Low-dose daily folic acid (400 µg) supplementation does not affect regulation of folate transporters found present throughout the terminal ileum and colon of humans: a randomized clinical trial.

BACKGROUND: Folic acid supplementation during the periconceptional period reduces the risk of neural tube defects in infants, but concern over chronic folic acid exposure remains. An improved understanding of folate absorption may clarify potential risks. Folate transporters have been characterized in the small intestine, but less so in the colon of healthy, free-living humans. The impact of folic acid fortification or supplementation on regulation of these transporters along the intestinal tract is unknown. OBJECTIVE: The objective was to characterize expression of folate transporters/receptor (FT/R) and folate hydrolase, glutamate carboxypeptidase II (GCPII), from the terminal ileum and throughout the colon of adults and assess the impact of supplemental folic acid. METHODS: In this 16-wk open-labeled randomized clinical trial, adults consumed a low folic acid-containing diet, a folate-free multivitamin, and either a 400 µg folic acid supplement or no folic acid supplement. Dietary intakes and blood were assessed at baseline, 8 wk, and 16 wk (time of colonoscopy). Messenger RNA (mRNA) expression and protein expression of FT/R and GCPII were assessed in the terminal ileum, cecum, and ascending and descending colon. RESULTS: Among 24 randomly assigned subjects, no differences in dietary folate intake or blood folate were observed at baseline. Mean ± SD red blood cell folate at 16 wk was 1765 ± 426 and 911 ± 242 nmol/L in the 400 and 0 µg folic acid group, respectively (P < 0.0001). Reduced folate carrier, proton-coupled folate transporter, and folate-receptor alpha expression were detected in the terminal ileum and colon, as were efflux transporters of breast cancer resistance protein and multidrug resistance protein-3. Other than a higher mRNA expression of FR-alpha and GCPII in the 400 µg supplement group in the ascending colon, no treatment differences were observed (P < 0.02). CONCLUSIONS: Folate transporters are present throughout the terminal ileum and colon; there is little evidence that a low dose of folic acid supplementation affects colonic absorption. This trial was registered at clinicaltrials.gov as NCT03421483.

Impact of Residing in Below Median Household Income Districts on Outcomes in Patients with Advanced Barrett's Esophagus.

Background: Barrett's esophagus (BE) is a premalignant condition to esophageal adenocarcinoma (EAC). Low socioeconomic (SES) status adversely impacts care and outcomes in patients with EAC, but this has not been evaluated in BE. As the treatment of BE is similarly intensive, we aimed to evaluate the effect of SES on achieving complete eradication of intestinal metaplasia (CE-IM), dysplasia (CE-D) and development of invasive EAC. Methods: Our study was a retrospective cohort study. Consecutive patients between January 1, 2010, to December 31, 2018, referred for BE-associated high-grade dysplasia or intramucosal adenocarcinoma were included. Pre, intra and post-procedural data were collected. Household income data was collected from the 2016 census based on postal code region. Patients were divided into income groups relative to the 2016 median household income in Ontario. Multivariate regression was performed for outcomes of interest. Results: Four hundred and fifty-nine patients were included. Rate of CE-IM was similar between income groups. Fifty-five per cent (n = 144/264) versus 65% (n = 48/264) in the below and above-income groups achieved CE-D, respectively, P = 0.02. Eighteen per cent (n = 48/264) versus 11% (n = 22/195) were found to have invasive EAC during their treatment course in below and above-income groups, respectively, P = 0.04. Residing in a below-median-income district was associated with developing invasive EAC (Odds Ratio, [OR] 1.84, 95% confidence interval [CI] 1.01 to 3.35) and failure to achieve CE-D (OR 0.64, 95% CI 0.42 to 0.97). Conclusions: Residing in low-income districts is associated with worse outcomes in patients with advanced BE. Further research is needed to guide future initiatives to address the potential impact of SES barriers in the optimal care of BE.

Outpatient flexible endoscopic diverticulotomy for the management of Zenker's diverticulum: a retrospective analysis of a large single-center cohort.

BACKGROUNDS AND AIMS: Flexible endoscopic Zenker's diverticulotomy (EZD) is well established as a safe and effective technique. Because of rare but concerning adverse events, most centers admit patients for observation and barium swallow study. Our center routinely performs EZD as a day procedure, discharging appropriate patients on the same day after clinical review. This study evaluates outcomes of this cohort compared with previously published studies where patients are admitted for observation. METHODS: A retrospective analysis was performed of EZD procedures done at our center using a flexible endoscope and, in most cases, a diverticulotomy overtube with patients under moderate sedation or general anesthesia. Patients were observed for 2 hours and discharged if no clinical concerns were found. Patient comorbidities, American Society of Anesthesiologists physical status, and endoscopic adverse events were recorded against the American Society for Gastrointestinal Endoscopy severity grading system. RESULTS: Two hundred forty EZD procedures were performed between January 2015 and February 2021. Eleven (4.6%) intraprocedural adverse events occurred: 4 perforations, 4 bleeds, and 1 each postprocedural pain, delirium, and vomiting, respectively. All were recognized within the 2-hour observation period and were managed conservatively, except 1 patient who required surgery. Six patients (2.5%) presented with delayed adverse events: 2 bleeds, 2 perforations, and 2 postprocedural pain. All patients recovered uneventfully with supportive care. CONCLUSIONS: All significant adverse events requiring endoscopic or surgical intervention were identified before discharge. Delayed adverse events occurred in 2.5% of cases, all of which were managed supportively. Our data are comparable with published cohorts of admitted patients, demonstrating that appropriately selected patients may be managed as outpatients while maintaining similar safety outcomes.

Predictors of recurrence of dysplasia or cancer in patients with dysplastic Barrett's esophagus following complete eradication of dysplasia: a single-center retrospective cohort study.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) and radiofrequency ablation (RFA) for Barrett's esophagus (BE)-related high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) are considered effective treatments for eradication of BE. Little is known about the impact of achieving complete eradication of intestinal metaplasia (CE-IM) following the complete eradication of neoplasia (CE-N), specifically if CE-IM reduces the risk of recurrent dysplasia. METHODS: Retrospective cohort study of consecutive patients with BE and HGD or intramucosal cancer (IMC)-treated endoscopically at a tertiary referral center between 2001 and 2019. Association between CE-IM and recurrent dysplasia after CE-N was evaluated. RESULTS: A total of 433 patients treated with EMR and/or RFA were included. Of these, 381 (88%) achieved CE-N, of which 345 (80%) had adequate follow-up for inclusion in the analysis. A total of 266 (77%) patients achieved CE-IM; with a median follow-up since initial treatment for HGD/IMC of 45.9 months (IQR 25.9, 93.1); 20 patients (5.8%) had recurrent dysplasia after achieving CE-N. Kaplan Meier survival curves revealed that time free of recurrence in those who achieved CE-IM was significantly higher (p = 0.002). In the multivariable analysis, CE-IM was associated with a significant lower hazard of recurrence (HR 0.2, 95% CI 0.1, 0.6), whereas the number of endoscopic treatments to achieve CE-N was associated with a significant higher hazard of recurrence (HR 1.1, 95% CI 1.0, 1.2). CONCLUSION: Achieving CE-IM following CE-N reduces the risk of recurrent dysplasia and should be considered a treatment target among patients with BE undergoing endoscopic therapies for HGD or EAC.

Clinical and pathological predictors of failure of endoscopic therapy for Barrett's related high-grade dysplasia and early esophageal adenocarcinoma.

BACKGROUND AND AIMS: Multimodal endoscopic treatment for Barrett's esophagus (BE) related high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) is safe and effective. However, there is a paucity of data to predict the response to endoscopic treatment. This study aimed to identify predictors of failure to achieve complete eradication of neoplasia (CE-N) and complete eradication of intestinal metaplasia (CE-IM). METHODS: We performed a retrospective analysis of prospectively collected data of all HGD/EAC cases treated endoscopically at a tertiary referral center. Only patients with confirmed HGD/EAC from initial endoscopic mucosal resection (EMR) were included. Potential predictive variables including clinical characteristics, endoscopic features, and index histologic parameters of the EMR specimens were evaluated using multivariate Cox regression. RESULTS: A total of 457 patients were diagnosed with HGD/EAC by initial EMR from January 2008 to January 2019. Of these, 366 patients who underwent subsequent endoscopic treatment with or without RFA were included. Cumulative incidence rates at 3 years for CE-N and CE-IM were 91.4% (95% CI 87.8-94.2%) and 66.8% (95% CI 61.2-72.3%), respectively during a median follow-up period of 35 months. BE segment of 3-10 cm (HR 0.45; 95% CI 0.36-0.57) and > 10 cm (HR 0.25; 95% CI 0.15-0.40) were independent clinical predictors associated with failure to achieve CE-N. With respect to CE-IM, increasing age (HR 0.88; 95% CI 0.78-1.00) was another predictor along with BE segment of 3-10 cm (HR 0.37; 95% CI 0.28-0.49) and > 10 cm (HR 0.15; 95% CI 0.07-0.30). Lymphovascular invasion increased the risk of CE-N and CE-IM failure in EAC cases. CONCLUSION: Failure to achieve CE-N and CE-IM is associated with long-segment BE and other clinical variables. Patients with these predictors should be considered for a more intensive endoscopic treatment approach at expert centers.

Risk factors for serious adverse events associated with multiband mucosectomy in Barrett's esophagus: an international multicenter analysis of 3827 endoscopic resection procedures.

BACKGROUND AND AIMS: Multiband mucosectomy (MBM) is a widely used technique for the treatment of Barrett's esophagus (BE). However, large multicenter studies enabling a generalizable estimation of the risk of serious adverse events, such as perforation and postprocedural bleeding, are lacking. The aim of this study was to estimate the rate of, and risk factors for, serious adverse events associated with MBM. METHODS: In this retrospective analysis, consecutive patients who underwent MBM for treatment of BE in 14 tertiary referral centers in Europe, the United States, Canada, and Australia were included. Primary outcomes were perforation and postprocedural bleeding rate. Potential risk factors were identified by logistic regression. RESULTS: Between 2001 and 2016, a total of 3827 MBM procedures were performed in 2447 patients (84% male, mean age 66 years, median BE length C2M4). Perforation occurred in 17 procedures (0.4%; 95% confidence interval [CI], 0.3-0.7), of which 15 could be treated endoscopically or conservatively. Female gender was an independent risk factor for perforation (odds ratio [OR], 2.77; 95% CI, 1.02-7.57; P = .05). Postprocedural bleeding occurred after 35 procedures (0.9%; 95% CI, 0.6-1.3). The number of resections (OR, 1.15; 95% CI, 1.06-1.25; P < .001) was significantly associated with postprocedural bleeding. CONCLUSION: The results of this study show that MBM for BE is safe with a low risk of serious adverse events. In addition, most of the adverse events could be managed endoscopically or conservatively. The number of resections was an independent risk factor for postprocedural bleeding.

Clinical characteristics of young patients with early Barrett's neoplasia.

BACKGROUND: Esophageal adenocarcinoma (EAC) and high-grade dysplasia (HGD) may appear in young patients with Barrett's esophagus (BE). However, characteristics of Barrett's-related neoplasia in this younger population remain unknown. AIM: To identify clinical characteristics that differ between young and old patients with early-stage Barrett's-related neoplasia. METHODS: We conducted a retrospective analysis of a prospectively maintained database comprised of consecutive patients with early-stage EAC (pT1) and HGD at a tertiary-referral center between 2001 and 2017. Baseline characteristics, drug and risk factor exposures, clinicopathological staging of EAC/HGD and treatment outcomes [complete eradication of neoplasia (CE-N), complete eradication of intestinal metaplasia (CE-IM), recurrence of neoplasia and recurrence of intestinal metaplasia] were retrieved. Multivariate analyses were performed to identify factors that differed significantly between older and younger (≤ 50 years) patients. RESULTS: We identified 450 patients with T1 EAC and HGD (74% and 26%, respectively); 45 (10%) were ≤ 50 years. Compared to the older group, young patients were more likely to present with ongoing gastroesophageal reflux disease (GERD) symptoms (55% vs 38%, P = 0.04) and to be obese (body mass index > 30, 48% vs 32%, P = 0.04). Multivariate logistic regression analysis showed that young patients were significantly more likely to have ongoing GERD symptoms [odds ratio (OR) 2.00, 95% confidence interval (CI) 1.04-3.85, P = 0.04] and to be obese (OR 2.06, 95%CI 1.07-3.98, P = 0.03) whereas the young group was less likely to have a smoking history (OR 0.39, 95%CI 0.20-0.75, P < 0.01) compared to the old group. However, there were no significant differences regarding tumor histology, CE-N, CE-IM, recurrence of neoplasia and recurrence of intestinal metaplasia (mean follow-up, 44.3 mo). CONCLUSION: While guidelines recommend BE screening in patients > 50 years of age, younger patients should be considered for screening endoscopy if they suffer from obesity and GERD symptoms.

Clinical characteristics may distinguish patients with esophageal adenocarcinoma arising from long- versus short-segment Barrett's esophagus.

BACKGROUND AND AIMS: Patients with long-segment Barrett's esophagus (LSBE; ≧3 cm) have higher risk of developing esophageal adenocarcinoma (EAC) than those with short-segment Barrett's esophagus (SSBE; <3 cm). However, it is unclear whether patients developing EAC from LSBE or SSBE differ significantly according to baseline clinical characteristics. METHODS: We conducted a retrospective analysis of a prospectively maintained database comprising consecutive patients with early EAC treated by endoscopic mucosal resection at a single, tertiary-referral center. Information regarding baseline clinical characteristics were determined. Univariate and multivariate logistic regression were performed to identify factors that differed significantly between patients with EAC arising from SSBE and LSBE. RESULTS: A total of 145 LSBE EAC and 179 SSBE EAC cases were identified. The LSBE EAC patients had a stronger association with having a hiatal hernia compared to the SSBE EAC patients. In contrast, inverse associations were observed in LSBE EAC patients with statin use and smoking pack-years relative to SSBE EAC patients. CONCLUSIONS: Patients who developed EAC on a background of LSBE were more likely to have a hiatus hernia compared to patients with SSBE EAC, who were more likely to have higher smoking pack-years and higher rates of statin use.

Combined EsophaCap cytology and MUC2 immunohistochemistry for screening of intestinal metaplasia, dysplasia and carcinoma.

Purpose: The incidence of esophageal adenocarcinoma (EAC) has increased by 700% in Western countries over the last 30 years. Although clinical guidelines call for endoscopic surveillance for EAC among high-risk populations, fewer than 5% of new EAC patients are under surveillance at the time of diagnosis. We studied the accuracy of combined cytopathology and MUC2 immunohistochemistry (IHC) for screening of Intestinal Metaplasia (IM), dysplasia and EAC, using specimens collected from the EsophaCap swallowable encapsulated cytology sponge from Canada and United States. Patients and methods: By comparing the EsophaCap cytological diagnosis with concurrent endoscopic biopsies performed on the same patients in 28 cases, we first built up the cytology diagnostic categories and criteria. Based on these criteria, 136 cases were evaluated by both cytology and MUC2 IHC with blinded to patient biopsy diagnosis. Results: We first set up categories and criteria for cytological diagnosis of EscophaCap samples. Based on these, we divided our evaluated cytological samples into two groups: non-IM group and IM or dysplasia or adenocarcinoma group. Using the biopsy as our gold standard to screen IM, dysplasia and EAC by combined cytology and MUC2 IHC, the sensitivity and specificity were 68% and 91%, respectively, which is in the range of clinically useful cytological screening tests such as the cervical Pap smear. Conclusions: Combined EsophaCap cytology and MUC2 IHC could be a good screening test for IM and Beyond.

Efficacy of Per-oral Methylene Blue Formulation for Screening Colonoscopy.

BACKGROUND & AIMS: Topically applied methylene blue dye chromoendoscopy is effective in improving detection of colorectal neoplasia. When combined with a pH- and time-dependent multimatrix structure, a per-oral methylene blue formulation (MB-MMX) can be delivered directly to the colorectal mucosa. METHODS: We performed a phase 3 study of 1205 patients scheduled for colorectal cancer screening or surveillance colonoscopies (50-75 years old) at 20 sites in Europe and the United States, from December 2013 through October 2016. Patients were randomly assigned to groups given 200 mg MB-MMX, placebo, or 100 mg MB-MMX (ratio of 2:2:1). The 100-mg MB-MMX group was included for masking purposes. MB-MMX and placebo tablets were administered with a 4-L polyethylene glycol-based bowel preparation. The patients then underwent colonoscopy by an experienced endoscopist with centralized double-reading. The primary endpoint was the proportion of patients with 1 adenoma or carcinoma (adenoma detection rate [ADR]). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for differences in detection between the 200-mg MB-MMX and placebo groups. False-positive (resection rate for non-neoplastic polyps) and adverse events were assessed as secondary endpoints. RESULTS: The ADR was higher for the MB-MMX group (273 of 485 patients, 56.29%) than the placebo group (229 of 479 patients, 47.81%) (OR 1.46; 95% CI 1.09-1.96). The proportion of patients with nonpolypoid lesions was higher in the MB-MMX group (213 of 485 patients, 43.92%) than the placebo group (168 of 479 patients, 35.07%) (OR 1.66; 95% CI 1.21-2.26). The proportion of patients with adenomas ≤5 mm was higher in the MB-MMX group (180 of 485 patients, 37.11%) than the placebo group (148 of 479 patients, 30.90%) (OR 1.36; 95% CI 1.01-1.83), but there was no difference between groups in detection of polypoid or larger lesions. The false-positive rate did not differ significantly between groups (83 [23.31%] of 356 patients with non-neoplastic lesions in the MB-MMX vs 97 [29.75%] of 326 patients with non-neoplastic lesions in the placebo group). Overall, 0.7% of patients had severe adverse events but there was no significant difference between groups. CONCLUSIONS: In a phase 3 trial of patients undergoing screening or surveillance colonoscopies, we found MB-MMX led to an absolute 8.5% increase in ADR, compared with placebo, without increasing the removal of non-neoplastic lesions. Clinicaltrials.gov no: NCT01694966.

A prospective multicenter study using a new multiband mucosectomy device for endoscopic resection of early neoplasia in Barrett's esophagus.

BACKGROUND AND AIMS: Early neoplasia in Barrett's esophagus (BE) can be effectively and safely removed by endoscopic resection (ER) using multiband mucosectomy (MBM). This study aimed to document performance of a novel MBM device designed for improved visualization, easier passage of accessories, and better suction power compared with other marketed MBM devices. METHODS: This international, single-arm, prospective registry in 14 referral centers (Europe, 10; United States, 3; Canada, 1) included patients with early BE neoplasia scheduled for ER. The primary endpoint was successful ER defined as complete resection of the delineated area in 1 procedure. Secondary outcomes were adverse events and procedure time. RESULTS: A total of 332 lesions was included in 291 patients (248 men; mean age, 67 years [standard deviation, 9.6]). ER indication was high-grade dysplasia in 64%, early adenocarcinoma in 19%, lesion with low-grade dysplasia in 11%, and a lesion without definite histology in 6%. Successful ER was reached in 322 of 332 lesions (97%; 95% confidence interval [CI], 94.6%-98.4%). A perforation occurred in 3 of 332 procedures (.9%; 95% CI, .31%-2.62%), all were managed endoscopically, and patients were admitted with intravenous antibiotics during days 2, 3, and 9. Postprocedural bleeding requiring an intervention occurred in 5 of 332 resections (1.5%; 95% CI, .65%-3.48%). Dysphagia requiring dilatation occurred in 11 patients (3.8%; 95% CI, 2.1%-6.6%). Median procedure time was 16 minutes (interquartile range, 12.0-26.0). CONCLUSIONS: In expert hands, the novel MBM device proved to be effective for resection of early neoplastic lesions in BE, with successful ER in 97% of procedures. Severe adverse events were rare and were effectively managed endoscopically or conservatively. (Clinical trial registration number: NCT02482701.).

Pedunculated polyp of the ileum protruding from a large diverticulum.

INTRODUCTION: A 52-year-old woman presented with iron deficiency anaemia and postprandial right lower quadrant pain. Abdominal examination was unremarkable and laboratory results showed mild anaemia (haemoglobin 11.3 g/dL). Upper and lower endoscopies did not reveal any source of bleeding. Video capsule endoscopy was performed which showed a large polypoid lesion in the mid-ileum (figure 1). Abdominal contrast enhanced CT demonstrated a heterogeneously enhancing pedunculated polyp measuring approximately 6 cm (figure 2). Retrograde double-balloon enteroscopy was performed which revealed a large pedunculated polyp with hyperplastic-like mucosa protruding from a large diverticulum located approximately 70 cm proximal to the ileocaecal valve (figure 3A). The stalk appeared to arise from the base of the diverticulum (figure 3B). A technetium-99m pertechnetate scintigraphy revealed no ectopic gastric mucosa.Figure 1Video capsule endoscopy shows a large polypoid lesion.Figure 2CT shows a heterogeneously enhancing pedunculated polyp (arrow).Figure 3Retrograde double-balloon enteroscopy images. (A) Large pedunculated polyp protruding from a large diverticulum. (B) The stalk appears to arise from the base of the diverticulum. QUESTION: What is the diagnosis?

Hot avulsion may be effective as salvage treatment for focal Barrett's esophagus remaining after endoscopic therapy for dysplasia or early cancer: a preliminary study.

BACKGROUND AND STUDY AIM: Both endoscopic mucosal resection (EMR) and radiofrequency ablation (RFA) are used to treat Barrett's esophagus (BE) complicated by dysplasia and intramucosal cancer. However, focal areas of BE can remain after otherwise successful application of these techniques. We report the results of hot avulsion using a hot biopsy forceps to resect these residual focal areas. PATIENTS AND METHODS: This was a retrospective study from a prospective database in a tertiary reference center from August 2013 to May 2015. All included patients had undergone hot avulsion for eradication of residual focal areas of BE that were ≤ 1 cm and not suspicious for dysplasia, following at least one previous endoscopic treatment for dysplasia or intramucosal cancer. RESULTS: 35 patients harboring 124 residual areas of 1 - 7 mm were treated with hot avulsion. After a mean follow-up of 17.4 months, all patients achieved complete eradication of residual focal BE. One of the patients required a second hot avulsion treatment. Hot avulsion provided samples in all cases but limited the assessment of dysplasia (cautery artifact) in 20.2 % of them. The only complication was bleeding in two patients, which was easily stopped by soft coagulation. CONCLUSIONS: Hot avulsion appears to be effective and safe in removing focal BE ≤ 1 cm at its greatest length remaining after endoscopic treatment for dysplasia or early cancer. Further studies are required before this technique can be considered the standard of care.

Endoscopic diagnosis and treatment of early esophageal squamous neoplasia.

Esophageal cancer is one of the leading causes of cancer-related death and is associated with high morbidity and mortality. It carries a poor prognosis as more than half of patients present with advanced and unresectable disease. One contributing factor is the increased risk of lymph node metastases at early stages of disease. As such, it is essential to detect squamous cell neoplasia (SCN) at an early stage. In order to risk stratify lesions, endoscopists must be able to perform image enhanced endoscopy including magnification and Lugol's chromoendoscopy. The assessment of both the horizontal extent and depth of any lesion is also of utmost importance prior to treatment. Endoscopic mucosal resection and submucosal dissection remain the standard of care with literature supportive their respective use. Radiofrequency ablation and other endoscopic treatments are currently available although should not be considered first line at this time. Our objective is to review the current options for the endoscopic diagnosis and treatment of esophageal SCN.

A feasibility study of photoacoustic imaging of ex vivo endoscopic mucosal resection tissues from Barrett's esophagus patients.

BACKGROUND AND STUDY AIMS: Accurate endoscopic detection of dysplasia in patients with Barrett's esophagus (BE) remains a major clinical challenge. The current standard is to take multiple biopsies under endoscopic image guidance, but this leaves the majority of the tissue unsampled, leading to significant risk of missing dysplasia. Furthermore, determining whether there is submucosal invasion is essential for proper staging. Hence, there is a clinical need for a rapid in vivo wide-field imaging method to identify dysplasia in BE, with the capability of imaging beyond the mucosal layer. We conducted an ex vivo feasibility study using photoacoustic imaging (PAI) in patients undergoing endoscopic mucosal resection (EMR) for known dysplasia. The objective was to characterize the esophageal microvascular pattern, with the long-term goal of performing in vivo endoscopic PAI for dysplasia detection and therapeutic guidance. MATERIALS AND METHODS:  EMR tissues were mounted luminal side up. The tissues were scanned over a field of view of 14 mm (width) by 15 mm (depth) at 680, 750, and 850 nm (40 MHz acoustic central frequency). Ultrasound and photoacoustic images were simultaneously acquired. Tissues were then sliced and fixed in formalin for histopathology with hematoxylin and eosin staining. A total of 13 EMR specimens from eight patients were included in the analysis, which consisted of co-registration of the photoacoustic images with corresponding pathologist-classified histological images. We conducted mean difference test of the total hemoglobin distribution between tissue classes. RESULTS: Dysplastic and nondysplastic BE can be distinguished from squamous tissue in 84 % of region-of-interest comparisons (42/50). However, the ability of intrinsic PAI to distinguish dysplasia from NDBE, which is the clinically important challenge, was only about 33 % (10/30). CONCLUSION: We demonstrated the technical feasibility of this approach. Based on our ex vivo data, changes in total hemoglobin content from intrinsic PAI (i. e. without exogenous contrast) can differentiate BE from squamous esophageal mucosa. However, most likely intrinsic PAI is unable to differentiate dysplastic from nondysplastic BE with adequate sensitivity for clinical translation.