Methylation analysis of DCC gene in saliva samples is an efficient method for non-invasive detection of superficial hypopharyngeal cancer.

BACKGROUND: Advances in upper gastrointestinal endoscopic technology have enabled early detection and treatment of hypopharyngeal cancer. However, in-depth pharyngeal observations require sedation and are invasive. It is important to establish a minimally invasive and simple evaluation method to identify high-risk patients. METHODS: Eighty-seven patients with superficial hypopharyngeal cancer and 51 healthy controls were recruited. We assessed the methylation status of DCC, PTGDR1, EDNRB, and ECAD, in tissue and saliva samples and verified the diagnostic accuracy by methylation analyses of their promoter regions using quantitative methylation-specific PCR. RESULTS: Significant differences between cancer and their surrounding non-cancerous tissues were observed in the methylation values of DCC (p = 0.003), EDNRB (p = 0.001), and ECAD (p = 0.043). Using receiver operating characteristic analyses of the methylation values in saliva samples, DCC showed the highest area under the curve values for the detection of superficial hypopharyngeal cancer (0.917, 95% confidence interval = 0.864-0.970), compared with those for EDNRB (0.680) and ECAD (0.639). When the cutoff for the methylation values of DCC was set at ≥0.163, the sensitivity to detect hypopharyngeal cancer was 82.8% and the specificity was 90.2%. CONCLUSIONS: DCC methylation in saliva samples could be a non-invasive and efficient tool for early detection of hypopharyngeal cancer in high-risk patients.

Long-term monitoring of gastric mucosa-associated lymphoid tissue lymphoma in patients with extra copies of the MALT1 gene.

The objective of this study was to clarify the long-term prognosis of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma with additional copies of MALT1. In this multicenter retrospective study, we enrolled 145 patients with gastric MALT lymphoma who underwent fluorescence in situ hybridization (FISH) analysis to detect t(11;18) translocation. The patient cohort was divided into three groups: Group A (n = 87), comprising individuals devoid of the t(11;18) translocation or extra MALT1 copies; Group B (n = 27), encompassing patients characterized by the presence of the t(11;18) translocation; and Group C (n = 31), including patients with extra MALT1 copies. The clinical outcomes in each cohort were collected. Over the course of a mean follow-up of 8.5 ± 4.2 years, one patient died of progressive MALT lymphoma, while 15 patients died due to etiologies unrelated to lymphoma. The progression or relapse of MALT lymphoma was observed in 11 patients: three in Group A, two in Group B, and six in Group C. In Groups A, B, and C, the 10-year overall survival rates were 82.5%, 93.8%, and 86.4%, respectively, and the 10-year event-free survival rates were 96.1%, 96.0%, and 82.9%, respectively. The event-free survival rate in Group C was significantly lower than that in Group A. However, no differences were observed in the 10-year event-free survival rates among individuals limited to stage I or II1 disease (equivalent to excluding patients with stage IV disease in this study, as there were no patients with stage II2), with rates of 98.6%, 95.8%, and 92.3% for Groups A, B, and C, respectively. In conclusion, the presence of extra copies of MALT1 was identified as an inferior prognostic determinant of event-free survival. Consequently, trisomy/tetrasomy 18 may serve as an indicator of progression and refractoriness to therapeutic intervention in patients with gastric MALT lymphoma, particularly stage IV gastric MALT lymphoma.

Association of direct oral anticoagulant and delayed bleeding with pharmacokinetics after endoscopic submucosal dissection.

BACKGROUND AND AIMS: Pharmacokinetic parameters, such as drug plasma level at trough, time to maximum plasma concentration (Tmax), and coagulation factor Xa (FXa) activity generally predict factors for the anticoagulant effects of direct oral anticoagulants (DOACs). Although GI bleeding is a major adverse event after endoscopic submucosal dissection (ESD), little is known about the association between post-ESD bleeding in patients taking DOACs and the pharmacologic parameters. This study aimed to evaluate pharmacologic risk factors for post-ESD bleeding in patients taking DOACs. METHODS: We prospectively evaluated the incidence of post-ESD bleeding in patients taking DOACs between April 2018 and May 2022 at 21 Japanese institutions and investigated the association with post-ESD bleeding and pharmacologic factors, including plasma concentration and FXa activity at trough and Tmax. RESULTS: The incidence of post-ESD bleeding was 12.8% (14 of 109; 95% confidence interval [CI], 7.2-20.6). Although plasma DOAC concentration and plasma level/dose ratio at trough and Tmax varied widely among individuals, a significant correlation with plasma concentration and FXa activity was observed (apixaban: correlation coefficient, -0.893; P < .001). On multivariate analysis, risk factors for post-ESD bleeding in patients taking DOACs were higher age (odds ratio [OR], 1.192; 95% CI, 1.020-1.392; P = .027) and high anticoagulant ability analyzed by FXa activity at trough and Tmax (OR, 6.056; 95% CI, 1.094-33.529; P = .039). CONCLUSIONS: The incidence of post-ESD bleeding in patients taking DOACs was high, especially in older patients and with high anticoagulant effects of DOACs. Measurement of pharmacokinetic parameters of DOACs may be useful in identifying patients at higher risk of post-ESD bleeding.

Endoscopic Manifestations and Clinical Characteristics of Localized Gastric Light-Chain Amyloidosis.

To determine the endoscopic and clinical features of localized gastric amyloid light-chain (AL) amyloidosis, we retrospectively examined the characteristics of nine patients (eight men and one woman) encountered by the hospitals in our network. Lesions were predominantly flat and depressed with surface vascular dilatation (n=5); others were characterized by subepithelial lesions (n=2), mucosal color change (n=1), and a mass-like morphology with swollen mucosal folds (n=1). Colonoscopy (n=7), video capsule enteroscopy (n=2), serum (n=5) and urine immunoelectrophoresis (n=4), and bone marrow examination (n=3) were performed to exclude involvement of organs other than the stomach. As treatment for gastric lesions of AL amyloidosis, one patient each underwent endoscopic submucosal dissection (n=1) and argon plasma coagulation (n=1), while the remaining seven patients underwent no specific treatment. During a mean follow-up of 4.2 years, one patient died 3.2 years after diagnosis, but the cause of death, which occurred in another hospital, was unknown. The remaining eight patients were alive at the last visit. In conclusion, although localized gastric AL amyloidosis can show various macroscopic features on esophagogastroduodenoscopy, flat, depressed lesions with vascular dilatation on the surface are predominant.

Long-term outcomes of patients with primary intestinal follicular lymphoma managed with watch-and-wait strategy.

Patients with primary intestinal follicular lymphoma are often followed-up without a specific treatment, and this approach is called the "watch-and-wait approach." However, the long-term outcomes of this patient group have not been sufficiently investigated. We enrolled patients with primary intestinal follicular lymphoma who were diagnosed before 2016 and managed with the watch-and-wait approach in 20 institutions. We retrospectively investigated the overall, disease-specific, and event-free survival rates as well as the rate of spontaneous regression. Among the 248 patients with follicular lymphoma with gastrointestinal involvement, 124 had localized disease (stage I or II1). We analyzed the data of 73 patients who were managed using the watch-and-wait approach. During the mean follow-up period of 8.3 years, the follicular lymphoma had spontaneously resolved in 16.4% of the patients. The 5-year and 10-year overall survival rates were 92.9% and 87.1%, respectively. With disease progression (n = 7), initiation of therapy (n = 7), and histologic transformation to aggressive lymphoma (n = 0) defined as events, the 5-year and 10-year event-free survival rates were 91.1% and 86.9%, respectively. No patient died of progressive lymphoma. Thus, both 5-year and 10-year disease-specific survival rates were 100%. In conclusion, an indolent long-term clinical course was confirmed in the patients with primary intestinal follicular lymphoma. The watch-and-wait strategy is a reasonable approach for the initial management of these patients.

Usefulness of Acetic Acid Spray with Narrow-Band Imaging for Identifying the Margin of Sessile Serrated Lesions.

BACKGROUND: Sessile serrated lesions (SSLs) are precursors of colon cancer, especially in cases of large, right colon. However, they are difficult to not only detect, but only clarify the margin of the lesion, which can lead to the poor endoscopic treatment outcomes. AIMS: This study evaluated the usefulness of acetic acid spray with narrow-band imaging (A-NBI) for the better visualization of the margin of SSLs. METHODS: From January 2013 to March 2022, patients with superficial elevated polyps suspected of being SSLs ≥ 10 mm with an endoscopic diagnosis that had been endoscopically resected at Hiroshima City Hiroshima Citizens Hospital were enrolled. Endoscopic images with white-light imaging (WLI), narrow-band imaging (NBI), indigo-carmine (IC), and A-NBI were recorded in each lesion and were randomly arranged and assessed by 10 endoscopists. We compared the visibility score (1 to 4) and color differences (ΔE) between inside and outside of the lesions among WLI, NBI, IC, and A-NBI. RESULTS: Forty-one lesions in 33 cases were included, and a total of 164 images were evaluated. As for the visibility score, most of the lesions were scored as 1 or 2 on WLI, whereas most were scored 4 on A-NBI. The median ΔE of A-NBI was also significantly higher than that of WLI, NBI, or IC (20.5 vs. 8.3 vs. 8.2 vs. 12.3, P < 0.01). A significant correlation was observed between the color difference and visibility score (r = 0.53, P < 0.01). CONCLUSIONS: A-NBI may be a useful modality for identifying the margin of SSLs.

Clinicopathological Characteristics of Superficial Barrett's Adenocarcinoma in a Japanese Population: A Retrospective, Multicenter Study.

Objective Although Barrett's adenocarcinoma (BA) remains a minor disease in Japan, its incidence has been gradually increasing. We analyzed the characteristics of BA in Japanese populations. Methods We retrospectively reviewed medical records and analyzed the clinicopathological differences between short-segment Barrett's esophagus (SSBE) and long-segment Barrett's esophagus (LSBE), as well as metastasis. Local recurrence and metachronous lesions were analyzed only in patients who underwent endoscopic resection (ER). Patients Consecutive patients who had pathological T1 BAs resected by ER or surgery from January 2003 to December 2017. Results A total of 168 patients were analyzed, including 139 with SSBE and 29 with LSBE. In total, 67% of the SSBE lesions and 32% of the LSBE lesions were located between 0 and 3 o'clock (p=0.0014). No patients who achieved pathological margin-free resection (pR0) and 17% of patients who did not achieve pR0 experienced local recurrence (p=0.0131). None of the patients without lymphovascular involvement, a poorly differentiated component, lesion size of >30 mm, and submucosal invasion of >500 µm experienced metastasis. The 5-year cumulative incidence rate of metachronous BA after ER was 0% in patients with SSBE and 40% in patients with LSBE (p=0.0005). Conclusion Superficial BA was likely to be detected at the right anterior wall of SSBE in the Japanese population. The risk for metachronous BA after ER was high in Japanese patients with LSBE, as in Western patients.

Clinical utility of a serum glycome analysis in patients with colorectal cancer.

BACKGROUND AND AIM: Serum glycans are known to be good markers for the early diagnosis and prognostic prediction in many cancers. The aims of this study were to reveal the serum glycan changes comprehensively during the process of carcinogenesis from colorectal adenoma (CRA) to colorectal cancer (CRC) and to evaluate the usefulness of the glycan profiles as clinical markers for CRC. METHODS: Serum samples were obtained from 80 histologically proven CRC and 36 CRA cases. The levels of glycans in the serum were examined with a comprehensive, quantitative, high-throughput unique glycome analysis, and their diagnostic and prognostic abilities were evaluated. RESULTS: Among 34 stably detected glycans, nine were differentially expressed between CRC and CRA. Serum levels of hybrid type glycans were increased in patients with CRC compared with those with CRA (P < 0.001), and both hybrid-type and multi-antennary glycans were significantly increased in advanced cancer cases. The glycan, m/z 1914, showed the highest diagnostic value among the decreased glycans, whereas m/z 1708 showed the highest among the increased glycans. The glycan ratio m/z 1708/1914 showed a higher area under the receiver operating characteristic curve (0.889) than any other single glycan or conventional tumor marker, such as carcinoembryonic antigen (0.766, P = 0.040) and carbohydrate antigen 19-9 (0.615, P < 0.001). High m/z 1708/1914 was also correlated with an advanced cancer stage and short overall survival. CONCLUSION: Serum glycans, especially the m/z 1708/1914 ratio, were useful for the diagnosis, staging, and prognosis prediction of CRC.

Prognosis after curative resection for stage IA gastric cancer in elderly patients: endoscopic submucosal dissection versus surgery.

PURPOSE: To establish whether gastrectomy for early gastric cancer (EGC) in elderly patients is related to poor survival. METHODS: The subjects of this retrospective study were patients aged ≥ 75 years with primary stage IA EGC, who underwent curative resection with endoscopic submucosal dissection (ESD) or surgery. RESULTS: We analyzed data on 365 patients who underwent ESD and 170 patients who underwent surgery. Overall survival (OS) was not significantly different for the ESD group vs. the surgery group (5-year cumulative rates, 81.5% vs. 79.7%; log-rank test, P = 0.506). Multivariate analysis revealed that treatments; namely, ESD or surgery, were not associated with OS (hazard ratio 1.09, 95% confidence interval 0.77-1.51). Similar results were observed even in the subgroups with worse conditions, such as age > 80 years, Eastern Cooperative Oncology Group performance status 2-3, Charlson comorbidity index ≥ 2, and prognostic nutritional index ≤ 46.7. Using propensity score matching, we selected 88 pairs of patients who underwent ESD or surgery with baseline characteristics matched and found that OS was not different between the two groups (log-rank test, P = 0.829). CONCLUSION: OS was comparable for elderly patients who underwent ESD and those who underwent surgery for EGC. Surgical invasiveness did not worsen the prognosis, even for elderly patients.

Association Between Immune-Related Adverse Events and the Prognosis of Patients with Advanced Gastric Cancer Treated with Nivolumab.

BACKGROUND: Little is known about the association between immune-related adverse events (irAEs) and the efficacy and survival outcomes of nivolumab in patients with advanced gastric cancer (AGC). OBJECTIVE: The present study examined the association between irAEs and the prognosis of patients with AGC treated with nivolumab. PATIENTS AND METHODS: From July 2017 to November 2020, patients who had been diagnosed with advanced unresected gastric cancer and treated with nivolumab at our institution were included in this analysis. We compared the clinical and survival outcomes between the irAE and non-irAE groups. We also evaluated the factors associated with better survival in patients treated with nivolumab. RESULTS: A total of 52 patients were included in the present study, and irAEs were observed in 13 (25%). Among the patients with measurable lesions (n = 29), the disease control rates were significantly higher in the irAE group than in the non-irAE group (88 vs. 24%; P = 0.0033). At the 8- and 12-week landmark analyses, the median overall survival (OS) in the irAE group was significantly longer than that in the non-irAE group, whereas the median progression-free survival was comparable between the groups. A multivariate analysis by Cox proportional hazard regression at the 8-week landmark revealed that the development of irAEs (hazard ratio 0.18; 95% confidence interval 0.0099-0.86) alone was positively associated with a longer OS. CONCLUSIONS: The development of irAEs might be associated with survival outcomes with nivolumab treatment in patients with AGC.

Continued Aspirin Treatment May Be a Risk Factor of Delayed Bleeding after Gastric Endoscopic Submucosal Dissection under Heparin Replacement: A Retrospective Multicenter Study.

Objective Gastric endoscopic submucosal dissection (ESD) under heparin replacement (HR) of warfarin reportedly has a high risk of delayed bleeding (24-57%). It is possible that the delayed bleeding risk may have changed over the years. We evaluated the current risk of delayed bleeding after gastric ESD under HR of anticoagulant agents. Methods We retrospectively reviewed the delayed bleeding rate and analyzed the risk factors for delayed bleeding. Patients Consecutive patients who underwent gastric ESD under HR of anticoagulant agents from July 2015 to June 2017. Results A total of 32 patients with a solitary early gastric cancer and taking anticoagulant agents were analyzed, including 24 patients on warfarin (the warfarin group) and 8 patients on direct oral anticoagulants (the DOAC group). Three (9.4%) patients experienced delayed bleeding: three (12.5%) patients in the warfarin group and no patients in the DOAC group. Continued aspirin treatment was identified to be a risk factor of delayed bleeding (p=0.01). Conclusion Careful management may be required for patients undergoing gastric ESD under continued aspirin treatment in addition to HR of anticoagulant agents; although the delayed bleeding risk after gastric ESD under HR of anticoagulant agents might have decreased over the years.

Current evidence and issues of endoscopic submucosal dissection for gastric neoplasms during antithrombotic therapy.

Endoscopic submucosal dissection (ESD) for gastric neoplasms is a useful treatment globally. However, postoperative bleeding after gastric ESD is a serious, and sometimes life-threatening complication in patients receiving antithrombotic drugs, because antithrombotic drugs are considered to increase the risk of postoperative bleeding after gastric ESD. In contrast, withdrawal of antithrombotic drugs during the perioperative period increases the risk of thrombotic complications. Guidelines for the management of antithrombotic drugs during the periendoscopic period have been published by different countries, and recent guidelines place greater emphasis on the risk of thromboembolism with the discontinuation of antithrombotic drugs than on the risk of bleeding with the continuation of antithrombotic drugs. Several studies have reported on the validity of these guidelines, and clinical evidence is being established. Most studies reported that gastric ESD under continuation of aspirin or cilostazol did not increase the risk of bleeding, whereas heparin replacement was strongly associated with a higher risk of bleeding. However, the data regarding some clinical issues about the management of antithrombotic drugs, such as the safety of gastric ESD under continuation of thienopyridine, administration of multiple antithrombotic drugs including dual antiplatelet and anticoagulants (warfarin and direct oral anticoagulant), and effective prophylactic methods for postoperative bleeding after gastric ESD are lacking. Larger clinical data are needed to resolve the remaining issues in the future.

Diagnostic Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Gastric Mesenchymal Tumors.

There have been no comparative studies investigating the results of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients with gastric mesenchymal tumors, including leiomyomas, leiomyosarcomas, schwannomas, and gastrointestinal stromal tumors (GISTs). We retrospectively reviewed the data of 142 patients with pathologically diagnosed gastric mesenchymal tumors treated at 11 institutions. We analyzed the correlation between the maximum standardized uptake value (SUVmax) evaluated using fluorodeoxyglucose-positron emission tomography (FDG-PET) and the tumor size. The correlation between the SUVmax and mitotic index was also investigated in GISTs. The SUVmax (mean ± standard deviation) was 0.5 ± 0.6 in very low-risk GISTs (n = 42), 2.1 ± 0.7 in low-risk GISTs (n = 26), 4.9 ± 0.8 in intermediate-risk GISTs (n = 22), 12.3 ± 0.8 in high-risk GISTs (n = 20), 1.0 ± 1.0 in leiomyomas (n = 15), 6.9 ± 1.2 in schwannomas (n = 10), and 3.5 in a leiomyosarcoma (n = 1). The SUVmax of GISTs with an undetermined risk classification was 4.2 ± 1.3 (n = 8). Linear associations were observed between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax of GISTs with a high mitotic index was significantly higher than that of GISTs with a low mitotic index (9.6 ± 7.6 vs. 2.4 ± 4.2). In conclusion, we observed positive correlations between the SUVmax and tumor size in GISTs, leiomyomas, and schwannomas. The SUVmax also positively correlated with the mitotic index and risk grade in GISTs. Schwannomas showed a higher FDG uptake than GISTs and leiomyomas.

Impact of Computed Tomography Evaluation Before Colonoscopy for the Management of Colonic Diverticular Hemorrhage.

GOALS: The purpose of this study was to investigate and summarize our experience of a standardized strategy using computed tomography (CT) followed by colonoscopy for the assessment of colonic diverticular hemorrhage with focus on a comparison of CT and colonoscopy findings in patients with colonic diverticular hemorrhage. BACKGROUND: Colonic diverticular hemorrhage is usually diagnosed by colonoscopy, but it is difficult to identify the responsible bleeding point among many diverticula. STUDY: We retrospectively included 257 consecutive patients with colonic diverticular hemorrhage. All patients underwent a CT examination before colonoscopy. All-cause mortality and rebleeding-free rate after discharge were analyzed by Kaplan-Meier analysis and compared using the log-rank test. RESULTS: In CT examinations, 184 patients (71.6%) had definite diverticular hemorrhage with 31.9% showing intraluminal high-density fluid on plain CT, 39.7% showing extravasation, and 31.1% showing arteriovenous increase of extravasation on enhanced CT. In colonoscopy, 130 patients (50.6%) showed endoscopic stigmata of bleeding with 12.1% showing active bleeding, 17.1% showing a nonbleeding visible vessel, and 21.4% showing an adherent clot. A comparison of the locations of bleeding in CT and colonoscopy showed that the agreement rate was 67.3%, and the disagreement rate was 0.8% when the lesion was identified by both modalities patients with definite diverticular hemorrhage identified by CT had a longer hospital stay, higher incidences of hemodynamic instability and rebleeding events than did patients with presumptive diverticular hemorrhage. CONCLUSION: CT evaluation before colonoscopy can be a good option for managing patients with colonic diverticular hemorrhage.

The Progression of Esophageal Mucosa-associated Lymphoid Tissue Lymphoma after Helicobacter pylori Eradication Therapy: A Case Report and Discussion of Therapeutic Options.

A 50-year-old woman with epigastric discomfort was referred to our hospital. Esophagogastroduodenoscopy showed flat, elevated, submucosal tumor-like lesions in the esophagus. Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) of the esophagus was diagnosed based on the examination of an endoscopic biopsy specimen. Computed tomography showed the enlargement of a lymph node in the gastric cardia. The present case showed disease progression despite Helicobacter pylori eradication therapy and achieved partial remission after rituximab monotherapy. The patient remained in partial remission for 20 months. This case suggests that esophageal MALT lymphoma with lymph node involvement does not respond to H. pylori eradication therapy and that it requires systemic treatment.

Monitoring serum proangiogenic cytokines from hepatocellular carcinoma patients treated with sorafenib.

BACKGROUND AND AIM: Several factors, including proangiogenic cytokines, have been reported as predictive markers for the treatment effect of sorafenib in patients with hepatocellular carcinoma (HCC); however, most of them were determined based on one-time measurements before treatment. METHODS: We consecutively recruited 80 advanced HCC patients who were treated with sorafenib prospectively. Serum levels of eight proangiogenic cytokines and the appearance of adverse events were monitored periodically, and their correlations with the prognoses of the patients were evaluated. RESULTS: Among six significant risk factors for overall survival in univariate analyses, high angiopoietin-2 (hazard ratio, 2.06), high hepatocyte growth factor (hazard ratio, 2.08), and poor performance status before the treatment (hazard ratio, 2.48) were determined as independent risk factors. In addition, high angiopoietin-2 at the time of progressive disease was a marker of short post-progression survival (hazard ratio, 4.27). However, there was no significant variable that predicted short progression-free survival except the presence of hepatitis B virus surface antigen. CONCLUSIONS: Predictions of overall survival and post-progression survival were possible by periodically measuring serum proangiogenic cytokines, especially angiopoietin-2, in patients with HCC treated with sorafenib.

Dexmedetomidine for conscious sedation with colorectal endoscopic submucosal dissection: a prospective double-blind randomized controlled study.

OBJECTIVE: Conscious sedation for colorectal endoscopic submucosal dissection (ESD) has not been standardized, and there are no studies of sedation for colorectal ESD. METHODS: We conducted a prospective double-blind randomized controlled trial to clarify the usefulness of DEX during colorectal ESD. In total 80 patients with colorectal ESD from April 2016 to May 2017 were assigned to the placebo group or the DEX group (40 cases each). The primary outcome was patient satisfaction (visual analogue scale: VAS). Secondary outcomes were evaluated for 13 factors, including patient pain level (VAS), endoscopist satisfaction (VAS), objective patient pain level viewed from the endoscopist's perspective (VAS), rate of patient response, rate of side effects, etc., from the patient's and endoscopist's perspectives. RESULTS: Patient satisfaction was 8.4 and 9.1 (P = 0.018) in the placebo group and the DEX group, respectively. Secondary outcomes of patient pain level, endoscopist satisfaction, objective patient pain level from the endoscopist's perspective for the placebo and DEX groups were 1.2 and 0.4 (P = 0.045), 8.2 and 9.3 (P < 0.001), and 1.2 and 0.5 (P = 0.002), respectively. All of these were significantly positive results (more comfortable and less pain) in the DEX group. The rate of a patient response was 100% in all cases. The side effects (hypoxia/bradycardia/hypotension) were 0%/0%/0% and 7.5%/7.5%/5% (P = 0.030). However, these rates were less than the reported side effect occurrence rate, and no additional medication was needed. CONCLUSION: DEX enables conscious sedation, and is useful not only for patient and endoscopist satisfaction but also for pain relief. DEX is an effective sedation method for colorectal ESD.