Is the incidence of esophageal adenocarcinoma increasing in Japan? Trends from the data of a hospital-based registration system in Akita Prefecture, Japan

Development of a prediction score for Barrett's esophagus in Japanese health checkup settings

BACKGROUND

The incidence of esophageal adenocarcinoma has recently increased in Asia, including Japan. A system to identify individuals at high risk for Barrett's esophagus (BE), a pre-cancerous condition of esophageal adenocarcinoma, among the general population is needed to perform endoscopic surveillance appropriately. We therefore developed risk prediction scores for BE at health checkups in Japan.

METHODS

4128 consecutive health checkup examinees were retrospectively enrolled from October 2021 to March 2022. A prediction score for BE was developed based on the linear transformation of β-regression coefficients in a multivariable regression model incorporating BE predictors. Internal validation was performed by evaluating discrimination and calibration of the prediction model.

RESULTS

Three prediction scores corresponding to BE based on its length were developed: all lengths, ≥ 1 cm, ≥ 2 cm. All scores were internally validated, and the model calibration was excellent. The performance of the prediction models was better for longer BE, with a c-statistic of 0.70 for BE ≥ 2 cm, than for shorter values. The prediction score for BE ≥ 2 cm yielded sensitivity and specificity of 52.9% and 78.6% in high-risk subjects and 91.2% and 29.3% in intermediate- or high-risk subjects, respectively.

CONCLUSIONS

This prediction score can potentially increase the endoscopic detection of BE by identifying potentially high-risk individuals from the general population. This is the first report on developing a prediction score for BE that may suit the Japanese population.

Cancer risk by length of Barrett's esophagus in Japanese population: a nationwide multicenter retrospective cohort study

BACKGROUND

The cancer risk for each length of Barrett's esophagus (BE) in Japanese is unknown. This nationwide, multi-institutional study aims to clarify the cancer risk by length of BE in the general Japanese population.

METHODS

Consecutive subjects who underwent upper endoscopic screening at 17 centers between 2013 and 2017 and had at least one follow-up endoscopy by December 2022 were included. The presence/absence of BE and, if present, its length were retrospectively assessed using the retrieved endoscopic images recorded at baseline. Information on the subsequent occurrence of esophageal adenocarcinoma and other upper gastrointestinal cancers was also collected. Cancer incidence was calculated and expressed as %/year.

RESULTS

A total of 33,478 subjects were enrolled, and 17,884 (53.4%), 10,641 (31.8%), 4889 (14.6%), and 64 (0.2%) were diagnosed as absent BE, BE < 1 cm, 1-3 cm, and ≥ 3 cm, respectively. During a median follow-up of 80 months, 11 cases of esophageal adenocarcinoma developed. The annual incidence of esophageal adenocarcinoma is 0%/year for absent BE, 0.0032 (0.00066-0.013)%/year for BE < 1 cm, 0.026 (0.011-0.054)%/year for 1-3 cm, and 0.58 (0.042-2.11)%/year for ≥ 3 cm, respectively. Meanwhile, the incidence of esophageal squamous cell carcinoma and gastric cancer were 0.039 (0.031-0.049)%/year and 0.16 (0.14-0.18)%/year, respectively.

CONCLUSIONS

By enrolling a large number of subjects with long-term follow-up, this study demonstrated that the risk of cancer increased steadily with increasing length of BE in the Japanese population. Therefore, it is important to consider the length of BE when determining the management strategy for BE.

Etiologic factors for Barrett's esophagus: toward countermeasures in Asia

INTRODUCTION

Over the past several decades, Europe and the United States have experienced a rapid increase in esophageal adenocarcinoma. Research and countermeasures against Barrett's esophagus, its precancerous lesion, are progressing. Because esophageal adenocarcinoma has an extremely poor prognosis when diagnosed in an advanced stage, recommendations for early cancer detection have been made based on the various proven etiological factors of Barrett's esophagus and the actual cancer risk of Barrett's esophagus. In recent years, there have been indications of an increase in esophageal adenocarcinoma in Japan, and a similar trend of cancer will occur shortly in other Asian countries. Consequently, Asian countries must implement similar countermeasures against Barrett's esophagus and esophageal adenocarcinoma, referencing the knowledge gained thus far in Europe and the United States.

AREAS COVERED

This review summarizes the latest findings on the etiologic factors of Barrett's esophagus and discusses the differences between Westerners and Asians. The current status of Barrett's esophagus in Japan and other Asian countries is also summarized.

EXPERT OPINION

The etiological factors and cancer incidence of Barrett's esophagus in Asia diverge somewhat from those observed in Europe and America. Therefore, it is imperative to implement measures that are tailored to the actual circumstances of Asian people.

Endoscopic Artificial Intelligence for Image Analysis in Gastrointestinal Neoplasms

BACKGROUND

Artificial intelligence (AI) using deep learning systems has recently been utilized in various medical fields. In the field of gastroenterology, AI is primarily implemented in image recognition and utilized in the realm of gastrointestinal (GI) endoscopy. In GI endoscopy, computer-aided detection/diagnosis (CAD) systems assist endoscopists in GI neoplasm detection or differentiation of cancerous or noncancerous lesions. Several AI systems for colorectal polyps have already been applied in colonoscopy clinical practices. In esophagogastroduodenoscopy, a few CAD systems for upper GI neoplasms have been launched in Asian countries. The usefulness of these CAD systems in GI endoscopy has been gradually elucidated.

SUMMARY

In this review, we outline recent articles on several studies of endoscopic AI systems for GI neoplasms, focusing on esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cancer (GC), and colorectal polyps. In ESCC and EAC, computer-aided detection (CADe) systems were mainly developed, and a recent meta-analysis study showed sensitivities of 91.2% and 93.1% and specificities of 80% and 86.9%, respectively. In GC, a recent meta-analysis study on CADe systems demonstrated that their sensitivity and specificity were as high as 90%. A randomized controlled trial (RCT) also showed that the use of the CADe system reduced the miss rate. Regarding computer-aided diagnosis (CADx) systems for GC, although RCTs have not yet been conducted, most studies have demonstrated expert-level performance. In colorectal polyps, multiple RCTs have shown the usefulness of the CADe system for improving the polyp detection rate, and several CADx systems have been shown to have high accuracy in colorectal polyp differentiation.

KEY MESSAGES

Most analyses of endoscopic AI systems suggested that their performance was better than that of nonexpert endoscopists and equivalent to that of expert endoscopists. Thus, endoscopic AI systems may be useful for reducing the risk of overlooking lesions and improving the diagnostic ability of endoscopists.

Disproportionate cancer worries in ultra-short-segment Barrett's esophagus in Japan

Objectives

Although Barrett's esophagus (BE), especially ultra-short-segment BE (USSBE), is very frequently diagnosed in Japan, how subjects feel about receiving a diagnosis of BE is unclear. We therefore prospectively investigated cancer worry in subjects who received a BE diagnosis.

Methods

Self-administered questionnaires were sent to subjects who were diagnosed with BE at three health checkup institutes in Akita Prefecture, Japan. The cancer worry scale (CWS) was used to quantitatively assess the fear of developing cancer. The BE subjects were classified into USSBE <1 cm and non-USSBE ≥1 cm groups. Factors associated with the CWS were investigated using logistic regression analyses.

Results

A total of 325 (31%) subjects, comprising 229 USSBE and 96 non-USSBE patients were included in this study. Compared with the USSBE group, the non-USSBE group had a significantly higher frequency of a history of a BE diagnosis and perception of carcinogenesis. However, the CWS was similar between the USSBE and non-USSBE groups, with a median CWS of 12.5 (3.75) versus 12.7 (3.65). A multivariate logistic regression analysis revealed that while positive reflux symptoms were significantly associated with a positive CWS, the BE length was not significantly associated with it, with an odds ratio (95% confidence interval) of 1.3 (0.75-2.2).

Conclusions

A BE diagnosis promotes a similar level of worry about cancer among subjects, irrespective of the length of BE. In Japan, since USSBE poses a much lower cancer risk than non-USSBE, the former may frequently be associated with a disproportionate cancer worry relative to the latter. (UMIN000044010).

Cancer Stem Cells of Esophageal Adenocarcinoma are Suppressed by Inhibitors of TRPV2 and SLC12A2

BACKGROUND

The potential of membrane transporters activated in cancer stem cells (CSCs) as new therapeutic targets for cancer is attracting increasing interest. Therefore, the present study examined the expression profiles of ion transport-related molecules in the CSCs of esophageal adenocarcinoma (EAC).

METHODS

Cells that highly expressed aldehyde dehydrogenase 1 family member A1 (ALDH1A1) were separated from OE33 cells, a human Barrett's EAC cell line, by fluorescence-activated cell sorting. CSCs were identified based on the formation of tumorspheres. Gene expression profiles in CSCs were examined by a microarray analysis.

RESULTS

Among OE33 cells, ALDH1A1 messenger RNA levels were higher in CSCs than in non-CSCs. Furthermore, CSCs exhibited resistance to cisplatin and had the capacity to redifferentiate. The results of the microarray analysis of CSCs showed the up-regulated expression of several genes related to ion channels/transporters, such as transient receptor potential vanilloid 2 (TRPV2) and solute carrier family 12 member 2 (SLC12A2). The cytotoxicities of the TRPV2 inhibitor tranilast and the SLC12A2 inhibitor furosemide were higher at lower concentrations in CSCs than in non-CSCs, and both markedly reduced the number of tumorspheres. The cell population among OE33 cells that highly expressed ALDH1A1 also was significantly decreased by these inhibitors.

CONCLUSIONS

Based on the present results, TRPV2 and SLC12A2 are involved in the maintenance of CSCs, and their specific inhibitors, tranilast and furosemide, respectively, have potential as targeted therapeutic agents for EAC.

A Case of Early Barrett's Adenocarcinoma With Eosinophilic Esophagitis

A 61-year-old man presented with epigastric pain and underwent upper gastrointestinal endoscopy. A strongly erythematous area was found in the short segment of the Barrett's esophagus, and a biopsy revealed well-differentiated adenocarcinoma. Linear furrows were observed in the lower esophagus, and a biopsy of the lesion revealed eosinophil infiltration of 30 eosinophils per high-power field. Therefore, a diagnosis of Barrett's adenocarcinoma with eosinophilic esophagitis was made. Although rare, the incidence of Barrett's adenocarcinoma and eosinophilic esophagitis has been increasing in Japan in recent years, and the number of cases may increase in the future.

Clinical characteristics and changing trajectories of esophageal cancer and gastric cancer in China from 2010 to 2019: An analysis of a hospital-based database of 24,327 patients

Purpose

This analysis aimed to investigate the clinical characteristics and changing trajectories of gastric cancer (GC) and esophageal cancer (EC).

Methods

We collected data from a large cancer hospital in Beijing, China, from 2010 to 2019. Joinpoint regression was used to analyze the trends of histological characteristics and comorbidities.

Results

From 2010 to 2019, there were a total of 10,083 EC patients and 14,244 GC patients. Patients were mainly men and diagnosed at 55-64 years old. Metabolic comorbidity was the most common comorbidity, with hypertension being predominant. The percentages of stage I showed significant increases for EC [average annual percent change (AAPC): 10.5%] and GC (AAPC: 9.7%) patients. We also observed an increasing trend of EC and GC patients over 65 years old. For EC patients, esophageal squamous cell carcinoma (93.1%) remained as the prioritized subtype, and the middle third of the esophagus was the most common site. EC patients with three or more comorbidities increased from 0.1% to 2.2% (AAPC, 27.7%; 95% CI, 14.7% to 42.2%). For GC patients, adenocarcinoma accounts for 86.9% of the total cases, and cardia was the most common site. The ulcerative comorbidity rate decreased from 2.0% to 1.2% (AAPC, −6.1%; 95% CI, −11.6% to −0.3%).

Conclusion

ESCC remained as the prioritized histological subtype, and the middle third of the esophagus was the most common site of EC. The majority of GC patients had adenocarcinoma, and the cardia was the most common site. There was an increasing trend of patients diagnosed at stage I. These findings provide scientific evidence to guide future treatment.

Inflammatory prognostic factors in advanced or recurrent esophageal squamous cell carcinoma treated with nivolumab

BACKGROUND

In Japan, nivolumab administration is the standard treatment for patients with unresectable advanced or recurrent esophageal squamous cell carcinoma (ESCC) who are refractory or intolerant to fluoropyrimidines and platinum-based chemotherapy. We determined if inflammatory prognostic factors are useful in patients with ESCC treated with nivolumab monotherapy.

METHODS

The clinical data of patients with ESCC treated with nivolumab monotherapy as the second- or later-line treatment were retrospectively analyzed. Neutrophil/lymphocyte, platelet/lymphocyte, and C-reactive protein/albumin ratios (CAR); prognostic index; and prognostic nutritional index were investigated. Cut-off values for each factor were determined according to overall survival using time-dependent receiver operating characteristic curves.

RESULTS

During January 2017-June 2021, 93 consecutive patients with ESCC were enrolled from five institutions (median age, 70 years; male, 77%). With a median follow-up period of 9.1 (range, 1.0-34.7) months, the median overall and progression-free survival were 12.8 (95% confidence interval [CI], 9.0-16.6) and 4.0 (95% CI, 2.6-5.4) months, respectively. Of five inflammatory prognostic factors, the cut-off value for CAR was 0.62; prognosis was significantly longer in those with CAR < 0.62 (hazard ratio, 0.39; 95% CI, 0.22-0.67; p = 0.001).

CONCLUSIONS

Inflammatory prognostic factors were useful in predicting prognosis for ESCC patients pretreated with nivolumab, especially for those with CAR < 0.62, suggesting that CAR adequately reflects prognosis.

Diverse contributions of the visceral fat area to the etiology of two distinct subtypes of esophago-gastric junctional adenocarcinoma

BACKGROUND

There are two distinct etiologies of esophago-gastric junctional adenocarcinomas (EGJACs): one associated with extensive gastric mucosal atrophy (GA), resembling non-cardiac gastric cancers; and the other related to gastro-esophageal reflux disease, resembling esophageal adenocarcinoma. In this study, we investigated the associations between the visceral fat area (VFA) and EGJACs separately in the two subtypes of EGJACs, depending on the extent of background GA.

METHODS

Sixty-four consecutive patients with EGJACs (Siewert type 2) were enrolled from a population-based database in Akita Prefecture, Japan, between 2014 and 2019. Two age- and sex-matched healthy controls were randomly assigned to each EGJAC case. The extents of GA were evaluated endoscopically, and the VFA values were measured based on computed tomography images. Logistic regression analyses were performed to investigate the associations between EGJACs and the VFA.

RESULTS

Study subjects were classified into 2 subgroups depending on the extent of endoscopic GA: 29 (45.3%) without and 35 (54.7%) with extensive GA. Multivariable regression analyses revealed that a VFA of ≥100 cm² was significantly associated with EGJACs in subjects without extensive GA [odds ratio (95% confidence interval): 2.65 (1.08-6.54)], while there was no such association in subjects with extensive GA [odds ratio (95% confidence interval): 1.52 (0.60-3.83)].

CONCLUSIONS

The contribution of the VFA to the etiology of EGJACs seems to differ depending on the extent of background GA, with the VFA more prominently associated with EGJACs in subjects without extensive GA than in those with it, providing further rationale concerning the heterogeneous nature of EGJAC etiology.

Nature and Clinical Outcomes of Acute Hemorrhagic Rectal Ulcer

Acute hemorrhagic rectal ulcer (AHRU) is a relatively rare disease that can lead to massive hematochezia. Although AHRU is a potentially life-threatening disease, its characteristics and clinical course are not fully understood. In this study, the clinical features were compared between AHRU and lower gastrointestinal bleeding (LGIB) from other causes (non-AHRU). Then, risk factors for all-cause in-hospital mortality in patients with AHRU were identified. A total of 387 consecutive adult patients with LGIB who were managed at two tertiary academic hospitals in Akita prefecture in Japan were retrospectively enrolled. Subjects were divided into AHRU and non-AHRU groups according to the source of bleeding. Regression analyses were used to investigate significant associations, and the results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). AHRU was found as the bleeding source in 72 (18.6%) of the patients. In comparison to non-AHRU, having AHRU was significantly associated with in-hospital onset, age > 65 years, and systolic blood pressure < 90 mmHg. The AHRU group had a significantly higher in-hospital mortality rate in comparison to the non-AHRU group (18.0% vs. 8.3, p = 0.02), and hypoalbuminemia (<2.5 g/dL) was significantly associated with in-hospital mortality in the AHRU group (OR, 4.04; 95%CI, 1.11−14.9; p = 0.03). AHRU accounts for a substantial portion (18.6%) of LGIB in our area, where the aging rate is the highest in Japan. Since AHRU is a potentially life-threatening disease that requires urgent identification and management, further studies to identify robust risk factors associated with serious clinical outcomes are required.

Visceral obesity is associated with an increased risk of developing esophago-gastric junctional adenocarcinoma in Japan: a population-based case-control study in Akita Prefecture

BACKGROUND

While an association between esophago-gastric junctional adenocarcinomas (EGJACs) and obesity, especially visceral obesity, has been suggested in Western countries, the association remains unclear in Asia, including Japan. In this population-based case-control study, we investigated the association between EGJACs and obesity.

METHODS

To perform near-population-based data collection for all early-stage EGJACs occurring in Akita Prefecture from 2014 to 2019, clinical data, including endoscopic and computed tomography (CT) findings, were collected from 11 cancer treatment base hospitals in the area. Age- and gender-matched controls were extracted at a case-to-control ratio of 1:2 from healthy subjects who received health checkups in the same area. The visceral fat area (VFA) was calculated using CT images. Logistic regression analyses were performed to investigate the associations between EGJACs and obesity-related parameters.

RESULTS

In total, 74 EGJAC cases (62 males, median age of 70 years old) and 148 controls were extracted. Multivariable analyses showed a significantly negative association between the BMI and EGJACs and a significantly positive association between the VFA and EGJACs with odds ratios (ORs) (95% confidence intervals [CIs]) of 0.65 (0.53-0.80) and 1.01 (1.01-1.02), respectively. These findings were confirmed in another dataset (40 EGJACs and 80 controls). In addition, as a categorical variable, VFA ≥ 100 cm² showed a significantly positive association with EGJACs (OR [95% CI] 1.96 [1.02-3.76]).

CONCLUSIONS

We found paradoxical associations between EGJACs and obesity-related parameters (BMI vs. VFA) in a Japanese population, suggesting a potentially pivotal role of the VFA rather than the BMI as a risk factor for EGJACs.

Low risk of esophageal adenocarcinoma among patients with ultrashort-segment Barrett's esophagus in Japan

OBJECTS

Ultrashort-segment Barrett's esophagus (USSBE; length of <1 cm) is very frequently diagnosed in Japan, but the cancer risk of USSBE is unknown. In this study, by retrieving endoscopic images, we retrospectively investigated the incidence of esophageal adenocarcinoma (EAC) by the grade of Barrett's esophagus (BE) and compared the findings with those of gastric cancer by the degree of endoscopic gastric atrophy in the same population.

METHODS

Among consecutive participants who had undergone endoscopy for an annual health checkup in 2014, the 9121 who had received at least one follow-up endoscopy by December 2020 were enrolled in this study. Using the retrieved endoscopic images, we retrospectively evaluated BE and gastric atrophy. Information on the subsequent occurrence of EAC and gastric cancer as of December 2020 was also collected. The incidence of cancer by the extent of BE and gastric atrophy was calculated and expressed as the percentage per year.

RESULTS

On reviewing the endoscopic image in 2014, 4190 (45.9%) were found to have been diagnosed with BE, of whom 3318 (36.4%) were judged to have USSBE. During an observation period of 54.1 (17.9) months, 89 gastric cancers and only two EACs were identified. The incidence of EAC in USSBE was 0.0068%/year, which was nearly as low as the incidence of gastric cancer in atrophy-free patients (0.0068% vs. 0.0059%/year).

CONCLUSIONS

Although the prevalence of USSBE is quite high (36.4%), the incidence of EAC in USSBE is very low (0.0068%/year). Accordingly, USSBE can be excluded from targets for endoscopic surveillance in Japan.

Association of Esophageal Cancer Mortality with Municipal Socioeconomic Deprivation Level in Japan, 2013–2017: An Ecological Study Using Nationwide Data

This study aimed to show geographical differences in esophageal cancer mortality in Japan and reveal an association of esophageal cancer mortality with municipal socioeconomic deprivation level. Esophageal cancer mortality data in the Vital Statistics from 2013 to 2017 for each municipality and corresponding population data were analyzed. The deprivation level was derived from the municipal socioeconomic variables by principal component analysis. Municipalities were classified into five quintiles based on the deprivation level, and an association between the level and esophageal cancer mortality was evaluated using a Bayesian spatial model. As a result of regression analysis, the relative risk of esophageal cancer mortality tended to become larger as the deprivation level increased irrespective of sex, and the relative risk of esophageal cancer mortality was significantly higher in quintile 5 (most deprived) than quintile 1 (least deprived) among men and women. These results suggest that the deprivation level increases the risk of esophageal cancer mortality in Japan.

Implementation of artificial intelligence in upper gastrointestinal endoscopy

The application of artificial intelligence (AI) using deep learning has significantly expanded in the field of esophagogastric endoscopy. Recent studies have shown promising results in detecting and differentiating early gastric cancer using AI tools built using white light, magnified, or image-enhanced endoscopic images. Some studies have reported the use of AI tools to predict the depth of early gastric cancer based on endoscopic images. Similarly, studies based on using AI for detecting early esophageal cancer have also been reported, with an accuracy comparable to that of endoscopy specialists. Moreover, an AI system, developed to diagnose pharyngeal cancer, has shown promising performance with high sensitivity. These reports suggest that, if introduced for regular use in clinical settings, AI systems can significantly reduce the burden on physicians. This review summarizes the current status of AI applications in the upper gastrointestinal tract and presents directions for clinical practice implementation and future research.

Current status of surveillance for Barrett's esophagus in Japan and the West

Prospective studies in western countries have shown that the obvious risk factors for Barrett's esophageal cancer are male sex, smoking habit, a longer length of Barrett's esophagus, and low‐grade dysplasia. However, few reports have prospectively examined risk factors for adenocarcinoma development from Barrett's esophagus in Japan. In the West, where adenocarcinoma is common among esophageal cancer, endoscopic surveillance of Barrett's esophagus every 2–5 years is recommended for early detection of adenocarcinoma. However, there is no established surveillance method in Japan. In recent years, the incidence of adenocarcinoma from long‐segment Barrett's esophagus and short‐segment Barrett's esophagus longer than 2 cm in Japan has been reported to be similar to the West. For surveillance of adenocarcinoma arising from Barrett's esophagus, recognizing the characteristics of superficial adenocarcinoma and carefully observing the entire Barrett's esophagus are needed. It has been reported that representative characteristics of Barrett's adenocarcinoma are a reddish area or a lesion located on the anterior to the right sidewall. It is necessary to establish surveillance methods for Barrett's esophagus sooner in Japan.

Long-term endoscopic surveillance for Barrett's esophagus in Japan: Multicenter prospective cohort study

OBJECTS

Although a recent study showed the cancer incidence of Barrett's esophagus (BE) to be 1.2%/year in 251 patient-years in Japan, the long-term outcomes remain unclear. The present study estimated the cancer risk of BE in Japan using our original prospective multicenter cohort.

METHODS

A total of 98 patients with BE of maximum length of ≥2 cm were enrolled during the period of 2010-2012 and received at least one follow-up endoscopy over 5 years thereafter. Cancer incidence rates with 95% confidence interval for occurrence of esophageal adenocarcinoma (EAC) were calculated as the number of events divided by patient-years of follow-up and were expressed as %/year.

RESULTS

Overall, the median endoscopic follow-up period was 59.9 (first and third quartiles, 48.5-60.8) months, constituting a total of 427 patient-years of observation. Since two EAC cases developed, the cancer incidence was 0.47% (0.01%-1.81%)/year. The cancer incidence was 0.39% (-0.16% to 2.44%) in 232 patient-years and 0.31% (-0.13% to 1.95%)/year in 318 patient-years for 55 cases with specialized intestinal metaplasia and 70 with BE ≥3 cm (maximum), respectively. At the end of follow-up, 12 of 92 patients (13.0%) died, but none died from EAC.

CONCLUSION

This is the largest prospective follow-up study with endoscopy to investigate the incidence of EAC in unequivocal BE with the maximum length of ≥2 cm in Japan. Although a further large-scale study will be required to validate our results, the cancer risk of BE in Japan would be lower than previously reported (0.47% vs 1.2%/year).

Genetic profiles of Barrett's esophagus and esophageal adenocarcinoma in Japanese patients

The genetic characteristics of Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) in the Japanese population is unclear. This study aims to investigate the genetic characteristics from nondysplastic BE (NDBE) to early EAC in Japan. Clinical information was collected. Moreover, the genetic profile of NDBE without concurrent dysplasia, early EAC, and surrounding BE were also investigated using endoscopic biopsy samples and formalin-fixed, paraffin-embedded specimens from Japanese patients by targeted next-generation sequencing. Immunohistochemical staining for p53 was also performed for EAC lesions. Targeted NGS was performed for 33 cases with 77 specimens. No significant difference exists in the NDBE group between the number of putative drivers per lesion in the short-segment Barrett’s esophagus (SSBE) and long-segment Barrett’s esophagus (LSBE) [0 (range, 0–1) vs. 0 (range, 0–1). p = 1.00]. TP53 putative drivers were found in two patients (16.7%) with nondysplastic SSBE. TP53 was the majority of putative drivers in both BE adjacent to EAC and EAC, accounting for 66.7% and 66.7%, respectively. More putative drivers per lesion were found in the EAC than in the NDBE group [1 (range, 0–3) vs. 0 (range, 0–1). p < 0.01]. The genetic variants of TP53 in the Japanese early EAC were similar to those in western countries. However, TP53 putative drivers were detected even in Japanese patients with nondysplastic SSBE. This is significant because such nondysplastic SSBE might have higher risk of progressing to high-grade dysplasia or EAC. The risks of progression may not be underestimated and appropriate follow-ups may be necessary even in patients with SSBE.

Trial registration: This study was registered at the University Hospital Medical Information Network (UMIN000034247).

PDZK1 induces resistance to apoptosis in esophageal adenocarcinoma cells

BACKGROUND

Esophageal cancer is a lethal malignancy with a poor prognosis. The incidence of esophageal adenocarcinoma, which develops from Barrett's esophagus (BE), has recently been increasing. In a previous study, we found that PDZK1 expression is higher in long segment BE compared to that in short-segment BE. However, the function of PDZK1 in the mucosa of BE is unclear.

AIMS

Clarify the role of PDZK1 in BE mucosa using PDZK1 overexpressed cells.

METHODS

Human adenocarcinoma-derived OE33 cells were used as a parental cell line and transfected to generate PDZK1 overexpressed OE33 cells (PC cells) or transfected with empty vector as control cells (NC cells). Cell growth of NC and PC cells in 10% fetal bovine serum was evaluated by cell counting. The effect of PDZK1 on proteasome inhibitor (PSI)-induced apoptosis was qualified by fluorescence microscopy and quantified by flow cytometry. Expression of apoptosis-related proteins was evaluated by western blotting.

RESULTS

There were no significant differences in cell growth between NC and PC cells. PSI significantly increased apoptosis in NC cells, but not in PC cells. In response to PSI, increased levels of cleaved-caspase3 and decreased pro-caspase3 levels were found in NC cells, but not in PC cells. In NC cells, PSI significantly decreased Bcl-2 expression without affecting Bax levels. In contrast, high expression of both Bcl-2 and Bax was observed in PC cells.

CONCLUSION

Overexpression of PDZK1 protein induces an apoptosis-resistant phenotype in BE cells, which may be a potential therapeutic target.

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in 40-69-years subjects

BACKGROUND

Visceral fat obesity can be defined quantitatively by abdominal computed tomography, however, the usefulness of measuring visceral fat area to assess the etiology of gastrointestinal reflux disease has not been fully elucidated.

METHODS

A total of 433 healthy subjects aged 40-69 years (234 men, 199 women) were included in the study. The relationship between obesity-related factors (total fat area, visceral fat area, subcutaneous fat area, waist circumference, and body mass index) and the incidence of reflux erosive esophagitis was investigated. Lifestyle factors and stomach conditions relevant to the onset of erosive esophagitis were also analyzed.

RESULTS

The prevalence of reflux erosive esophagitis was 27.2% (118/433; 106 men, 12 women). Visceral fat area was higher in subjects with erosive esophagitis than in those without (116.6 cm² vs. 64.9 cm², respectively). The incidence of erosive esophagitis was higher in subjects with visceral fat obesity (visceral fat area ≥ 100 cm²) than in those without (61.2% vs. 12.8%, respectively). Visceral fat obesity had the highest odds ratio (OR) among obesity-related factors. Multivariate analysis showed that visceral fat area was associated with the incidence of erosive esophagitis (OR = 2.18), indicating that it is an independent risk factor for erosive esophagitis. In addition, daily alcohol intake (OR = 1.54), gastric atrophy open type (OR = 0.29), and never-smoking history (OR = 0.49) were also independently associated with the development of erosive esophagitis.

CONCLUSIONS

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in subjects aged 40-69 years.

Burden, trends, and risk factors of esophageal cancer in China from 1990 to 2017: an up-to-date overview and comparison with those in Japan and South Korea

Background

The epidemiology of esophageal cancer (EC) can elucidate its causes and risk factors and help develop prevention strategies. We aimed to provide an overview of the burden, trends, and risk factors of EC in China from 1990 to 2017. We also investigated the differences between China, Japan, and South Korea and discussed the possible causes of the disparities.

Methods

We used the Global Burden of Disease Study 2017 to obtain data on incident cases, deaths, disability-adjusted life-year (DALY) cases, age-standardized incidence rate (ASIR), age-standardized death rate (ASDR), and age-standardized DALY rate of EC in China, Japan, and South Korea from 1990 to 2017. Trend analysis was performed using joinpoint analysis. We measured the associations between ASIR, ASDR, and age-standardized DALY rate and the socio-demographic index (SDI) for 1990–2017. We also analyzed the risk factors associated with EC deaths and DALYs.

Results

China recorded 234,624 (95% uncertainty intervals: 223,240–246,036) incident cases of and 212,586 (202,673–222,654) deaths from EC in 2017. The ASIR and ASDR declined from 1990 to 2017. Until 2017, the ASIR was 12.23, and ASDR was 11.25 per 100,000 persons. The DALYs were 4,464,980 (4,247,816–4,690,846) with an age-standardized rate of 222.58 per 100,000 persons in 2017. The ASIR, ASDR, and age-standardized DALY rate in China were twice those of Japan and South Korea. These three indicators showed a decreasing trend, whereas SDI increased, in all three countries from 1990 to 2017. Tobacco and alcohol use remained the major risk factors for EC death and DALYs, especially for men in China and women in Japan and South Korea. High body mass index (BMI) and low-fruit diet were the main risk factors for women in China.

Conclusions

The incident cases and deaths of EC in China, Japan, and South Korea increased from 1990 to 2017, whereas the ASIR, ASDR, and age-standardized DALY rate declined. China had the greatest burden of EC among three countries. SDI and aging along with tobacco use, alcohol use, high BMI, and low-fruit diet were the main risk factors of death and DALYs and should be paid more attention.

The Efficacy of Linked Color Imaging in the Endoscopic Diagnosis of Barrett's Esophagus and Esophageal Adenocarcinoma

Background

The present study aimed to evaluate the efficacy of linked color imaging (LCI) in diagnosing Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC).

Methods

A total of 112 and 12 consecutive patients with BE and EAC were analyzed. The visibility scores of BE and EAC ranging from 4 (excellent visibility) to 0 (not detectable) were evaluated by three trainees and three experts using white light imaging (WLI), LCI mode, and blue laser imaging bright (BLI-b) mode. In addition, L∗a∗b∗ color values and color differences (ΔE∗) were evaluated using the CIELAB color space system.

Results

The visibility score of the BE in LCI mode (2.94 ± 1.32) was significantly higher than those in WLI (2.46 ± 1.48) and BLI-b mode (2.35 ± 1.46) (p < 0.01). The color difference (ΔE∗) from the adjacent gastric mucosa in LCI mode (17.11 ± 8.53) was significantly higher than those in other modes (12.52 ± 9.37 in WLI and 11.96 ± 6.59 in BLI-b mode, p < 0.01). The visibility scores of EAC in LCI mode (2.56 ± 1.47) and BLI-b mode (2.51 ± 1.28) were significantly higher than that in WLI (1.64 ± 1.46) (p < 0.01). The color difference (ΔE∗) from the adjacent normal Barrett's mucosa in LCI mode (19.96 ± 7.97) was significantly higher than that in WLI (12.95 ± 11.86) (p = 0.03).

Conclusion

The present findings suggest that LCI increases the visibility of BE and EAC and contributes to the improvement of the detection of these lesions.

Use of Immunostaining for the diagnosis of Lymphovascular invasion in superficial Barrett's esophageal adenocarcinoma

BACKGROUND

The prevalence of Barrett's esophageal adenocarcinoma (BEA) is increasing in Japan. Accurate assessment of lymphovascular invasion (LVI) after endoscopic resection or surgery is essential in evaluating treatment response. This study aimed to assess the usefulness of immunostaining in determining the extent of LVI in superficial BEA.

METHODS

We retrospectively included 41 patients who underwent endoscopic resection or surgery between January 2007 and July 2018. In all cases, 3-μm serial sections from paraffin-embedded resected specimens were used for hematoxylin and eosin (H-E) staining and immunostaining for D2-40 and CD31. Two specialized gastrointestinal pathologists (T.Y. and T.T.), blinded to clinical information, independently evaluated the extent of LVI from these specimens. The LVI-positivity rate was evaluated with respect to the depth of invasion, changes in the positivity rate on immunostaining, pathological characteristics of patients with LVI, lymph node metastasis or relapse, and course after treatment.

RESULTS

H-E staining alone identified LVI in 7 patients (positivity rate: 17.1%). Depths of invasion were categorized based on extension to the submucosa (SM) or deeper. On immunostaining for D2-40 and CD31, additional positivity was detected in 2 patients with SM1 and 1 SM3, respectively; LVI was detected in 10 patients (positivity rate: 24.4%). LVI-positivity rates with invasion of the superficial muscularis mucosa (SMM)/lamina propria mucosa (LPM)/deep muscularis mucosa (DMM), SM 1, 2, and 3 were 0, 75, 28.6, and 55.6%, respectively.

CONCLUSIONS

Combined H-E staining and immunostaining is useful in diagnosing LVI in superficial BEA, particularly in endoscopically resected specimens.

How to decide surgical procedure for esophagogastric junction cancer?

Standard surgical procedure for esophagogastric junction cancer, especially adenocarcinoma, has still remained controversial. Various procedures has been allowed and applied for Siewert type II tumors. Negative long resection margin had been regarded as essential in decision on the procedure. Recent papers have, however, shown the priority of invasion length to each side (esophagus and stomach), because it relates the frequency and sites of lymph node metastasis to be dissected. And, the size of remnant stomach is, also, important when a proximal gastrectomy is considered.

Is the new potent acid-inhibitory drug vonoprazan effective for healing idiopathic peptic ulcers? A multicenter observational study in Akita Prefecture, Japan

BACKGROUND

The incidence of peptic ulcers unrelated to H. pylori infection and non-steroidal anti-inflammatory drugs (NSAIDs), termed idiopathic peptic ulcers (IPUs), has increased worldwide. We recently reported that IPUs were refractory to proton pump inhibitor (PPI) treatment. Vonoprazan, which was recently developed in Japan, has shown a more potent acid-inhibitory effect than ordinary PPIs. In the present study, we compared the healing rates among peptic ulcers of different etiologies following treatment with vonoprazan.

METHOD

A multicenter observational study was performed at six participating hospitals in Akita Prefecture, Japan. Consecutive patients who had endoscopically confirmed gastro-duodenal ulcers were enrolled between August 2016 and March 2018. For each patient, the Helicobacter pylori infection status and NSAID use, including aspirin, were checked, and 20 mg vonoprazan was administered for 6 weeks for duodenal ulcers and 8 weeks for gastric ulcers. The healing status was checked by endoscopy at the end of vonoprazan treatment. Patients were divided into four subgroups according to the H. pylori status and NSAID usage.

RESULTS

The proportion of IPUs was 18.2%. A total of 162 patients completed the study protocol. The healing rate of IPUs was marginally lower than that of simple H. pylori-associated ulcers (81.2% vs. 93.5%, P = 0.05). Similarly, the healing rate of NSAID-related ulcers, irrespective of concomitant H. pylori infection, was significantly lower than that of simple H. pylori-associated ulcers.

CONCLUSIONS

Six- or 8-week vonoprazan treatment still seems to be insufficient for healing IPUs. Longer-term vonoprazan or another treatment option may be required to heal potentially refractory peptic ulcers.

Time trends in the incidence of esophageal adenocarcinoma, gastric adenocarcinoma, and superficial esophagogastric junction adenocarcinoma

BACKGROUND

In Japan, the incidence of esophageal adenocarcinoma (EAC) and esophagogastric junction (EGJ) adenocarcinoma is expected to increase and that of gastric adenocarcinoma (GAC) is expected to decrease due to Westernization of the diet and the decreasing prevalence of Helicobacter pylori infection. However, few reports about these trends have included the latest data, and no reports about the time trend in the incidence of EGJ adenocarcinoma have focused on the etiologies (gastric cardia adenocarcinoma or EAC, including Barrett's adenocarcinoma). We therefore investigated the time trends in the incidence of these cancers by including the latest data.

METHODS

First, we investigated the time trends in EAC and GAC using population-based cancer registry data in Osaka Prefecture (1985-2014). We then investigated the time trend in superficial EGJ adenocarcinoma with clinicopathological features at Osaka International Cancer Institute (2006-2017).

RESULTS

From 1985 to 2014 in Osaka Prefecture, the incidence of EAC gradually increased in both sexes, while that of GAC in men did not significantly change and that in women decreased. The ratio of the EAC/GAC incidence increased 3.5 times in men and 1.8 times in women. In the secondary time trend survey for EGJ adenocarcinoma, the numbers of patients with endoscopic Barrett's esophagus and those without gastric mucosal atrophy increased, and the number of patients with lesions located above the EGJ line and histologically diagnosed as Barrett's adenocarcinoma increased.

CONCLUSIONS

The incidence of EAC and superficial EGJ adenocarcinoma with characteristics similar to those of EAC, including Barrett's adenocarcinoma, might be increasing.

Chronological Changes in the Gastric Cancer Subsite in Akita, Japan: The Trends from the Data of a Hospital-Based Registration System

With the decreasing global trend in the Helicobacter pylori infection rate, compositional changes in the gastric cancer subsites have occurred worldwide. However, the compositional changes in Asian countries, including Japan, remain to be clarified. The aim of this study is to investigate the latest chronological changes in the gastric cancer subsite using a hospital-based registration system in Akita prefecture in Japan. From 2007-2015, subsites of gastric cancers were coded according to the International Classification of Diseases for Oncology (ICD-03). The nine-year registration period was divided into the three 3-year periods: 2007-2009, 2010-2012, and 2013-2015. A total of 10,804 cases of gastric cancer were registered. The proportion of cardiac cancer among total gastric cancer slightly but significantly declined from 12.1% in 2007-2009 to 9.2% in 2013-2015 (P < 0.01). Among non-cardia cancer, the proportion of corpus cancer significantly increased from 41.3% to 50.2% during the study period (P < 0.01), while that of antropylorus cancer significantly decreased from 37.6% to 34.3% (P < 0.05). Such compositional changes in the gastric cancer subsite were observed largely in men, regardless of the histologic subtype of cancer. With the decreasing H. pylori infection rate, compositional changes in the gastric cancer subsite are occurring in Japan. While the proportion of cardia and antropylorus cancer is declining, that of corpus cancer is increasing, indicating diverse etiology of gastric carcinogenesis depending on the subsites. Identifying the most common sites of occurrence, may help to improve the efficiency of screening for gastric cancer.