Macroscopic qualitative evaluation of solid pancreatic lesion specimens from endoscopic ultrasound-guided fine needle aspiration/biopsies.

OBJECTIVES: To pathologically clarify the macroscopic features of endoscopic ultrasound-guided fine needle aspiration/biopsy (EUS-FNA/B) specimens in representative pancreatic diseases and establish tissue-handling standards based on the macroscopic findings. METHODS: We gathered EUS-FNA/B specimens of cases at our institution with the final diagnoses of pancreatic ductal adenocarcinoma (PDAC, n = 172), neuroendocrine tumor (NET, n = 19), and chronic inflammatory lesion (CIL, n = 24) including autoimmune pancreatitis. We classified the specimens' macroscopic features in five categories (red strings, mixed-red-and-white strings, white cores, gray tissues, gelatinous tissues) and compared the specimens' features on cytological and histological slides. RESULTS: All five macroscopic categories were observed in variable combinations in the PDACs; red strings and white cores predominated in the NETs and CILs. White cores represented neoplastic (PDAC, NET) or lesion (CIL) tissues. Mixed-red-and-white strings were unique to PDACs and contained cancerous cells. Neoplastic cells were numerous in red strings in NETs but not the other groups. Gray and gelatinous tissues represented necrosis and mucin, respectively, and the former were almost exclusively observed in PDACs. Red strings, mixed-red-and-white strings, and white cores were suitable for histological examination, whereas gray and gelatinous tissues were suitable for cytological examination. The white cores, mixed-red-and-white strings, and gelatinous tissues may be composed of non-neoplastic tissues such as contaminated gastrointestinal epithelium. In seven PDACs, although white cores were obtained, a histological diagnosis was not established. CONCLUSIONS: Macroscopic evaluations of EUS-FNA/B can enable the identification of specimen components and a possible diagnosis. They also contribute to the selection of the optimal tissue-handling methods.

Long-term outcomes of drug-induced autoimmune-like hepatitis after pulse steroid therapy.

AIM: Pulse steroid therapy occasionally causes drug-induced autoimmune-like hepatitis (DI-ALH), but the long-term outcome of treated patients is not well known. In this study, we investigated the long-term outcomes of DI-ALH due to pulse steroid therapy. METHODS: We retrospectively reviewed the medical records of 405 patients treated with pulse high-dose methylprednisolone in Kurashiki Central Hospital. The frequency and clinicopathological characteristics of acute liver injury that occurred within 3 months after the therapy were analyzed. The diagnosis of DI-ALH was made according to the revised international autoimmune hepatitis group criteria. RESULTS: Among the 405 patients treated with methylprednisolone, 61 (15.1%) had acute liver injury after the pulse steroid therapy, and DI-ALH was diagnosed in five patients (1.2%). Absence of oral prednisolone tapering after the pulse steroid therapy was a significant risk factor for the subsequent development of DI-ALH (odds ratio 11.9; p = 0.017). One patient was treated with 3 days of intravenous methylprednisolone followed by oral prednisolone. Two patients were treated with glycyrrhizin followed by oral prednisolone due to ineffectiveness of glycyrrhizin. Remission was achieved with glycyrrhizin alone, and spontaneous remission without drug therapy occurred in one patient each. During the median follow-up period of 34 months, no relapse was evident in all the patients without maintenance therapy. CONCLUSIONS: Pulse steroid therapy can cause DI-ALH, especially when subsequent prednisolone is not tapered. Prednisolone is effective for DI-ALH due to pulse steroid therapy, and can be safely withdrawn once remission is achieved.

[Antiemetic Therapy for Vomiting and Nausea Related to Hepatic Arterial Infusion Chemotherapy Using Cisplatin in Patients with Hepatocellular Carcinoma].

Combination therapy using multiple antiemetic drugs is recommended for intravenous administration of cisplatin, a highly emetogenic agent, whereas a 5-HT3 receptor antagonist alone is commonly used in hepatic arterial infusion chemotherapy using cisplatin for hepatocellular carcinoma owing to its less toxicity than that in the intravenous administration. Given that optimal antiemetic therapy is not yet established, we retrospectively investigated the efficacy of antiemetic drugs for hepatic arterial infusion chemotherapy using cisplatin. This study enrolled 72 patients with hepatocellular carcinoma who received hepatic arterial infusion chemotherapy using cisplatin at Kurashiki Central Hospital between January 2011 and May 2019. A 5-HT3 receptor antagonist was used in all cases, while aprepitant and/or dexamethasone were used concomitantly in 6 cases. After chemotherapy, a complete response rate for 5 days was achieved in 73.6% of the patients; however, complete control could be achieved only in 29.2%. During these 5 days, both rates were lower on days 2-5 than on day 1. In addition, younger age was associated with worse control rates. Our findings suggest that more effective antiemetic therapy is needed for hepatic arterial infusion chemotherapy using cisplatin, especially in non-elderly patients.

Two Types of Polyp Shape Observed in the Stomach of Patients with Peutz-Jeghers Syndrome.

The characteristics of gastric polyps in patients with Peutz-Jeghers (PJ) syndrome (PJS) have not been fully investigated. The objective of this study was to reveal the endoscopic and pathologic findings of gastric polyps in patients with PJS. We reviewed 11 patients with PJS treated at 6 institutions, and summarized the endo-scopic and pathologic features of their gastric polyps. The polyps were mainly classified into 2 types: (i) soli-tary or sporadic polyps > 5 mm, reddish in color with a sessile or semi-pedunculated morphology (n = 9); and (ii) multiple sessile polyps ≤ 5 mm with the same color tone as the peripheral mucosa (n = 9). Patients who underwent endoscopic mucosal resection for polyps > 5 mm were diagnosed with PJ polyps (n = 2), whereas those who underwent biopsy were diagnosed with hyperplastic polyps. Polyps ≤ 5 mm were pathologically diagnosed as fundic gland polyps or hyperplastic polyps. This study revealed that patients with PJS present with 2 types of polyps in the stomach. Endoscopic mucosal resection of polyps > 5 mm seems necessary for the pathologic diagnosis of PJ polyps.

Efficacy and safety of cold forceps biopsy for diminutive pharyngeal neoplasms: Single-center, prospective pilot study.

BACKGROUND: Management of diminutive pharyngeal neoplasms is controversial. Thus, we conducted a single-center, prospective pilot study to investigate the efficacy and safety of endoscopic excision with cold forceps biopsy (CFB) of these lesions. PATIENTS AND METHODS: Thirty-nine lesions endoscopically diagnosed with narrow-band imaging as pharyngeal neoplasms of 3 mm or smaller were excised with CFB using jumbo biopsy forceps (cap diameter 2.8 mm, jaw volume 12.4 mm3 ). The primary outcome was endoscopically determined local remnant/recurrence rate 3 months after CFB. The secondary outcomes were histopathologically determined local remnant/recurrence rate; risk factors associated with the endoscopic remnant/recurrence; and incidence of intraoperative or delayed bleeding and other adverse events. RESULTS: Histological diagnosis of the 39 CFB-excised lesions were: 11 high-grade dysplasia (28.2%), 22 low-grade dysplasia (56.4%), two basal cell hyperplasia (5.1%) and four atypical squamous epithelium (10.3%).Twenty-seven patients (30 lesions) underwent follow-up endoscopy 3 months after CFB; the endoscopic and pathological local remnant/recurrence rate was 20% (6/30; 95% confidence interval (CI), 7.7-36.6%) and 16.7% (5/30; 95% CI, 5.6-34.7%), respectively. Location of the lesion in the hypopharynx was a significant risk factor associated with the endoscopic local remnant/recurrence (P = 0.049). No significant adverse events occurred. CONCLUSIONS: Cold forceps biopsy with jumbo biopsy forceps appears to be a safe and effective technique for excising diminutive pharyngeal neoplasms. Although small, the excised lesions may have a remarkably high frequency of high-grade dysplasia. (Clinical trial registration number: UMIN000037980).

[Nivolumab‒Induced Severe Thrombocytopenia in a Patient with Advanced Gastric Cancer].

Here, we report a case of severe thrombocytopenia induced by nivolumab. A 70‒year‒old woman with advanced gastric cancer was treated with nivolumab. After the first dose, she noticed an erythematous rash. During the second cycle, fever and purpura on the lower extremities were also noted. Laboratory examinations revealed severe thrombocytopenia of grade 4, mild hemolytic anemia, leukopenia, and coagulopathy. Immune‒related adverse events(irAE)were suspected, and we started 40 mg(0.7 mg/kg)prednisolone(PSL)per day. Her symptoms and laboratory data immediately improved. However, when we reduced the dose of PSL, she developed rash and thrombocytopenia again. We increased the dose of PSL to 40 mg, which was effective for improving these abnormalities. We then gradually reduced the PSL, paying attention to avoid a relapse of irAEs. We could not restart chemotherapy thereafter, and she died from progression of gastric cancer. As shown in this case, PSL is effective for immune‒related thrombocytopenia; however, determining how to reduce the dose of PSL and when to restart chemotherapy requires careful consideration.

Impact of submucosal saline solution injection for cold snare polypectomy of small colorectal polyps: a randomized controlled study.

BACKGROUND AND AIMS: Cold snare polypectomy (CSP) of small colorectal polyps is widely used. However, the technique is still troubled by insufficient resection depth, which may prevent precise pathologic evaluation. In this study, we investigated whether submucosal injection of saline solution helps to achieve deeper resection in CSP. METHODS: The study was a single-center, prospective, randomized trial. Patients with small (3- to 10-mm diameter) nonpedunculated adenomatous or sessile serrated colorectal polyps were randomly allocated to either conventional CSP (C-CSP) or CSP with submucosal injection (CSP-SI). Primary outcome was the rate of complete muscularis mucosae (MM) resection, defined by the proportion of MM under the tumor more than 80% of the tumor's horizontal dimension. Secondary outcomes were the rates of negative lateral and vertical margins, fragmentation of resected specimens, conversion to hot snare mucosal resection, intraprocedural bleeding, delayed bleeding, and perforation. RESULTS: Two hundred fourteen patients were randomly assigned to the CSP-SI (n = 107) or C-CSP (n = 107) group. The rate of complete MM resection was 43.9% in the CSP-SI group and 53.3% in the C-CSP group, a statistically insignificant difference. The rates of negative lateral margin and vertical margin (42.3% and 56.7%, respectively) in the CSP-SI group were significantly lower than those (58% and 76%) in the C-CSP group (P = .03 and P = .006, respectively). There was no polypectomy-related major bleeding or perforation. CONCLUSIONS: Saline solution injection into the submucosa did not improve the resection depth of CSP of small colorectal polyps, and the method resulted in lower rates of negative lateral and vertical margins of resected lesions. (Clinical trial registration number: UMIN000037980.).

Effect of Vonoprazan on Delayed Bleeding after Endoscopic Submucosal Dissection for Gastric Neoplasia among Antithrombotic Drug Users: A Single-Center, Single-Arm Prospective Observational Case Control Study.

Antithrombotic therapy is a major risk factor for delayed bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasia. A potassium-competitive acid blocker, vonoprazan, is expected to prevent delayed bleeding better than conventional proton pomp inhibitors (PPIs), but the evidence is controversial. We sought to clarify the efficacy of vonoprazan for prevention of delayed bleeding after gastric ESD in patients under antithrombotic therapy. We prospectively registered 50 patients who underwent gastric ESD while receiving antithrombotic therapy and vonoprazan in our institution between October 2017 and September 2018. The incidence of delayed bleeding was compared with that in a historical control group of 116 patients treated with conventional PPI. We also evaluated risk factors associated with delayed bleeding. Delayed bleeding was observed in 8 of 50 patients (16.0%), which was not dissimilar from the incidence in the historical control group (12.1%) (p=0.49). In the univariate analysis, age (> 70 years) (p=0.034), multiple antithrombotic drug use (p<0.01), procedure time (> 200 min) (p=0.038) and tumor size (> 40 mm) (p<0.01) were associated with delayed bleeding after gastric ESD, but vonoprazan was not (p=0.49). Vonoprazan may not be more effective than conventional PPIs in preventing delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Post-polypectomy bleeding in hot-snare polypectomy of colonic polyps under continued warfarin or short interruption of direct oral anticoagulants.

BACKGROUND: Newly published guidelines of the Japanese Gastroenterological Endoscopy Society (JGES) suggest to consider endoscopic procedures with high risk of bleeding without stopping warfarin and with stopping direct oral anticoagulants (DOACs) only on the day of the procedure. In this study, we aimed to test the validity of these recommendations. PATIENTS AND METHODS: We retrospectively reviewed medical records of 344 patients with anticoagulant therapy who underwent hot-snare polypectomy between January 2012 and October 2018. Patients (n = 132) with interruption of anticoagulants (3-7 days for warfarin and 2-3 days for DOACs before the procedure) and without heparin-bridging were excluded. Among the remaining 212 patients, the incidence of post-polypectomy bleeding was compared between the following 2 patient groups: patients who had interruption of anticoagulants with heparin-bridging (HB group, n = 139) and patients treated according to the new JGES guideline (FG group, n = 73). RESULTS: The rate of post-polypectomy bleeding (PPB) in FG group (9.6%) was not significantly different from that in HB group (12.9%, p = 0.5). In subgroup analysis, the incidence of bleeding in patients with warfarin (12.2%) and with DOAC (6.3%) in FG group was not significantly different from corresponding figures in HB group (14.2%, 0%). In multivariate analysis, number of resected polyps was associated with PPB, but the administration of anticoagulants according to the new guidelines was not a significant risk factor for PPB (p = .98). CONCLUSIONS: Our study affirms the recommendations of JGES for the management of anticoagulants in patients who undergo colonic polypectomy regarding post-polypectomy bleeding.

[Recurrence of malignant lymphoma immediately after treatment for hepatitis C virus using direct-acting antivirals].

A Japanese male in his 70s with chronic hepatitis C was diagnosed with diffuse large B-cell lymphoma and achieved and maintained complete remission following treatment with eight cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisolone). Seven years later, he received the direct-acting antivirals (DAAs) sofosbuvir/ledipasvir for hepatitis C virus (HCV) genotype 1b. Although the patient achieved sustained virological response immediately after the initial treatment period, laboratory data showed elevation of LD and soluble IL-2R. Computer tomography showed diffuse intraabdominal lymph node swelling and splenomegaly. Lymph node biopsy revealed the relapse of lymphoma. The lymphoma cells were resistant to chemotherapy, and the patient died five months later. Several studies reported early recurrence of hepatocellular carcinoma after HCV treatment using DAAs. However, the relationship between DAAs and hepatocellular carcinoma recurrence remains unclear. Nonetheless, possible cancer recurrence should be considered in patients with a history of lymphoma who are prescribed DAAs to treat HCV.

[Sclerosing mesenteritis diagnosed using computed tomography- and ultrasound-guided needle biopsy -utility of the coaxial technique].

Here, we report the case of an 82-year-old woman with sclerosing mesenteritis diagnosed using needle biopsy under the guidance of computed tomography (CT) and ultrasound (US). The patient manifested appetite loss, weight loss, and epigastric pain. CT of the abdomen and pelvis revealed increased density of the mesentery adjacent to the small bowel along with enlarged lymph nodes. Hence, we suspected sclerosing mesenteritis but also considered malignancies, such as lymphoma. We then performed CT- and US-guided needle biopsy with coaxial technique. We inserted an introducer needle by verifying its location using CT and extracted multiple specimens using a finer needle that passed through the introducer without incident. The collected specimens were adequate and histological diagnosis revealed sclerosing mesenteritis. We treated the patient with corticosteroids, and her symptoms and radiographic findings improved. Thus, the coaxial technique was a useful and minimally invasive tool for the diagnosis of sclerosing mesenteritis.

Risk factors for recurrent bleeding from acute hemorrhagic rectal ulcer.

OBJECTIVES: Acute hemorrhagic rectal ulcer (AHRU) occurs suddenly with painless massive bleeding from rectal ulcers, usually in patients who have severe underlying disorders. The rate of recurrent bleeding from AHRU is high, but there have been few studies on the risk factors for recurrent bleeding. The aim of this study was to identify risk factors for recurrent bleeding from AHRU. METHODS: Among 27,151 patients who underwent colonoscopy from 2006 November to 2017 March in our hospital, 120 patients with AHRU were retrospectively reviewed to identify risk factors for recurrent bleeding. Factors analyzed were: age, sex, Charlson Comorbidity Index (CCI), comorbidities (congestive heart failure, liver cirrhosis, renal failure, respiratory failure, diabetes mellitus and malignancy), medications (antiplatelet drugs, anticoagulants and steroids); endoscopic therapy and endoscopic features of AHRU. RESULTS: Recurrent bleeding from AHRU occurred in 30% of patients (36/120). In multi-variate analysis, individual comorbidities, medications, endoscopic features and endoscopic hemostasis were not significant or independent risk factors for recurrent bleeding. However, a high CCI score (4 or more) was a risk factor (odds ratio, 7.0; 95% confidence interval, 1.8-27.1). Endoscopic hemostasis was performed in 61% (73/120) of AHRU patients, and successful hemostasis was achieved in 99% of the treated patients (72/73). CONCLUSIONS: High CCI score was a predictor of recurrent bleeding from AHRU, but individual comorbidities, medications, endoscopic features or endoscopic hemostasis were not. Endoscopic hemostasis for bleeding from AHRU was achieved in most patients, but the recurrent bleeding rate was high.

Safety of cold polypectomy for small colorectal neoplastic lesions: a prospective cohort study in Japan.

BACKGROUND: Cold polypectomy has been widely accepted for removal of small colorectal polyps. However, no large-scale prospective study exists as for its safety in Japan. We investigated this issue in this single-center, prospective cohort study in a total of 1198 colorectal polyps resected with cold polypectomy. PATIENTS AND METHODS: Four hundred and seventy-four patients who underwent cold polypectomy for colorectal neoplastic lesions less than 10-mm diameter between September 2014 and October 2016 were enrolled. Primary outcome was the incidence of delayed bleeding within 2 weeks after the procedure. Secondary outcomes were the rate of immediate bleeding, perforation, endoscopic en bloc resection, and advanced histology. RESULTS: Cold polypectomy was performed on 1198 polyps in the 474 patients. No delayed bleeding or colonic perforation was observed. Immediate bleeding during the procedure, requiring endoscopic hemostasis, occurred in 97 lesions (8.1%), and all of them were successfully managed endoscopically. The endoscopic en bloc resection rate was 97.2%. Twenty-eight lesions (2.3%) were histologically diagnosed as advanced neoplasia; among them, three lesions were well-differentiated adenocarcinomas, and in two of them, a negative margin was not histologically confirmed. CONCLUSIONS: Cold polypectomy for small colorectal polyps is a safe technique without significant complication, but careful endoscopic diagnosis at cold polypectomy is necessary to identify advanced neoplasia. The reliability of cold polypectomy in excision of polyps with high-grade neoplasia should be established before the procedure becomes standard in the excision of small colorectal polyps. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000014812.

Multicenter Prospective Study on the Safety of Upper Gastrointestinal Endoscopic Procedures in Antithrombotic Drug Users.

BACKGROUND: The Japan Gastroenterological Endoscopy Society updated its guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment in July 2012. However, the safety of endoscopic procedures in antithrombotic drug users has not been fully investigated. AIMS: To evaluate the safety of upper gastrointestinal endoscopic procedures in antithrombotic drug users. METHODS: From September 2013 to September 2015, patients who were taking antithrombotic drugs and who underwent upper gastrointestinal endoscopic procedures were prospectively enrolled at five hospitals. Incidences of bleeding and thrombosis during endoscopic procedures were evaluated. RESULTS: A total of 270 patients [221 for endoscopic mucosal biopsy and 49 for endoscopic mucosal resection (EMR)/endoscopic submucosal dissection (ESD) were enrolled. The bleeding rate was 0.9% for endoscopic mucosal biopsy and 22% for EMR/ESD, respectively. The bleeding rate after endoscopic mucosal biopsy was not significantly high, even if antithrombotic drugs were continued (0 vs. 1%, P > 0.99), while it was significantly higher among multiple antithrombotic drug users than single drug users (5.9 vs. 0%, P < 0.05). The bleeding rate after EMR/ESD was also higher among multiple antithrombotic drug users than single drug users, but was not significantly different (33 vs. 14%, P = 0.17). Moreover, there were no differences in bleeding rates according to the cessation or continuance of antithrombotic drugs (20 vs. 25%, P = 0.74). There were no thromboembolisms in all cases. CONCLUSIONS: Upper gastrointestinal endoscopic procedures performed under the new guidelines appear acceptable. However, endoscopic procedures among multiple antithrombotic drug users show a greater potential for bleeding.

Two cases of acute gastric dilation after radiofrequency catheter ablation for supraventricular arrhythmia.

We describe our experience with two cases of acute gastric dilation after radiofrequency catheter ablation (RFCA) for supraventricular arrhythmia. After the RFCA procedure, patients experienced epigastric pain, abdominal distension, and vomiting. Computed tomography showed marked dilation of their stomachs, but without apparent obstruction of the gastric antrum or the duodenum. Esophagogastroduodenoscopy and upper gastrointestinal series revealed significant gastroparesis. We considered that gastric hypomotility had been induced by vagus nerve injury after RFCA. Peristaltic stimulants effectively improved the patients' symptoms by improving gastric motility. There have been few reports of acute gastric dilation after RFCA in Japan to date, but the possibility of encountering this condition is expected to increase in parallel with the recent increased use of RFCA. Therefore, gastroenterologists should be alert to this rare complication.

Risk factors for active bleeding from colonic angiodysplasia confirmed by colonoscopic observation.

PURPOSE: Colonic angiodysplasia is an important cause of lower gastrointestinal bleeding in the elderly. Here, we investigated the risk factors for bleeding from colonic angiodysplasia seen at endoscopy. METHODS: We conducted a retrospective case-control study by reviewing records of 435 patients with angiodysplasia at colonoscopy from November 2006 to November 2015 in our hospital. To identify risk factors for active bleeding, the following were analyzed: age, sex, comorbidities, use of antithrombotic drugs and non-steroidal anti-inflammatory drugs, and the size and location of the lesions. RESULTS: Among the 435 patients, active bleeding from angiodysplasia was observed at endoscopy in 29 patients (6.7 %). Using multivariate analysis, we identified advanced age (odds ratio 5.15, 95 % confidence interval, 1.61-16.5), comorbidity of heart disease (6.88, 1.04-45.5), use of anticoagulant drug (4.22, 1.21-14.7), multiple lesions (6.67, 1.77-25.2), and small lesions (≤5 mm) (17.7, 4.90-64.0) as independent and significant risk factors for active bleeding. Actively bleeding colonic angiodysplasia lesions were very small in most cases (1-2 mm, 24/29, 83 %) and predominantly located in the right-side colon (26/29, 90 %). All of the 29 patients with active bleeding were successfully and safely treated endoscopically, but re-bleeding occurred in nine patients (31 %, 9/29) during the follow-up period of 2-84 months. CONCLUSIONS: Multiple and small colonic angiodysplasia lesions in patients of advanced age, with heart disease, or receiving anticoagulants have increased risk for bleeding. We should be aware that small colonic angiodysplasia lesions in the right-side colon at colonoscopy in these patients may be a source of bleeding.

The preventive effects of low-dose enteric-coated aspirin tablets on the development of colorectal tumours in Asian patients: a randomised trial.

OBJECTIVE: To evaluate the influence of low-dose, enteric-coated aspirin tablets (100 mg/day for 2 years) on colorectal tumour recurrence in Asian patients with single/multiple colorectal tumours excised by endoscopy. DESIGN: A double-blinded, randomised, placebo-controlled multicentre clinical trial was conducted. PARTICIPANTS: 311 subjects with single/multiple colorectal adenomas and adenocarcinomas excised by endoscopy were enrolled in the study (152 patients in the aspirin group and 159 patients in the placebo group). Enrolment began at the hospitals (n=19) in 2007 and was completed in 2009. RESULTS: The subjects treated with aspirin displayed reduced colorectal tumourigenesis and primary endpoints with an adjusted OR of 0.60 (95% CI 0.36 to 0.98) compared with the subjects in the placebo group. Subgroup analysis revealed that subjects who were non-smokers, defined as those who had smoked in the past or who had never smoked, had a marked reduction in the number of recurrent tumours in the aspirin-treated group. The adjusted OR for aspirin treatment in non-smokers was 0.37 (CI 0.21 to 0.68, p<0.05). Interestingly, the use of aspirin in smokers resulted in an increased risk, with an OR of 3.44. In addition, no severe adverse effects were observed in either group. CONCLUSIONS: Low-dose, enteric-coated aspirin tablets reduced colorectal tumour recurrence in an Asian population. The results are consistent with those obtained from other randomised controlled trials in Western countries. THE CLINICAL TRIAL REGISTRY WEBSITE AND THE CLINICAL TRIAL NUMBER: http://www.umin.ac.jp (number UMIN000000697).

Prevalence of Helicobacter pylori infection by birth year and geographic area in Japan.

BACKGROUND: Helicobacter pylori (H. pylori)-related diseases are responsible for a tremendous amount of morbidity and mortality in Japan. We estimated the prevalence of H. pylori infection by sex, birth year, and geographic area among Japanese adults. MATERIALS AND METHODS: This cross-sectional study included 14,716 subjects aged 20 years or more who underwent a health checkup between May 1997 and March 2013 in seven geographic areas throughout Japan. Relevant information on the demographics and status of H. pylori infection was retrieved from the electronic database. The univariate log-binominal regression model was used to estimate the prevalence of H. pylori infection, taking birth year into consideration. The multivariate log-binominal regression model was used to compare the prevalence of H. pylori infection between seven geographic areas. RESULTS: The overall prevalence of H. pylori infection was 37.6% in women and 43.2% in men. Among seven geographic areas, Hokkaido showed the lowest prevalence (29.4%), while Yamagata Prefecture represented the highest (54.5%). The prevalence of H. pylori infection was highest in the 1940-1949 birth cohort and then decreased in the ensuing birth cohorts; the risk ratio (RR) was 0.85 (95% confidence interval (CI) 0.84-0.87) for changes in the 10-year birth cohort. Individuals in Yamagata Prefecture had the highest RR of acquiring H. pylori infection in all three birth cohorts (RR = 1.53 for 1940, RR = 1.69 for 1950, and RR = 1.85 for 1960) when compared with those in Hokkaido. CONCLUSIONS: The prevalence of H. pylori infection increases with age and exhibits geographic variation in Japan. There has been a striking decrease in the prevalence of H. pylori infection, especially in younger Japanese populations.