopic and surgical treatment were reclassified based on the final treatment results.

Results

The number of enrolled patients was 440, with males representing 64.1% of the study population; 11.8% of the participants reported that they had undergone endoscopy for the first time in their cancer diagnosis. The percentage of stage I cancer at diagnosis significantly decreased as the interval from the previous endoscopy to diagnosis increased (65.4%, 63.2%, 64.2%, 45.9%, and 35.2% for intervals of <12 months, 12–23 months, 24–35 months, ≥36 months, and no previous endoscopy, respectively, P<0.01). Cancer-related mortality was significantly lower for a 3-year interval of endoscopy (P<0.001).

Conclusions

A 3-year interval of endoscopic screening reduces gastric-cancer-related mortality, particularly in cases of UD histology.

Identification of gaze pattern and blind spots by upper gastrointestinal endoscopy using an eye-tracking technique

BACKGROUND

The lesion detection rate of esophagogastroduodenoscopy (EGD) varies depending on the degree of experience of the endoscopist and anatomical blind spots. This study aimed to identify gaze patterns and blind spots by analyzing the endoscopist's gaze during real-time EGD.

METHODS

Five endoscopists were enrolled in this study. The endoscopist's eye gaze tracked by an eye tracker was selected from the esophagogastric junction to the second portion of the duodenum without the esophagus during insertion and withdrawal, and then matched with photos. Gaze patterns were visualized as a gaze plot, blind spot detection as a heatmap, observation time (OT), fixation duration (FD), and FD-to-OT ratio.

RESULTS

The mean OT and FD were 11.10 ± 11.14 min and 8.37 ± 9.95 min, respectively, and the FD-to-OT ratio was 72.5%. A total of 34.3% of the time was spent observing the antrum. When observing the body of the stomach, it took longer to observe the high body in the retroflexion view and the low-to-mid body in the forward view.

CONCLUSIONS

It is necessary to minimize gaze distraction and observe the posterior wall in the retroflexion view. Our results suggest that eye-tracking techniques may be useful for future endoscopic training and education.

Use of direct oral anticoagulants does not significantly increase delayed bleeding after endoscopic submucosal dissection for early gastric neoplasms

Direct oral anticoagulants (DOACs) are widely prescribed for the prevention of stroke in elderly patients with atrial fibrillation and approved indication for DOAC has been expanded. We aimed to evaluate the risk of delayed bleeding in patients who had taken DOAC and underwent endoscopic submucosal dissection (ESD) for gastric neoplasms. We included consecutive patients who underwent ESD between January 2016 and July 2019 in Seoul National University Hospital. Patients were divided into four groups (no med; no medication, DOAC, WFR; warfarin, anti-PLT; anti-platelet agent) according to the medications they had been taken before the procedure. We defined delayed bleeding as obvious post-procedural gastrointestinal bleeding sign including hematemesis or melena combined with hemoglobin drop ≥ 2 g/dL. Among 1634 patients enrolled in this study, 23 (1.4%) patients had taken DOAC and they usually stopped the medication for 2 days before the ESD and resumed within 1 or 2 days. We compared rates of delayed bleeding between groups. Delayed bleeding rates of the groups of no med, DOAC, WFR, and anti-PLT were 2.1% (32/1499) 8.7% (2/23), 14.3% (2/14), 11.2% (11/98), respectively (P < 0.001). However, there was no difference of delayed bleeding rate between no med and DOAC group after propensity score matching (no med vs DOAC, 1.7% vs 10.0%, P = 0.160). Taking DOAC was not associated statistically with post-ESD bleeding when adjusted by age, sex, comorbidities and characteristics of target lesion (Adjusted Odds Ratio: 2.4, 95% Confidence intervals: 0.41-13.73, P = 0.335). Crude rate of bleeding in DOAC users seemed to be higher than no medication group after performing ESD with 2 days of medication cessation. When adjusted by age, sex, and comorbidity, however, this difference seems to be small, which suggests that gastric post-ESD bleeding may be influenced by patients' underlying condition in addition to medication use.

Efficacy and Safety of Rebamipide versus Its New Formulation, AD-203, in Patients with Erosive Gastritis: A Randomized, Double- Blind, Active Control, Noninferiority, Multicenter, Phase 3 Study

Background/Aims

The mucoprotective drug rebamipide is used to treat gastritis and peptic ulcers. We compared the efficacy of Mucosta^Ⓡ (rebamipide 100 mg) and its new formulation, AD-203 (rebamipide 150 mg), in treating erosive gastritis.

Methods

This double-blind, active control, noninferiority, multicenter, phase 3 clinical trial randomly assigned 475 patients with endoscopically proven erosive gastritis to two groups AD-203 twice daily or Mucosta^Ⓡ thrice daily for 2 weeks. The intention-to-treat (ITT) analysis included 454 patients (AD-203, n=229; Mucosta^Ⓡ, n=225), and the per-protocol (PP) analysis included 439 patients (AD-203, n=224; Mucosta^Ⓡ, n=215). The posttreatment assessments included the primary (erosion improvement rate) and secondary endpoints (erosion and edema cure rates; improvement rates of redness, hemorrhage, and gastrointestinal symptoms). Drug-related adverse events were evaluated.

Results

According to the ITT analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta^Ⓡ-treated patients were 39.7% and 43.8%, respectively. According to the PP analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta^Ⓡ-treated patients were 39.3% and 43.7%, respectively. The one-sided 97.5% lower limit for the improvement rate difference between the study groups was −4.01% (95% confidence interval [CI], –13.09% to 5.06%) in the ITT analysis and −4.44% (95% CI, –13.65% to 4.78%) in the PP analysis. The groups did not significantly differ in the secondary endpoints in either analysis. Twenty-four AD-203-treated and 20 Mucosta^Ⓡ-treated patients reported adverse events but no serious adverse drug reactions; both groups presented similar adverse event rates.

Conclusions

The new formulation of rebamipide 150 mg (AD-203) twice daily was not inferior to rebamipide 100 mg (Mucosta^Ⓡ) thrice daily. Both formulations showed a similar efficacy in treating erosive gastritis.

Lymphatic metastasis-related TBL1XR1 enhances stemness and metastasis in gastric cancer stem-like cells by activating ERK1/2-SOX2 signaling

The poor prognosis of gastric cancer (GC) results largely from metastasis and chemotherapy resistance. Toward novel therapeutic strategies that target or evade these phenomena, we evaluated the function of the transcriptional regulator transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) in GC cells, including stem-like cells. In this study, the correlation of expression of TBL1XR1 and clinical features and GC patients' outcomes was evaluated. Knockdown or exogenous expression of TBL1XR1 was combined with in vitro (2D and 3D cultures) and in vivo (mouse lung and lymphatic metastasis models) assays to evaluate the function of TBL1XR1. TBL1XR1's downstream signaling was delineated by phospho-kinase array and knockdown of candidate mediators. Analysis of clinical data showed that TBL1XR1 overexpression was correlated with worse prognosis. Functional assays showed that TBL1XR1 promoted stemness, epithelial-mesenchymal transition (EMT), and lung and lymphatic metastasis in GC cells. TBL1XR1 activated ERK1/2-Sox2 signaling and was dependent on signaling via PI3K/AKT, in GC stem-like cells distinguished by CD44 expression. Moreover, inhibition of these signaling proteins reversed chemoresistance in in vitro and in vivo models. Taken together, our results indicate that TBL1XR1 promotes stemness and metastasis in GC, making it a potential prognostic indicator. The PI3K/AKT-TBL1XR1-ERK1/2-Sox2 axis may represent a target for the treatment of GC.

Role of Endoscopic Ultrasound in Selecting Superficial Esophageal Cancers for Endoscopic Resection

BACKGROUND

Endoscopic submucosal dissection (ESD) is a curative treatment option for superficial esophageal cancer with a minimal risk for lymph node metastasis. Before ESD, accurate clinical staging is important to select the appropriate candidate. We aimed to estimate the practicality of endoscopic ultrasound (EUS) to select pTis and pT1a.

METHODS

We included patients with squamous esophageal cancers who underwent surgical resection or ESD between 2005 and 2018. Pathologic reports were reviewed retrospectively, and pathologic T staging was compared with clinical stage evaluated by EUS.

RESULTS

Among 532 patients, 321 had superficial esophageal cancer (pTis: 42; pT1a: 115; and pT1b: 164). Accuracy rates, sensitivity, specificity, positive predicted value, and negative predicted value for selecting cT1a by EUS were 82.3%, 60.5%, 91.5%, 74.8%, and 84.7%, respectively. The rate of overstaged pTis-T1a was 39.5%. Upon multivariable analysis, tumor size (>2 cm), poor differentiation, protruding gross type, and use of conventional EUS (versus miniprobe) were associated factors for overstaging of pTis-T1a.

CONCLUSIONS

The accuracy of prediction of EUS for selecting mucosal esophageal cancer that can be treated with ESD was favorable. Target lesions with a large size (>2 cm), poor differentiation, and protruding morphology were related to T overstaging; precaution should be taken when evaluating the clinical stage for cancers with those conditions. Furthermore, miniprobe EUS provides higher accuracy for squamous esophageal cancers confined to mucosa.

Efficacy and Safety of Ghrelin Agonists in Patients with Diabetic Gastroparesis: A Systematic Review and Meta-Analysis

Background/Aims

Ghrelin agonists are emerging prokinetic agents for treating gastroparesis. Although recent clinical trials have demonstrated their efficacy in patients with diabetic gastroparesis (DG), the impact of such agents on symptoms and gastric dysmotility remains unclear. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of ghrelin agonists in patients with DG.

Methods

A search of common electronic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials) was preformed, using keyword combinations that referenced ghrelin and DG and retrieving all eligible randomized controlled trials (RCTs) of ghrelin agonists versus placebo in patients with DG. The primary outcome measure was the change in patient-reported overall gastroparesis symptom scores. Secondary outcomes included the change in gastric emptying time, specific symptoms related to gastroparesis, and adverse events. A random-effects model was applied to all study outcomes. Heterogeneity among studies was determined by the chi-square test and I² statistics.

Results

We selected six RCTs of patients with DG (n=557) for meta-analysis. Ghrelin agonist administration (vs placebo) significantly improved overall gastroparesis symptoms (standardized mean difference, –0.34; 95% confidence interval, –0.56 to –0.13) and significantly improved symptoms related to gastroparesis, including nausea, vomiting, early satiety, and abdominal pain. Adverse events recorded for ghrelin agonists and placebo did not differ significantly. There was no significant heterogeneity among eligible studies.

Conclusions

Compared with placebo, ghrelin agonists are effective and well-tolerated for the treatment of DG.

CDK5RAP3 as tumour suppressor negatively regulates self-renewal and invasion and is regulated by ERK1/2 signalling in human gastric cancer

BACKGROUND

Toward identifying new strategies to target gastric cancer stem-like cells (CSCs), we evaluated the function of the tumour suppressor CDK5 regulatory subunit-associated protein 3 (CDK5RAP3) in gastric CSC maintenance.

METHODS

We examined the expression of CDK5RAP3 and CD44 in gastric cancer patients. The function and mechanisms of CDK5RAP3 were checked in human and mouse gastric cancer cell lines and in mouse xenograft.

RESULTS

We show that CDK5RAP3 is weakly expressed in gastric CSCs and is negatively correlated with the gastric CSC marker CD44. CDK5RAP3 overexpression decreased expression of CSC markers, spheroid formation, invasion and migration, and reversed chemoresistance in gastric CSCs in vitro and vivo. CDK5RAP3 expression was found to be regulated by extracellular-related kinase (ERK) signalling. ERK inhibitors decreased spheroid formation, migration and invasion, and the expression of epithelial-to-mesenchymal transition (EMT)-related proteins in both GA cells and organoids derived from a genetically engineered mouse model of GA. Finally, CDK5RAP3 expression was associated with reduced lymph-node metastasis and better prognosis, even in the presence of high expression of the EMT transcription factor Snail, among patients with CD44-positive GA.

CONCLUSIONS

Our results demonstrate that CDK5RAP3 is suppressed by ERK signalling and negatively regulates the self-renewal and EMT of gastric CSCs.

Diagnostic Accuracy of MRI-Based Morphometric Parameters for Detecting Olfactory Nerve Dysfunction

BACKGROUND AND PURPOSE

Although olfactory dysfunction is a common cranial nerve disorder, there are no simple objective morphometric criteria to assess olfactory dysfunction. The aim of this study was to evaluate the diagnostic performance of MR imaging morphometric parameters for detecting olfactory dysfunction.

MATERIALS AND METHODS

This prospective study enrolled patients from those presenting with olfactory symptoms who underwent both an olfactory function test and MR imaging. Controls without olfactory dysfunction were recruited during the preoperative work-up for pituitary adenoma. Two independent neuroradiologists measured the olfactory bulb in 3D and assessed olfactory bulb concavity on MR imaging while blinded to the clinical data. Diagnostic performance was assessed using receiver operating characteristic curve analysis.

RESULTS

Sixty-four patients and 34 controls were enrolled. The patients were significantly older than the controls (mean age, 57.8 ± 11.9 years versus 47.1 ± 12.1 years; P < .001). Before age adjustment, the olfactory bulb height was the only olfactory bulb parameter showing a significant difference between patients and controls (1.6 ± 0.3 mm versus 2.0 ± 0.3 mm, P < .001). After age adjustment, all parameters and olfactory bulb concavity showed significant intergroup differences, with the olfactory bulb height having the highest area under the curve (0.85). Olfactory bulb height was confirmed to be the only significant parameter showing a difference in the detection of olfactory dysfunction in 22 pairs after matching for age and sex (area under the curve = 0.87, P < .001). Intraclass correlation coefficients revealed moderate-to-excellent degrees of inter- and intrareader agreement.

CONCLUSIONS

MR imaging morphometric analysis can differentiate patients with olfactory dysfunction, with the olfactory bulb height having the highest diagnostic performance for detecting olfactory dysfunction irrespective of age.

Helicobacter pylori eradication affects platelet count recovery in immune thrombocytopenia

Helicobacter pylori (H. pylori) infection is on the rise as a cause of immune thrombocytopenia (ITP). It has been suggested that platelet recovery can be achieved following successful microbial eradication, although, the exact pathophysiology has yet to be fully elucidated. This study evaluated the long-term effects of H. pylori eradication monotherapy on platelet count recovery in patients with ITP. H. pylori eradication was analysed in 61 ITP patients. Patients who maintained a complete response (CR) for more than six months were classified as sustained responders (SR). The prevalence of H. pylori infection was 54.3% (75/138), and the success rate of eradication with first-line therapy was 71.4% (35/49). Patients who had achieved a CR at 2 months maintained a higher platelet count thereafter. At 1 year following eradication, platelet counts had increased 2.78 times in the eradicated group, 1.36 times in the sustained infection group, and 1.33 times in the no infection group compared with the baseline (P = 0.016).

Multidisciplinary and Multisociety Practice Guideline on Reprocessing Flexible Gastrointestinal Endoscopes and Endoscopic Accessories

The area of endoscopic application has been continuously expanded since its introduction in the last century and the frequency of its use also increased stiffly in the last decades. Because gastrointestinal endoscopy is naturally exposed to diseased internal organs and contact with pathogenic materials, endoscopy mediated infection or disease transmission becomes a major concern in this field. Gastrointestinal endoscopy is not for single use and the proper reprocessing process is a critical factor for safe and reliable endoscopy procedures. What needed in these circumstances is a practical guideline for reprocessing the endoscope and its accessories which is feasible in the real clinical field to guarantee acceptable prevention of pathogen transmission. This guideline contains principles and instructions of the reprocessing procedure according to the step by step. And it newly includes general information and updated knowledge about endoscopy-mediated infection and disinfection. Multiple societies and working groups participated to revise; Korean Association for the Study of the Liver, the Korean Society of Infectious Diseases, Korean College of Helicobacter and Upper Gastrointestinal Research, the Korean Society of Gastroenterology, Korean Society of Gastrointestinal Cancer, Korean Association for the Study of Intestinal Diseases, Korean Pancreatobiliary Association, the Korean Society of Gastrointestinal Endoscopy Nurses and Associates and Korean Society of Gastrointestinal Endoscopy. Through this cooperation, we enhanced communication and established a better concordance. We still need more researches in this field and fill up the unproven area. And our guidelines will be renewed accordingly.

Diagnostic performance of MRI to detect metastatic cervical lymph nodes in patients with thyroid cancer: a systematic review and meta-analysis

AIM

To evaluate the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of metastatic cervical lymph nodes.

MATERIALS AND METHODS

Ovid-MEDLINE and EMBASE databases were searched up until 12 June 2018. Eleven articles were included in the qualitative systematic review and nine of the 11 in the quantitative analysis. Two radiologists independently performed data extraction and methodological quality assessment using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A qualitative systematic review and quantitative analysis were performed, followed by a meta-regression analysis to determine factors causing heterogeneity.

RESULTS

The pooled sensitivity and specificity in the diagnosis of metastatic cervical lymph nodes were 80% (95% confidence interval [CI]: 68-88%) and 85% (95% CI: 63-95%), respectively. The sensitivity and false-positive rate (correlation coefficient, 0.655) showed a positive correlation due to a threshold effect, which was responsible for heterogeneity across the studies, as indicated by a Q-test (p<0.01) and Higgins I² statistic (sensitivity, I²=90.11%; specificity, I²=92.49%). In the meta-regression analysis, fat-suppressed imaging, and the analysis method were significant factors influencing the heterogeneity in diagnostic performance.

CONCLUSIONS

MRI shows moderate diagnostic performance in the diagnosis of metastatic lymph nodes in patients with thyroid cancer in the neck. MRI may be an optional or complementary imaging method to ultrasound or computed tomography (CT) in thyroid cancer patients.

CT and MRI Findings of Glomangiopericytoma in the Head and Neck: Case Series Study and Systematic Review

Glomangiopericytoma is a rare sinonasal mesenchymal tumor of borderline or low malignant potential. We reviewed the CT and MR imaging findings of head and neck glomangiopericytoma via a retrospective case series study and systematic review. Our study revealed that glomangiopericytoma is a well-defined lobulated avidly enhancing soft-tissue mass with erosive bony remodeling that is most commonly found in the sinonasal cavity. Typically, it is hyperintense on T2-weighted images with vascular signal voids, has a high mean ADC value, and a wash-in and washout pattern on dynamic contrast-enhanced MR imaging. Although the CT findings are nonspecific, typical MR imaging findings, including those on the ADC map and dynamic contrast-enhanced MR imaging, may be helpful for differentiating glomangiopericytomas from other hypervascular tumors in the head and neck.

CDX1 Expression Induced by CagA-Expressing Helicobacter pylori Promotes Gastric Tumorigenesis

Intestinal-type gastric cancer often results from Helicobacter pylori infection through intestinal metaplasia, a transdifferentiated premalignant phenotype. Because H. pylori virulence factor CagA has been associated with aberrant expression of the transcription factor CDX1, which regulates intestinal differentiation, we explored its relationship with H. pylori infection and function during gastric carcinogenesis in normal gastric epithelial cells and gastric cancer cell lines. Infection of HFE 145 cells with CagA⁺ H. pylori increased expression of CDX1, as well as the epithelial-to-mesenchymal transition (EMT) markers Snail and Slug, increased invasion and migration, but those effects were not found in HFE 145 cells infected with CagA-deficient H. pylori. CDX1 overexpression increased expression of the intestinal markers Villin, sucrose isomaltase (SI), and MUC2, induced spheroid formation, and enhanced expression of the stem cell markers CD44, SOX2, Oct4, and Nanog, while CDX1 knockdown inhibited proliferation and intestinal stemness. Treatment of CDX1-expressing cells with metformin, an antidiabetic drug known to decrease the risk of gastric cancer, decreased expression of EMT and stemness markers, and reduced spheroid formation. In a murine xenograft model, combining metformin or shCDX1 with cisplatin reduced tumor growth, increased caspase-3 cleavage, and reduced expression of CD44 and MMP-9 to a greater degree than cisplatin alone. Patients with more advanced intestinal metaplasia staging exhibited higher CDX1 expression than those with earlier intestinal metaplasia staging (P = 0.039), and those with H. pylori tended to have more CDX1 expression than noninfected patients (P = 0.061). Finally, human tissue samples with higher CDX1 levels showed prominent CD44/SOX2 expression. Our findings indicate CagA⁺ H. pylori-induced CDX1 expression may enhance gastric cancer tumorigenesis and progression, and support therapeutic targeting of CDX1 in gastric cancer. IMPLICATIONS: This study shows that CDX1 contributes to the tumorigenesis and progression of gastric cancer and suggests the potential of targeting CDX1 to treat this malignancy.

Abstract 4680: KRAS activation in gastric adenocarcinoma stimulates epithelial-to-mesenchymal transition to cancer stem-like cells and promotes metastasis

BACKGROUND:

Our previous work showed that in a mouse model of gastric adenocarcinoma (GA) with loss of p53 and Cdh1 that adding oncogenic Kras (a.k.a triple conditional or Tcon mice) accelerates tumorigenesis and metastasis. The Receptor Tyrosine Kinase (RTK)-RAS signaling pathway is altered in 60% of GAs, and KRAS is amplified or mutated in 17% of GAs. There is some evidence that RTK-RAS signaling and oncogenic KRAS are important in the epithelial-to-mesenchymal transition (EMT) and maintenance of cancer stem-like cells (CSCs). We hypothesized that RTK-RAS activation in GA CSCs increases the metastatic potential of these cells.

METHODS:

The RTK-RAS pathway and KRAS were examined in nontransformed HFE-145 gastric epithelial cells, tumor-derived organoids derived from Tcon mice, human GA cell lines (AGS and KATOIII), AGS xenografts, and a tissue microarray of human GAs from 115 patients undergoing surgical resection. KRAS was inhibited using shRNA, and the RTK-RAS pathway was blocked using a MEK inhibitor PD0325901.

RESULTS:

Kras activity was much higher in GA cell lines grown as spheroids compared to GA cell lines grown monolayers. Metastasis following KRAS activation in GA cells results from stimulation of epithelial-to-mesenchymal transition (EMT) to cancer stem-like cells (CSCs). In organoids derived from our mouse model, Kras knockdown decreased spheroid formation, expression of EMT-related proteins, migration, and invasion; similar effects, as well as reversal of chemoresistance, were observed following KRAS knockdown in patient tumor-derived GA cell lines. KRAS inhibition in GA spheroid cells led to reduced flank xenograft growth, loss of the infiltrative tumor border, fewer lung metastases, and increased survival. Supporting clinical relevance, high tumor levels of CD44 (a marker of CSCs) and KRAS activation were independent predictors of worse overall survival in 115 GA patients.

CONCLUSION:

In this study, we show that the addition of oncogenic KRAS into gastric epithelial cells leads to EMT and acquisition of CSC phenotypes. Inhibition of KRAS in GA cell lines and in tumor derived organoids reverses EMT and inhibit CSC phenotypes. We conclude that metastasis following KRAS activation in GA cells likely results from stimulation of EMT and transition to CSCs.

Citation Format: Changhwan Yoon, Jacob Till, Soo-Jeong Cho, Kevin Chang, Jian-Xian Lin, Sandra Ryeom, Sam Yoon. KRAS activation in gastric adenocarcinoma stimulates epithelial-to-mesenchymal transition to cancer stem-like cells and promotes metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4680.

KRAS Activation in Gastric Adenocarcinoma Stimulates Epithelial-to-Mesenchymal Transition to Cancer Stem-Like Cells and Promotes Metastasis

Our previous work showed that in a mouse model of gastric adenocarcinoma with loss of p53 and Cdh1 that adding oncogenic Kras (a.k.a. Tcon mice) accelerates tumorigenesis and metastasis. Here, we sought to examine KRAS activation in epithelial-to-mesenchymal transition (EMT) and generation of cancer stem-like cells (CSC). Transduction of nontransformed HFE-145 gastric epithelial cells with oncogenic KRAS^G12V significantly decreased expression of the epithelial marker E-cadherin, increased expression of the mesenchymal marker vimentin and the EMT transcription factor Slug, and increased migration and invasion by 15- to 17-fold. KRAS^G12V also increased expression of self-renewal proteins such as Sox2 and increased spheroid formation by 2.6-fold. In tumor-derived organoids from Tcon mice, Kras knockdown decreased spheroid formation, expression of EMT-related proteins, migration, and invasion; similar effects, as well as reversal of chemoresistance, were observed following KRAS knockdown or MEK inhibition in patient tumor-derived gastric adenocarcinoma cell lines (AGS and KATOIII). KRAS inhibition in gastric adenocarcinoma spheroid cells led to reduced AGS flank xenograft growth, loss of the infiltrative tumor border, fewer lung metastases, and increased survival. In a tissue microarray of human gastric adenocarcinomas from 115 patients, high tumor levels of CD44 (a marker of CSCs) and KRAS activation were independent predictors of worse overall survival. In conclusion, KRAS activation in gastric adenocarcinoma cells stimulates EMT and transition to CSCs, thus promoting metastasis. IMPLICATIONS: This study provides rationale for examining inhibitors of KRAS to block metastasis and reverse chemotherapy resistance in gastric adenocarcinoma patients.

Prevalence and Implications of Bone Marrow Involvement in Patients with Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Background/Aims

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach is an uncommon disease. Bone marrow involvement is reported even in patients with only a mucosal lesion. We evaluated the prevalence and risk factors of marrow involvement and its implications for diagnosis and treatment.

Methods

In total, 132 patients who were diagnosed with gastric MALT lymphoma at the National Cancer Center in Korea between January 2001 and December 2016 were enrolled in the study. The patient data were collected and analyzed retrospectively.

Results

Of the 132 patients, 47 (35.6%) were male, with a median age of 52 years (range, 17 to 81 years). The median follow-up duration was 48.8 months (range, 0.5 to 169.9 months). Helicobacter pylori infection was detected in 82 patients (62.1%). Most patients (80.3%) had stage IE1 according to the modified Ann Arbor staging system. Ninety-two patients underwent bone marrow evaluation, and four patients (4.3%) had marrow involvement. Of these patients, one presented with abdominal lymph node involvement, while the other three had stage IE1 disease if marrow involvement was disregarded. All three patients had no significant symptoms and were monitored after local treatment without evidence of disease aggravation.

Conclusions

Bone marrow involvement was found in 4.3% of the patients with gastric MALT lymphoma. Bone marrow examination may be deferred because marrow involvement does not change the treatment options or outcome in gastric MALT lymphoma confined to the stomach wall.