Background factors of idiopathic peptic ulcers and optimal treatment methods: a multicenter retrospective Japanese study.

This study investigated the trends in idiopathic peptic ulcers, examined the characteristics of refractory idiopathic peptic ulcer, and identified the optimal treatment. The characteristics of 309 patients with idiopathic peptic ulcer were examined. We allocated idiopathic peptic ulcers that did not heal after 8 weeks' treatment (6 weeks for duodenal ulcers) to the refractory group and those that healed within this period to the healed group. The typical risk factors for idiopathic peptic ulcer (atherosclerosis-related underlying disease or liver cirrhosis complications) were absent in 46.6% of patients. Absence of gastric mucosal atrophy (refractory group: 51.4%, healed group: 28.4%; p = 0.016), and gastric fundic gland polyps (refractory group: 17.6%, healed group: 5.9%; p = 0.045) were significantly more common in the refractory group compared to the healed group. A history of H. pylori eradication (refractory group: 85.3%, healed group: 66.0%; p = 0.016), previous H. pylori infection (i.e., gastric mucosal atrophy or history of H. pylori eradication) (refractory group: 48.5%, healed group: 80.0%; p = 0.001), and potassium-competitive acid blocker treatment (refractory group: 28.6%, healed group, 64.1%; p = 0.001) were significantly more frequent in the healed group compared to the refractory group. Thus, acid hypersecretion may be a major factor underlying the refractoriness of idiopathic peptic ulcer.

[A case of severe inflammatory bowel disease triggered by vaccination with SARS-CoV-2 mRNA].

A 64-year-old woman received a third dose of SARS-CoV-2 mRNA vaccine. On the next day, she developed fever, diarrhea, and abdominal pain and had bloody stools. Total colonoscopy revealed deep ulceration on the whole colon. She was treated with corticosteroid and infliximab and her symptoms improved. She was diagnosed with severe enteritis resembling ulcerative colitis triggered by SARS-CoV-2 mRNA vaccination.

A Follow-up Report on the Diagnosis of Gastrointestinal Cancer during the COVID-19 Pandemic in Akita Prefecture, Japan in 2021.

We recently reported the decrease in the number of gastrointestinal (GI) cancer diagnoses in 2020 due to disturbance of the healthcare system by the coronavirus disease 2019 (COVID-19) pandemic, using a hospital-based cancer registration system in Akita prefecture, Japan. In this study, we extended the research by showing the latest data (2021) on the number of cancers and examinations. Information on the occurrence and stage of esophageal, gastric, and colorectal cancers was collected from the same database. The number of GI examinations (cancer screening procedures and endoscopic examinations) was also investigated. Following the immediate decrease in the numbers of both GI examinations and GI cancer diagnoses in 2020, a rebound increase in the numbers of GI cancer diagnoses-especially colorectal cancers-was observed in 2021, resulting from an increased number of GI examinations i.e., the total number of colorectal cancers in 2021 increased by 9.0% and 6.8% in comparison to 2020 and pre-pandemic era, respectively. However, the rebound increase in 2021 was largely due to an increase in early-stage cancers, and there was no apparent trend toward the increased predominance of more advanced cancers. It therefore seems that we managed to escape from the worst-case scenario of disturbance of the healthcare system due to pandemic (i.e., an increase in the number of more advanced cancers due to delayed diagnoses). We need to continue to watch the trends in Akita prefecture, which has the highest rate of mortality from the 3 major GI cancers in Japan.

Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort.

BACKGROUND & AIMS: We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study. METHODS: We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C). RESULTS: Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS. CONCLUSION: ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

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.

Leucine-Rich Alpha-2 Glycoprotein in Monitoring Disease Activity and Intestinal Stenosis in Inflammatory Bowel Disease.

Leucine-rich alpha-2 glycoprotein (LRG) is a novel biomarker for monitoring disease activity in inflammatory bowel disease (IBD). The aim of this study was to evaluate its utility in monitoring disease activity. In this retrospective study based on case records between August 2020 and July 2021 at our two centers, we examined the correlation between serum levels of LRG and C-reactive protein (CRP) with disease activity in IBD patients. Background factors related to serum LRG levels were also analyzed. Overall, 47 Crohn's disease (CD) and 123 ulcerative colitis (UC) patients were evaluated. In patients with CD, LRG and CRP levels correlated with Harvey-Bradshaw Index (HBI) and Simple Endoscopic Score for CD (SES-CD) (LRG and HBI, r = 0.397; LRG and SES-CD, r = 0.637; CRP and HBI, r = 0.253; CRP and SES-CD, r = 0.332). In patients with UC, LRG and CRP significantly correlated with the partial Mayo score (PMS) and Mayo endoscopic subscore (MES) (LRG and PMS, r = 0.3; CRP and PMS, r = 0.282; LRG and MES, r = 0.424; CRP and MES, r = 0.459). In CD patients with normal CRP, serum LRG level was significantly higher in those with mucosal inflammation than in those with mucosal healing (16.4 vs. 10.7 µg/ mL). Stenosis was associated with serum LRG levels in CD group using multiple regression analysis. Therefore, LRG is a useful biomarker for monitoring disease activity and mucosal inflammation, and indicates the status of intestinal stenosis in IBD patients.

Disturbance of Gastrointestinal Cancers Diagnoses by the COVID-19 Pandemic in a Depopulated Area of Japan: A Population-Based Study in Akita Prefecture.

Disruption of cancer screening programs and diagnoses of gastrointestinal cancers by the COVID-19 pandemic has been reported; however, little attention has been paid to the situation in depopulated areas with low infection rates. Akita Prefecture is one of the most depopulated areas of Japan and has the lowest COVID-19 infection rate per capita; at the same time, the prefecture has been top-ranked for mortality due to gastrointestinal cancer for years. In this population-based study in Akita Prefecture, we investigated the occurrence of gastrointestinal cancers and the number of cancer screening procedures over the five-year period of 2016-2020, employing a database from the collaborative Akita Prefecture hospital-based registration system of cancers. The occurrence of gastrointestinal cancers, especially esophago-gastric cancers, declined by 11.0% in 2020, when the COVID-19 pandemic affected the overall healthcare system, compared with the average of 2016-2019. Nonetheless, the occurrence of advanced-stage (stage IV) esophago-gastric cancers increased by 7.2% in 2020. The decrease in the gastrointestinal cancer diagnosis rate in 2020 coincided with a 30% decline in the total number of regular population-based screening programs. Under the ongoing COVID-19 pandemic, cancer screening was uniformly suspended throughout Japan. Accordingly, the COVID-19 pandemic has substantially disrupted the cancer screening system, leading to delays in diagnoses of gastrointestinal cancer, even in depopulated areas (Akita Prefecture) of Japan with a low prevalence of infection. Suspension of cancer screening procedures during an infectious disease pandemic should be thoroughly considered for each region based on the cancer incidence and infection status in that area.

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.

Does Esophagectomy Provide a Survival Advantage to Patients Aged 80 Years or Older? Analyzing 5066 Patients in the National Database of Hospital-based Cancer Registries in Japan.

OBJECTIVE: To determine whether esophagectomy provides a survival advantage in octogenarians with resectable thoracic esophageal cancer. SUMMARY BACKGROUND DATA: Elderly patients with thoracic esophageal cancer do not always receive the full standard treatment; however, advanced age alone should not preclude the use of effective treatment that could meaningfully improve survival. METHODS: We retrieved the 2008 to 2011 data from the National Database of Hospital-based Cancer Registries from the National Cancer Centerin Japan, divided the patients into a ≥75 group (75-79 years; n = 2935) and a ≥80 group (80 years or older; n = 2131), and then compared the patient backgrounds and survival curves. A multivariable Cox proportional hazards regression model was developed to compare the effects of esophagectomy and chemoradiotherapy in the 2 groups. RESULTS: A significantly greater percentage of patients were treated with esoph-agectomy in the ≥75 group (34.6%) than the ≥80 group (18.4%). Among patients who received esophagectomy, the 3-year survival rate was 51.1% in the ≥ 75 group and 39.0% in the ≥80 group (P < 0.001). However, among patients who received chemoradiotherapy, there was no difference in survival curve between the 2 groups (P = 0.17). Multivariable Cox proportional hazard analysis revealed that esoph-agectomy for clinical Stage ii-iii patients was significantly associated to better survival (adjusted HR: 0.731) (95%CI: 0.645-0.829, P < 0.001) in the ≥75 group but not the ≥ 80 group when compared with chemoradiotherapy. CONCLUSIONS: Many octogenarians do not necessarily get a survival benefit from esophagectomy. However, patients should be evaluated based on their overall health before ruling out surgery based on age alone.

Limited endoscopic mucosal inflammation on equivalent to Mayo endoscopic subscore of 0 unaffect clinical relapse of ulcerative colitis.

BACKGROUND AND AIM: Mayo endoscopic subscore is a simple and validated endoscopic score for ulcerative colitis but the range of inflammation was not considered for scoring. There were few reports analyzing the range of inflammation for clinical relapse using Mayo endoscopic subscore (MES). The aim of this study is to investigate the relapsing potential of limited mucosal inflammation on endoscopic remission equivalent to MES of 0. METHODS: For this retrospective observational study, ulcerative colitis patients underwent total colonoscopy were enrolled. Small mucosal lesion (SML) was defined as limited inflammation of range less than 3 cm. Clinical relapse was analyzed using the Kaplan-Meier curve with log-rank test, and factors associated with clinical relapse was analyzed using the cox proportional hazard regression model. RESULTS: A total of 102 periods with mucosal healing or modified MES of 0 with SML were analyzed. In 12-months observation periods, clinical relapse occurred more frequently in MES of 1 than in MES of 0 or modified MES of 0 with SML, but it was comparable between MES of 0 and modified MES of 0 with SML. When compared to patients with modified MES of 0 with SML, the hazard ratio in patients with MES of 1 (6.55; p = .028) was significantly high but similar in those with MES of 0 (2.59; p = .29). CONCLUSIONS: Small mucosal inflammation in UC does not affect the clinical relapse if most of the mucosa achieved a score similar to MES of 0.

Potent Acid Suppression With Vonoprazan vs Proton Pump Inhibitors Does Not Have Higher Association With Clostridioides difficile Infection.

INTRODUCTION: Proton pump inhibitors (PPIs) are associated with the onset of Clostridioides difficile infection (CDI). Although a new potassium-competitive acid blocker, vonoprazan, consistently shows a more potent acid inhibitory effect in comparison to PPIs, the risk of CDI in vonoprazan-treated patients relative to those treated with PPIs is unknown. In this retrospective case-control study, using a nationwide hospital-based administrative database in Japan, we investigated the association of the onset of CDI in patients treated with vonoprazan. METHODS: A CDI case was defined as a case in which a patient was diagnosed and treated for CDI. For each CDI case, 3 non-CDI patients were extracted as controls. Information on the usage of acid suppressants in the 2 months before the onset of CDI and other confounding factors was collected. Relative associations of gastric acid suppressants with the onset of CDI were estimated. RESULTS: A total of 4,466 CDI cases and 13,220 of non-CDI controls were extracted. A multivariate conditional regression analysis revealed that PPI or vonoprazan use was modestly, but significantly associated with CDI (odds ratio [95% confidence interval]: PPI, 1.3 [1.2-1.4]; vonoprazan, 1.4 [1.2-1.7]). With PPI users as a reference, vonoprazan did not show a stronger association with CDI (odds ratio [95% confidence interval]: 1.07 [0.91-1.26]). DISCUSSION: We found a significant positive association between vonoprazan use and CDI; however, the magnitude of the association was not beyond that in PPI users. This is the first report on any potential adverse effects of vonoprazan.

Effect of acid-reducing agents on clinical relapse in ulcerative colitis with pH-dependent-released 5-aminosalicylic acid: a multicenter retrospective study in Japan.

BACKGROUND/AIMS: 5-Aminosalicylic acid (5-ASA) is a basic drug for inducing and maintaining remission for ulcerative colitis. One of its formulations has a coating with a pH-dependent degradation that ensures the release 5-ASA at the terminal ileum. No evidence has been shown concerning the effects of proton pump inhibitors (PPIs) or H2 receptor antagonists (H2RAs) on the clinical course of ulcerative colitis patients in remission. The present study assessed the effect of PPIs or H2RAs on the relapse of ulcerative colitis patients in clinical remission maintained by pH-dependent released 5-ASA. METHODS: Ulcerative colitis patients who had been prescribed time- or pH-dependent-released 5-ASA between January 2015 and December 2018 were enrolled in this multicenter retrospective study. The period of remission until relapse occurred was analyzed among the patients taking time-dependent-released 5-ASA or pH-dependent-released 5-ASA with/without PPIs or H2RAs. RESULTS: One hundred and nineteen patients were analyzed in this study. In the primary endpoint, the relapse rate was higher in patients taking pH-dependent-released 5-ASA and PPIs or H2RAs than in those taking the pH-dependent-released 5-ASA without PPIs or H2RAs, while the relapse rate was similar in patients taking the time-dependent-released 5-ASA with or without PPIs or H2RAs concomitantly. Patients with a short duration of disease and middle-aged patients more frequently showed relapse with PPIs or H2RAs than the other patients. CONCLUSIONS: The coadministration of PPIs or H2RAs affects the clinical course of ulcerative colitis in remission maintained by pH-dependent-released 5-ASA.

Aggressive Inflammatory Myofibroblastic Tumor without Anaplastic Lymphoma Kinase Gene Rearrangement in the Rectum with Liver Metastasis.

Inflammatory myofibroblastic tumor is a rare intermediate-grade tumor. We herein report the case of an 81-year-old man with rectal ulceration and abnormal retroperitoneal soft tissue with a high serum level of IgG4. The administration of prednisolone reduced the retroperitoneal lesion; however, the rectal ulceration expanded. Surgical resection was performed. A histopathological examination revealed proliferating spindle cells accompanied by inflammatory cells and plasma cells. Liver metastasis emerged two months after surgical resection, and the histology of the proliferating spindle cells sampled by a fine-needle biopsy was similar to that of the rectal tissue. The patient ultimately died of inflammatory myofibroblastic tumor.

Risks for Rebleeding and In-Hospital Mortality after Gastrointestinal Bleeding in a Tertiary Referral Center in Japan.

BACKGROUND: Gastrointestinal bleeding (GIB) is one of the most common medical emergencies. We investigated the overall mortality after GIB in our institute and analyzed the prognostic factors in upper GIB (UGIB) and lower GIB (LGIB) separately. SUMMARY: Between January 2010 and December 2018, 190 patients diagnosed with GIB in our hospital were retrospectively enrolled. Clinical records and biological data were collected. Risks for rebleeding and in-hospital mortality were assessed by a logistic regression analysis. Overall, the rebleeding rate and in-hospital mortality were 22.6 and 7.6%, respectively. GIB itself was not the direct cause of death in any cases. While older age (>65 years) was a significant risk factor for rebleeding in UGIB with an OR of 6.1 and 95% CI of 1.3-29.1, a poorer performance status (PS; ≥3) was a strong risk factor for rebleeding in LGIB, with an OR of 11.8 and 95% CI of 1.7-83.8. Poor PS and tachycardia (>100/min) were significantly associated with mortality in both UGIB and LGIB. In contrast, hypoalbuminemia (<3.0 g/dL) was associated with the mortality in LGIB alone. Key Messages: There were considerable differences in the risk factors for rebleeding and in-hospital mortality between UGIB and LGIB. The overall in-hospital mortality was 7.9% after GIB, including that a substantial portion of patients with GIB died from systemic complications after successful endoscopic hemostasis. Physicians need to diligently perform systematic treatment for GIB, which may be particularly important in societies of advancing aging, like Japan.

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.

Risk Factors Linking Esophageal Squamous Cell Carcinoma With Head and Neck Cancer or Gastric Cancer.

GOALS: To investigate retrospectively the risk factors for synchronous and metachronous cancers in the upper gastrointestinal tract in patients with superficial esophageal squamous cell carcinoma (ESCC). BACKGROUND: In patients who have received endoscopic resection (ER) for ESCC, synchronous and metachronous cancers are frequently detected not only in the esophagus but also in the head and neck area and the stomach. STUDY: A total of 285 patients who received ER for superficial ESCC were enrolled in this analysis. These patients were periodically followed-up endoscopically. Cumulative occurrence rates of the metachronous second primary cancers were determined by Kaplan-Meier method. Risk factors for synchronous and metachronous cancers in the head and neck area and the stomach were determined by logistic regression analyses. RESULTS: During a mean follow-up period of 76 months, the 5-year cumulative occurrence of metachronous esophageal, head and neck, and stomach cancer was 14.0%, 2.8%, and 4.1%, respectively. Although the presence of multiple lugol-voiding lesions in the esophagus was a significant risk factor for synchronous and metachronous head and neck cancers (odds ratio, 3.8; 95% confidence interval, 1.7-9.0), older age (>65 y) was a significant risk factor for synchronous and metachronous gastric cancer (odds ratio, 3.1; 95% confidence interval, 1.2-9.3). CONCLUSIONS: The risk factors for the cooccurrence of head and neck cancer and that of gastric cancer in patients with ESCC differ. This information will likely be useful for managing patients who have been treated with ER for ESCC and who possess carcinogenic potential throughout the upper gastrointestinal tract.

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.

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

BACKGROUND: At present, squamous cell carcinoma accounts for most esophageal cancers in Japan; however, there is concern that the incidence of esophageal adenocarcinoma in Japan is increasing in comparison to Western countries. Akita Prefecture, with a population of 1 million, has the highest rate of esophageal cancer-associated mortality in Japan; the vast majority of these cases are squamous cell carcinoma. The aim of the present study was to investigate the latest trends in the incidence of esophageal adenocarcinoma in Akita Prefecture using a registration system. METHODS: We examined the data from a collaborative hospital-based registration system for cancer patients. Eleven of the main hospitals in Akita Prefecture participate in this system, which covers 90% of the cancer cases in the region and which provides near population-based data. Using this registration system, we examined the sequential trends in the percentage of adenocarcinoma cases in relation to total esophageal cancer cases in Akita Prefecture from 2007 to 2014. RESULTS: In 2007-2014, a total of 2527 esophageal cancer patients were registered in the system. Among these, only 43 (1.8%) had adenocarcinoma. However, the number of adenocarcinoma patients gradually increased from 1 case in 2007 to 14 cases in 2014. Consequently, the percentage of adenocarcinoma cases showed a significant increase from 0.66% in the first 4 years of the study period to 2.5% in the latter 4 years of the study period (P < 0.01). CONCLUSIONS: The latest hospital-based registration data for 2007-2014 suggest that the incidence of esophageal adenocarcinoma may have begun to increase in Akita Prefecture; this may reflect recent trends in other parts of Japan.