Jeongmin Choi

Comparison of endoscopic ultrasonography (EUS), positron emission tomography (PET), and computed tomography (CT) in the preoperative locoregional staging of resectable esophageal cancer.

BackgroundEndoscopic ultrasonography (EUS) has been a useful method for the accurate staging of esophageal cancer. This study aimed to compare the diagnostic performance of EUS, positron emission tomography (PET), and computed tomography (CT) in the locoregional staging of resectable esophageal cancer.MethodsA total of 109 patients with resectable esophageal cancer were prospectively enrolled and retrospectively reviewed for evaluation of preoperative EUS, PET, and CT. The sensitivity, specificity, and accuracy of tumor depth (T) staging and regional lymph nodal (N) staging for each test were compared with the postoperative histopathologic stage as the gold standard.ResultsThe overall accuracy of EUS for T staging was 72%, and it was the only method for delineating the layers of the esophageal wall. The sensitivities for N staging were 42% for EUS, 49% for PET, and 35% for CT, and their specificities were, respectively, 91, 87, and 93%. The accuracy for N staging was 66% for EUS, 68% for PET, and 63% for CT, and it did not differ significantly across the three tests.ConclusionsPreoperative EUS for the locoregional staging of esophageal cancer provides excellent T staging accuracy and similar accuracy for N staging compared with PET and CT. Especially in T staging, EUS could play an important role in the choice of candidates for esophageal cancer surgery.

Eradication of Helicobacter pylori After Endoscopic Resection of Gastric Tumors Does Not Reduce Incidence of Metachronous Gastric Carcinoma

BACKGROUND & AIMS It is not clear whether eradication of Helicobacter pylori infection reduces the risk for metachronous gastric carcinoma. We performed a prospective, randomized, open-label trial of the effects of H pylori eradication on the incidence of metachronous carcinoma after endoscopic resection of gastric tumors. METHODS From April 2005 through February 2011 there were 901 consecutive patients with H pylori infection who had been treated with endoscopic resection for gastric dysplasia or cancer and who were assigned randomly to groups given therapy to eradicate the infection (n = 444) or no therapy (controls, n = 457). The eradication group received 20 mg omeprazole, 1 g amoxicillin, and 500 mg clarithromycin twice daily for 1 week. Patients underwent endoscopic examination 3, 6, and 12 months after treatment, and then yearly thereafter. The primary outcome was development of metachronous gastric carcinoma. RESULTS During a median follow-up period of 3 years, 10 patients who received H pylori eradication and 17 controls developed metachronous carcinoma; this difference was not significant (P = .15). The incidence of metachronous carcinoma between the 2 groups did not differ significantly at 1, 2, 3, and 4 years after administration of the therapy. There were no significant differences in the development of metachronous carcinoma among patients who were positive (n = 16) or negative (n = 11) for H pylori infection (P = .32). CONCLUSIONS In this prospective trial, eradication of H pylori after endoscopic resection of gastric tumors did not significantly reduce the incidence of metachronous gastric carcinoma. ClinicalTrials.gov Number: NCT01510730.

Endoscopic prediction of tumor invasion depth in early gastric cancer.

BACKGROUND Although conventional endoscopy is a good diagnostic tool to evaluate tumor depth (T staging) in early gastric cancer (EGC), its accuracy has not been determined and no consensus has been reached regarding standard endoscopic criteria. OBJECTIVE To evaluate the diagnostic accuracy of endoscopic T staging and to identify the characteristic endoscopic features for mucosal (T1m) and submucosal (T1sm) tumors. DESIGN Retrospective study. PATIENTS A consecutive 2105 patients with EGC who underwent either surgical (n=1624) or endoscopic (n=481) resection. INTERVENTION Endoscopic staging was performed by consensus of 2 endoscopists based on the characteristic endoscopic criteria of T1m (smooth surface protrusion or depression, slight marginal elevation, and the smooth tapering of converging folds) and T1sm (irregular surface, marked marginal elevation, and clubbing/abrupt cutting/fusion of converging folds). The endoscopic staging was compared with the pathologic staging of the resected specimen. RESULTS The overall accuracy of endoscopic staging was 78.0% (1642/2105). The sensitivity, specificity, and positive and negative predictive values of T1m endoscopic staging were 85.5%, 73.9%, 82.0%, and 78.5%, whereas those for T1sm were 72.6%, 81.9%, 71.9%, and 82.4%, respectively. LIMITATIONS Retrospective study. Endoscopic predictions for T1sm tumors were correct in only 72% of cases. CONCLUSIONS Conventional endoscopy was found to provide reliable accuracy for T staging in EGC and may be an effective method for assessing penetration depth. A detailed endoscopic evaluation regarding tumor base, margin, and converging folds may provide useful information to determine tumor depth and to select the optimal therapeutic strategy, particularly for endoscopic resection.

Do antiplatelets increase the risk of bleeding after endoscopic submucosal dissection of gastric neoplasms

BACKGROUND It is rarely known whether antiplatelets increase the risk of bleeding after endoscopic submucosal dissection (ESD). OBJECTIVE To evaluate the effect of antiplatelets on post-ESD bleeding. DESIGN Retrospective study. SETTING Single, tertiary-care referral center. PATIENTS This study involved 1591 gastric neoplasms (815 adenomas and 776 early gastric cancers) in 1503 patients who had ESD between April 2005 and April 2010. INTERVENTION ESD. MAIN OUTCOME MEASUREMENTS Overt hematemesis/hematochezia, a drop of hemoglobin >2 g/dL from baseline, or requirement of endoscopic hemostasis, angiographic embolization, and/or transfusion. RESULTS Of 1591 subjects, 274 took antiplatelets, among whom 102 discontinued them for 7 days or more before ESD. Post-ESD bleeding occurred in 94 subjects including 20 from the continuation group, 6 from the withdrawal group, and 68 from the no-antiplatelet group. In univariate analysis, antiplatelets, early gastric cancer (EGC), comorbidity, and specimen diameter were related to post-ESD bleeding. In multivariate analysis, EGC (odds ratio [OR] 1.839; 95% confidence interval [CI], 1.168-2.896; P = .009), comorbidity (OR 2.246; 95% CI, 1.280-3.939; P = .005), and specimen diameter (OR 2.315; 95% CI, 1.282-4.180; P = .005) were independent risk factors of post-ESD bleeding, whereas antiplatelet usage was not (OR 1.596; 95% CI, 0.877-2.903; P = .126). In subgroup analysis, continuous antiplatelet usage was not found to be an independent risk factor of post-ESD bleeding in multivariate analysis (OR 2.027; P = .146). Among 102 subjects who discontinued antiplatelets, 1 developed an acute cerebral infarction (1.0%). LIMITATION A retrospective, single-center analysis. CONCLUSION In ESD for antiplatelet users, continuous administration was not found to have an independent significant association with bleeding.

Comparison of detection and miss rates of narrow band imaging, flexible spectral imaging chromoendoscopy and white light at screening colonoscopy: a randomised controlled back-to-back study

Objective Virtual chromoendoscopy (CE) is expected to enhance adenoma yield and reduce variation in performance between colonoscopists. This study aimed to compare the efficacy of narrow band imaging (NBI), flexible spectral imaging CE (FICE) and white light (WL) colonoscopy and their impact for less experienced endoscopists. Methods We performed a randomised tandem colonoscopy trial controlling for withdrawal time and bowel preparation. Average-risk adults undergoing screening colonoscopy were enrolled and randomly assigned to first withdrawal with one of the three imaging modalities (NBI (NBI-WL group), FICE (FICE-WL group) and WL (WL-WL group)). Eight colonoscopists were categorised into expert and non-expert subgroups. Results 1650 subjects (mean age 51.4 years, 63.9% men) were included (550 in each group). Compared with WL, neither NBI nor FICE increased the mean number of adenomas detected per patient (0.37 vs 0.35 and 0.36; p=0.591) or the percentage of patients with adenoma (25.3% vs 24.5% and 23.6%; p=0.753). For all three modalities, expert subgroups had higher yields of adenomas than non-expert subgroups. Learning curves were observed only for non-expert subgroups with all three modalities. The percentage of missed adenomas did not differ between the three groups (20.8% by WL vs 22.9% by NBI and 26.0% by FICE, p=0.300) and was not affected by endoscopists’ expertise. Conclusions Neither NBI nor FICE improved adenoma detection or miss rates, with no difference in diagnostic efficacy between the two systems. Virtual CE had no additional benefits over WL for non-experts. Clinical trial registration number: KCT0000570.

Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, 13C-urea breath test, and serology

Background and Aims:  This study aimed to evaluate the efficacy of a new polyclonal enzyme immunoassay for the detection of Helicobacter pylori (H. pylori) antigen in stool by determination of the optimal cut‐off value in the screening population.

Helicobacter pylori Serology Inversely Correlated With the Risk and Severity of Reflux Esophagitis in Helicobacter pylori Endemic Area: A Matched Case-Control Study of 5,616 Health Check-Up Koreans

Background/Aims The role of Helicobacter pylori in gastroesophageal reflux disease remains still controversial and the effect of the organism on severity of reflux esophagitis have been rarely issued. The aim of this study was to investigate the relationship between H. pylori infection and reflux esophagitis, and especially the severity of reflux esophagitis. Methods We performed a cross-sectional case-control study of 5,616 subjects undergoing both upper endoscopy and H. pylori serology during health Check-up (2,808 cases vs age- and sex-matched controls). Smoking, alcohol, body mass index and waist circum - ference were added to a multiple regression model. Results Prevalence of H. pylori infection was lower in cases with reflux esophagitis than in controls (38.4% vs 58.2%, P < 0.001) and negative associations with H. pylori infection continued across the grade of esophagitis (46.7% in Los Angeles classification M [LA-M], 34.3% in LA-A or LA-B and 22.4% in LA-C or LA-D, P < 0.001). Positive serology for H. pylori independently reduced the risk of reflux esophagitis (adjusted OR, 0.44; 95% CI, 0.39-0.49). Notably, the negative associations continued across the grade of esophagitis with adjusted ORs of 0.63 in LA-M, 0.36 in LA-A or LA-B and 0.20 in LA-C or LA-D (P < 0.001). Conclusions In a age-sex matched Korean, H. pylori seropositivity was independently and inversely associated with the risk and severity of reflux esophagitis, suggesting the organism may have a protective role against gastroesophageal reflux disease.

Effects of Screening on Gastric Cancer Management: Comparative Analysis of the Results in 2006 and in 2011

Purpose This study aimed to analyze the effect of screening by using endoscopy on the diagnosis and treatment of gastric cancer. Materials and Methods The clinicopathologic characteristics of gastric cancer were compared in individuals who underwent an endoscopy because of symptoms (non-screening group) or for screening purposes (screening group). The distributions of gastric cancer stages and treatment modalities in 2006 and 2011 were compared. Results The proportion of patients in the screening group increased from 45.1% in 2006 to 65.4% in 2011 (P<0.001). The proportion of stage I cancers in the entire patient sample also increased (from 60.5% in 2006 to 70.6% in 2011; P=0.029). In 2011, the percentages of patients with cancer stages I, II, III, and IV were 79.9%, 8.2%, 10.9%, and 1.1%, respectively, in the screening group, and 47.9%, 10.8%, 29.8%, and 11.5%, respectively, in the non-screening group. The proportion of laparoscopic and robotic surgeries increased from 9.6% in 2006 to 48.3% in 2011 (P<0.001), and endoscopic submucosal dissection increased from 9.8% in 2006 to 19.1% 2011 (P<0.001). Conclusions The proportion of patients diagnosed with gastric cancer by using the screening program increased between 2006 and 2011. This increase was associated with a high proportion of early-stage cancer diagnoses and increased use of minimally invasive treatments.

Lymph node metastasis in multiple synchronous early gastric cancer.

BACKGROUND Although endoscopic resection for early gastric cancer (EGC) is increasingly available, it has not been determined whether indications for endoscopic resection are equally acceptable for multiple EGCs. OBJECTIVE To compare the various clinicopathologic factors and risk of lymph node (LN) metastasis between multiple and solitary EGCs. DESIGN Case-control study. SETTING University hospital. PATIENTS This study involved 1717 patients with 156 multiple and 1561 solitary EGCs. INTERVENTION Gastrectomy with LN dissection. MAIN OUTCOME MEASUREMENTS Incidence of LN metastasis. RESULTS In multiple EGCs, main lesions had larger tumor size and deeper invasion depth than the accessory lesions (P < .001). The clinicopathologic features of multiple EGCs were similar to those of solitary EGCs with respect to tumor size, depth of invasion, lymphovascular invasion, and incidence of LN metastasis. Importantly, the risk of LN metastasis in multiple EGCs that met the indication criteria for endoscopic resection was not significantly different from that in solitary EGCs. Tumors meeting conventional indications for endoscopic resection had no risk of LN metastasis, whereas tumors meeting expanded indications showed a similar risk of LN metastasis in the two groups. In multiple EGCs, tumor size ≥3 cm and lymphovascular invasion were independent risk factors of LN metastasis. LIMITATIONS Small number of patients with multiple EGCs studied. CONCLUSION Multiple EGCs had clinicopathologic characteristics and risk of LN metastasis similar to those of solitary EGCs. Endoscopic resection may be adopted as curative treatment for multiple EGCs that meet indications for endoscopic resection. Further studies are needed to verify the present study results.

Vasoconstrictive eicosanoid responses to extracorporeal circulation with or without an oxygenator in fetal lambs.

Introduction This study measured levels of vasoconstrictive eicosanoids during ovine fetal cardiac bypass and compared the measurements between two groups: (1) a group in which the placenta functioned as the only source of oxygen supply during the bypass (the placenta group), and (2) a group in which an artificial oxygenator, instead of the placenta, was included in the bypass circuit (the oxygenator group). Materials and Methods A total of 16 fetal lambs were randomly assigned into either the oxygenator group or the placenta group. Following anesthesia, the fetal cardiac bypass procedure was performed. The placenta group used a centrifugal pump as the pumping device without an oxygenator during the bypass. The bypass circuit in the oxygenator group consisted of a roller pump and a membrane oxygenator. The fetal cardiac bypass procedure was performed for 30 minutes at normothermia in both groups. For the measurements of thromboxane B2(TXB2) and prostaglandin E2 (PGE2), blood sampels were taken before the bypass, at 5 minutes, 15 minutes, and 30 minutes after the start of cardiac bypass, and at 15 minutes after weaning from the bypass. TXB2 and PGE2 levels were determined by radioimmunoassay with PGE2(125I) and TXB2(125I) assay systems. Hemodynamic observations and arterial blood gas analyses were done every 10 minutes. Results The mean arterial pressure and heart rate ranged from 69.8 to 82.6 mmHg and 169 to 182/min during the bypass in the oxygenator group, and from 14.4 to 44.7 mmHg and 64.3 to 75/min in the placenta group. Arterial blood gas analysis showed severe hypercapnia and hypoxemia with acidosis during and after the bypass in the placenta group. Bypass flow rates were maintained at 140.3–164.0 ml/kg/min in the oxygenator group, while flow rates were suboptimal (74.3–97.0 ml/kg/min) in the placenta group. There were no statistically significant differences in PGE2 concentrations before, during, or after bypass, although the placenta group displayed a tendency to higher measurements during bypass, compared to the oxygenator group. The placenta group also showed higher TXB2 measurements than the oxygenator group during the bypass (p=0.0457). Conclusions We have demonstrated increase measurements of PGE2 and TXB2 in the placenta group when compared with the oxygenator group in an ovine fetal cardiac bypass model, although the PGE2 difference failed to reach statistical significance.