Magnifying narrowband imaging is more accurate than conventional white-light imaging in diagnosis of gastric mucosal cancer

Usefulness of Demarcation of Differentiated-Type Early Gastric Cancers after Helicobacter pylori Eradication by Magnifying Endoscopy with Narrow-Band Imaging

BACKGROUND/AIMS

Early gastric cancer after Helicobacter pylori (Hp) eradication is difficult to demarcate. We used the vessel plus surface classification system (VSCS) to determine whether magnifying endoscopy with narrow-band imaging (ME-NBI) could demarcate differentiated-type early gastric cancers after Hp eradication, and to identify causes of an unclear demarcation line (DL).

METHODS

Among 100 lesions of differentiated-type early gastric cancer resected endoscopically, 34 lesions in the Hp-eradicated group and 66 in the Hp-infected group were retrospectively compared. Clinicopathological factors and ME-NBI findings, including the presence or absence of the DL, were examined. Histopathologically, histological gastritis, the surface structure at the tumor border, well-differentiated adenocarcinoma with low-grade atypia (tub1-low), and non-neoplastic epithelium (NE) coverage rate on the tumor surface and at the tumor border were evaluated.

RESULTS

DL (-) cases were more frequent in the Hp-eradicated group (11.8%, 4/34) than in the Hp-infected group (1.5%, 1/66; p < 0.05). The Hp-eradicated group had a higher NE coverage rate than the Hp-infected group (p < 0.05). All DL (-) cases had tub1-low or NE at the tumor border.

CONCLUSION

ME-NBI with VSCS can identify the DL in most patients (88.2%) with differentiated-type early gastric cancer after Hp eradication.

Blue laser imaging-bright improves the real-time detection rate of early gastric cancer: a randomized controlled study

BACKGROUND AND AIMS

Blue laser imaging-bright (BLI-bright) has shown promise as a more useful tool for detection of early gastric cancer (EGC) than white-light imaging (WLI). However, the diagnostic performance of BLI-bright in the detection of EGC has not been investigated. We aimed to compare real-time detection rates of WLI with that of BLI-bright for EGC.

METHODS

This was a prospective, randomized, controlled study in 2 Japanese academic centers. We investigated 629 patients undergoing follow-up endoscopy for atrophic gastritis with intestinal metaplasia or surveillance after endoscopic resection of EGC. Patients were randomly assigned to receive primary WLI followed by BLI-bright or primary BLI-bright followed by WLI. The real-time detection rates of EGC were compared between primary WLI and primary BLI-bright.

RESULTS

There were 298 patients in each group. The real-time detection rate of EGC with primary BLI-bright was significantly greater than that with primary WLI (93.1% vs 50.0%; P = .001). Primary BLI-bright had a significantly greater ability to detect EGCs in patients with a history of endoscopic resection for EGC, no Helicobacter pylori infection in the stomach after eradication therapy, lesions with an open-type atrophic border, lesions in the lower third of the stomach, depressed-type lesions, small lesions measuring <10 mm and 10 to 20 mm in diameter, reddish lesions, well-differentiated adenocarcinomas, and lesions with a depth of invasion of T1a.

CONCLUSIONS

BLI-bright has a higher real-time detection rate for EGC than WLI. BLI-bright should be performed during surveillance endoscopy in patients at high risk for EGC. (Clinical trial registration number: UMIN000011324.).

The incidence of lymph node metastasis in submucosal early gastric cancer according to the expanded criteria: a systematic review

BACKGROUND

For successful endoscopic treatment of early gastric cancer (EGC), absolute criteria for a curative en bloc resection were initially established to include predominantly differentiated mucosal lesions ≤ 2 cm in diameter without ulceration. These indications were subsequently expanded to include larger, ulcerated, and predominantly undifferentiated mucosal lesions. In addition, differentiated type adenocarcinomas ≤ 3 cm with slight submucosal invasion of < 500 µm (pT1b1) are regarded as "curative" under the expanded criteria. However, data derived from studies of surgical specimens in patients with pT1b1 EGC have yielded varying rates of lymph node metastasis (LNM).

METHOD

A systemic review was conducted using the pooled analysis to calculate the incidence of LNM in pT1b1 EGC, and to investigate whether using a cut-off value of < 300 µm would decrease the risk of LNM in patients with submucosal EGC.

RESULTS

Nineteen articles were included. 1507 patients with pT1b1 EGC met the expanded indications. The incidence of LNM was 3% (45 out of 1507 patients). In a subgroup analysis of three studies, there was no significant difference in the LNM between pT1b EGC < 300 µm and < 500 µm [3/121(2.5%) vs. 5/180 (2.8%)] (OR 0.89, 95% CI 0.22-3.54).

CONCLUSION

Overall, expanding the indications for endoscopic resection of EGC to include lesions ≤ 3 cm T1b1 is associated with a potential risk of LNM of 3%. In countries outside of Japan, we found a slightly higher risk of LNM (4.0%). These estimates of LNM should be incorporated into decisions regarding further management of patients with EGC ≤ 3 cm who are found to have slight submucosal invasion (< 500 µm) in an ESD specimen. Standardization of specimen handling and histological evaluation is essential if the Japanese results of endoscopic treatment for EGC are to be successfully applied in other parts of the world.

Objective image analysis of non-magnifying image-enhanced endoscopy for diagnosis of small depressed early gastric cancers

Background  Gastric cancers (GC) after H. pylori eradication are difficult to diagnose even by magnifying narrow-band imaging (NBI) or blue laser imaging (BLI) endoscopy. Little is known with regard to non-magnifying (NM)-NBI/BLI for early GC so we examined the efficacy of NM-NBI/BLI for early GC diagnosis. Methods  We retrospectively analyzed the images of 29 small (≤ 1 cm) intramucosal GC that had been treated with endoscopic submucosal dissection and 137 benign depressed lesions (BDLs). The brightness and shape of the GCs and BDLs by NM-NBI/BLI were assessed with ImageJ software. Results  The NBI/BLI-index, which indicates the brightness of NBI/BLI for visualization, was significantly higher in GC than BDLs in both the H. pylori -infected ( P  = 0.009) and -eradicated group ( P  < 0.0001), indicating that GC exhibited brighter colors than the normal surrounding mucosa. The C-index, which refers to the circularity of the lesion, was also significantly higher in GC than BDLs in both H. pylori -infected ( P  = 0.006) and -eradicated cases ( P  = 0.004). Based on receiver-operating characteristic curve analysis, cutoff values for the NBI/BLI- and C-indices for GC were 1.04 and 0.58 in the H. pylori -infected cases, and 0.98 and 0.64 in the H. pylori -eradicated cases. With the reference value of the NBI/BLI-index set at ≥ 0.69 with the C-index at ≥ 0.21 in the H. pylori -infected and the NBI/BLI-index at ≥ 0.80 with the C-index at ≥ 0.32 in the H. pylori -eradicated cases, both the sensitivity and negative predictive value for early GC were 100 %. A high NBI/BLI-index tended to be associated with a wide length of the intervening part histologically in the H. pylori -eradicated cases ( P  = 0.09). Conclusions  The small depressed-type early GC had brighter color and rounder shape compared to BDLs in both H. pylori -infected and -eradicated cases. The NBI/BLI- and C-indices calculated by the image analysis may facilitate identification of small depressed-type GC.

Usefulness of Narrow-Band Imaging in Endoscopic Submucosal Dissection of the Stomach

There have been many advances in endoscopic imaging technologies. Magnifying endoscopy with narrow-band imaging is an innovative optical technology that enables the precise discrimination of structural changes on the mucosal surface. Several studies have demonstrated its usefulness and superiority for tumor detection and differential diagnosis in the stomach as compared with conventional endoscopy. Furthermore, magnifying endoscopy with narrow-band imaging has the potential to predict the invasion depth and tumor margins during gastric endoscopic submucosal dissection. Classifications of the findings of magnifying endoscopy with narrow-band imaging based on microvascular and pit patterns have been proposed and have shown excellent correlations with invasion depth confirmed by microscopy. In terms of tumor margin prediction, magnifying endoscopy with narrow-band imaging offers superior delineation of gastric tumor margins compared with traditional chromoendoscopy with indigo carmine. The limitations of narrow-band imaging, such as the need for considerable training, long procedure time, and lack of studies about its usefulness in undifferentiated cancer, should be resolved to confirm its value as a complementary method to endoscopic submucosal dissection. However, the role of magnifying endoscopy with narrow-band imaging is expected to increase steadily with the increasing use of endoscopic submucosal dissection for the treatment of gastric tumors.

Clinical Significance of Reddish Depressed Lesions Observed in the Gastric Mucosa after Helicobacter pylori Eradication

BACKGROUND AND AIM

Reddish depressed lesions (RDLs) frequently observed in patients following Helicobacter pylori eradication are indistinguishable from gastric cancer. We examined the clinical and histological feature of RDLs and its relevant endoscopic diagnosis including magnifying narrow-band imaging (M-NBI).

METHODS

We enrolled 301 consecutive patients with H. pylori eradication who underwent endoscopy using white light imaging (WLI). We examined the prevalence and host factors contributing to the presence of RDLs. Next, we used M-NBI in 90 patients (104 RDLs), and compared the diagnostic efficacy between M-NBI and WLI groups using propensity-score matching analysis.

RESULTS

In 301 patients after eradication, 117 (39%) showed RDLs. Male, open-type atrophy, and gastric cancer history were risk factors for RDLs. A gastric biopsy was needed in 83 (71%) during WLI observation and only 2 were diagnosed with adenocarcinoma. In M-NBI group, a biopsy was performed in 21 (20%), and 9 were diagnosed with adenocarcinoma. A biopsy was required in fewer patients, and the positive predictive value of a biopsy was statistically higher in M-NBI than in the WLI group (p < 0.01).

CONCLUSIONS

RDLs are frequently observed in high-risk patients for gastric cancer after eradication. M-NBI demonstrated significantly superior diagnostic efficacy with respect to RDL.

Detection of aberrant crypt foci with image-enhanced endoscopy

Background and study aims  Conventional detection of aberrant crypt foci (ACF) with dye-spraying and magnifying observation is labor- and skill-intensive. We performed a prospective non-inferiority study to investigate the utility of image-enhanced endoscopy (IEE) for detection of ACF. Patients and methods  Patients with a history of colorectal neoplasm were eligible. The number of ACF in the lower rectum was counted first using IEE magnification with narrow-band imaging (NBI) or blue-laser imaging (BLI), and subsequently using the methylene blue method. The primary endpoint was the ACF detection rate with IEE, i. e., the number of ACF detected with IEE relative to the number of ACF detected with methylene blue. The secondary endpoints were bowel preparation time, ACF detection time, and the detection rate with NBI or BLI. Results  A total of 40 patients were enrolled (NBI 20 and BLI 20). The overall detection rate for ACF with IEE was 81.7 % (503/616; 95 %CI 78.8 - 84.6 %), meeting the primary endpoint. The detection rate for ACF with BLI (84.9 %, 258/304) was significantly higher than with NBI (78.5 %, 245/312; P  < 0.05). Both bowel preparation time and ACF detection time were significantly shorter with IEE versus the methylene blue method ( P  < 0.01, respectively). The detection rates for dysplastic and non-dysplastic ACF with IEE were 84.4 % (27/32) and 80.3 % (469/584), respectively. Conclusion  IEE is able to detect ACF during colonoscopy with sensitivity non-inferior to that of the conventional methylene blue method. IEE is simpler than the methylene blue method and is therefore a potentially useful new tool for ACF detection.

Magnifying Blue Laser Imaging versus Magnifying Narrow-Band Imaging for the Diagnosis of Early Gastric Cancer: A Prospective, Multicenter, Comparative Study

BACKGROUND/AIMS

The diagnostic efficacy of magnifying blue laser imaging (M-BLI) and M-BLI in bright mode (M-BLI-bright) in the identification of early gastric cancer (EGC) was evaluated for comparison to that of magnifying narrow-band imaging (M-NBI).

METHODS

This prospective, multicenter study evaluated 114 gastric lesions examined using M-BLI, M-BLI-bright, and M-NBI between May 2012 and November 2012; 104 EGCs were evaluated by each modality. The vessel plus surface classification system was used to evaluate the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP).

RESULTS

M-BLI, M-BLI-bright, and M-NBI revealed a DL for 96.1, 98.1, and 98.1% and irregular MVP for 95.1, 95.1, and 96.2% of lesions, respectively, with no significant difference. Irregular MSP was observed by M-BLI, M-BLI-bright, and M-NBI in 97.1, 90.4, and 78.8% of lesions, respectively, with significant differences (p < 0.001). The proportion of moderately differentiated adenocarcinoma with irregular MSP on M-BLI and absent MSP on M-NBI was significantly higher than that with irregular MSP on M-BLI and M-NBI (35.0 and 9.9%, respectively; p = 0.002).

CONCLUSION

M-BLI and M-BLI-bright provided excellent visualization of microstructures and microvessels similar to M-NBI. Irregular MSP in a moderately differentiated adenocarcinoma might be frequently visualized using M-BLI and M-BLI-bright compared with using M-NBI.

Reevaluation of laparoscopic versus open distal gastrectomy for early gastric cancer in Asia: A meta-analysis of randomized controlled trials

BACKGROUND

The benefits and risks of laparoscopic distal gastrectomy (LADG) are not yet sufficiently clear for acceptance as a standard treatment of early gastric cancer. Previous meta-analyses were not powered to reach definitive conclusions.

MATERIALS AND METHODS

Randomized controlled trials comparing LADG with open distal gastrectomy (ODG) for early gastric cancer in Asia and published between January 1994 and January 2018 were retrieved from PubMed, Embase, the Cochrane Library, and Google Scholar. Patient characteristics, oncological safety and efficacy, and surgical safety were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Grading of Recommendations Assessment, Development and Evaluation guidelines (GRADE) guidelines. Trial Sequential Analysis (TSA) reduced random error and reinforced the reliability and strength of evidence.

RESULTS

Eight trials including 2666 participants were selected. LADG benefits were an 11.6 cm shorter incision (95% CI: -13.31 to -9.88 cm; P < 0.0001), 103.81 ml less blood loss (95% CI: -133.68 to -73.94; P < 0.0001), 1.73 times less analgesic use (95% CI: -2.21 to -1.24; P < 0.0001), 0.51 days shorter time to first flatus (95% CI: -0.88 to -0.15 days; P = 0.006), lower risk of wound dehiscence (RR = 0.24, 95% CI: 0.08-0.78; P = 0.02), lower risk of surgical adverse events (RR = 0.69, 95% CI: 0.53-0.91; P = 0.008), and lower risk of respiratory complications (RR = 0.40; 95% CI: 0.20-0.79; P = 0.009) than ODG. LADG had 2.22 fewer resected lymph nodes (95% CI: -4.33 to -0.12; P = 0.04) and 76.61 min longer procedures (76.61 min, 95% CI: 57.74-95.47 min; P < 0.0001).

CONCLUSIONS

In Asian patients, LADG had similar mortality and oncological safety, better surgical safety, less operative morbidity, less trauma, and faster recovery than ODG. It has a high role to play in node-negative cases due to better short-term outcomes but less nodal harvest. It is a recommended alternative treatment for experienced surgeons in high-volume centers.

Computer-aided diagnosis for identifying and delineating early gastric cancers in magnifying narrow-band imaging

BACKGROUND AND AIMS

Magnifying narrow-band imaging (M-NBI) is important in the diagnosis of early gastric cancers (EGCs) but requires expertise to master. We developed a computer-aided diagnosis (CADx) system to assist endoscopists in identifying and delineating EGCs.

METHODS

We retrospectively collected and randomly selected 66 EGC M-NBI images and 60 non-cancer M-NBI images into a training set and 61 EGC M-NBI images and 20 non-cancer M-NBI images into a test set. After preprocessing and partition, we determined 8 gray-level co-occurrence matrix (GLCM) features for each partitioned 40 × 40 pixel block and calculated a coefficient of variation of 8 GLCM feature vectors. We then trained a support vector machine (SVM_Lv1) based on variation vectors from the training set and examined in the test set. Furthermore, we collected 2 determined P and Q GLCM feature vectors from cancerous image blocks containing irregular microvessels from the training set, and we trained another SVM (SVM_Lv2) to delineate cancerous blocks, which were compared with expert-delineated areas for area concordance.

RESULTS

The diagnostic performance revealed accuracy of 96.3%, precision (positive predictive value [PPV]) of 98.3%, recall (sensitivity) of 96.7%, and specificity of 95%, at a rate of 0.41 ± 0.01 seconds per image. The performance of area concordance, on a block basis, demonstrated accuracy of 73.8% ± 10.9%, precision (PPV) of 75.3% ± 20.9%, recall (sensitivity) of 65.5% ± 19.9%, and specificity of 80.8% ± 17.1%, at a rate of 0.49 ± 0.04 seconds per image.

CONCLUSIONS

This pilot study demonstrates that our CADx system has great potential in real-time diagnosis and delineation of EGCs in M-NBI images.

Development of Image-enhanced Endoscopy of the Gastrointestinal Tract: A Review of History and Current Evidences

Endoscopy imaging of the gastrointestinal (GI) tract has evolved tremendously over the last few decades. Key milestones in the development of endoscopy imaging include the use of various dyes for chromoendoscopy, the application of optical magnification in endoscopy, the introduction of high-definition image capturing and display technology and the application of altered illuminating light to achieve vascular and surface enhancement. Aims of this review paper are to summarize the development and evolution of modern endoscopy imaging and in particular, imaged-enhanced endoscopy (IEE), to promote appropriate usage, and to guide future development of good endoscopy practice. A search of PubMed database was performed to identify articles related to IEE of the GI tract. Where appropriate, landmark trials and high-quality meta-analyses and systematic reviews were used in the discussion. In this review, the developments and evolutions in endoscopy imaging and in particular, IEE, were summarized into discernible eras and the literature evidence with regard to the strengths and weaknesses in term of their detection and characterization capability in each of these eras were discussed. It is in the authors' opinion that IEE is capable of fairly good detection and accurate characterization of various GI lesions but such benefits may not be readily reaped by those who are new in the field of luminal endoscopy. Exposure and training in making confident diagnoses using these endoscopy imaging technologies are required in tandem with these new developments in order to fully embrace and adopt the benefits.

Clinical predictors of histologic type of gastric cancer

BACKGROUND AND AIMS

Gastric cancer is classified into differentiated and undifferentiated types according to the degree of glandular differentiation. Undifferentiated-type early gastric cancer (EGC) carries a higher risk of lymph-node metastasis than differentiated type, and therefore the indication criteria for endoscopic resection differ. This study aimed to clarify the ability of clinical predictors to distinguish between differentiated-type and undifferentiated-type EGCs.

METHODS

This was a post hoc study of a multicenter prospective trial carried out in 5 Japanese hospitals, including 343 patients with cT1 EGC of ≥10 mm. According to the protocol, age, sex, and endoscopic findings of cancer (diameter, location, macroscopic type, and invasion depth) were evaluated, and the final diagnosis was confirmed from resected specimens. We evaluated the associations between these clinical factors and the histologic type of cancer and calculated the ability of the factors to diagnose differentiated-type EGC. The diagnostic ability of forceps biopsy was also calculated as a reference.

RESULTS

Multivariate analysis identified older age (≥72 years), male sex, larger tumor size (>30 mm), elevated type, and shallower invasion depth (cT1a) as independent significant predictors for differentiated-type EGC, with elevated type showing the highest positive likelihood ratio. The sensitivity, specificity, accuracy, and positive and negative likelihood ratios of elevated type for differentiated-type EGC were 24%, 99%, 38%, 15.7, and 0.77, respectively, compared with 96%, 86%, 95%, 7.0, and 0.04 for forceps biopsy.

CONCLUSIONS

Endoscopic elevated type is a significant predictor for differentiated-type EGC and may exclude undifferentiated-type EGC without the need for forceps biopsy.

In vivo diagnosis of early-stage gastric cancer found after Helicobacter pylori eradication using probe-based confocal laser endomicroscopy

BACKGROUND AND AIM

Early-stage gastric cancer (EGC) found after Helicobacter pylori (Hp) eradication often displays non-tumorous regenerative epithelium and/or maturated tumorous epithelium overlying the cancerous tissue, which may confuse endoscopic and histological diagnosis. Probe-based confocal laser endomicroscopy (pCLE) enables in vivo real-time optical biopsy. We compared the diagnostic yields for these EGC cases using conventional white light endoscopy (WL), magnifying endoscopy with narrow-band imaging (ME-NBI), pCLE, and endoscopic biopsy; we also compared the accuracy of the horizontal extent diagnosis between ME-NBI and pCLE.

METHODS

This study enrolled 30 patients with 36 EGC lesions after successful Hp eradication. Diagnostic yields of WL, ME-NBI, pCLE, and endoscopic biopsy were prospectively compared. Four points of cancerous margins (oral, anal, anterior, and posterior sites) were also prospectively evaluated with M-NBI and pCLE to determine the horizontal extent of the EGC.

RESULTS

Diagnostic yield was significantly higher with pCLE than with WL and endoscopic biopsy (97 vs 72%, 97 vs 72%, P = 0.0159, 0.0077, respectively), whereas it did not differ from ME-NBI (88.9%, P = 0.371). Height of non-tumorous regenerative epithelium or maturated atypical glands was 104.7 ± 34.2 μm in the pCLE-positive cases, whereas it was 188.3 ± 27.1 μm in a pCLE-negative case (P = 0.0004). Diagnostic accuracy of the horizontal margin of EGC was significantly higher with pCLE than with ME-NBI (92 vs 70%, P = 0.0159).

CONCLUSION

pCLE may be helpful for the diagnosis of ambiguous ECG found after Hp eradication because it enables real-time scanning throughout the lesion and detection of subsurface microstructure.

Histological verification of the usefulness of magnifying endoscopy with narrow-band imaging for horizontal margin diagnosis of differentiated-type early gastric cancers

BACKGROUND

Although magnifying endoscopy with narrow-band imaging (ME-NBI) can help identify the horizontal margin (HM) of early gastric cancer (EGC), little is known about the factors that can clarify the HM by using ME-NBI. We aimed to characterize the pathological features of lesions in which the HM was identified using ME-NBI.

METHODS

The HMs of 639 differentiated-type EGCs treated with endoscopic submucosal dissection or surgery were analyzed using conventional endoscopy and ME-NBI. The number and width of the intervening parts (IP) and the number, width, and depth of the subepithelial capillaries (SEC) in cancerous and noncancerous areas were measured.

RESULTS

In 13 lesions (2.0%), more than 90% of the HM was not recognized with conventional endoscopy, but 11 of these lesions were detectable with ME-NBI (NBI group). The HMs of the other 626 lesions were mostly recognized using conventional endoscopy (WLI/CE group). In the NBI group, the IP width, standard deviation (SD), and number of IPs did not significantly differ between the cancerous and noncancerous areas. However, the SEC number was significantly larger and the depth was shallower in cancerous areas. In the WLI/CE group, the IP width and SD were significantly larger, but the IP number was significantly smaller in cancerous areas. The SEC depth was significantly shallower in cancerous areas.

CONCLUSIONS

Differences of IP width, SD, and IP number may be factors for identifying HMs with conventional endoscopy. Because NBI can better visualize vessel structures, the increased SEC number and shallow SECs may clarify the HM.

The accuracy of magnifying narrow band imaging (ME-NBI) in distinguishing between cancerous and noncancerous gastric lesions: A meta-analysis

BACKGROUND

Previous clinical trials have demonstrated the diagnostic accuracy of magnifying narrow-band (ME-NBI) for gastric cancerous lesions, but the results are inconsistent. The purpose of this meta-analysis is to investigate the accuracy of ME-NBI in distinguishing between cancerous and noncancerous gastric lesions.

METHODS

Systematic literature searches were conducted until October 2016 in PubMed, Embase by 2 independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity. Two authors independently evaluated studies for inclusion, rated methodological quality, and abstracted relevant data. Meta-analytic method was used to construct summary receiver operating characteristic curves, and pooled sensitivity, specificity were calculated.

RESULTS

Nine studies enrolling 5398 lesions were included. The pooled sensitivity, specificity were 88% (95% confidence interval [CI]: 78-93%), 96% (95% CI: 91-98%), respectively. The area under the curve (AUC) was 0.97. There was a large heterogeneity between the included studies. Studies with lesions ≤ 10 mm still had a high pooled sensitivity of 81% (95% CI: 73-90%) and specificity of 97% (95% CI: 95-100%). Studies which analyzed resected specimens had a sensitivity of 91% (95 CI: 82-99%) and specificity of 88% (95% CI: 83-94%), and studies which analyzed biopsied specimens had a sensitivity of 85% (95 CI: 74-96%) and specificity of 99% (95% CI: 98-99%).

CONCLUSIONS

ME-NBI is highly accurate and consistent to distinguish between gastric cancerous and noncancerous lesions.

The incidence of lymph node metastasis in early gastric cancer according to the expanded criteria in comparison with the absolute criteria of the Japanese Gastric Cancer Association: a systematic review of the literature and meta-analysis

BACKGROUND AND AIMS

Japanese criteria for curative endoscopic resection of early gastric cancer initially included nonulcerated, well-differentiated mucosal lesions ≤2 cm in diameter, known as the absolute criteria. Subsequently, these indications were expanded to include larger, ulcerated, and undifferentiated mucosal lesions as well as differentiated lesions with slight submucosal invasion. Whether patients meeting the expanded criteria can be managed safely without gastrectomy and lymph node dissection has been controversial. The risk of lymph node metastasis (LNM) in patients who met the expanded criteria is a critical factor in determining the best course of management for these patients.

METHODS

We comprehensively searched main reference databases for studies that included patients who underwent gastrectomy and lymph node dissection for early gastric cancer. A meta-analysis was conducted by using the random effects model. Relative risk reduction was used to compare the incidence of LNM in patients meeting the absolute criteria as compared with those meeting the expanded criteria.

RESULTS

Twelve studies met the inclusion criteria, providing a total of 9798 patients. The incidence of LNM was 0.2% for patients who met the absolute criteria as compared with 0.7% for patients who met the expanded criteria. Analysis of the various components of the expanded criteria was conducted, revealing that the incidence of LNM for differentiated mucosal lesions ≤3 cm with ulceration and for differentiated mucosal lesions without ulceration, irrespective of size, was 16 of 2814 (0.57%), reference range (RR) 3.01; P = .02 and 8 of 3004 (0.27%), RR 1.69; P = .37, respectively, only marginally higher than the risk of LNM associated with the absolute criteria. In contrast, undifferentiated mucosal lesions ≤2 cm and differentiated lesions <3 cm with slight submucosal invasion had a significantly higher incidence of LNM in comparison with the absolute criteria (25/972 [2.6%], RR 6.79; P = .0004 and 8/315 [2.5%], RR 6.30; P = .004, respectively).

CONCLUSION

Overall, expanding the indication for endoscopic resection to include mucosal nonulcerated differentiated lesions irrespective of size and differentiated mucosal ulcerated lesions <3 cm is justified with minimal increased risk in comparison to the absolute criteria. However, expanding the indication for undifferentiated lesions ≤2 cm and differentiated lesions with slight submucosal invasion (T1b) should be balanced with the risks of surgery, given the increased risk of LNM in these patients.

Multiple convex demarcation line for prediction of benign depressed gastric lesions in magnifying narrow-band imaging

BACKGROUND AND STUDY AIMS

 With magnifying narrow-band imaging (M-NBI) of the gastric mucosa, a characteristic demarcation line (DL) is occasionally found in non-cancerous depressed lesions. This DL forms multiple convex shapes along the edge of the epithelia of surrounding mucosa. We have termed this novel finding a multiple convex DL (MCDL). In this study, we clarified the prevalence of an MCDL in depressed gastric lesions detected in patients at high risk for gastric cancer and determined the diagnostic yield necessary to distinguish between cancer and non-cancer.

PATIENTS AND METHODS

 This was a post hoc analysis of a multicenter prospective trial. In total, 362 small (≤ 10 mm) depressed lesions were detected in 1353 patients. Presence or absence of a DL in target lesions was evaluated on M-NBI images. The proportion of MCDLs among lesions with a DL was evaluated.

RESULTS

Images of 347 lesions (39 cancerous and 308 non-cancerous) were evaluable. A DL was present in 252/347 lesions (73 %). When the cutoff value for the proportion of MCDLs needed to distinguish non-cancer from cancer was set at two-thirds, an MCDL was observed in 86/252 lesions (34 %). In 86 lesions with an MCDL, 83 (97 %) were non-cancerous. The sensitivity, specificity, positive predictive value, and negative predictive value of an MCDL for non-cancerous lesions were 38 %, 91 %, 97 %, and 19 %, respectively.

CONCLUSIONS

 Presence of an MCDL had high specificity and positive predictive value for non-cancerous lesions. Evaluating the shape of the DL is useful for differentiation between cancer and non-cancerous lesions.

Diagnostic performance of routine esophagogastroduodenoscopy using magnifying endoscope with narrow-band imaging for gastric cancer

BACKGROUND AND AIM

In Japan, an increase in the number of routine esophagogastroduodenoscopy procedures is expected because several studies have reported that endoscopy screening has reduced gastric cancer mortality. Magnifying narrow-band imaging has been reported to be effective for accurate diagnosis of gastric abnormalities such as cancers, adenomas, and intestinal metaplasia. However, the efficacy of this method in routine esophagogastroduodenoscopy has not been clarified.

METHODS

We divided 3763 patients into two groups. The non-magnification group included 1842 patients who underwent endoscopy screening using GIF-H260/LUCERA-SPECTRUM between October 2014 and February 2015, whereas the magnification group included 1921 patients who underwent screening using GIF-H290Z/LUCERA-ELITE between March 2015 and May 2015. In the magnification group, diagnosis of cancer was conducted using the VS classification system. We did not carry out a biopsy when results were confirmed as non-cancer using magnifying narrow-band imaging. If cancer was diagnosed, or when a cancer or non-cancer diagnosis was difficult, we carried out a biopsy. We analyzed and compared the diagnostic performance between the two groups.

RESULTS

Gastric biopsy rate was significantly lower in the magnification group (29%) than in the non-magnification group (41%) (P < 0.001). Positive predictive value (PPV) for gastric cancer was significantly higher in the magnification group (5.5%) than in the non-magnification group (2.5%) (P < 0.001). Furthermore, PPV for gastric epithelial neoplasia was significantly higher in the magnification group (7.9%) than in the non-magnification group (3.2%) (P < 0.001).

CONCLUSION

Magnifying narrow-band imaging improves the diagnostic performance of routine esophagogastroduodenoscopy.

Importance of optical diagnosis in early gastric cancer: A case report of early gastric signet ring cell carcinoma

Gastric signet ring cell carcinoma (SRCC) is a rare form of highly malignant adenocarcinoma. It is an epithelial malignancy characterized by the histologic appearance of more than 50% of cells as signet ring cells filled with mucin. The incidence of SRCC is rising,[1],[2] therefore, the diagnosis of these cancers in the early stage is important as it is the only stage that curative measures can be done. A 49-year-old female was hospitalized due to epigastric pain, postprandial bloating for 3 months. Upper gastrointestinal endoscopy with narrow band imaging (NBI) showed 1.5 cm lesion in the lesser curvature of the stomach with irregular pit pattern and accentuated vascularization of the surrounding mucosa. Histopathology confirmed the presence of more than 50% of the cells as signet ring cells. We report on the importance of optical diagnosis in early gastric cancer with the help of NBI, the subsequent patient management, and prognosis.

Gastric Cancer as Preventable Disease

Gastric cancer, 1 of the 5 most common causes of cancer death, is associated with a 5-year overall survival rate less than 30%. A minority of cancers occurs as part of syndromic diseases; more than 90% of adenocarcinomas are considered as the ultimate consequence of a longstanding mucosal inflammation. Helicobacter pylori infection is the leading etiology of non-self-limiting gastritis, which may result in atrophy of the gastric mucosa and impaired acid secretion. Gastric atrophy establishes a field of cancerization prone to further molecular and phenotypic changes, possibly resulting in cancer growth. This well-understood natural history provides the clinicopathologic rationale for primary and secondary cancer prevention strategies. A large body of evidence demonstrates that combined primary (H pylori eradication) and secondary (mainly endoscopy) prevention efforts may prevent or limit the progression of gastric oncogenesis. This approach, which is tailored to different country-specific gastric cancer incidence, socioeconomic, and cultural factors, requires that the complementary competences of gastroenterologists, oncologists, and pathologists be amalgamated into a common strategy of health policy.

Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer

BACKGROUND AND STUDY AIMS

 Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa.

PATIENTS AND METHODS

 Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d'Eclairage).

RESULTS

 We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI ( P  < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia ( P  = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI.

CONCLUSION

 LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.

Magnifying NBI Patterns of Gastric Mucosa After Helicobacter pylori Eradication and Its Potential Link to the Gastric Cancer Risk

BACKGROUND

Gastric cancer develops after successful H. pylori eradication in patients with severe atrophic gastritis. We classified atrophic and non-atrophic mucosa of gastric body using magnifying NBI endoscopy in patients after successful H. pylori eradication.

MATERIALS AND METHODS

One hundred and twenty-five patients after successful H. pylori eradication (median period after eradication: 36 months) were enrolled. Magnifying NBI patterns in the uninvolved gastric body were divided into the following: restored-small, round pits, accompanied with honeycomb-like subepithelial capillary networks; atrophic-well-demarcated oval or tubulovillous pits with clearly visible coiled or wavy vessels. The subjects were also classified into the three types: Grade 0-restored pattern is shown in all or almost the entire area of gastric body; Grade 1-mixture of restored and atrophic pattern, there is a considerable portion of the atrophic area in the lesser curvature; Grade 2-atrophic pattern is shown in all or almost the entire area of the gastric body.

RESULTS

Sensitivity and specificity for atrophic type for detection of histological intestinal metaplasia were 95.9 and 98.3%, respectively. No association was observed between the prevalence of Grades 0, 1 and 2 and duration after eradication, while grades 1 and 2 were significantly frequent in gastric cancer patients diagnosed both before (27/35: 77%) and after (23/31: 74%) eradication, compared to the cancer-free subjects (15/59: 25%) (P < 0.001). The grades 1 and 2 were also common in patients who underwent H. pylori eradication for gastric ulcer.

CONCLUSIONS

Magnifying the NBI pattern well correlates with pathological status of gastric mucosa after H. pylori eradication and may predict gastric cancer occurrence.

Evaluation of image-enhanced endoscopic technology using advanced diagnostic endoscopy for the detection of early gastric cancer: a pilot study

BACKGROUND AND STUDY AIMS

Image-enhanced endoscopy (IEE) plays an important role in early detection and detailed examination of early gastric cancer (EGC). The current study aimed to clarify the efficacy of IEE using advanced diagnostic endoscopy for EGC detection without magnification.

PATIENTS AND METHODS

We performed endoscopic examinations without magnification in patients referred to our hospital with a diagnosis of upper gastrointestinal tumor detected through routine screening endoscopy. In this study, we used three IEE technologies: narrow-band imaging; blue laser imaging; and i-scan optical enhancement. The detection rates for EGC between IEE and white-light imaging (WLI) were compared.

RESULTS

Between July 2013 and June 2014, 156 patients were enrolled. Among upper gastrointestinal tumors, we analyzed endoscopic examination results of 119 lesions that were histologically diagnosed as EGC in 109 patients. The EGC detection rate in the IEE plus WLI groups was 77.3 %. Although the EGC detection rate in the IEE group was higher than that in the WLI group (80.0 % vs. 70.3 %), there was no significant difference between these two modalities. An important detection factor using IEE was tumor circumference, where the rate of detection in the anterior wall and lesser curvature was significantly higher than that in the posterior wall and greater curvature ( P  = 0.046). An important detection factor using WLI was color variation, where the rate of occurrence of a reddened or pale tumor was significantly higher than that of normal colored tumors ( P  = 0.030).

CONCLUSIONS

The detection rate of EGC without magnification was similar between the IEE group and the WLI group. Important detection factors differed between IEE and WLI; therefore, the IEE and WLI modalities have different characteristics regarding EGC detection. Consequently, we propose to use both IEE and WLI in the evaluation of EGC.

Endoscopic features of lymphoid follicles using blue laser imaging (BLI) endoscopy in the colorectum and its association with chronic bowel symptoms

Background/Aim

In the colorectum, lymphoid follicles hyperplasia (LH) is sometimes observed as small, round, yellowish-white nodules. The novel image-enhanced endoscopy system named blue laser imaging (BLI) provides enhanced the contrast of surface vessels using lasers for light illumination. We investigated the endoscopic features of LH observed by using BLI endoscopy and its association with chronic bowel symptoms.

Patients/Methods

300 participants undergoing colonoscopy for various indications were enrolled. Entire colorectum was observed by using BLI-bright mode with non-magnification view. LH was defined as well demarcated white nodules. Elevated LH with erythema was distinguished as LH severe.

Results

LHs were observed more clearly by using BLI-bright mode compared to conventional white light colonoscopy and were also histologically confirmed as intense infiltration of lymphocytes or plasmacytes. LH was observed in 134 subjects (44.6%) and 67 (22.3%) were LH severe. LH was associated younger age (Odds ratio (OR) = 1.05, 95%Confidence Interval (95%CI) = 1.03–1.07, P<0.0001) and chronic bowel symptoms including constipation, hard stools, diarrhea and loose stools (all LH: OR = 4.03, 95%CI = 2.36–6.89, P<0.0001, LH severe: OR = 5.31, 95%CI = 2.64–10.71, P<0.0001). LH severe was closely associated with both constipation associated symptoms (OR = 3.94, 95%CI = 1.79–8.66, P = 0.0007) and diarrhea associated symptoms (OR = 5.22, 95%CI = 2.09–13.05, P = 0.0004). In particular, LH severe in the ascending colon was strongly associated with bowel symptoms (P<0.0001).

Conclusion

LH, visualized by using BLI endoscopy was associated with bowel symptom, raising the possibility of pathogenic role of this endoscopic finding in the functional lower gastrointestinal disorders.

Linked colour imaging benefits the endoscopic diagnosis of distal gastric diseases

Gastric diseases are common in China, and gastroduodenoscopy could provide accurate diagnoses. Our previous study verified that linked colour imaging (LCI) can improve endoscopic diagnostic accuracy. This study aimed for the first time to establish an LCI-based endoscopic model called colour-microstructure-vessel (CMV) criteria and validated its clinical feasibility for detecting distal gastric diseases manifested as red mucosal lesions under endoscopy in a cohort of 62 patients. Colour features were extracted from the endoscopic images and categorized into 3 types. Colour type 1 was a typical red; Colour type 2 was red ringed with purple and Colour type 3 was red with yellow in the centre and purple around the periphery, allowing for predicting chronic nonatrophic gastritis, chronic atrophic gastritis and gastric cancer. The sensitivity, specificity and Youden index of Colour type 3 with abnormal M or V for gastric cancer were 100.0%, 98.2% and 98.2%. The kappa values for intra-observer and inter-observer agreement for predicting the pathology were 0.834 and 0.791 for experienced endoscopists and 0.788 and 0.732 for endoscopy learners, and these values were comparable regardless of the experience of the endoscopists (P > 0.05). These findings support that the CMV criteria are a promising model for accurate endoscopic diagnosis.

Interobserver agreement in detection of "white globe appearance" and the ability of educational lectures to improve the diagnosis of gastric lesions

BACKGROUND

White globe appearance (WGA) refers to a small white lesion of globular shape underneath cancerous gastric epithelium that can be clearly visualized by magnifying endoscopy with narrowband imaging (M-NBI). WGA has been reported to be a novel endoscopic marker that is highly specific in differentiating early gastric cancer (GC) from low-grade adenoma, and has a significantly higher prevalence in early GCs than in noncancerous lesions. However, interobserver agreement in detecting WGA and whether training intervention can improve diagnostic accuracy are unknown.

METHODS

Twenty sets of M-NBI images were examined by 16 endoscopists. The endoscopists attended a lecture about WGA, and examined the images again after the lecture. Interobserver agreement in detecting WGA in the second examination and increases in the proportion of correct diagnoses and the degree of confidence of diagnoses of cancerous lesions were evaluated.

RESULTS

The kappa value for interobserver agreement in detecting WGA in the second examination was 0.735. The proportion of correct diagnoses was significantly higher in the second examination compared with the first examination when WGA was present (95.5% vs 55.4%; P < 0.001), but not when WGA was absent (61.6% vs 52.7%; P = 0.190). The proportion of correct diagnoses with a high degree of confidence was significantly higher in the second examination, both with WGA (91.1% vs 29.5%; P < 0.001) and without WGA (36.6% vs 20.5%; P = 0.031).

CONCLUSIONS

The detection of WGA by endoscopists was highly reproducible. A brief educational lecture about WGA increased the proportion of correct diagnoses and the degree of confidence of diagnoses of GC with WGA.

A guide to multimodal endoscopy imaging for gastrointestinal malignancy - an early indicator

Multimodality imaging is an essential aspect of endoscopic surveillance for the detection of neoplastic lesions, such as dysplasia or intramucosal cancer, because it improves the efficacy of endoscopic surveillance and therapeutic procedures in the gastrointestinal tract. This approach reveals mucosal abnormalities that cannot be detected by standard endoscopy. Currently, these imaging techniques are divided into those for primary detection and those for targeted imaging and characterization, the latter being used to visualize areas of interest in detail and permit histological evaluation. This Review outlines the use of virtual chromoendoscopy, narrow-band imaging, autofluorescence imaging, optical coherence tomography, confocal endomicroscopy and volumetric laser endomicroscopy as new imaging techniques for diagnostic investigation of the gastrointestinal tract. Insights into use of multimodal endoscopic imaging for early disease detection, in particular for pre-malignant lesions, in the oesophagus, stomach and colon are described.

Examination time as a quality indicator of screening upper gastrointestinal endoscopy for asymptomatic examinees

BACKGROUND AND AIM

The significance of examination time of esophagogastroduodenoscopy (EGD) for asymptomatic examinees is yet to be established. We aimed to clarify whether endoscopists who allot more examination time can detect higher numbers of neoplastic lesions among asymptomatic examinees.

METHODS

We reviewed a database of consecutive examinees who underwent EGD in our hospital from April 2010 to September 2015. Staff endoscopists were classified into fast, moderate, and slow groups based on the mean examination time of EGD without a biopsy. Neoplastic lesion detection rate among these groups was compared using multiple logistic regression.

RESULTS

Of the 55 786 consecutive examinees who underwent EGD, 15 763 asymptomatic examinees who were screened by staff doctors were analyzed. Mean examination time of 13 661 EGD without biopsy was 6.2 min (range, 2-18 min). When cut-off times of 5 and 7 min were used, four endoscopists were classified into the fast (mean duration, 4.4 ± 1.0 min), 12 into the moderate (6.1 ± 1.4 min), and four into the slow (7.8 ± 1.9 min) groups. Neoplastic lesion detection rates in the fast, moderate, and slow groups were 0.57% (13/2288), 0.97% (99/10 180), and 0.94% (31/3295), respectively. Compared with that in the fast group, odds ratios for the neoplastic lesion detection rate in the moderate and slow groups were 1.90 (95% confidence interval [CI], 1.06-3.40) and 1.89 (95% CI, 0.98-3.64), respectively.

CONCLUSION

Endoscopists who do not allot adequate examination time may overlook neoplastic lesions in the upper gastrointestinal tract.

Clinical Usefulness of the VS Classification System Using Magnifying Endoscopy with Blue Laser Imaging for Early Gastric Cancer

BACKGROUND

Blue laser imaging (BLI) enables the acquisition of more information from tumors' surfaces compared with white light imaging. Few reports confirm the validity of magnifying endoscopy (ME) with BLI (ME-BLI) for early gastric cancer (EGC). We aimed to assess the detailed endoscopic findings from EGCs using ME-BLI.

METHODS

We enrolled 386 consecutive patients with 417 EGCs that were diagnosed using ME-BLI and resected by endoscopic submucosal dissection. Using the VS classification system, three highly experienced endoscopists (HEEs) and three less experienced endoscopists (LEEs) evaluated the demarcation line (DL), microsurface pattern (MSP), and microvascular pattern (MVP) within the endoscopic images of EGCs obtained using ME-BLI, assigning high-confidence (HC) or low-confidence (LC) levels. We investigated the clinicopathological features associated with each confidence level.

RESULTS

The HEEs' evaluations determined the presence of DL in 99%, irregular MSP in 96%, and irregular MVP in 96%, and the LEEs' evaluations determined the presence of DL in 98%, irregular MSP in 95%, and irregular MVP in 95% of the EGCs. When DL was present, HC levels in the Helicobacter pylori- (H. pylori-) eradicated group and noneradicated group were evident in 65% and 89%, a difference that was significant (p < 0.001).

CONCLUSIONS

In the diagnosis of EGC with ME-BLI, the VS classification system with ME-NBI can be applied, but identifying the DL after H. pylori was difficult.

Flexible magnifying endoscopy with narrow band imaging for the diagnosis of uterine cervical tumors: A cooperative study among gastrointestinal endoscopists and gynecologists to explore a novel microvascular classification system

Narrow band imaging with magnifying endoscopy (NBI-ME), which is useful for the assessment of micro-vessels, has excellent diagnostic potential for early gastrointestinal epithelial neoplasia. Conventional diagnostic tools for uterine cervical epithelial tumors are still unsatisfactory. An accurate diagnostic tool for uterine cervical epithelial tumors is required to preserve the reproductive ability of young women with uterine cervical tumors. Flexible NBI-ME was performed in patients with cervical squamous cell lesions that required further examinations based on their Pap smear results (cytology ≥ low-grade squamous intraepithelial lesion) at Kagawa University Hospital between April 2014 and April 2015. NBI-ME results concordant with the punch biopsy sites were compared with the histological results. A retrospective review of the NBI-ME images identified abnormal NBI-ME results regarding micro-vascular patterns. All images were categorized as having abnormal features. NBI-ME revealed the following vascular pattern differences of different stage tumors: Dot-like vessels without irregular arrangements and high density in cervical intraepithelial neoplasia (CIN) CIN1-CIN2; dot-like vessels with irregular arrangements and high density in CIN3-carcinoma in situ; crawling vessels in minimum invasive cancer; and willow branch vessels and new tumor vessels in invasive cancer. NBI-ME may be an effective diagnostic tool for uterine cervical epithelial tumors, which may lead to the establishment of a novel classification system.

Narrow-band imaging endoscopy is advantageous over conventional white light endoscopy for the diagnosis and treatment of children with Peutz-Jeghers syndrome

Using narrow-band imaging (NBI), the micro morphology of polyp surfaces was visualized at high resolution when the contrast between the lesions and the surrounding tissue areas was intensified. The objective of the study was to compare NBI and conventional white light endoscopy (C-WLI) for diagnostic efficacy and treatment of children with Peutz-Jeghers syndrome (PJS), a rare autosomal dominant-genetic disease.We retrospectively analyzed the clinical data of 18 patients diagnosed with PJS and 72 diagnosed with juvenile polyps during the same time period. Endoscopy was used to observe the morphology of polyps, which were classified according to the Kudo pit pattern. Eighty-two and 76 polyps were resected using endoscopy from PJS and juvenile polyp patients, respectively, and pathologically examined for comparison with NBI or C-WLI endoscopic observations.With NBI, 57 (69.5%) type I, 10 (12.2%) type II, and 13 (15.9%) type III polyps were identified in 82 (100%) polyps excised from 18 PJS patients, whereas 69 (88.5%) type I, 5 (6.4%) type II and 4 (5.1%) type III were identified in 78 (100%) of polyps removed from 72 juvenile polyp patients. The combined ratios of types II and III were higher in PJS (28.1%) than in juvenile polyp patients (11.5%). Pathological diagnosis identified 69 of 82 PJS polyps as hamartoma and 13 as adenoma, whereas NBI detected 10 adenomas and C-WLI only 4. The sensitivity, specificity, and accuracy of NBI in the diagnosis of adenoma were 76.9%, 97.1%, and 93.9%, respectively, whereas those of C-WLI were 30.8%, 94.2%, and 84.1%.NBI endoscopy had higher sensitivity and specificity than C-WLI for the diagnosis of adenomatous polyps and is recommended for the diagnosis, characterization, and resection of polyps in children with PJS.

Endoscopic Management of Early Gastric Adenocarcinoma and Preinvasive Gastric Lesions

Early gastric cancer (ECG) can be difficult to diagnose endoscopically. Endoscopists should be familiar with subtle changes and endoscopic features of EGC. Chromoendoscopy and image-enhanced endoscopy improve diagnostic accuracy and facilitate endoscopic resection. Endoscopic submucosal dissection is a preferred endoscopic technique for resection of EGC and offers a comparable overall survival to surgical resection. Endoscopic management of benign gastric epithelial polyps (fundic gland polyps, hyperplastic polyps, and gastric adenoma) depends on patient symptomatology, patient's comorbidities (eg, familial syndromes), lesions' characteristics, and risk of malignant transformation. This article provides an overview of endoscopic management of EGC and common premalignant gastric lesions.

Role of targeted biopsy under magnifying endoscopy with narrow band imaging may be not necessary: a prospective diagnostic accuracy study

BACKGROUND AND AIMS

Targeted biopsy under the guidance of magnifying endoscopy with narrow band imaging (ME-NBI) has higher accuracy than endoscopic forceps biopsy (EFB) in the differential diagnosis of cancerous lesions from noncancerous lesions. The aims of this study were to validate diagnostic efficacy of targeted biopsy under the guidance of ME-NBI (MNTB) and further evaluate whether it is necessary to perform MNTB when combined with ME-NBI.

METHODS

This study prospectively analyzed 211 gastric lesions of suspected cancerous tissues. The sensitivity, specificity, positive predictive value, and negative predictive value of EFB, ME-NBI, MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI for the diagnosis of cancerous lesions were determined, respectively. The accuracy, sensitivity, specificity of EFB and MNTB, EFB plus ME-NBI, and MNTB plus ME-NBI were also compared, respectively.

RESULTS

The accuracy, sensitivity, and specificity with 95% confidence intervals were 68.2% (61.4-74.4%), 62.3% (54.1-69.9%), 84.2% (71.6-92.1%) for EFB, 75.4% (68.9-80.9%), 72.7% (64.9-79.4%), 82.5% (69.6-90.8%) for MNTB, 76.8% (70.4-82.2%), 73.4% (65.5-80.0%), 86.0% (73.7-93.3%) for ME-NBI, 82.0% (76.0-86.8%), 85.7% (79.0-90.6%), 71.9% (58.3-82.6%) for EFB plus ME-NBI, 84.8% (79.1-89.3%), 89.6% (83.4-93.8%), and 71.9% (58.3-82.6%) for MNTB plus ME-NBI, respectively. The sensitivity of MNTB was significantly higher than that of EFB (P=0.048). There was no significant difference in the sensitivity (P=0.307), specificity (P=1.000), and accuracy (P=0.337) between EFB plus ME-NBI and MNTB plus ME-NBI.

CONCLUSION

Although MNTB has a higher diagnostic efficacy than EFB in the diagnosis of cancerous lesions, it may be not necessary to perform MNTB when combined with ME-NBI.

Diagnostic ability of magnifying endoscopy with blue laser imaging for early gastric cancer: a prospective study

BACKGROUND

Blue laser imaging (BLI) is a new image-enhanced endoscopy technique that utilizes a laser light source developed for narrow-band light observation. The aim of this study was to evaluate the usefulness of BLI for the diagnosis of early gastric cancer.

METHODS

This single center prospective study analyzed 530 patients. The patients were examined with both conventional endoscopy with white-light imaging (C-WLI) and magnifying endoscopy with BLI (M-BLI) at Kyoto Prefectural University of Medicine between November 2012 and March 2015. The diagnostic criteria for gastric cancer using M-BLI included an irregular microvascular pattern and/or irregular microsurface pattern, with a demarcation line according to the vessel plus surface classification system. Biopsies of the lesions were taken after C-WLI and M-BLI observation. The primary end point of this study was to compare the diagnostic performance between C-WLI and M-BLI.

RESULTS

We analyzed 127 detected lesions (32 cancers and 95 non-cancers). The accuracy, sensitivity, and specificity of M-BLI diagnoses were 92.1, 93.8, and 91.6 %, respectively. On the other hand, the accuracy, sensitivity, and specificity of C-WLI diagnoses were 71.7, 46.9, and 80.0 %, respectively.

CONCLUSIONS

M-BLI had improved diagnostic performance for early gastric cancer compared with C-WLI. These results suggested that the diagnostic effectiveness of M-BLI is similar to that of magnifying endoscopy with narrow-band imaging (M-NBI).

Past and current trends in endoscopic diagnosis for early stage gastric cancer in Japan

Methodology for the diagnosis and staging of early gastric cancer (EGC) has improved in Japan since the development of the gastro-camera and determination of a definition of EGC. Imaging technology has been steadily evolving in the endoscopy field. Improvements in the resolution of standard endoscopy images used in screening and surveillance provide greater opportunities to find gastric cancer earlier. Image enhancement endoscopy (IEE), such as narrow band imaging (NBI), highlights mucosal structures and vascularity. In particular, when NBI is used with magnifying endoscopy, it reveals fine details of subtle superficial abnormalities of EGC that are difficult to recognize using standard white light endoscopy. IEE-assisted magnifying endoscopy has improved the accuracy of the differentiation of superficial gastric cancer as well as delineation of the diseased mucosa. The advanced imaging technology enables precise assessment of the risk of lymph node metastasis of EGC and is widely used to determine indications for endoscopic treatment. It is not an overstatement to say that this has become the basis for the current development and dissemination of endoscopic treatments. Moreover, the resolution of endoscopic imaging has been upgraded to the microscopy level by the development of endomicroscopy, including endocytoscopy and confocal laser endomicroscopy. Endomicroscopy allows real-time histological analysis of living tissue during routine endoscopy and may reduce the number of biopsies needed to reach the correct diagnosis, minimizing the risk of sampling errors.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Advanced endoscopic imaging in gastric neoplasia and preneoplasia

Conventional white light endoscopy remains the current standard in routine clinical practice for early detection of gastric cancer. However, it may not accurately diagnose preneoplastic gastric lesions. The technological advancements in the field of endoscopic imaging for gastric lesions are fast growing. This article reviews currently available advanced endoscopic imaging modalities, in particular chromoendoscopy, narrow band imaging and confocal laser endomicroscopy, and their corresponding evidence shown to improve diagnosis of preneoplastic gastric lesions. Raman spectrometry and polarimetry are also introduced as promising emerging technologies.

Development of an e-learning system for teaching endoscopists how to diagnose early gastric cancer: basic principles for improving early detection

We developed an internet e-learning system in order to improve the ability of endoscopists to diagnose gastric cancer at an early stage. The efficacy of this system at expanding knowledge and providing invaluable experience regarding the endoscopic detection of early gastric cancer was demonstrated through an international multicenter randomized controlled trial. However, the contents of the system have not yet been fully described in the literature. Accordingly, we herein introduce the contents and their principles, which comprise three main subjects: technique, knowledge, and experience. Since all the e-learning contents and principles are based on conventional white-light endoscopy alone, which is commonly available throughout the world, they should provide a good reference point for any endoscopist who wishes to devise learning materials and guidelines for improving their own clinical practice.

Endoscopic management of mucosal lesions in the gastrointestinal tract

With the increasing role of endoscopy in patient evaluation, more mucosal lesions, including gastric, duodenal and colonic polyps, are encountered during routine examinations. It is imperative for gastroenterologists to become familiar with the endoscopic management of these various gastrointestinal lesions. In this article, various resection techniques will be discussed, including hot/cold forceps polypectomy, hot/cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The article will also discuss the evidence regarding the efficacy and safety of these techniques and the future direction of endoscopic management of mucosal lesions in the gastrointestinal tract.

Evidence based review of the impact of image enhanced endoscopy in the diagnosis of gastric disorders

Gastric cancer is the third most common cause of cancer-related death. Advanced stages of gastric cancers generally have grim prognosis. But, good prognosis can be achieved if such cancers are detected, diagnosed and resected at early stages. However, early gastric cancers and its precursors often produce only subtle mucosal changes and therefore quite commonly remain elusive at the conventional examination with white light endoscopy. Image-enhanced endoscopy makes mucosal lesions more conspicuous and can therefore potentially yield earlier and more accurate diagnoses. Recent years have seen growing work of research in support of various types of image enhanced endoscopy (IEE) techniques (e.g., dye-chromoendoscopy; magnification endoscopy; narrow-band imaging; flexible spectral imaging color enhancement; and I-SCAN) for a variety of gastric pathologies. In this review, we will examine the evidence for the utilization of various IEE techniques in the diagnosis of gastric disorders.

Can magnifying endoscopy with narrow-band imaging discriminate between carcinomas and low grade adenomas in gastric superficial elevated lesions?

Background and study aims: The aim of this study was to investigate the capability of magnifying endoscopy with narrow-band imaging (ME-NBI) to discriminate between early carcinomas (EC) and low grade adenomas (LGA) in gastric superficial elevated epithelial neoplasias. Patients and methods: We investigated 100 consecutive cases of gastric superficial elevated epithelial neoplasias that were removed using endoscopic submucosal dissection. The pathological diagnostic criteria were based on the revised Vienna classification; category 4 (mucosal high grade neoplasia) and category 5 (submucosal invasion by carcinoma) lesions were diagnosed as EC, whereas category 3 (mucosal low grade neoplasia) lesions were diagnosed as LGA. The associations between the postoperative pathological diagnoses and the ME-NBI findings were analyzed, and included the shape, specification, and area of irregularity in the microvascular architecture (MV) and the microsurface structure (MS). Results: Seventy-nine EC and 21 LGA cases diagnosed postoperatively were evaluated retrospectively. The lesion size (median; range (mm)) was significantly larger in the EC group (14; 2 - 95) compared to the LGA group (5; 2 - 16) (P < 0.001). Wavy forms in the MV shapes (P = 0.031), extension in the MV specifications (P = 0.035), and area with MV irregularity (P = 0.001) were found to be statistically significant predictive findings for EC. Villous forms in the MS shapes (P = 0.026), enlargement in the MS specifications (P = 0.044), and area with MS irregularity (P = 0.021) were also found to be statistically significant predictive findings for EC. The rates of preoperative sensitivity, specificity, and diagnostic accuracy of ME-NBI for discriminating EC were 86.1 %, 38.9 %, and 75 %, respectively. Conclusions: The present study suggests that ME-NBI is useful for the differential diagnosis of EC and LGA in gastric superficial elevated epithelial neoplasias.

STUDY REGISTRATION

UMIN000012925.

Diagnosis of Helicobacter pylori-related chronic gastritis, gastric adenoma and early gastric cancer by magnifying endoscopy

Evaluating the prevalence and severity of gastritis by endoscopy is useful for estimating the risk of gastric cancer (GC). Moreover, understanding the endoscopic appearances of gastritis is important for diagnosing GC due to the fact that superficial mucosal lesions mimicing gastritis (gastritis-like lesions) are quite difficult to be detected even with optimum preparation and the best technique, and in such cases tissue biopsy is often not very accurate for the diagnosis of gastric epithelial neoplasia. Magnifying endoscopy is a highly accurate technique for the detection of early gastric cancer (EGC). Recent reports have described that various novel endoscopic markers which, visualized by magnifying endoscopy with image-enhanced system (ME-IEE), can predict specific histopathological findings. Using ME-IEE with vessels and surface classification system (VSCS) may represent an excellent diagnostic performance with high confidence and good reproducibility to the endoscopists if performed under consistent conditions, including observation under maximal magnification. The aim of this review was to discuss how to identify high-risk groups for GC by endoscopy, and how to detect effectively signs of suspicious lesions by conventional white light imaging (C-WLI) or chromoendoscopy (CE). Furthermore, to characterize suspicious lesions using ME-IEE using the criteria and classification of EGC based upon VSCS.

Transnasal endoscopy: no gagging no panic!

BACKGROUND

Transnasal endoscopy (TNE) is performed with an ultrathin scope via the nasal passages and is increasingly used. This review covers the technical characteristics, tolerability, safety and acceptability of TNE and also diagnostic accuracy, use as a screening tool and therapeutic applications. It includes practical advice from an ear, nose, throat (ENT) specialist to optimise TNE practice, identify ENT pathology and manage complications.

METHODS

A Medline search was performed using the terms "transnasal", "ultrathin", "small calibre", "endoscopy", "EGD" to identify relevant literature.

RESULTS

There is increasing evidence that TNE is better tolerated than standard endoscopy as measured using visual analogue scales, and the main area of discomfort is nasal during insertion of the TN endoscope, which seems remediable with adequate topical anaesthesia. The diagnostic yield has been found to be similar for detection of Barrett's oesophagus, gastric cancer and GORD-associated diseases. There are some potential issues regarding the accuracy of TNE in detecting small early gastric malignant lesions, especially those in the proximal stomach. TNE is feasible and safe in a primary care population and is ideal for screening for upper gastrointestinal pathology. It has an advantage as a diagnostic tool in the elderly and those with multiple comorbidities due to fewer adverse effects on the cardiovascular system. It has significant advantages for therapeutic procedures, especially negotiating upper oesophageal strictures and insertion of nasoenteric feeding tubes.

CONCLUSIONS

TNE is well tolerated and a valuable diagnostic tool. Further evidence is required to establish its accuracy for the diagnosis of early and small gastric malignancies. There is an emerging role for TNE in therapeutic endoscopy, which needs further study.