Outcome of endoscopic mucosal resection in Barrett's esophagus determined by systematic quantification of epithelial glands using volumetric laser endomicroscopy.

BACKGROUND: Dysplastic Barrett's esophagus (BE) lesions ≤2 cm in size can be targeted for en-bloc endoscopic mucosal resection (EMR). White-light endoscopy can underestimate the size of a lesion, limiting complete resection. Volumetric laser endomicroscopy (VLE) provides high-resolution cross-sectional imaging of BE. Epithelial glands are a VLE feature associated with BE dysplasia. We study the association between VLE gland quantification and outcome of resection. METHODS: EMR specimens of BE lesions targeted for en-bloc resection were imaged with VLE using an established protocol. Manual and automated quantification of epithelial glands was performed blinded to resection outcome. The presence of epithelial glands at the resection margins was recorded. Histologic en-bloc (R0) resection of the targeted lesion was defined by the absence and incomplete (R1) resection by the presence of dysplasia/neoplasia at specimen margins. RESULTS: Thirty-seven EMRs with a mean (standard deviation) size of 1.04 (0.37) cm were imaged with VLE. The highest grade of dysplasia found was low-grade dysplasia (n = 12), high-grade dysplasia (n = 19), and intramucosal cancer (n = 6). The en-bloc resection rate was 37.8% (R0, n = 14; R1, n = 23). The mean (standard deviation) number of epithelial glands quantified with VLE was 13.0 (6.7) and 28.8 (23.9) for R0 and R1 specimens, respectively, with a significant mean difference of 15.8 glands (95% confidence interval, 2-29; P = .02). The presence of glands at the specimen margin was associated with incomplete resection (P < .001). CONCLUSION: Systematic quantification of BE epithelial glands using VLE can determine the outcome of endoscopic resection. VLE may have a potential role in assessment of lesion margins.

Volumetric laser endomicroscopy interpretation and feature analysis in dysplastic Barrett's esophagus.

BACKGROUND AND AIM: Volumetric laser endomicroscopy (VLE) is used to identify Barrett's esophagus (BE) dysplasia. Selection of a dysplastic region of interest (ROI) can be challenging due to feature variability across a large amount of data. The degree of agreement among VLE users in selecting a ROI has not been studied. METHODS: High-definition videos that divided a VLE scan from 18 patients with biopsy-proven BE dysplasia into 1-cm segments were reviewed using a four-quadrant grid superimposed for systematic interpretation. VLE scans were selected based on image quality and appropriate visualization of BE epithelium. Four experienced VLE users rated each quadrant as dysplastic or non-dysplastic. For quadrants rated as dysplastic, reviewers selected a single timeframe with representative features. A high-degree of agreement among reviewers was defined as ≥75% agreement on the quadrant diagnosis and ≥50% agreement on selected timeframe (±2 s). RESULTS: Thirty-one videos, each 32 s in length, comprising 124 quadrants were reviewed. There was high-agreement among reviewers in 99 (80%) quadrants, of which 68 (69%) were rated as dysplastic. Compared with quadrants rated as non-dysplastic, ROIs of quadrants rated as dysplastic contained a higher number of epithelial glands (12.7 vs 1.2, P < 0.001) with atypical architecture (54 vs 1, P < 0.001). A statistically significant difference was observed between the signal intensity profiles of quadrants rated as dysplastic and quadrants rated as non-dysplastic (P = 0.004). CONCLUSION: This study highlights that experienced VLE users can identify ROIs with high-degree of agreement. Selected ROIs contained VLE features associated with BE dysplasia.

Comparative diagnostic performance of volumetric laser endomicroscopy and confocal laser endomicroscopy in the detection of dysplasia associated with Barrett's esophagus.

BACKGROUND AND AIMS: Probe-based confocal laser endomicroscopy (pCLE) and volumetric laser endomicroscopy (VLE) (also known as frequency domain optical coherence tomography) are advanced endoscopic imaging modalities that may be useful in the diagnosis of dysplasia associated with Barrett's esophagus (BE). We performed pCLE examination in ex-vivo EMR specimens and compared the diagnostic performance of using the current VLE scoring index (previously established as OCT-SI) and a novel VLE diagnostic algorithm (VLE-DA) for the detection of dysplasia. METHODS: A total of 27 patients with BE enrolled in a surveillance program at a tertiary-care center underwent 50 clinically indicated EMRs that were imaged with VLE and pCLE and classified into neoplastic (N = 34; high-grade dysplasia, intramucosal adenocarcinoma) and nonneoplastic (N = 16; low-grade dysplasia, nondysplastic BE), based on histology. Image datasets (VLE, N = 50; pCLE, N = 50) were rated by 3 gastroenterologists trained in the established diagnostic criteria for each imaging modality as well as a new diagnostic algorithm for VLE derived from a training set that demonstrated association of specific VLE features with neoplasia. Sensitivity, specificity, and diagnostic accuracy were assessed for each imaging modality and diagnostic criteria. RESULTS: The sensitivity, specificity, and diagnostic accuracy of pCLE for detection of BE dysplasia was 76% (95% confidence interval [CI], 59-88), 79% (95% CI, 53-92), and 77% (95% CI, 72-82), respectively. The optimal diagnostic performance of OCT-SI showed a sensitivity of 70% (95% CI, 52-84), specificity of 60% (95% CI, 36-79), and diagnostic accuracy of 67%; (95% CI, 58-78). The use of the novel VLE-DA showed a sensitivity of 86% (95% CI, 69-96), specificity of 88% (95% CI, 60-99), and diagnostic accuracy of 87% (95% CI, 86-88). The diagnostic accuracy of using the new VLE-DA criteria was significantly superior to the current OCT-SI (P < .01). CONCLUSION: The use of a new VLE-DA showed enhanced diagnostic performance for detecting BE dysplasia ex vivo compared with the current OCT-SI. Further validation of this algorithm in vivo is warranted.

Clinical and histologic determinants of mortality for patients with Barrett's esophagus-related T1 esophageal adenocarcinoma.

BACKGROUND & AIMS: Superficial (T1) esophageal adenocarcinoma (EAC) commonly is treated by endoscopic resection, yet little is known about factors that predict outcomes of this approach. We assessed clinical and histologic variables associated with the overall survival times of patients with T1 EAC who received therapy. METHODS: In a retrospective analysis, we collected data from patients who underwent endoscopic mucosal resection (EMR) for T1 EAC (194 patients with T1a and 75 patients with T1b) at the Mayo Clinic, from 1995 through 2011. EMR specimens were reviewed systematically for depth of invasion, presence of lymphovascular invasion, grade of differentiation, and status of resection margins. Kaplan-Meier curves and proportional hazards regression models were used in statistical analyses. RESULTS: Demographic characteristics were similar between patients with T1a and T1b EAC. Overall survival at 5 years after EMR was 74.4% for patients with T1a (95% confidence interval [CI], 67.6%-81.8%) and 53.2% for patients with T1b EAC (95% CI, 40.3%-70.1%). Of surviving patients with T1a EAC, 94.1% remained free of cancer (95% CI, 89.8%-98.5%), and 94.7% of surviving patients with T1b EAC remained free of cancer (95% CI, 85.2%-100%). A multivariable model associated older age (per 10-year increment), evidence of lymphovascular invasion, and deep margin involvement with reduced overall survival in patients with T1 EAC. CONCLUSIONS: Systematic assessment of EMR specimens can help predict mortality and potentially guide treatment options for patients with T1 EAC.

Obstructive sleep apnea is a risk factor for Barrett's esophagus.

BACKGROUND & AIMS: Common risk factors for obstructive sleep apnea (OSA) and Barrett's esophagus (BE) include obesity and gastroesophageal reflux disease (GERD). The aims of this study were to assess the association between OSA and BE and to determine whether the association is independent of GERD and body mass index (BMI). METHODS: Patients who had undergone a diagnostic polysomnogram and esophagogastroduodenoscopy were identified by using Mayo Clinic (Rochester, Minnesota) databases from January 2000-November 2011. They were randomly matched for age, sex, and BMI at time of polysomnogram into the following groups: BE but no OSA (n = 36), OSA but no BE (n = 78), both (n = 74), or neither (n = 74). Clinical and demographic variables were abstracted from medical records. The association between OSA and BE was assessed by using a multiple variable logistic model that incorporated age, sex, BMI, clinical diagnosis of GERD, and smoking history. RESULTS: Subjects with OSA had an 80% increased risk for BE compared with subjects without OSA (odds ratio, 1.8; 95% confidence interval, 1.1-3.2; P = .03). These findings were independent of age, sex, BMI, GERD, and smoking history. Increasing severity of OSA, measured by using the apnea-hypopnea index, was associated with an increased risk of BE (odds ratio, 1.2 per 10-unit increase in apnea-hypopnea index; 95% confidence interval, 1.0-1.3; P = .03). CONCLUSIONS: In this case-control study, OSA was associated with an increased risk of BE, potentially through BMI and GERD independent mechanisms. Patients with OSA may benefit from evaluation for BE.

Recurrence of esophageal intestinal metaplasia after endoscopic mucosal resection and radiofrequency ablation of Barrett's esophagus: results from a US Multicenter Consortium.

BACKGROUND & AIMS: Radiofrequency ablation (RFA) is an established treatment for dysplastic Barrett's esophagus (BE). Although short-term end points of ablation have been ascertained, there have been concerns about recurrence of intestinal metaplasia (IM) after ablation. We aimed to estimate the incidence and identify factors that predicted the recurrence of IM after successful RFA. METHODS: We analyzed data from 592 patients with BE treated with RFA from 2003 through 2011 at 3 tertiary referral centers. Complete remission of intestinal metaplasia (CRIM) was defined as eradication of IM (in esophageal and gastroesophageal junction biopsy specimens), documented by 2 consecutive endoscopies. Recurrence was defined as the presence of IM or dysplasia after CRIM in surveillance biopsies. Two experienced gastrointestinal pathologists confirmed pathology findings. RESULTS: Based on histology analysis, before RFA, 71% of patients had high-grade dysplasia or esophageal adenocarcinoma, 15% had low-grade dysplasia, and 14% had nondysplastic BE. Of patients treated, 448 (76%) were assessed after RFA. Fifty-five percent of patients underwent endoscopic mucosal resection before RFA. The median time to CRIM was 22 months, with 56% of patients in CRIM by 24 months. Increasing age and length of BE segment were associated with longer times to CRIM. Twenty-four months after CRIM, the incidence of recurrence was 33%; 22% of all recurrences observed were dysplastic BE. There were no demographic or endoscopic factors associated with recurrence. Complications developed in 6.5% of subjects treated with RFA; strictures were the most common complication. CONCLUSIONS: Of patients with BE treated by RFA, 56% were in complete remission after 24 months. However, 33% of these patients had disease recurrence within the next 2 years. Most recurrences were nondysplastic and endoscopically manageable, but continued surveillance after RFA is essential.

Positive correlation between endoscopist radiofrequency ablation volume and response rates in Barrett's esophagus.

BACKGROUND: Radiofrequency ablation (RFA) has become an accepted form of endoscopic treatment for Barrett's esophagus (BE), yet reported response rates are variable. There are no accepted quality measures for performing RFA, and provider-level characteristics may influence RFA outcomes. OBJECTIVE: To determine whether endoscopist RFA volume is associated with rates of complete remission of intestinal metaplasia (CRIM) after RFA in patients with BE. DESIGN: Retrospective analysis of longitudinal data. SETTING: Three tertiary-care medical centers. PATIENTS: Patients with BE treated with RFA. INTERVENTION RFA MAIN OUTCOME MEASUREMENTS: For each endoscopist, we recorded RFA volume, defined as the number of unique patients treated as well as corresponding CRIM rates. We calculated a Spearman correlation coefficient relating these 2 measures. RESULTS: We identified 417 patients with BE treated with RFA who had at least 1 post-RFA endoscopy with biopsies. A total of 73% of the cases had pretreatment histology of high-grade dysplasia or adenocarcinoma. The procedures were performed by 7 endoscopists, who had a median RFA volume of 62 patients (range 20-188). The overall CRIM rate was 75.3% (provider range 62%-88%). The correlation between endoscopist RFA volume and CRIM rate was strong and significant (rho = 0.85; P = .014). In multivariable analysis, higher RFA volume was significantly associated with CRIM (P for trend .04). LIMITATIONS: Referral setting may limit generalizability. Limited number of endoscopists analyzed. CONCLUSION: Endoscopist RFA volume correlates with rates of successful BE eradication. Further studies are required to confirm these findings and to determine whether RFA volume is a valid predictor of treatment outcomes in BE.

Prediction of response to endoscopic therapy of Barrett's dysplasia by using genetic biomarkers.

BACKGROUND: Endoscopic therapy for the treatment of high-grade dysplasia (HGD) and intramucosal cancer (IMC) in Barrett's esophagus (BE) may not always result in complete remission of dysplasia (CRD). OBJECTIVE: To determine whether genetic alterations in the Barrett's mucosa can predict response to endoscopic therapy. DESIGN: Retrospective cohort study. SETTING: Tertiary-care institution. PATIENTS: Selected patients who underwent endoscopic therapy for BE containing HGD/IMC between 2003 and 2010. INTERVENTIONS: Endoscopic therapy combining mucosal resection and different ablation modalities was performed based on patient characteristics, endoscopic findings, and technique evolution. Fluorescence in situ hybridization was used to evaluate genetic alterations on baseline endoscopic cytology brushings by using probes directed to loci 8q24 (MYC), 9p21 (CDKN2A; alias P16), 17q12 (ERBB2; alias Her-2/neu), and 20q13.2 (ZNF217). MAIN OUTCOME MEASUREMENTS: Genetic biomarkers predicting achievement of CRD after endoscopic therapy. RESULTS: A total of 181 patients were included (145 men; 66 ± 10 years of age). There were 130 patients (72%) who responded to endoscopic therapy with CRD. Multiple gains detected by fluorescence in situ hybridization was found to be a negative predictor (hazard ratio 0.57; 95% confidence interval, 0.40-0.82) after adjusting for potential clinical confounders. Similar results were found when analyses were restricted to patients (n = 66) undergoing radiofrequency ablation (hazard ratio 0.58; 95% confidence interval, 0.31-1.09). LIMITATIONS: Retrospective study, heterogeneity of treatment modalities. CONCLUSION: Patients with multiple gains detected by brush cytology specimens may have a lower response rate to endoscopic therapy. The presence of multiple gains can be an adjunct to standard histology in prognosticating BE patients with HGD/IMC undergoing endoscopic therapy.

Safety of endoscopic mucosal resection for Barrett's esophagus.

OBJECTIVES: Endoscopic mucosal resection (EMR) is an established technique for the management of Barrett's esophagus (BE). Although EMR is generally perceived to be a relatively safe procedure, the published data regarding EMR-related complications are variable and the expertise of those performing EMR is often not disclosed. Our aim was to determine the complication rates in a large cohort of patients who underwent EMR at a specialized BE unit. METHODS: A prospectively maintained database was reviewed for patients with BE who underwent EMR from January 1995 to August 2008. EMR was performed in patients with neoplastic appearing lesions. Bleeding, stricture, and perforation related to EMR were reviewed as the main outcome measurements. RESULTS: In all, 681 patients (83% male; mean age 70 years old) underwent a total of 1,388 endoscopic procedures and 2,513 EMRs. Median length of BE was 3.0 cm (interquartile range (IQR) 1-7). A single experienced endoscopist performed 99% of the EMR procedures. EMR was performed using commercially available EMR kits in 95% (77% cap-snare and 18% band-snare) and a variceal band ligation device in 5% of cases. No EMR-related perforations occurred during the study period. The rate of post-EMR bleeding was 1.2% (8 patients). Seven patients were successfully treated endoscopically and one needed surgery. The rate for symptomatic strictures after EMR was 1.0% (7 cases), and all of the cases did not involve intervening ablation therapies. All strictures were successfully treated with endoscopic dilation. CONCLUSIONS: This is the largest series reported to date on EMR in BE. In this large retrospective study, EMR for BE was associated with a low rate of complications for selected patients when performed by experienced hands.

A new era: endoscopic tissue transplantation.

PURPOSE OF REVIEW: To describe basic principles of tissue engineering with emphasis on the potential role of gastrointestinal endoscopy in regenerative medicine. RECENT FINDINGS: Stricturing associated with endoscopic submucosal resection and circumferential endoscopic mucosal resection can be prevented through transplantation of autologous epidermal cell sheets or seeded decellularized biological scaffolds. Lower esophageal sphincter augmentation through injection of muscle-derived cells is a novel potential treatment for gastroesophageal reflux disease. Stem cell derived tissue has been used to repair injured colon in a mouse model of colitis. A bioengineered internal anal sphincter has been successfully implanted in mice and showed preserved functionality. SUMMARY: The immediate foreseeable application of tissue engineering in gastrointestinal endoscopy is in the field of mucosal repair after acute injury. Tissue regeneration can be achieved through expansion of autologous somatic cells or by induction of multipotent or pluripotent stem cells. Advances in cellular scaffolding have made bioengineering of complex tissues a reality. Tissue engineering in endoscopy is also being pioneered by studies looking at enteral sphincter augmentation and regeneration. The availability of engineered tissue for endoscopic application will increase with advances in cell-culturing techniques.

Utility of baseline positron emission tomography with computed tomography for predicting endoscopic resectability and survival outcomes in patients with early esophageal adenocarcinoma.

BACKGROUND AND AIMS: Positron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes. METHODS: EAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver). RESULTS: There were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio=2.77, 95% confidence interval 1.26-7.73, P=0.0075). Using a cut-off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false-positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival. CONCLUSIONS: SUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work-up.

Safety of prior endoscopic mucosal resection in patients receiving radiofrequency ablation of Barrett's esophagus.

BACKGROUND & AIMS: Radiofrequency ablation (RFA) is safe and effective treatment for flat dysplasia associated with Barrett's esophagus (BE). However, there are limited data on the safety of RFA in patients who had prior endoscopic mucosal resection (EMR), which might increase the risk of complications. We compared complications and histologic outcomes between patients who had EMR before RFA and those who received only RFA. METHODS: We performed a retrospective analysis of data collected from patients treated for BE, associated with dysplasia or intramucosal cancer, at the Mayo Clinic in Rochester, Minnesota, from 1998-2009. Patients were divided into groups that had RFA after EMR (group 1, n = 44) or only RFA (group 2, n = 46). We compared the incidence of complications (strictures, bleeding, and esophageal perforation) and histologic features (complete resolution of dysplasia and complete resolution of intestinal metaplasia [CR-IM]) between groups. Logistic regression analysis was performed to assess predictors of stricture formation. RESULTS: Stricture rates were 14% in group 1 and 9% in group 2 (odds ratio, 1.53; 95% confidence interval [CI], 0.26-9.74). The rates of CR-IM were 43% in group 1 and 74% in group 2 (odds ratio, 0.33; 95% CI, 0.14-0.78). The rates of complete resolution of dysplasia were 76% in group 1 and 71% in group 2 (odds ratio, 1.28; 95% CI, 0.39-4.17). The adjusted odds ratio for CR-IM in group 1 (adjusting for age, segment length, and grade of dysplasia) was 0.50 (95% CI, 0.15-1.66). CONCLUSIONS: Stricture rates among patients who receive only RFA are comparable to those of patients who had prior EMR. EMR appears safe to perform prior to RFA.

Overutilization of endoscopic surveillance in nondysplastic Barrett's esophagus: a multicenter study.

BACKGROUND: Guidelines suggest that patients with nondysplastic Barrett's esophagus (BE) undergo endoscopic surveillance every 3 to 5 years, but actual use of surveillance endoscopy and the determinants of variation in surveillance intervals are not known. OBJECTIVE: To measure use of surveillance endoscopy and its variation in patients with nondysplastic BE. DESIGN: Multicenter, cross-sectional study. SETTING: Three sites in Arizona, Minnesota, and North Carolina. PATIENTS: This study involved patients who had prevalent BE without a history of high-grade dysplasia or esophageal adenocarcinoma. INTERVENTION: Participants were given validated measures of quality of life, numeracy, and cancer risk perception, and the total number of prior endoscopic surveillance examinations was measured. MAIN OUTCOME MEASUREMENTS: Oversurveillance was defined as >1 surveillance examination per 3-year period. RESULTS: Among 235 patients with nondysplastic BE, 76% were male and 94% were white. The average (± standard deviation [SD]) duration of BE was 6.5 ± 5.9 years. The mean (± SD) number of endoscopies per 3-year period was 2.7 ± 2.6. Oversurveillance was present in 65% of participants, resulting in a mean of 2.3 excess endoscopies per patient. Neither numeracy skills nor patient perception of cancer risk were associated with oversurveillance. LIMITATIONS: Endoscopies were measured by patient report, which is subject to error. Results may be generalizable only to patients seen in academic centers. CONCLUSION: Most patients with nondysplastic BE had more surveillance endoscopic examinations than is recommended by published guidelines. Patient factors did not predict oversurveillance, indicating that other factors may influence decisions about the interval and frequency of surveillance examinations.

Diagnostic performance of two confocal endomicroscopy systems in detecting Barrett's dysplasia: a pilot study using a novel bioprobe in ex vivo tissue.

BACKGROUND: There are currently 2 existing confocal laser endomicroscopy (CLE) platforms: probe-based CLE (pCLE) and endoscope-based CLE (eCLE) systems, each with its own criteria for identifying dysplasia in Barrett's esophagus (BE). The diagnostic performance of these 2 systems has not been directly compared. DESIGN: Preclinical, feasibility study. OBJECTIVES: We compared the interrater agreement and diagnostic performance of the pCLE and eCLE systems. In addition, we evaluated a new BE endomicroscopy criteria based on fluorescent glucose intensity uptake. PATIENTS: Thirteen patients with Barrett's esophagus and high-grade dysplasia or early cancer undergoing 16 EMR. INTERVENTION: CLE imaging was performed using two different probes with 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose, a fluorescent glucose analog with preferential uptake in dysplastic mucosa to supply contrast. Four quadrants were imaged per specimen with a total of 64 imaged mucosal sites presented to three gastroenterologists. MAIN OUTCOME MEASUREMENTS: Interobserver agreement and accuracy for dysplasia was assessed of images classified according to Miami criteria, stacked eCLE images classified using the Mainz criteria and a novel fluorescence intensity criteria. RESULTS: The interrater agreements were 0.17, 0.68, and 0.87 for the Miami, Mainz, and the fluorescence intensity criteria, respectively. Overall accuracy in detecting dysplasia was 37% (95% CI, 30.3-43.9), 44.3% (95% CI, 37.3-50.9), and 78.6% (95% CI, 72.2-83.3) for the Miami, Mainz, and the fluorescence intensity criteria, respectively. LIMITATIONS: This imaging technique and proposed fluorescence intensity criteria using 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose in EMR tissue will require in vivo validation and cannot be directly used with the current eCLE and pCLE clinical applications. CONCLUSIONS: In this preclinical feasibility study, the use of an eCLE system with a topical fluorescent contrast in ex vivo EMR tissue demonstrated higher interrater agreement and accuracy.

Synergistic effects of photodynamic therapy with HPPH and gemcitabine in pancreatic cancer cell lines.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) is a potential treatment for pancreatic cancer. A second-generation photosensitizer, 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide (HPPH) has a long wavelength absorption, high-tumor selectivity, and shorter duration of skin photosensitivity. We investigated the efficacy of PDT with HPPH and gemcitabine in inducing cell death in multiple pancreatic cancer cell lines. METHODS: We used three pancreatic cancer cell lines (PANC-1, MIA PaCa-2, and BXPC-3) incubated with HPPH concentration of 0, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, and 0.5 µg/ml for 6 hours, followed by photoradiation at a light dose of 60 J/cm(2). Afterwards, each cell line was treated with gemcitabine at concentrations of 0, 1, 10, and 100 µM and incubated for another 96 hours. Cell death was detected with SYTOX green staining. We also assessed the difference in cytotoxicity in adding gemcitabine before and after PDT. RESULTS: HPPH-PDT can effectively induce cell death in all cell lines in a dose-dependent manner, with a 100% of cell death at the 0.5 µg/ml HPPH concentration. In contrast, monotherapy with gemcitabine alone (100 µM) only achieved <45% cell death. Combining gemcitabine to HPPH-PDT resulted in synergistic cytotoxic effect with 20-50% more cell death across all cell lines. There was no difference in cytotoxicity in adding gemcitabine before or after PDT. CONCLUSION: This is the first study on HPPH-PDT for pancreatic cancer. HPPH-PDT-induced cell death occurs in a dose-dependent manner. HPPH-PDT and gemcitabine have synergistic effects in inducing cell death in multiple pancreatic cancer cell lines.

Prevalence of esophageal eosinophils in patients with Barrett's esophagus.

OBJECTIVES: Recent studies have demonstrated high esophageal eosinophil counts in patients with GERD similar to eosinophilic esophagitis (EoE) yet the frequency of esophageal eosinophilia in GERD is unknown. Our aim was to determine the prevalence of dense esophageal eosinophilia in patients with Barrett's esophagus as a manifestation of GERD. METHODS: The Mayo Clinic pathology database was reviewed for patients diagnosed with Barrett's esophagus from January to December 2008 with squamous mucosa obtained during endoscopic surveillance. Clinical, endoscopic, and histologic findings were reviewed. Patients with ≥15 eosinophils per high powered field were identified and compared to those without esophageal eosinophilia. RESULTS: Two hundred patients with Barrett's esophagus and squamous tissue obtained at the time of biopsy were identified. Fourteen of the 200 patients (7%) had ≥15 eosinophils per high powered field. Demographics, symptoms, and proton pump inhibitor therapies were similar between those with and without esophageal eosinophilia. Endoscopic features suggestive of EoE were found in the squamous mucosa of 2 patients with and 7 patients without esophageal eosinophilia. Use of photodynamic, radiofrequency ablation, or monopolar electrocoagulation therapy for ablation of Barrett's mucosa was not associated with a higher rate of esophageal eosinophilia. Basal cell hyperplasia, papillary elongation, and spongiosis occurred frequently in association with esophageal eosinophilic infiltration. CONCLUSIONS: High esophageal eosinophil counts were found in 7% of this cohort of 200 patients with Barrett's esophagus and likely underestimates prevalence. The finding of esophageal eosinophilia in this cohort was independent of proton pump inhibitor use, features of EoE, or endoscopic therapy for Barrett's esophagus. Further studies are needed to assess if these findings are applicable to all patients with GERD.

Epidemiology and natural history of intestinal metaplasia of the gastroesophageal junction and Barrett's esophagus: a population-based study.

OBJECTIVES: Population-based data on the epidemiology and outcomes of subjects with intestinal metaplasia of the gastroesophageal junction (IMGEJ) and Barrett's esophagus (BE) are limited. The objectives of this study were to (i) estimate the incidence of IMGEJ and BE diagnosed from clinically indicated endoscopy in Olmsted County, MN, over three decades (1976-2006) and prevalence as of 1 January 2007, (ii) compare baseline characteristics of subjects with IMGEJ and BE, and (iii) study the natural history and survival of both cohorts. METHODS: This was a population-based cohort study. The study setting was Olmsted County, MN. Patients with BE (columnar segment >1 cm with intestinal metaplasia) and IMGEJ (intestinal metaplasia in biopsies from the gastroesophageal junction) from 1976 to 2006 in Olmsted County, MN, were identified using Rochester Epidemiology Project resources. Demographic and clinical data were abstracted from medical records and pathology confirmed by gastrointestinal pathologists. The association of baseline characteristics with overall and progression-free survival was assessed using proportional hazards regression models. Outcome measures were baseline characteristics and overall survival of subjects with IMGEJ compared to those with BE. RESULTS: In all, 487 patients (401 with BE and 86 with IMGEJ) were identified and followed for a median interval of 7 (BE subjects) to 8 (IMGEJ subjects) years. Subjects with BE were older, heavier, reported reflux symptoms more often, and had higher prevalence of advanced neoplasia than those with IMGEJ. No patient with IMGEJ progressed to esophageal adenocarcinoma (EAC) in contrast to BE subjects who had a cumulative risk of progression of 7% at 10 years and increased risk of death from EAC (standardized mortality ratio 9.62). The overall survival of subjects with BE and IMGEJ did not differ from that expected in similar age- and sex-distributed white Minnesota populations. CONCLUSIONS: Subjects with IMGEJ appear to have distinct clinical characteristics and substantially lower cancer progression risk compared to those with BE.

Outcomes of T1b esophageal adenocarcinoma patients.

BACKGROUND: Esophagectomy is usually recommended for patients with submucosal esophageal adenocarcinoma (T1b EAC) because of the potential for lymph node metastasis (LNM). Endoscopic management often differs based on the risk of metastasis. There is limited information on the difference in outcomes for T1b-EAC with and without esophagectomy. OBJECTIVES: To investigate (1) the outcomes of T1b EAC treatments with and without esophagectomy and (2) the percentage of LNM at esophagectomy for T1b-EAC. DESIGN: Retrospective cohort. SETTING: A tertiary Barrett's esophagus unit. PATIENTS: Sixty-eight T1b EAC patients based on EMR histology. INTERVENTIONS: Esophagectomy and endoscopic therapies. MAIN OUTCOME MEASUREMENTS: Survival duration and mortality rate. RESULTS: A total of 68 patients had T1b EAC; cumulative mortality rate was 30.9% and median survival duration was 39.5 months. Thirty-nine underwent esophagectomy and 29 did not. Among patients who underwent esophagectomy, 13 (33.3%) had LNM, and the mortality rate was 50.0% and 11.1% for those with and without LNM, respectively (P < .01). For those with and without esophagectomy, the cumulative mortality rates were 25.6% and 37.9%, and median survival duration was 48.9 and 34.8 months, respectively. There was no statistical difference in Charlson comorbidity index, number of EMRs, mortality rate, or survival duration. In Cox proportional hazard model analysis, the hazard ratio for esophagectomy was 0.5 (P = .21). LIMITATIONS: Retrospective, nonrandomized small sample size cohort. CONCLUSION: Among the patients with T1b EAC found in EMR specimens who underwent esophagectomy, one third had regional LNM. In our small series, patients who underwent esophagectomy did not have a significantly different survival duration from that of those who did not, indicating that these patients may have similar outcomes [corrected].

Scissor-type knife improves the safety of endoscopic submucosal dissection (ESD) among endoscopists without experience in ESD: a randomized ex vivo study.

Background and study aims Endoscopic submucosal dissection (ESD) is technically challenging, difficult to learn, and carries a substantial risk of perforation, all of which remain significant barriers to its adoptability. We aimed to determine whether use of a novel scissor-type knife improved efficacy and safety among novice performers of ESD. Materials and methods Following a brief didactic session on ESD, participants performed ESD of two lesions (2 cm diameter) in an ex vivo porcine gastric model. One resection was performed with a conventional knife and the other with the scissor knife (order of knife randomized). We recorded procedure time, successful en bloc resection, and adverse events (including full-thickness perforation and muscle injury) for each dissection. Participants completed a post-study survey. Results 10 endoscopists (8 trainees, 2 staff) considered novices in ESD participated. Compared with the conventional knife, use of the scissor knife was associated with a significantly shorter time to completion of submucosal dissection (mean 6.2 [SD 5.6] vs. 15.6 [SD 15.6] minutes; P  = 0.04) and total procedure time was not significantly different (22.1 [SD 13.3] vs. 24.9 [SD 26.5] minutes; P  = 0.65). Scissor knife use was also associated with a significantly lower proportion of perforation and/or muscle injury (10.0 % vs. 70.0 %; P  < 0.01) and proportion of muscle injury alone (10.0 % vs. 60.0 %; P  = 0.02). Conclusions Among novices performing ESD on an ex vivo animal model, use of a scissor knife was associated with a significantly lower proportion of adverse events without prolonging procedure time. Scissor-type knives may improve ESD safety, at least among novices.