Screening and treating intermediate lesions to prevent gastric cancer

Characteristics of overlooked synchronous gastric epithelial neoplasia after endoscopic submucosal dissection

Since endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for early gastric cancer (EGC) without risk of lymph node metastasis, synchronous gastric epithelial neoplasia is no longer rare in the clinical practice. Knowledge about the characteristics associated with synchronous gastric epithelial neoplasia is of great importance to prevent delayed diagnosis.Between November 2008 and December 2014, a retrospective study was conducted in a single tertiary referral hospital. Consecutive patients who underwent ESD due to EGC or high-grade dysplasia were analyzed to evaluate the incidence of synchronous gastric epithelial neoplasia and the factors associated with synchronous and overlooked synchronous lesions.A total of 488 patients were analyzed in this study. Synchronous lesions were found in 59 patients (12.1%) during the mean 37.7 months of follow-up. Among 77 synchronous lesions, 25 lesions (32.4%) were overlooked at the time of initial ESD. Age of ≥ 65 years, moderate to severe endoscopic atrophic gastritis, and elevated morphology of primary lesions were associated with synchronous gastric epithelial neoplasia. An important factor associated with overlooked lesions is the non-elevated morphology of lesions.Careful endoscopic examination of the whole stomach is necessary in patients who are older and who have moderate to severe atrophic gastritis and elevated morphology of lesions to prevent delayed diagnosis of synchronous gastric epithelial neoplasia, especially non-elevated lesions.

Basic principles and practice of gastric cancer screening using high-definition white-light gastroscopy: Eyes can only see what the brain knows

Endoscopic diagnosis of gastrointestinal tumors consists of the following processes: (i) detection; (ii) differential diagnosis; and (iii) quantitative diagnosis (size and depth) of a lesion. Although detection is the first step to make a diagnosis of the tumor, the lesion can be overlooked if an endoscopist has no knowledge of what an early-stage 'superficial lesion' looks like. In recent years, image-enhanced endoscopy has become common, but white-light endoscopy (WLI) is still the first step for detection and characterization of lesions in general clinical practice. Settings and practice of routine esophagogastroduodenoscopy (EGD) such as use of antispasmodics, number of endoscopic images taken, and observational procedure are customarily decided in each facility in each country and are not well standardized. Therefore, in the present article, we attempted to outline currently available evidence and actual Japanese practice on gastric cancer screening using WLI, and provide tips for detecting EGC during routine EGD which could become the basis of future research.

Optimizing early upper gastrointestinal cancer detection at endoscopy

Survival rates for upper gastrointestinal cancers are poor and oesophageal cancer incidence is increasing. Upper gastrointestinal cancer is also often missed during examinations; a predicament that has not yet been sufficiently addressed. Improvements in the detection of premalignant lesions, early oesophageal and gastric cancers will enable organ-preserving endoscopic therapy, potentially reducing the number of advanced upper gastrointestinal cancers and resulting in improved prognosis. Japan is a world leader in high-quality diagnostic upper gastrointestinal endoscopy and the clinical routine in this country differs substantially from Western practice. In this Perspectives article, we review lessons learnt from Japanese gastroscopy technique, training and screening for risk stratification. We suggest a key performance indicator for upper gastrointestinal endoscopy with a minimum total procedure time of 8 min, and examine how quality assurance concepts in bowel cancer screening in the UK could be applied to upper gastrointestinal endoscopy and improve clinical practice.

Comparison between narrow-band imaging combined with magnifying endoscopy and gastric biopsy for diagnosis of early gastric cancer

AIM: To evaluate the diagnostic performance of narrow-band imaging combined with magnifying endoscopy (NBI-ME) for early gastric cancer by comparing with gastric biopsy.

METHODS: Patients with suspicious early gastric lesions (including abnormal mucosal morphology and abnormal mucosal color) as revealed by white light endoscopy (WLE) were enrolled in the study. These suspicious lesions were examined by NBI-ME to give a diagnosis. Biopsy specimens were then taken from suspicious lesions for pathological examination. All patients received endoscopic resection or surgical intervention. The diagnostic performance of the two modalities was compared.

RESULTS: A total of 123 patients were enrolled, including 76 men and 47 women. The final pathology showed 51 cases of gastritis, 24 cases of low grade intraepithelial neoplasia, and 48 cases of early gastric cancer. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of NBI-ME for diagnosing early gastric cancer were 97.9%, 80.0%, 75.8%, 98.4%, and 87.0%, respectively; the corresponding percentages for endoscopic biopsy were 66.7%, 94.7%, 88.9%, 81.6%, and 83.7%, respectively. The sensitivity of NBI-ME was significantly better than that of endoscopic biopsy (P < 0.005), but specificity was lower than that of endoscopic biopsy (P < 0.005). There was no statistical difference in diagnostic accuracy between the two modalities. The Kappa value for the two modalities was 0.642 (P < 0.05).

CONCLUSION: NBI-ME can improve the diagnosis of early gastric cancer. When early gastric cancer is diagnosed by NBI-ME, further intervention treatment is required.

Diagnostic efficacy of magnifying endoscopy with narrow-band imaging for gastric neoplasms: a meta-analysis

Background

Magnifying endoscopy with narrow-band imaging (ME-NBI) is a novel, image-enhanced endoscopic technique for differentiating gastrointestinal neoplasms and potentially enabling pathological diagnosis.

Objectives

The aim of this analysis was to assess the diagnostic performance of ME-NBI for gastric neoplasms.

Methods

We performed a systematic search of the PubMed, EMbase, Web of Science, and Cochrane Library databases for relevant studies. Meta-DiSc (version 1.4) and STATA (version 11.0) software were used for the data analysis. Random effects models were used to assess diagnostic efficacy. Heterogeneity was tested by the Q statistic and I² statistic. Meta-regression was used to analyze the sources of heterogeneity.

Results

A total of 10 studies, with 2151 lesions, were included. The pooled characteristics of these studies were as follows: sensitivity 0.85 (95% confidence interval [CI]: 0.81–0.89), specificity 0.96 (95% confidence interval [CI]: 0.95–0.97), and area under the curve (AUC) 0.9647. In the subgroup analysis, which compared the diagnostic efficacy of ME-NBI and white light imaging (WLI), the pooled sensitivity and specificity of ME-NBI were 0.87 (95% CI: 0.80–0.92) and 0.93 (95% CI: 0.90–0.95), respectively, and the area under the curve (AUC) was 0.9556. In contrast, the pooled sensitivity and specificity of WLI were 0.61 (95% CI: 0.53–0.69) and 0.65 (95% CI: 0.60–0.69), respectively, and the area under the curve (AUC) was 0.6772.

Conclusions

ME-NBI presents a high diagnostic value for gastric neoplasms and has a high specificity.

Diagnostic performance and limitations of magnifying narrow-band imaging in screening endoscopy of early gastric cancer: a prospective multicenter feasibility study

BACKGROUND

Curative treatment of patients with gastric cancer requires reliable detection of early gastric cancer. Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the accurate preoperative diagnosis of early gastric cancer. However, the role of M-NBI in screening endoscopy has not been established. The aims of this study were to determine the feasibility and limitations of M-NBI in screening endoscopy.

METHODS

We conducted a multicenter prospective uncontrolled trial of patients undergoing routine screening endoscopy patients. We determined the diagnostic accuracy, sensitivity and specificity of M-NBI according to the degree of certainty and need for biopsy, as assessed using the VS (vessel plus surface) classification system. We analyzed the endoscopic and histopathological characteristics of both false negative and false positive high confidence M-NBI diagnoses. We then developed a provisional diagnostic strategy based on the diagnostic performance and limitations identified in this study.

RESULTS

A total of 1097 patients were enrolled in the study. We analyzed 371 detected lesions (20 cancers and 351 non-cancers). The accuracy, sensitivity and specificity of high confidence M-NBI diagnoses were 98.1, 85.7 and 99.4 %, respectively. The false negative case was a pale mucosal lesion with tissue diagnosis of signet-ring cell carcinoma. Exclusion of pale mucosal lesions increased the accuracy, sensitivity and specificity of high confidence M-NBI diagnoses to 99.4, 100 and 99.4 %, respectively. We therefore propose a practical strategy targeting non-pale mucosal lesions.

CONCLUSIONS

With a refined strategy considering its limitations, M-NBI can act as an "optical biopsy" in screening endoscopies.