Publications by authors named "Yasushi Oda"
Background And Aim: The risk of colorectal cancer among fecal immunochemistry test-positive individuals who had undergone previous colonoscopies remains unclear. Therefore, this study aimed to determine the differences in the risk of colorectal cancer among fecal immunochemistry test-positive individuals according to the timing of their previous colonoscopies.
Methods: This multicenter, retrospective, observational study was conducted in Japan as a subgroup analysis of the J-SCOUT study (UMIN000040690), which integrated and analyzed a database comprising all colonoscopies performed at participating Japanese institutions between 2010 and 2020.
Article Synopsis
- * A total of 82,005 colonoscopy cases were analyzed, revealing 71 identified colorectal NENs, which corresponds to a detection rate of 0.087%. Most cases were small lesions in the rectum.
- * Findings suggest that the detection rate of colorectal NENs during colonoscopy is higher than previously anticipated, indicating the importance of thorough screening.
Article Synopsis
- The study investigates how colonoscopy insertion and withdrawal times affect the adenoma detection rate (ADR), which is important for cancer screening effectiveness.
- Using data from a large sample of colonoscopies performed by various endoscopists in Japan, researchers found that longer cecal insertion times were linked to lower ADRs, while longer withdrawal times were associated with higher ADRs.
- The findings suggest that both insertion and withdrawal times should be considered as quality indicators for colonoscopy procedures.
Background & Aims: To date, no regional evidence of long-term colorectal cancer (CRC) risk reduction after endoscopic premalignant lesion removal has been established. We aimed to analyze this over a long-term follow-up evaluation.
Methods: This was a prospective cohort study of participants from the Japan Polyp Study conducted at 11 Japanese institutions.
Objectives: To examine whether reasonable detection rate of endoscopically diagnosed lesions as adenoma ("endoscopic" adenoma detection rate [ADR]) could be calculated with a database generated from colonoscopy reports and whether it could be used as a surrogate colonoscopy quality indicator of "pathological" ADR.
Methods: A lesion-by-lesion database of colonoscopies performed between 2010 and 2020 at eight Japanese endoscopy centers and corresponding pathology database were integrated. Differences in numbers of detected polyps, "endoscopic" and "pathological" adenomas, and what these differences could be attributed to were examined.
Background: This is the first report from a multicenter prospective cohort study of colorectal neuroendocrine tumor (NET), the C-NET STUDY, conducted to assess the long-term outcomes of the enrolled patients. This report aimed to elucidate the clinicopathological features of the enrolled patients and lesions.
Methods: Colorectal NET patients aged 20-74 years were consecutively enrolled and followed up at 50 institutions.
Article Synopsis
- A study analyzed the impact of findings from initial and first surveillance colonoscopies on the risk of advanced neoplasia in participants who had undergone multiple colonoscopies.
- Patients were grouped into four categories based on their colonoscopy results: normal findings, no high-risk results, one high-risk finding, and high-risk findings in both.
- Results showed that those with high-risk findings in both colonoscopies (Category D) had a significantly higher incidence of advanced neoplasia (27.4%) compared to those with normal findings (Category A) at only 4.0%, indicating a need for better risk stratification in colonoscopy follow-up.
Objective: To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).
Design: A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions.
Article Synopsis
- A study in Japan explored how baseline colonoscopy findings affect the risk of advanced neoplasia over a 5-year period, focusing on 3115 individuals over 40 years old who had repeat colonoscopies.
- The results showed that those with advanced adenomas and invasive cancer had a significantly higher risk of developing advanced neoplasia compared to those with no neoplasia or small adenomas.
- The findings suggest that using baseline colonoscopy results can help tailor the frequency of surveillance colonoscopies for better patient outcomes.
Background And Aim: Right colon polyps can especially be overlooked when they are located on the backs of haustral folds. Previous studies have reported that repeated forward-view examinations in the right colon were effective in reducing adenoma miss rates. The aim of this study was to clarify the impact of retroflexion in the right colon after repeated forward-view examinations.
View Article and Find Full Text PDFBackground And Aim: The impact of frequent colonoscopy on colorectal cancer (CRC) remains unclear. The present study aimed to determine the relationship between frequency of surveillance colonoscopy and CRC prevention.
Methods: From April 2010 to April 2011, patients who underwent surveillance colonoscopy after screening and polypectomy in four Japanese endoscopy centers were enrolled in this multicenter historical cohort study.
A hyperplastic polyp (HP) >10 mm is described as a large hyperplastic polyp (LHP). Previous studies have considered LHP and sessile serrated adenoma/polyp (SSA/P) as synonymous. Although HP and SSA/P have previously been morphologically distinguished, differences between LHP and SSA/P have not yet been reported.
View Article and Find Full Text PDFBackground & Aims: Flat- and depressed-type neoplasias along with laterally spreading tumors (LSTs) have been reported in colorectal neoplasias. We estimated the prevalence of flat and depressed types and LSTs along with their proportion among advanced neoplasias in a large average-risk population undergoing screening colonoscopy.
Methods: This was a cross-sectional study performed at a single, general community institution, with subjects who were 40 to 79 years old, asymptomatic, and who had undergone their first colonoscopy for screening between 2003 and 2009 (n = 4910).
Objective: The National Polyp Study is used as the basis of recommendations for colonoscopic surveillance after polypectomy, establishing an interval of 3 years after removal of newly diagnosed adenomas. The aim of this retrospective cohort study was to estimate the incidence of advanced neoplasia after initial colonoscopy and compare the differences among risk groups.
Methods: Patients over 40 years who were referred for initial colonoscopy at six institutes were selected.
Background & Aims: Adenomatous polyps are main precursors of colorectal cancers (CRCs). In Japan, de novo cancers, which do not arise from preexisting adenomas, are considered to account for a substantial number of CRCs, but the relative importance of de novo carcinogenesis remains controversial. This study estimated the proportion of de novo cancers among CRCs in Japan.
View Article and Find Full Text PDFPurpose: Somatostatin analogs have been administered to patients with pancreatic endocrine tumors in an attempt to inhibit hormone hypersecretion and prevent tumor growth. It is speculated that their efficacy is correlated with the expression of specific subtypes of somatostatin receptors. The aim of this study was to immunohistochemically evaluate the expression of somatostatin receptor subtypes in human pancreatic endocrine tumors, and to determine whether the expression of these subtypes is correlated with the effectiveness of the somatostatin analogs.
View Article and Find Full Text PDFBackground: Acute pancreatitis can develop after either ERCP or endoscopic sphincterotomy (ES). The pathogenesis of this complication remains poorly understood.
Methods: The frequency and severity of acute pancreatitis were retrospectively evaluated after 17,602 ERCP procedures and 3003 ES procedures.