Efficacy of narrow-band imaging for detecting intestinal metaplasia in adult patients with symptoms of dyspepsia. / La eficacia de la imagen de banda estrecha para la detección de metaplasia intestinal en pacientes adultos con síntomas de dispepsia.

INTRODUCTION AND OBJECTIVE: Atrophy and intestinal metaplasia are early phenotypic markers in gastric carcinogenesis. White light endoscopy does not allow direct biopsy of intestinal metaplasia due to a lack of contrast of the mucosa. Narrow-band imaging is known to enhance the visibility of intestinal metaplasia, to reduce sampling error, and to increase the diagnostic yield of endoscopy for intestinal metaplasia in Asian patients. The aim of our study was to validate the diagnostic performance of narrow-band imaging using 1.5× electronic zoom endoscopy (with no high magnification) to diagnose intestinal metaplasia in Mexican patients. MATERIALS AND METHODS: A retrospective cohort study was conducted on consecutive patients with dyspeptic symptoms at a private endoscopy center within the time frame of January 2015 to December 2016. RESULTS: A total of 338 patients (63±8.4 years of age, 40% women) were enrolled. The prevalence of H. pylori infection was 10.9% and the incidence of intestinal metaplasia in the gastric antrum and corpus was 23.9 and 5.9%, respectively. Among the patients with intestinal metaplasia, 65.3% had the incomplete type, 42.7% had multifocal disease, and one third had extension to the gastric corpus. Two patients had low-grade dysplasia. The sensitivity of white light endoscopy was 71.2%, with a false negative rate of 9.9%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of narrow-band imaging (with a positive light blue crest) were 85, 98, 86.8, 97.7, and 87.2%, respectively. CONCLUSION: The prevalence of H. pylori infection and intestinal metaplasia in dyspeptic Mexican patients was not high. Through the assessment of the microsurface structure and light blue crest sign, non-optical zoom narrow-band imaging had high predictive values for detecting intestinal metaplasia in patients from a general Western setting.

Development of an E-learning System for the Endoscopic Diagnosis of Early Gastric Cancer: An International Multicenter Randomized Controlled Trial.

BACKGROUND: In many countries, gastric cancer is not diagnosed until an advanced stage. An Internet-based e-learning system to improve the ability of endoscopists to diagnose gastric cancer at an early stage was developed and was evaluated for its effectiveness. METHODS: The study was designed as a randomized controlled trial. After receiving a pre-test, participants were randomly allocated to either an e-learning or non-e-learning group. Only those in the e-learning group gained access to the e-learning system. Two months after the pre-test, both groups received a post-test. The primary endpoint was the difference between the two groups regarding the rate of improvement of their test results. FINDINGS: 515 endoscopists from 35 countries were assessed for eligibility, and 332 were enrolled in the study, with 166 allocated to each group. Of these, 151 participants in the e-learning group and 144 in the non-e-learning group were included in the analysis. The mean improvement rate (standard deviation) in the e-learning and non-e-learning groups was 1·24 (0·26) and 1·00 (0·16), respectively (P<0·001). INTERPRETATION: This global study clearly demonstrated the efficacy of an e-learning system to expand knowledge and provide invaluable experience regarding the endoscopic detection of early gastric cancer (R000012039).

Proton pump inhibitor after endoscopic resection for esophageal squamous cell cancer: multicenter prospective randomized controlled trial.

BACKGROUND: Whether proton pump inhibitors (PPIs) relieve heartburn or precordial pain after endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate the efficacy of PPI therapy for these symptoms after ER for ESCC. METHODS: We conducted a multicenter prospective randomized controlled trial among 15 hospitals in Japan. In total, 229 patients with cT1a ESCC were randomly assigned to receive PPI therapy for 5 weeks after ER (the PPI group, n = 115) or follow-up without PPI therapy (the non-PPI group, n = 114). The primary end point was the incidence of gastroesophageal reflux disease (GERD)-like symptoms after ER from a self-reported questionnaire (Frequency Scale for Symptoms of GERD). Secondary end points were ulcer healing rate at 5 weeks, incidence of pain, improvement rate of symptoms in those who started PPI therapy because of GERD-like symptoms in the non-PPI group, and adverse events. RESULTS: No significant difference was observed in the incidence of GERD-like symptoms after ER between the non-PPI and PPI groups (30 % vs 34 %, respectively). No significant differences were observed in the ulcer healing rate at 5 weeks (84 % vs 85 %) and incidence of pain within 1 week (36 % vs 45 %). In nine of ten patients (90 %) who started PPI therapy because of GERD-like symptoms in the non-PPI group, PPI administration relieved GERD-like symptoms. No adverse events related to PPI administration were observed. CONCLUSION: PPI therapy is not efficacious in reducing symptoms and did not promote healing of ulcers in patients undergoing ER for ESCC.

Identification of serum miRNAs as novel non-invasive biomarkers for detection of high risk for early gastric cancer.

BACKGROUND: Many micro-RNAs (miRNAs) are differentially expressed in Helicobacter pylori-infected gastric mucosa and in gastric cancer tissue and previous reports have suggested the possibility of serum miRNAs as complementary tumour markers. The aim of the study was to investigate serum miRNAs and pepsinogen levels in individuals at high risk for gastric cancer both before and after H. pylori eradication. METHODS: Patients with recent history of endoscopic resection for early gastric cancer and the sex- and age-matched controls were enrolled. Serum was collected from subjects before or after eradication and total RNA was extracted to analyse serum levels of 24 miRNAs. Serum pepsinogen (PG) I and II levels were measured using enzyme-linked immunosorbent assay kits. RESULTS: Using miR-16 as an endogenous control, the relative levels of miR-106 and let-7d before and after H. pylori eradication and miR-21 after eradication were significantly higher in the high-risk group than in the controls. H. pylori eradication significantly decreased miR-106b levels and increased let-7d only in the control group. After eradication, the combination MiR-106b with miR-21 was superior to serum pepsinogen and the most valuable biomarker for the differentiating high-risk group from controls. CONCLUSION: Serum miR-106b and miR-21 may provide a novel and stable marker of increased risk for early gastric cancer after H. pylori eradication.

Intralesional steroid injection to prevent stricture after endoscopic submucosal dissection for esophageal cancer: a controlled prospective study.

BACKGROUND AND STUDY AIMS: The frequency of stricture after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma with a mucosal defect involving more than three-quarters of the circumference is 70% - 90%. Stricture decreases quality of life and requires multiple endoscopic balloon dilation (EBD) sessions. We investigated the efficacy and safety of a single session of intralesional steroid injections to prevent post-ESD stricture. PATIENTS AND METHODS: We conducted a prospective study on 30 patients with esophageal squamous cell carcinoma treated by ESD, who had a more than three-quarter but less than whole circumferential defect. A single session of intralesional steroid injections was undertaken immediately after ESD. Esophagogastroduodenoscopy was performed whenever patients reported dysphagia and 2 months after ESD in patients without dysphagia. Results were compared with a historical control group of 29 patients who underwent ESD without intralesional steroid injection. The primary endpoint was the post-ESD stricture rate. Secondary endpoints were the number of EBD sessions and the complication rate. RESULTS: Compared with the historical control group, the study group had a significantly lower stricture rate (10%, 3/30 patients vs. 66%, 19/29 patients; P < 0.0001) and a lower number of EBD sessions (median 0, range 0 - 2 vs. median 2, range 0 - 15; P < 0.0001). The study group had a complication rate of 7 % (2 /30 patients), comprising a submucosal tear in one patient and bleeding in another, which were not a direct result of EBD. CONCLUSIONS: A single session of intralesional steroid injections showed promising results for the prevention of stricture after ESD for esophageal cancer.

Clinical features and outcomes of delayed perforation after endoscopic submucosal dissection for early gastric cancer.

Perforation is a major complication of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). However, there have been no reports on delayed perforation after ESD for EGC. We aimed to elucidate the incidence and outcomes of delayed perforation after ESD. Clinical courses in 1159 consecutive patients with 1329 EGCs who underwent ESD were investigated. Delayed perforation occurred in six patients (0.45 %). All these patients had complete en bloc resection without intraoperative perforation during ESD. Five of six perforations were located in the upper third of the stomach, while one lesion was found in the middle third. Symptoms of peritoneal irritation with rebound tenderness presented within 24 h after ESD in all cases. One patient did not require surgery because the symptoms were localized, and recovered with conservative antibiotic therapy by nasogastric tube placement. The remaining five patients required emergency surgery. There was no mortality in this case series.

Endoscopic submucosal dissection for early gastric cancer performed by supervised residents: assessment of feasibility and learning curve.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) is feasible as a treatment for early gastric cancer (EGC) when it is performed by an experienced endoscopist. We investigated whether it was feasible for novice endoscopists to perform ESD for EGC, and how difficult it was to learn the procedure. METHODS: This case series study was performed in a cancer referral center. Three resident endoscopists, who had already learned basic procedures, performed ESD under supervision for 30 consecutive lesions, and their procedures were analyzed. The procedure was divided for assessment into (i) mucosal incision and (ii) submucosal dissection by completion of the circumferential mucosal cut. An insulated-tip knife was used for mucosal incision and submucosal dissection. A total of 90 mucosal EGCs (< or = 2 cm) without ulcers or scars in 87 patients were included. Outcomes were: rates of complete resection, complications, and self-completion; operation time; learning curve; and reasons for change of supervisor as an indicator of difficulty. RESULTS: Among the 90 procedures, there was a good overall complete resection rate of 93 %, with an acceptable complication rate of 4.4 %; the complications were delayed hemorrhage in two patients, and perforations in another two patients that were repaired successfully by endoscopic clipping. The self-completion rate and operation time were significantly worse for submucosal dissection than for mucosal incision. Two of the three operators showed a flat learning curve for submucosal dissection. Difficulty with the procedure was related mainly to uncontrollable hemorrhage. CONCLUSIONS: With appropriate supervision, gastric ESD by residents is feasible, with equivalent complete resection rates and acceptable complication rates compared with those of experienced endoscopists, although there was difficulty in achieving sufficient self-completion rates in submucosal dissection. Better control of bleeding during submucosal dissection may be a key to improving the procedure.

A new method of diagnosing gastric intestinal metaplasia: narrow-band imaging with magnifying endoscopy.

BACKGROUND AND STUDY AIMS: With endoscopy, there is a high rate of interobserver variability in the identification of gastric intestinal metaplasia, and the endoscopic findings correlate poorly with the histological findings. Previous studies by our group investigating the use of a narrow-band imaging system with magnifying endoscopy (NBI-ME) in the gastric mucosa suggested that the appearance of a light blue crest (LBC) on the epithelial surface may be a distinctive endoscopic finding associated with the presence of intestinal metaplasia. The aim of the present study was to clarify the value of NBI-ME for diagnosing gastric intestinal metaplasia. PATIENTS AND METHODS: The LBC was defined as a fine, blue-white line on the crests of the epithelial surface/gyri. To investigate the histology underlying the appearance of LBC, 44 biopsy specimens were obtained from regions containing LBC and 44 from non-LBC mucosa in 34 patients with atrophic gastritis. Three endoscopists then carried out NBI-ME in 107 consecutive patients to validate the diagnostic accuracy of the novel endoscopic technique. The degree of correlation between the LBC grading and the histological parameters of intestinal metaplasia was then assessed. RESULTS: The LBC grading correlated with cells that were positive for CD10 ( P = 0.0001) and Alcian blue ( P = 0.036). The appearance of LBC correlated with histological evidence of intestinal metaplasia with a sensitivity of 89 % (95 % CI, 83 - 96 %), a specificity of 93 % (95 % CI, 88 - 97 %), a positive predictive value of 91 % (95 % CI, 85 - 96 %), a negative predictive value of 92 % (95 % CI, 87 - 97 %), and an accuracy of 91 % (95 % CI, 88 - 95 %). CONCLUSIONS: In narrow-band imaging with magnifying endoscopy, observation of a light blue crest on the epithelial surface in the gastric mucosa is a highly accurate sign of the presence of histological intestinal metaplasia.

Helicobacter pylori-induced atrophic gastritis progressing to gastric cancer exhibits sonic hedgehog loss and aberrant CDX2 expression.

BACKGROUND: The loss of sonic hedgehog is an early change that occurs in the mucosa prior to neoplastic transformation and correlates with the type of intestinal metaplasia. Aberrant expression of CDX has also been shown to correlate with the development of intestinal metaplasia. AIM: To examine CDX2 expression in the non-cancerous mucosa of patients with gastric cancer and compared it to CDX2 expression in controls with intestinal metaplasia. METHODS: Sixty patients who had undergone endoscopic mucosal resection for early gastric cancer and 60 gender- and age-matched controls were studied. Two specimens each were obtained from the greater and lesser curves of the corpus and from the greater curve of the antrum. Expression of CDX2 and sonic hedgehog were evaluated by immunostaining. RESULTS: Gastric cancer was associated with a higher frequency of incomplete intestinal metaplasia (OR = 8.3; 95%CI, 3.7-18.9, P < 0.001). CDX2 negatively correlated with sonic hedgehog expression, however, multivariate analysis revealed that CDX2 correlated with the intestinal metaplasia scores. Sonic hedgehog indices were lower and CDX2 staining in the corpus lesser curve was higher in the cancer group than in the controls. Sonic hedgehog indices in the corpus decreased and CDX2 indices in both areas increased in patients in the ascending order of those without intestinal metaplasia, those with complete intestinal metaplasia and those with incomplete intestinal metaplasia (P < 0.001). CONCLUSIONS: Loss of sonic hedgehog expression and aberrant expression of CDX2 correlates with the type of intestinal metaplasia and may play a role in carcinogenesis.

Hypoacidity combined with high gastric juice nitrite induced by Helicobacter pylori infection is associated with gastric cancer.

BACKGROUND: In patients with Helicobacter pylori infection, the concentration of nitrite in gastric juice is elevated. The degree of elevation correlates with that of inflammation and H. pylori density. AIM: The aim of this study was to examine hypoacidity and high nitrite levels related to H. pylori infection in patients with gastric cancer. METHODS: We studied 88 patients with more than one history of endoscopic mucosal resection (EMR) for early gastric cancer and 88 age-matched controls. Concentration of nitrite in gastric juice was measured by Griess reaction, and serum pepsinogen levels were measured by RIA. RESULTS: Multiple malignant lesions were found in 20 of the 88 patients. Serum gastrin, gastric juice pH and nitrite levels in patients with gastric cancer were significantly higher and pepsinogen I and pepsinogen I/II significantly lower than in control subjects. Pepsinogen I level and I/II ratio were lower and gastric juice pH was higher in the protruded-type group than in the depressed-type group. Pepsinogen I and pepsinogen I/II were lower and gastric juice pH was higher in multiple than in single cases. CONCLUSIONS: Hypoacidity combined with high gastric juice nitrite induced by H. pylori infection is associated with the intestinal type of gastric cancer, especially protruded lesions.

Endoscopic resection with a two-channel videoendoscope for gastric carcinoid tumors.

BACKGROUND/AIMS: Endoscopic resection has been used to treat hypergastrinemia-associated early carcinoid tumors of the stomach. However, indications for endoscopic treatment of these tumors have not been established. Moreover, endoscopic resection of these tumors is often difficult with conventional polypectomy, because these tumors are often located in the submucosal layer. To completely remove these tumors, we used a two-channel videoendoscope with which both grasping forceps and a polypectomy snare could be used simultaneously. METHODOLOGY: At Osaka Medical Center for Cancer and Cardiovascular Diseases, eight carcinoid tumors in six patients were removed with a two-channel videoendoscope. Reports of early carcinoid tumor in Japanese literature were reviewed to analyze the relationship between lymph node metastasis and the size and depth of involvement of these tumors. RESULTS: Six carcinoid tumors were completely removed "en bloc", but two tumors were incompletely removed. In these two patients, submucosal tumor invasion was observed on the excision line. To completely remove these tumors, the oral side, but not the top, of the tumor should be strongly grasped and pulled toward the center of the lumen as far as possible by the grasping forceps, which had been passed through the snare loop. Endoscopic follow-up studies showed no local recurrence in any patients with and without complete tumor resection during the average observation period of 30 months. A review of histological reports in Japanese literature showed that lymph node metastasis did not occur when the tumors were less than 10 mm in diameter, and could be completely removed by an endoscope. CONCLUSIONS: Endoscopic resection with a two-channel videoendoscope is a useful and safe method for resection of small carcinoid tumors of the stomach.

Induction by bombesin of peritoneal metastasis of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

BACKGROUND: We investigated the effect of the gastrointestinal regulatory peptide, bombesin, on the development of peritoneal metastasis from gastric cancers induced in rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and on Rho activity in the gastric cancers. METHODS: Rats were allocated to three groups. All groups received MNNG (100 micrograms/ml) solution for 25 weeks from the start of the experiment. Group 1 (controls) received olive oil injections from the start of MNNG treatment; group 2 animals received alternate-day s.c. injections of bombesin (40 micrograms/kg body weight) in olive oil from the start of the experiment until the end of the experiment at week 52; and group 3 received the s.c. bombesin injection on alternate days from week 26 until week 52. The effect of bombesin on Rho activity in gastric cancer was examined by Western blotting. RESULTS: Bombesin given from the start of the experiment (group 2) and after the MNNG treatment (group 3) both significantly increased the incidence of gastric cancer metastasis, compared with controls, at week 52: The incidence of metastasis was significantly higher in group 2 than in group 3. Bombesin from the start of the experiment (group 2) significantly increased the incidence of tumors with deeper invasion or more infiltrative growth pattern, or lymphatic vessel tumor invasion, while bombesin after MNNG treatment (group 3) significantly increased the incidence of lymphatic vessel invasion. Bombesin also increased the activity of Rho protein in the tumors. CONCLUSION: Bombesin significantly increased the incidence of peritoneal metastasis from gastric cancers through the activation of Rho protein.

Attenuation by ambroxol of monochloramine-enhanced gastric carcinogenesis: a possible prevention against Helicobacter pylori-associated gastric carcinogenesis.

The effects of combined administration of a reactive oxidant, monochloramine, and a mucoregulatory agent, ambroxol, on the development of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in inbred Wistar rats. After receiving oral MNNG and regular chow pellets for 25 weeks, rats received regular chow pellets or chow pellets containing 20% ammonium acetate, and normal tap water or water containing 30 mM sodium hypochlorite, with or without subcutaneous injection of ambroxol at high or low doses, until the end of the experiment at week 52. Treatment with both ammonium acetate and sodium hypochlorite, which produce monochloramine, significantly increased the incidence of gastric cancers at week 52, whereas concomitant administration of ambroxol with ammonium acetate and sodium hypochlorite significantly attenuated this enhanced gastric carcinogenesis. Results also revealed that ambroxol scavenged monochloramine. Because monochloramine is closely related to Helicobacter pylori-associated gastric carcinogenesis, these findings suggest that ambroxol may prevent H. pylori-associated gastric carcinogenesis.

Effectiveness of endoscopic mucosal resection with submucosal saline injection technique for superficial squamous carcinomas of the esophagus.

BACKGROUND: Intraepithelial cancers (m1 cancer) and cancers that penetrate the basement membrane but do not approach the muscularis mucosae (m2 cancer) do not have lymph node metastasis and thus can be removed completely with mucosal resection. Therefore, in this study, the effectiveness of endoscopic mucosal resection with submucosal saline injection for removal of superficial esophageal cancers was investigated prospectively. METHODS: Twenty-five superficial esophageal cancers in 21 patients were removed with submucosal saline injection. When it was thought that a tumor had not been completely resected en bloc, it was removed completely in piecemeal fashion. Endoscopy was repeated 1, 3, 6, 12 months or more after endoscopic resection. RESULTS: All superficial esophageal cancers were completely removed: 18 (72%) en bloc and 7 (28%) by piecemeal resection. No recurrence was found during a mean observation period of 2.0 years (range 0.8 to 3.6) after resection. Bleeding occurred in 5 cases (24%) during or after resection but was successfully treated with the endoscopic alginate or thrombin spray technique. There was no perforation. CONCLUSION: Endoscopic mucosal resection with submucosal saline injection is effective for removal of superficial cancers of the esophagus.