Endoscopic submucosal dissection for early gastric cancer: a large-scale feasibility study

Low-density lipoprotein receptor expression is involved in the beneficial effect of photodynamic therapy using talaporfin sodium on gastric cancer cells

Photodynamic therapy (PDT) is a therapeutic method used to destroy tumor tissue via reactive oxygen. Notably, reactive oxygen is induced by a combination of photosensitizers, including talaporfin sodium (TS) and laser light. Gastric cancer cell lines, MKN45 and MKN74, were used to evaluate the effect of TS-PDT in vitro. The antitumor effect of TS-PDT, which was evaluated via cellular viability assay, on MKN74 was weaker than that on MKN45 cells, suggesting that MKN74 cell could be resistant to TS-PDT. However, using a higher TS concentration or setting a longer treatment time (24 h) resulted in effective TS-PDT treatment on MKN74 cells. In addition, when irradiation power of LED was raised up to 5.06 J/cm², TS-PDT was able to induce an antitumor effect on MKN74 cells. This suggested that the difference in TS-PDT efficacy between MKN45 and MKN74 cells is based on the difference in cellular uptake of TS. As expected, uptake of TS by MKN74 cells was lower than that by MKN45 cells. The expression levels of low-density lipoprotein (LDL) receptor in MKN74 cells were lower than those in MKN45 cells. With GW3965 treatment, an agonist/activator of Liver X Receptor, LDL receptor expression was reduced, weakening the TS-PDT effect. Furthermore, as a hydroxymethylglutaryl-Coenzyme A reductase inhibitor, treatment using simvastatin increased LDL receptor expression, leading to enhancement of the TS-PDT effect on MKN74 cells. In conclusion, the difference in LDL receptor expression between the two gastric cell lines could influence TS-PDT efficacy; simvastatin may enhance the antitumor effect of TS-PDT through upregulating the LDL receptor even on PDT-resistant gastric cancer cells.

Clinical utility of miniprobe endoscopic ultrasonography for prediction of invasion depth of early gastric cancer: A meta-analysis of diagnostic test from PRISMA guideline

BACKGROUND

Recently, some studies assessed the clinical utility of miniprobe endoscopic ultrasonography for prediction of invasion depth of early gastric cancer (GC). However, the results remain inconsistent.

OBJECTIVES

We conducted a meta-analysis to assess the clinical utility of miniprobe endoscopic ultrasonography for diagnostic of invasion depth of early GC.

METHODS

We systematically searched several online electronic databases including PubMed, China National Knowledge Infrastructure, Web of Science, Embase, and Wanfang from initial library to July 20, 2018, identifying the study about miniprobe endoscopic ultrasonography for diagnostic of invasion depth of early GC. Bivariate mixed effects models were used to calculate the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) with theirs 95% confidence intervals (CIs).

RESULTS

Nineteen studies with 3401 patients were included in the meta-analysis. The bivariate mixed effect model indicated that the overall diagnostic sensitivity was 0.86 (95%CI: 0.79-0.91) and the specificity was 0.73 (95%CI: 0.66-0.78). The area under the curve was 0.84 (95%CI: 0.81-0.87). We also estimated the other pooled parameters as follows: the pooled PLR was 3.13 (95%CI: 2.55-3.84), the pooled NLR was 0.19 (95%CI: 0.13-0.28), the diagnostic score was 2.78 (95%CI: 2.33-3.23), and the diagnostic odds ratio was 16.1 (95%CI: 10.23-25.36). Subgroup analysis indicated that ethnicity may be the decisive factor on heterogeneity.

CONCLUSIONS

The present study indicated that the miniprobe endoscopic ultrasonography had a moderate diagnostic ability for invasion depth of early GC. The diagnostic utility was influenced by ethnicity. Further research is required to confirm the present findings and explore the potential factors of heterogeneity.

Endoscopic submucosal dissection of gastrointestinal lesions on an outpatient basis

Background

Endoscopic submucosal dissection (ESD) is usually associated with hospital admission.

Objectives

To evaluate, prospectively, the feasibility, safety and efficacy of outpatient gastrointestinal ESD.

Methods

Patients with suitable lesions were invited to participate. Those that dwelt more than 1 hour from the hospital, lived alone, had severe co-morbidities, were <18 years old, had duodenal lesions, or that had ESD-related complications were admitted. The remaining patients were discharged if no complications were detected. A patients' inquiry was performed.

Results

Of the 164 ESD patients, 122 were outpatient-based, corresponding to 115 patients, 47% male and mean age 63 ± 12 years-old. Outpatients tended to be younger, female, to have gastric lesions, less advanced lesions, and shorter and less complicated ESDs (all p < 0.05). Outpatients' mean tumour size was 38 mm, en bloc and R0 resection rates were 88 and 78%, respectively. Seven ESD outpatients (5.7%) had complications: delayed bleeding (n = 4), pneumonitis (n = 2) or emphysema (n = 1), all managed conservatively. Colorectal location of the lesions was predictive of hospital admission (p = 0.03). In total, 97% of patients were satisfied with the outpatient strategy.

Conclusion

Risks of ambulatory ESD are low and complications can be successfully managed. This strategy has high patient satisfaction. More studies are needed to evaluate its implications on costs and patients' management.

Short-term outcomes of multicenter prospective cohort study of gastric endoscopic resection: 'Real-world evidence' in Japan

OBJECTIVES

A Japanese multicenter prospective cohort study examining endoscopic resection (ER) for early gastric cancer (EGC) has been conducted using a Web registry developed to determine the short-term and long-term outcomes based on absolute and expanded indications. We hereby present the short-term outcomes of this study.

METHODS

All consecutive patients with EGC or suspected EGC undergoing ER at 41 participating institutions between July 2010 and June 2012 were enrolled and prospectively registered into the Web registry. The baseline characteristics were entered before ER, and the short-term outcomes were collected at 6 months following ER.

RESULTS

Nine thousand six hundred and sixteen patients with 10 821 lesions underwent ER (endoscopic submucosal dissection [ESD]: 99.4%). The median procedure time was 76 min, and R0 resections were achieved for 91.6% of the lesions. Postoperative bleeding and intraoperative perforation occurred in 4.4% and 2.3% of the patients, respectively. Significant independent factors correlated with a longer procedure time (120 min or longer) were as follows: tumor size >20 mm, upper-third location, middle-third location, local recurrent lesion, ulcer findings, gastric tube, male gender, and submucosa. Histopathologically, 10 031 lesions were identified as common-type gastric cancers. The median tumor size was 15 mm. Noncurative resections were diagnosed for 18.3% of the lesions. Additional surgery was performed for 48.6% (824 lesions) of the 1695 noncurative ER lesions with a possible risk of lymph node (LN) metastasis. Among them, 64 (7.8%) exhibited LN metastasis.

CONCLUSIONS

This multicenter prospective study showed favorable short-term outcomes for gastric ESD.

Outcomes of endoscopic submucosal dissection for gastric epithelial neoplasm in chronic kidney disease patients: propensity score-matched case-control analysis

BACKGROUND

Little is known about the outcomes of gastric endoscopic submucosal dissection (ESD) in patients with chronic kidney disease (CKD). We compared the efficacy and safety of ESD between CKD and non-CKD patients.

METHODS

From January 2005 to December 2014, 102 CKD patients underwent ESD for gastric neoplasms at a tertiary medical institution were reviewed retrospectively. A propensity score-matched control group (102 patients) was selected from non-CKD patients to compare clinical outcomes between CKD and non-CKD patients.

RESULTS

En bloc resection (96.1%) and curative resection (88.2%) rates in the CKD group did not significantly differ from those in the non-CKD group. Median procedure times (25.0 vs. 21.5 min, p = 0.734) and perforation risk (p = 0.480) were similar between groups. The CKD group showed a tendency towards more bleeding events (p = 0.052) and had a significantly longer hospital stay (p = 0.001). In a subgroup analysis, stage 3 CKD patients exhibited a bleeding risk comparable to that exhibited by non-CKD patients (HR 1.35; 95% CI 0.36-5.06; p = 0.654), whereas stage 4 (HR 5.79; 95% CI 1.52-22.0; p = 0.010) and stage 5 (HR 4.80; 95% CI 1.58-14.6; p = 0.006) patients showed higher bleeding risks than non-CKD patients. In a multivariate analysis, stage 4/5 CKD was a significant predictor for bleeding risk (HR 4.99; 95% CI 1.32-18.8; p = 0.018).

CONCLUSIONS

ESD for gastric epithelial neoplasms can be performed in stage 3 CKD patients with comparable efficacy and safety to that performed in non-CKD patients. Stage 4 and 5 CKD patients should be closely monitored for bleeding events after ESD.

PRISMA - Practical meta-analysis of applying local triamcinolone acetonide injection for stenosis after esophageal cancer surgery

Objectives

To explore the practical method of endoscopic triamcinolone acetonide (TA) injection immediately after endoscopic surgery and combined with endoscopic dilation (ED) in the management of stenosis after esophageal cancer surgery based on their efficacy and safety.

Methods

A comprehensive search was performed in electronic databases including MEDLINE, EMBASE, the Cochrane Library, Web of Science, and China National Knowledge Infrastructure for possible controlled studies. Meta-analyses of the included studies were completed using Reviewer Manager software and were reported based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Results

Eight randomized studies and five controlled studies containing 575 patients were obtained. In five studies (n=282), TA injected after surgery reduced the risk of stenosis (risk difference [RD] =-0.51, 95% CI [-0.64, -0.39], P<0.01) and the required ED sessions (RD =-3.66, 95% CI [-5.87, -1.46], P<0.01). In eight studies (n=293), TA injection combined with ED reduced the risk of recurrence of stenosis (RD =-0.28, 95% CI [-0.47, -0.08], P<0.01) and the required ED sessions (RD =-0.71, 95% CI [-1.39, -0.04], P<0.05). TA injection therapy did not increase the risk of complications in seven studies (n=380; RD =-0.01, 95% CI [-0.04, 0.02], P=0.53) compared with control.

Conclusion

TA injection therapy after esophageal cancer surgery and combined with ED are both effective and safe in the management of stenosis, as they reduce the risk of stenosis and sequentially the required ED sessions without increasing complications.

Efficacy of second-look endoscopy in preventing delayed bleeding after endoscopic submucosal dissection of early gastric cancer

The present study aimed to evaluate whether second-look endoscopy (SLE) is able to prevent delayed bleeding after endoscopic submucosal dissection (ESD) of gastric carcinoma and to identify which types of lesion require SLE. ESD of gastric cancer at the early stage was performed on 210 patients between October 2014 and September 2016. Mucosal damage-associated bleeding within 24 h after ESD was considered as delayed bleeding. The association of the characteristics of patients and lesions, as well as surgical factors, with the incidence of bleeding as a measure of outcome was analyzed. A total of 110 patients with melena and/or hematemesis underwent SLE on the second day following gastric ESD. Within the entire cohort (n=210), late delayed bleeding (LDB) was defined as hematemesis or melena occurring following second-look endoscopy. Early delayed bleeding (EDB) was defined as hematemesis or melena occurring from the end of ESD to second-look endoscopy, or as active or possible bleeding at the time of the second-look endoscopy was reported in 17 (8.1%) and 20 patients(9.5%), respectively. The median interval between late delayed bleeding and ESD was one day (range, 1–10 days). The incidence of late delayed bleeding was significantly decreased in the SLE group compared with that in the non-SLE group (4.5 vs. 12%, P=0.028). Multivariate analyses revealed that ulcer, flat gross type, lesion diameter (>2 cm), the resected tumor size of >40 mm and Helicobacter pylori infection were independently associated with late delayed bleeding after ESD, while flat gross type, ulcer, the resected tumor size of >40 mm and artificial ulcer diameter >3 cm were independently associated with early delayed bleeding. Thus, the data of the present study indicates that second-look endoscopy following gastric ESD may be useful in preventing post-ESD delayed bleeding and should be performed on the second day.

Validation of classic and expanded criteria for endoscopic submucosal dissection of early gastric cancer: 7 years of experience in a Western tertiary cancer center

OBJECTIVE

Our aim was to evaluate the Japan Gastroenterological Endoscopy Society criteria for endoscopic submucosal resection of early gastric cancer (EGC) based on the experience in a Brazilian cancer center.

METHODS

We included all patients who underwent endoscopic submucosal resection for gastric lesions between February 2009 and October 2016. Demographic data and information regarding the endoscopic resection, pathological report and follow-up were obtained. Statistical calculations were performed with Fisher's exact test and chi-square tests, with 95% confidence intervals.

RESULTS

In total, 76% of the 51 lesions were adenocarcinomas, 16% were adenomas, and 8% had other diagnoses. The average size was 19.9 mm (±11.7). The average procedure length was 113.9 minutes (±71.4). The complication rate was 21.3%, with only one patient who needed surgical treatment (transmural perforation). Among the adenocarcinomas, 39.5% met the classic criteria for curability, 31.6% met the expanded criteria and 28.9% met the criteria for noncurative resection. Analysis of the indication criteria and curability revealed differences among cases with "only-by-size" expanded criteria (64.28%), other expanded criteria (40%) and classic criteria (89.47%), with a p-value of 0.049. During follow-up (15.8 months; ±14.3), 86.1% of the EGC patients had no recurrence. When well-differentiated and poorly differentiated lesions or lesions included in the classic and expanded criteria were compared, there were no differences in recurrence. The noncurative group presented a higher recurrence rate than the classic group (p=0.014).

CONCLUSION

These results suggest that the Japanese endoscopic submucosal resection criteria might be useful for endoscopic treatment of EGC in Western countries.

Long-Term Effects of Helicobacter pylori Eradication on Metachronous Gastric Cancer Development

Background/Aims

Gastric mucosal atrophy and intestinal metaplasia due to Helicobacter pylori infection are the main precursor lesions of gastric cancer. The aim of this study was to evaluate the long-term effects of H. pylori eradication on the progression of precancerous lesions to metachronous cancer after endoscopic resection of early gastric cancer (EGC).

Methods

Patients who underwent endoscopic resection of EGC were retrospectively reviewed. Changes in precancerous lesions and development of metachronous cancer were compared according to H. pylori eradication and final infection status.

Results

In total, 565 patients were followed for over 5 years after endoscopic resection of EGC. The grade of atrophy on corpus was significantly lower in the H. pylori-eradicated group than in the persistent group during follow-up (p=0.029). In patients ＜70 years of age, the cumulative incidence rate of metachronous cancer was significantly lower in the H. pylori-eradicated group than in the persistent group (p=0.018). Age was an independent risk factor for metachronous cancer development.

Conclusions

H. pylori eradication might prevent the development of metachronous cancer in patients ＜70 years of age by delaying the progression of precancerous lesions after endoscopic resection of EGC.

Secondary endoscopic submucosal dissection for locally recurrent or incompletely resected gastric neoplasms

AIM

To investigate the feasibility and safety of secondary endoscopic submucosal dissection (ESD) for residual or locally recurrent gastric tumors.

METHODS

Between 2010 and 2017, 1623 consecutive patients underwent ESD for gastric neoplasms at a single tertiary referral center. Among these, 28 patients underwent secondary ESD for a residual or locally recurrent tumor. Our analysis compared clinicopathologic factors between primary ESD and secondary ESD groups.

RESULTS

The en bloc resection and curative rate of resection of secondary ESD were 92.9% and 89.3%, respectively. The average procedure time of secondary ESD was significantly longer than primary ESD (78.2 min vs 55.1 min, P = 0.004), and the adverse events rate was not significantly different but trended slightly higher in the secondary ESD group compared to the primary ESD group (10.7% vs 3.8%, P = 0.095). Patients who received secondary ESD had favorable outcomes without severe adverse events. During a mean follow-up period, no local recurrence occurred in patients who received secondary ESD.

CONCLUSION

Secondary ESD of residual or locally recurrent gastric tumors appears to be a feasible and curative treatment though it requires greater technical efficiency and longer procedure time.

Propensity score-matching analysis to compare clinical outcomes of endoscopic submucosal dissection for early gastric cancer in the postoperative and non-operative stomachs

Background

Endoscopic submucosal dissection (ESD) of the postoperative stomach (ESD-P) for early gastric cancer (EGC) is considered a technically difficult procedure. However, it is difficult to compare the outcomes of ESD-P and ESD of the non-operative stomach (ESD-N) because their baseline characteristics are different. Therefore, we aimed to compare the technical outcomes of ESD-P with those of ESD-N using a propensity score-matching analysis to compensate for the differences.

Methods

The chart records of 1046 patients with EGC who were treated with ESD between January 2004 and July 2016 at Kitakyushu Municipal Medical Center in Japan were reviewed in this retrospective study. Multivariate analyses and propensity score-matching were performed for age, sex, lesion location, lesion size, tumor invasion, tumor size, ulcer (scar), and operator skill. The primary outcome was procedure time. Secondary outcomes were percentages of en bloc, complete, and curative resections, and percentages of adverse events, which were evaluated between the two groups.

Results

Forty-one patients were in the ESD-P group and 1005 patients were in the ESD-N group. Propensity score-matching created 41 matched pairs. According to the adjusted comparisons, ESD-P required a significantly longer procedure time (85 min vs 51 min, p < 0.001). Other treatment outcomes showed an en bloc resection rate of 100% for both groups (p = 1) and complete resection rates of 95.1 and 97.6% (p = 1), curative resection rates of 90.2 and 90.2% (p = 1), perforation during ESD rates of 2.4 and 0% (p = 1), and postprocedure bleeding rates of 2.4 and 2.4% (p = 1) for the ESD-P and ESD-N groups, respectively. For the ESD-P group, lesions on the suture line or anastomotic site were significantly associated with longer procedure times (p = 0.038).

Conclusions

ESD-P was a more time-consuming procedure than ESD-N. However, ESD-P and ESD-N achieved high rates of curative resection with a low rate of adverse events for the treatment of EGC. ESD could be selected as the treatment for EGC even in the postoperative stomach provided that careful attention is given to lesions on the suture line or anastomotic site.

Application of artificial intelligence using a convolutional neural network for detecting gastric cancer in endoscopic images

BACKGROUND

Image recognition using artificial intelligence with deep learning through convolutional neural networks (CNNs) has dramatically improved and been increasingly applied to medical fields for diagnostic imaging. We developed a CNN that can automatically detect gastric cancer in endoscopic images.

METHODS

A CNN-based diagnostic system was constructed based on Single Shot MultiBox Detector architecture and trained using 13,584 endoscopic images of gastric cancer. To evaluate the diagnostic accuracy, an independent test set of 2296 stomach images collected from 69 consecutive patients with 77 gastric cancer lesions was applied to the constructed CNN.

RESULTS

The CNN required 47 s to analyze 2296 test images. The CNN correctly diagnosed 71 of 77 gastric cancer lesions with an overall sensitivity of 92.2%, and 161 non-cancerous lesions were detected as gastric cancer, resulting in a positive predictive value of 30.6%. Seventy of the 71 lesions (98.6%) with a diameter of 6 mm or more as well as all invasive cancers were correctly detected. All missed lesions were superficially depressed and differentiated-type intramucosal cancers that were difficult to distinguish from gastritis even for experienced endoscopists. Nearly half of the false-positive lesions were gastritis with changes in color tone or an irregular mucosal surface.

CONCLUSION

The constructed CNN system for detecting gastric cancer could process numerous stored endoscopic images in a very short time with a clinically relevant diagnostic ability. It may be well applicable to daily clinical practice to reduce the burden of endoscopists.

Quality in upper gastrointestinal endoscopic submucosal dissection

Progress in the endoscopy technology field led to an increase in the diagnosis of early gastrointestinal (GI) superficial lesions and to an improvement of their treatment. Endoscopic submucosal dissection (ESD) has been developed in Japan with the aim of removing such lesions in one piece, in order to obtain a curative resection and to minimize the risk of local recurrence, and to preserve the native organ. ESD is widely used in Asia for the treatment of early upper and lower GI lesions and is currently gaining attention in Western countries too. However, ESD can be safely performed only by expert endoscopists and in specific clinical settings. Therefore, prior to decide whether ESD is feasible or not, the target lesion must be carefully assessed, in order to understand whether or not it is eligible for submucosal dissection. The aim of this paper is to review indications, limitations and technical aspects of upper GI ESD.

Clonal Structures of Regionally Synchronous Gastric Adenomas and Carcinomas

Purpose: Gastric adenoma (GA) is a premalignant lesion that precedes intestinal-type gastric carcinoma (GC). However, genetic progression mechanisms from GA to GC have not been clarified.Experimental Design: We performed whole-exome sequencing-based mutational analyses for 15 synchronous pairs of attached GAs and GCs.Results: There was no significant difference in the number of driver mutations or copy-number alterations between GAs and GCs. Well-known mutations of TP53, APC, RNF43, and RPL22 were recurrently detected in synchronous GA/GC pairs. In addition, we discovered novel KDM6A, PREX2, FAT1, KMT2C, GLI3, and RPL22 mutations and hypermutation in GAs, but did not identify recurrent drivers for GA-to-GC progression. Clonal structure analyses revealed that most GA/GC pairs exhibit parallel evolution with early divergence rather than stepwise evolution during GA-to-GC progression. Of note, three cases were identified as clonally nonrelated GA/GC pairs despite the lack of histologic differences. We found differences in dominant mutational signatures 1, 6, 15, and 17 in GA/GC trunks, GA branches, and GC branches. Compared with our previous work on synchronous colon adenoma/carcinoma genome structures, where most drivers were in the trunk with parallel evolution, synchronous GA/GC genomes showed a different model of parallel evolution, with many drivers in the branches.Conclusions: The preferred sequence of mutational events during GA-to-GC progression might be more context-dependent than colon adenoma progression. Our results show that nonclonal synchronous GA/GC is common and that GA genomes have already acquired distinct genomic alterations, suggesting caution in the diagnosis of synchronous GA and GC, especially in residual or recurrent cases. Clin Cancer Res; 24(19); 4715-25. ©2018 AACR.

Up-Regulation of miR-21, miR-25, miR-93, and miR-106b in Gastric Cancer

Background:

Differential expression profile of microRNAs (miRNAs) could be a diagnosis signature for monitoring gastric cancer (GC) progression. In this study, we focus on the comparison of expression levels of miR-21, miR-25, miR-93, miR-106b, and miR-375 during the sequential pattern of GC development, including normal gastric, gastric dysplasia, and GC sample.

Methods:

We used SYBR Green-based quantitative-PCR to quantify miRNAs expression.

Results:

Our analysis revealed the increased expression levels of miR-21 (p = 0.034), miR-25 (p = 0.0003), miR-93 (p = 0.0406), and miR-106b (p = 0.023) in GC samples. In addition, GC patients with positive lymph node metastasis showed the up-regulation of miR-25, miR-93, and miR-106b (p < 0.05).

Conclusion:

Our findings suggested that the expression of miR-21, miR-25, miR-93, and miR-106b altered in GC, and some of them may be further investigated as biomarkers for GC early detection and prognosis prediction.

Efficacy and safety of endoscopic submucosal dissection for gastric neoplasms in patients with compensated liver cirrhosis: a propensity score-matched case-control study

BACKGROUND AND AIMS

The clinical outcomes of endoscopic submucosal dissection (ESD) for gastric neoplasms in liver cirrhosis patients have not been adequately reported, leading to clinician concerns about adverse events, including bleeding and the deterioration of liver function. We compared the efficacy and safety of ESD between cirrhosis and noncirrhosis patients.

METHODS

Between January 2005 and December 2014, 158 cirrhosis patients underwent ESD for gastric neoplasms at a tertiary medical institution. Their clinical outcomes were compared with those of a propensity score-matched control group (158 patients) selected from noncirrhosis patients, using age, sex, histology, tumor location, and lesion size as variables.

RESULTS

En bloc resection (96.8%), curative resection (89.9%), and adverse event (bleeding [10.1%] and perforation [1.9%]) rates in the cirrhosis group did not differ significantly from those in the noncirrhosis group. The median procedure time (25.0 vs 23.0 minutes) was also comparable between the groups. In a survival analysis cirrhosis patients exhibited a significantly higher mortality risk than noncirrhosis patients (hazard ratio [HR], 3.52; 95% confidence interval [CI], 1.35-9.23; P = .01). Cirrhosis patients without hepatocellular carcinoma (HCC) showed no statistically significant difference in mortality compared with the noncirrhosis group (HR, 2.14; 95% CI, .72-6.39; P = .171). Three of 153 patients (2%) exhibited a deterioration of prognosis from Child-Pugh class A to B.

CONCLUSIONS

In compensated cirrhosis patients, especially those without HCC, ESD for gastric epithelial neoplasms can be performed with safety and efficacy comparable with that in noncirrhosis patients, without deterioration in liver function.

Gastric Cancer Caused by Adenoma: Predictive Factors Associated with Lesions Other Than the Expanded Indications

Background/Aims

We aimed to investigate whether the current indications for curative endoscopic resection (ER) of gastric cancer (GC) can be applied to GC caused by adenoma. Additionally, we attempted to identify factors predictive of lesions subsequently found in addition to the expanded indications for ER.

Methods

We retrospectively analyzed 342 patients diagnosed with GC caused by adenoma who underwent ER at a single tertiary center between February 2011 and December 2014. The gross whole tumor size was measured using the endoscopically resected specimen. The microscopic whole tumor size was measured using mapping paper. The estimated cancer size was calculated using the microscopic whole tumor size and the square root of the carcinoma component.

Results

A gross whole tumor size ≥3 cm, carcinoma component ≥35%, and gross ulceration were predictive of lesions other than the expanded indications for ER. The overall rate of lymph node metastasis was 0.3% (1/327), which only occurred in one patient with a lesion other than the expanded indications (4.5%, 1/22).

Conclusions

The current indications for curative ER in GC can be applied to GC caused by adenoma. In cases suspected of having lesions other than the expanded indications, patients should be cautiously selected for ER to reduce the risk of an inappropriate procedure.

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.

Endoscopic Submucosal Dissection: Indications and Application in Western Endoscopy Practice

Endoscopic submucosal dissection was developed in Japan, early in this century, to provide a minimally invasive yet curative treatment for the large numbers of patients with early gastric cancer identified by the national screening program. Previously, the majority of these patients were treated surgically at substantial cost and with significant risk of short- and long-term morbidity. En-bloc excision of these early cancers, most with a limited risk of nodal metastasis, allowed complete staging of the tumor, stratification of the subsequent therapeutic approach, and potential cure. This transformative innovation changed the nature of endoscopic treatment for superficial mucosal neoplasia and, ultimately, for the first time allowed endoscopists to assert that the early cancer had been definitively cured. Subsequently, Western endoscopists have increasingly embraced the therapeutic possibilities offered by endoscopic submucosal dissection, but with some justifiable scientific caution. Here we provide an evidence-based critical appraisal of the role of endoscopic submucosal dissection in advanced endoscopic tissue resection.

Conventional versus traction-assisted endoscopic submucosal dissection for gastric neoplasms: a multicenter, randomized controlled trial (with video)

BACKGROUND AND AIMS

The aim of this study was to clarify whether dental floss clip (DFC) traction improves the technical outcomes of endoscopic submucosal dissection (ESD).

METHODS

A superiority, randomized control trial was conducted at 14 institutions across Japan. Patients with single gastric neoplasm meeting the indications of the Japanese guidelines for gastric treatment were enrolled and assigned to receive conventional ESD or DFC traction-assisted ESD (DFC-ESD). Randomization was performed according to a computer-generated random sequence with stratification by institution, tumor location, tumor size, and operator experience. The primary endpoint was ESD procedure time, defined as the time from the start of the submucosal injection to the end of the tumor removal procedure.

RESULTS

Between July 2015 and September 2016, 640 patients underwent randomization. Of these, 316 patients who underwent conventional ESD and 319 patients who underwent DFC-ESD were included in our analysis. The mean ESD procedure time was 60.7 and 58.1 minutes for conventional ESD and DFC-ESD, respectively (P = .45). Perforation was less frequent in the DFC-ESD group (2.2% vs .3%, P = .04). For lesions located in the greater curvature of the upper or middle stomach, the mean procedure time was significantly shorter in the DFC-ESD group (104.1 vs 57.2 minutes, P = .01).

CONCLUSIONS

Our findings suggest that DFC-ESD does not result in shorter procedure time in the overall patient population, but it can reduce the risk of perforation. When selectively applied to lesions located in the greater curvature of the upper or middle stomach, DFC-ESD provides a remarkable reduction in procedure time.

Occurrence of metachronous multiple primary cancers occurred in different parts of the stomach with 2 pathologic features: A case report

RATIONALE

With the increasing survival rate of gastric cancer, more multiple primary cancers (MPC) have been reported. However, few cases involve metachronous multiple primary cancers which both occurred in the stomach.

PATIENT CONCERNS

An 83-year-old Chinese male had been diagnosed with gastric cardia cancer and underwent proximal gastrectomy. The pathological result was gastric adenocarcinoma. 13 years later the patient's gastroscope result deteriorated. The biopsy of the antrum revealed dysplasia with doubtful focal cancerization.

DIAGNOSES

Metachronous multiple primary cancers in the stomach.

INTERVENTIONS

Endoscopic submucosal dissection (ESD) was performed. The pathological result showed an intra-mucosal signet-ring carcinoma.

OUTCOMES

After treatment, the patient is alive with good condition until now.

LESSONS

This is an unusual case of MPC with different pathological features in different parts of the same organ in an interval of more than ten years and undergoing different operations.

Characteristics of Synchronous and Metachronous Multiple Gastric Tumors after Endoscopic Submucosal Dissection of Early Gastric Neoplasm

Background/Aims

Endoscopic submucosal dissection (ESD) has been widely accepted as a method of treatment of early gastric tumor. This study aimed to identify the incidence and characteristics of multiple gastric tumors after ESD.

Methods

Patients with early gastric tumors who were treated by ESD from January 2004 to June 2012 and followed up with endoscopic examination periodically for at least 1 year were enrolled. All multiple gastric lesions were subsequently treated with ESD and the medical records of the patients were retrospectively reviewed.

Results

In total, 643 patients were included. The mean duration of endoscopic follow-up was 45.27±27.59 (range, 12–148) months. Overall, 144 patients (22.4%) showed multiple gastric tumors during the follow-up period (44 synchronous [6.8%] and 100 metachronous [15.5%]). The cumulative incidence rate steadily increased during the follow-up period. More than 50% of the tumors that developed at the same longitudinal location of the stomach were of the same macroscopic and histological type as the primary lesions.

Conclusions

Because synchronous and/or metachronous gastric tumors are common, considerable attention should be paid to detect multiple gastric lesions after ESD of early gastric neoplasm.

Long-term outcomes after noncurative endoscopic resection of early gastric cancer: the optimal time for additional endoscopic treatment

BACKGROUND AND AIMS

We aimed to evaluate long-term outcomes with noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and surveillance strategies such as the optimal time for additional endoscopic treatment in patients with noncurative ESD.

METHODS

Of 2527 patients who underwent gastric ESD for EGC, 512 (20.3%) patients with noncurative resection were reviewed. Noncurative resection is defined as positive resected margins on histology, lymphovascular infiltration, or beyond the expanded criteria for ESD.

RESULTS

The mean ± standard deviation follow-up duration was 79.0 ± 55.7 months. A total of 264 patients (51.6%) and 50 patients (9.8%) underwent surgery and endoscopic treatment after noncurative resection, respectively, whereas 198 patients (38.7%) were observed. Cancer-specific survival and disease-free survival rates were significantly different among the surgery, other endoscopic treatment, and observation groups (96.7%, 86.8%, and 86.2%, respectively; P =.030; and 92.5%, 73.6%, and 63.0%, respectively; P < .001). When patients who underwent surgery were excluded, the disease-free survival rate of recurrence was not significantly different between the endoscopic treatment and observation groups (73.6% vs 63.0%; P = .548). To exclude the potential for the presence of lymph node metastasis, we further analyzed disease-free survival of local recurrence by comparing the patients with only a positive lateral resection margin. The disease-free survival rate was higher in the endoscopic treatment group than in the observation group (89.2% vs 69.1%; P = .023). Moreover, additional endoscopic treatment within 3 months showed significant associations with lower risk of local recurrence on multivariate analysis (hazard ratio, 0.017; 95% confidence interval, 0.002-0.260; P = .003).

CONCLUSIONS

In patients with noncurative ESD, additional surgery showed a better long-term outcome; moreover, when a positive lateral resection margin was the only noncurative factor, additional endoscopic treatment within 3 months could be considered to improve disease-free survival.

An aggressive early gastric cancer: Kodama's PenA type

BACKGROUND

To investigate the role of Kodama PenA subtype in influencing survival in patients with early gastric cancer (EGC).

METHODS

All patients surgically treated for EGC at 7 Italian centers (Forlì, Varese, Siena, Verona, Milan, Rome and Perugia) belonging to the Italian Research Group for Gastric Cancer (GIRCG) from January 1982 and December 2009 were included.

RESULTS

PenA patients were 230 (21.5%) while other types were 839 (78.5%). Nodal metastases were more common in PenA (30.7%) than non-PenA (10.4%) EGCs. Among preoperative variables, only age (OR 1.02; 95% CI 1.00-1.03, p = 0.009) and macrotype III (OR 1.95; 95% CI 1.39-2.75, p = 0.0001) were significantly associated with Pen A type. Survival analysis performed on N0 patients demonstrated that only size >2 cm (HR 1.85; 95% CI 1.12-3.05, p = 0.017) and age (HR 1.06; 95% CI 1.03-1.08, p < 0.0001) were independent poor prognostic factor. Among N+ patients age (HR 1.04; 95% CI 1.00-1.07, p = 0.048), number of positive lymph nodes (HR 1.13; 95% CI 1.05-1.20, p = 0.0002) and PenA (HR 4.23; 95% CI 1.70-10.55, p = 0.002) were significantly correlated with poor prognosis at multivariate analysis.

CONCLUSIONS

Kodama PenA subtype was the most powerful independent prognostic factor in patients with nodal metastases. Its status should always be investigated in EGCs patients.

Helicobacter pylori-induced modulation of the promoter methylation of Wnt antagonist genes in gastric carcinogenesis

BACKGROUND

This study aimed to investigate the changes in the promoter methylation and gene expression of multiple Wnt antagonists between the chronic infection and eradication of Helicobacter pylori (H. pylori) in gastric carcinogenesis.

METHODS

The levels of methylation and corresponding mRNA expression of seven Wnt antagonist genes (SFRP1, -2, -5, DKK1, -2, -3, WIF1) were compared among the patients with H. pylori-positive gastric cancers (GCs), and H. pylori-positive and H. pylori-negative controls, by quantitative MethyLight assay and real-time reverse transcription (RT)-polymerase chain reaction (PCR), respectively. The changes of the methylation and expression levels of the genes were also compared between the H. pylori eradication and H. pylori-persistent groups 1 year after endoscopic resection of GCs.

RESULTS

The methylation levels of SFRP and DKK family genes were significantly increased in the patients with H. pylori-positive GCs and followed by H. pylori-positive controls compared with H. pylori-negative controls (P < 0.001). SFRP1, -2, and DKK3 gene expression was stepwise downregulated from H. pylori-negative controls, H. pylori-positive controls, and to H. pylori-positive GCs (P < 0.05). Among the Wnt antagonists, only the degrees of methylation and downregulation of DKK3 were significantly reduced after H. pylori eradication (P < 0.05).

CONCLUSION

Epigenetic silencing of SFRP and DKK family genes may facilitate the formation of an epigenetic field during H. pylori-associated gastric carcinogenesis. The epigenetic field may not be reversed even after H. pylori eradication except by DKK3 methylation.

Incidence of gastric adenocarcinoma among lesions diagnosed as low-grade adenoma/dysplasia on endoscopic biopsy: A multicenter, prospective, observational study

BACKGROUND AND AIM

Differentiation between gastric adenocarcinoma and low-grade adenoma/dysplasia (LGA) on endoscopic forceps biopsy is difficult. We aim to clarify the incidence of carcinoma in specimens, obtained by endoscopic resection (ER), from cases that had been diagnosed as LGA (Vienna category 3) on endoscopic biopsy.

METHODS

In this multicenter, prospective, observational study, patients with gastric adenoma (Vienna category 3 or 4.1) diagnosed on endoscopic forceps biopsy were enrolled. All the specimens were subjected to histopathological central review. Primary endpoint was the incidence of carcinoma (Vienna category 4.2 or over) among the biopsy-proven gastric LGA. Secondary endpoints were the histological findings of resected specimens, clinicopathological features of carcinoma, and short-term outcomes of all ER cases.

RESULTS

Ninety-five patients with 104 lesions diagnosed as gastric adenoma were enrolled. After central review of the biopsy specimens, 47 lesions were diagnosed as LGA and seven lesions (15%) as adenocarcinoma (95% confidence interval, 7.6-28%). Carcinoma was detected in lesions that had a minimum size of 6 mm; the incidence of carcinoma was higher in the larger lesions. There was a histological discrepancy between biopsy and ER material in more than 60% of the cases.

CONCLUSIONS

A substantial proportion of biopsy-proven gastric LGA specimens were diagnosed as adenocarcinoma after ER. This indicated histological discrepancy between biopsy-proven gastric LGA and histology of the resected material.

Clinical outcomes of minimally invasive treatment for early gastric cancer in patients beyond the indications of endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) with laparoscopic sentinel lymph node dissection (ESN) and endoscopic full-thickness gastric resection with laparoscopic sentinel lymph node dissection (Hybrid-natural orifice transluminal endoscopic surgery, Hybrid-NOTES) are minimally invasive treatment options for early gastric cancer (EGC) beyond the indications of ESD. This study aimed to evaluate the short- and long-term clinical outcomes of ESN and Hybrid-NOTES.

METHODS

We retrospectively analyzed patients who had undergone ESN or Hybrid-NOTES for EGC from January 2009 to March 2013. A total of 48 patients, including 21 undergoing ESN and 27 undergoing Hybrid-NOTES, were enrolled. All patients had cancer stage T1N0M0, EGC less than 5 cm in size, and suspected submucosal invasion according to imaging or biopsy-proven diffuse-type histology.

RESULTS

In ESN and Hybrid-NOTES, the curative resection rates were 76.5% and 90.9% of patients, respectively. In the ESN group, 5 patients underwent an additional gastrectomy (1 for lymph node metastasis (LNM), 3 for surgical complications, and 1 for noncurative resection). In the Hybrid-NOTES group, 6 patients underwent additional gastrectomy, (1 for LNM, 3 for surgical complications, and 2 for noncurative resection). Of the 37 patients who were followed up in the long-term (a median follow-up of 59.8 months), one was found to have liver metastasis after ESN and received palliative chemotherapy.

CONCLUSIONS

ESN and Hybrid-NOTES have shown favorable long-term outcomes despite their technical limitations. These methods may be utilized as a bridge between ESD and gastrectomy in cases of EGC with a high risk of LNM beyond the ESD indications.

Effects of Vonoprazan Compared with Esomeprazole on the Healing of Artificial Postendoscopic Submucosal Dissection Ulcers: A Prospective, Multicenter, Two-Arm, Randomized Controlled Trial

Background

Vonoprazan affords more clinical benefits than proton pump inhibitors (PPIs) during the healing of gastroduodenal ulcers. However, it remains controversial whether vonoprazan is more effective than PPIs when used to heal artificial ulcers arising after endoscopic submucosal dissection (ESD).

Aim

This study investigated the effects of vonoprazan compared with esomeprazole on the healing of post-ESD artificial ulcers.

Methods

Sixty patients who underwent gastric ESD between May 2015 and May 2017 were randomized to treatment with vonoprazan (V group) or esomeprazole (E group) for 8 weeks. Upper endoscopy was performed at 4 and 8 weeks after ESD, and drug effects were estimated based on the ulcer healing rates and shrinkage rates.

Results

Fifty-three patients were analyzed. The respective 4- and 8-week ulcer healing rates did not differ significantly between V and E groups (8.0 versus 11.5%, P = 0.669; 88.9 versus 84.6%, P = 0.420). Similarly, the respective 4- and 8-week ulcer shrinkage rates did not differ significantly between V and E groups (96.8 versus 97.5%, P = 0.656; 100 versus 100%, P = 0.257).

Conclusion

The healing of artificial ulcers after ESD did not differ using vonoprazan or esomeprazole. Both vonoprazan and esomeprazole were effective when used to promote artificial ulcer healing after ESD.

CEACAM6 is upregulated by Helicobacter pylori CagA and is a biomarker for early gastric cancer

Early detection of gastric cancers saves lives, but remains a diagnostic challenge. In this study, we aimed to identify cell-surface biomarkers of early gastric cancer. We hypothesized that a subset of plasma membrane proteins induced by the Helicobacter pylori oncoprotein CagA will be retained in early gastric cancers through non-oncogene addiction. An inducible system for expression of CagA was used to identify differentially upregulated membrane protein transcripts in vitro. The top hits were then analyzed in gene expression datasets comparing transcriptome of gastric cancer with normal tissue, to focus on markers retained in cancer. Among the transcripts enriched upon CagA induction in vitro, a significant elevation of CEACAM6 was noted in gene expression datasets of gastric cancer. We used quantitative digital immunohistochemistry to measure CEACAM6 protein levels in tissue microarrays of gastric cancer. We demonstrate an increase in CEACAM6 in early gastric cancers, when compared to matched normal tissue, with an AUC of 0.83 for diagnostic validity. Finally, we show that a fluorescently conjugated CEACAM6 antibody binds avidly to freshly resected gastric cancer xenograft samples and can be detected by endoscopy in real time. Together, these results suggest that CEACAM6 upregulation is a cell surface response to H. pylori CagA, and is retained in early gastric cancers. They highlight a novel link between CEACAM6 expression and CagA in gastric cancer, and suggest CEACAM6 to be a promising biomarker to aid with the fluorescent endoscopic diagnosis of early neoplastic lesions in the stomach.

Protoporphyrinogen oxidase is involved in the fluorescence intensity of 5-aminolevulinic acid-mediated laser-based photodynamic endoscopic diagnosis for early gastric cancer

BACKGROUND/AIM

Laser-based photodynamic endoscopic diagnosis (LPDED) is a type of endoscopic diagnosis that uses the fluorescence caused by the photochemical reaction that occurs when a fluorescent substance is irradiated by a light of a specific wavelength. Although 5-aminolevulinic acid (5-ALA) can detect early gastric cancer (EGC) during LPDED, there is an unresolved issue of the differences in fluorescence intensity among histopathological types of gastric cancer. Thus, the aim of the present study was to assess whether protoporphyrinogen oxidase (PPOX), involved in the activation of protoporphyrin IX, can affect the fluorescence intensity in EGC.

METHODS

Thirty-three gastric tumor lesions in 30 patients were assessed by LPDED using a prototype endoscope equipped with a blue laser ray to cause excitation following oral 5-ALA administration. The tumors were then resected by endoscopic submucosal dissection or laparoscopic surgery. PPOX expression was examined immunohistochemically in the excised specimens. To explore the mechanisms of histopathological diversity in PPOX and coproporphyrinogen oxidase (CPOX) expression of EGC, immunohistochemical analysis was performed using 75 surgically resected specimens of diverse EGCs.

RESULTS

Among the 33 lesions, 26 tumors were detectable by LPDED, whereas seven were undetectable. Between the LPDED-positive and negative groups, there was a significant difference in histopathology. The expression of PPOX was higher in tubular adenocarcinoma (tub) than in signet-ring cell carcinoma (sig). There were significant differences in PPOX and CPOX expression scores of the surgically resected specimens among tub, poorly differentiated adenocarcinoma (por), and sig.

CONCLUSION

PPOX protein expression could be involved in the fluorescence intensity of LPDED in EGC, possibly reflecting histopathological features.

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.

Novel risk stratification for metachronous recurrence after curative endoscopic submucosal dissection for early gastric cancer

BACKGROUND AND AIMS

This study stratified the risk of developing metachronous gastric cancer (MGC) after curative endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) to enable customization of endoscopic surveillance for MGC.

METHODS

A total of 1115 patients who underwent curative ESD based on the expanded criteria for differentiated EGC from 2005 to 2014 at a single tertiary hospital were enrolled in this retrospective cohort study. They were followed up with annual endoscopy for a median of 50.1 months. Helicobacter pylori and histologic intestinal metaplasia (IM) were evaluated. The Kaplan-Meier method and Cox regression analysis were used for risk stratification.

RESULTS

Three risk groups were identified: group 1 comprised patients with a synchronous neoplasm; group 2 comprised male patients with corpus IM; and group 3 comprised male patients without corpus IM or female patients. The 5- and 7-year cumulative risks (95% confidence interval [CI]) for metachronous recurrence were 15.1% (95% CI, 7.7-22.5) and 26.1% (95% CI, 14.9-37.3), respectively, in group 1; 5.6% (95% CI, 3.1-8.1) and 9.3% (95% CI, 5.4-13.2), respectively, in group 2; and 3.8% (95% CI, 1.6-6.0) and 4.9% (95% CI, 2.4-7.4), respectively, in group 3 (P < .001 by log-rank test). The incidence of MGCs increased constantly even after 5 years in groups 1 and 2 but not in group 3. There was not enough evidence to show an association between H pylori eradication and metachronous recurrence in the data.

CONCLUSIONS

Meticulous annual endoscopic surveillance for MGC for more than 5 years is recommended for patients with synchronous neoplasm. Endoscopic surveillance may also be extended beyond 5 years in male patients with corpus IM.

Long-term outcome of endoscopic submucosal dissection is comparable to that of surgery for early gastric cancer: a propensity-matched analysis

BACKGROUND

Data concerning the long-term outcomes of endoscopic submucosal dissection (ESD) versus surgery for early gastric cancer (EGC) are limited. We aimed to compare the long-term outcomes of ESD and surgery for patients with EGC.

METHODS

Data were reviewed from patients treated by ESD or surgery for EGC in 2005-2010. The primary outcome was overall survival (OS). Secondary outcomes were disease-specific survival (DSS), disease-free survival (DFS), recurrence-free survival (RFS), treatment-related complications, and hospital stay duration.

RESULTS

Among 617 patients, 342 underwent ESD and 275 underwent surgery. The 5-year OS rates were similar between the ESD group and the surgery group (96.9% vs 98.1%, P = 0.581). In a propensity-score-matched analysis of 117 pairs, there were no significant differences in the OS rates (96.5% vs 99.1%, P = 0.125) and DSS rates (100% vs 99.1%, P = 0.317) between the ESD group and the surgery group. The ESD group had a significantly lower DFS rate (90.3% vs 98.0%, P = 0.002), a significantly lower RFS rate (95.1% vs 98.0%, P = 0.033), a significantly higher early complication rate (6.7% vs 1.5%, P < 0.001), a significantly lower late complication rate (0% vs 9.1%, P < 0.001), and a significantly shorter median hospital stay (3 days vs 10 days, P < 0.001) than the surgery group.

CONCLUSIONS

ESD and surgery have comparable OS rates in patients with EGC. ESD has benefits, including a lower late complication rate and shorter hospital stay. However, RFS and DFS rates might be lower after ESD than after surgery.

A non-randomized confirmatory trial of an expanded indication for endoscopic submucosal dissection for intestinal-type gastric cancer (cT1a): the Japan Clinical Oncology Group study (JCOG0607)

BACKGROUND

Endoscopic resection has been limited to intestinal-type gastric cancer (cT1a) with a low risk of lymph node metastasis (T1a ≤2 cm, without ulcers). This single-arm confirmatory trial evaluated the efficacy and safety of endoscopic submucosal dissection (ESD) for >2 cm ulcer-negative and ≤3 cm ulcer-positive intestinal-type gastric cancer (cT1a).

METHODS

The eligibility criteria included endoscopically diagnosed cT1a, a single primary intestinal-type gastric adenocarcinoma, an ulcer-negative lesion of any size or a ≤3 cm ulcer-positive lesion, cN0M0, and no prior treatment. If ESD resulted in noncurative resection, surgical resection was added. The primary endpoint was the 5-year overall survival (OS) (planned sample size was 470, with a one-sided alpha level of 2.5%). The threshold 5-year OS was 86.1%.

RESULTS

We enrolled 470 early gastric cancer patients [median tumor size, 25 (5-130) mm] from 29 institutions between June 2007 and October 2010. These patients had 152 ulcer-negative lesions (>2 and ≤3 cm), 111 ulcer-negative lesions (>3 cm), and 207 ulcer-positive lesions (≤3 cm). The success rate for en block resection was 99.1% (466/470). Additional gastrectomy was conducted in 131 patients (28%) who did not fulfill the curative resection criteria. The 5-year OS of all patients was 97.0% (95% confidence interval, 95.0-98.2%), which was higher than the threshold 5-year OS (86.1%). The 317 patients who satisfied the curative resection criteria had no recurrence. There were no ESD-related grade 4 adverse events.

CONCLUSION

ESD for early gastric cancers that met the expanded criteria for intestinal-type gastric cancer (cT1a) was acceptable and should be the standard treatment instead of gastrectomy.

Long-term outcomes of endoscopic submucosal dissection in comparison to surgery in undifferentiated-type intramucosal gastric cancer using propensity score analysis

BACKGROUND

The treatment of intramucosal early gastric cancer with undifferentiated-type histologies (UD-EGCs) using endoscopic submucosal dissection (ESD) is controversial. This study aimed to compare the clinical and oncologic long-term outcomes of ESD and surgery for UD-EGCs.

METHODS

A prospectively collected database of patients who underwent ESD or surgery between January 2006 and December 2012 was established. Patients who diagnosed with UD-EGC and satisfied the expanded indications of ESD were included. Clinical data from 111 patients treated with ESD and 382 patients underwent surgery were analyzed, and 1-1 propensity score-matched 81 pairs of patients were also compared.

RESULTS

In both groups, two-thirds of the UD-EGCs had signet ring cell (SRC)-type histology and about 90% of UD-EGCs were flat or depressed types. The mean size of tumors was smaller in ESD group (9.7 vs. 13.2 mm; P < 0.001). After propensity score-matched, case-matching covariates were not significantly different between the groups. Disease-free survival (DFS) was significantly shorter in the ESD group, but overall survival (OS) was not different between the two groups both in overall comparison (DFS; P < 0.001 and OS; P = 0.078) and propensity score-matched analysis (DFS; P < 0.001 and OS; P = 0.850). According to histologic type, OS of SRC histology was not different between the group, both in overall comparison and propensity score-matched analysis (P = 0.286 and P = 0.210). On the other hands, OS of poorly differentiated adenocarcinoma was significantly shorter in ESD group in overall comparison (P = 0.007), but was not as so in propensity score-matched analysis (P = 0.088).

CONCLUSIONS

ESD might be a complementary option for the treatment of UD-EGCs, especially in those with SRC-type histology based on strict expanded indications. Nonetheless, close endoscopic surveillance is required because of a high incidence of intragastric recurrence.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: short- and long-term outcomes

BACKGROUND AND AIMS

Application of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancers (EGCs) remains controversial owing to limited data regarding long-term outcomes. We aimed to evaluate the feasibility of ESD for undifferentiated-type EGCs that meet the expanded criteria (EC).

METHODS

We performed a retrospective analysis of 66 patients who underwent ESD for undifferentiated-type EGC between January 2005 and December 2014. We evaluated the rates of en bloc, complete, and curative resections along with overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS).

RESULTS

Of the 66 patients, the EC group included 38 patients and the beyond-EC group included 28 patients. The overall rates of en bloc, complete, and curative resection of the 66 lesions were 92.4% (61/66), 65.2% (43/66), and 48.5% (32/66), respectively. Of the 34 patients with non-curative resection, 18 underwent additional surgery. Local remnant cancer was detected in 1 patient (1/18, 5.6%), and none of the 18 patients had lymph node metastasis. On multivariate analysis, tumors > 2 cm [odd ratio (OR) 6.183, 95% confidence interval (CI) 1.279-29.880, p = 0.023) and submucosal invasion depth (OR 6.226, 95% CI 1.881-20.606, p = 0.003) were independent predictors of incomplete resection. All 26 patients with more than 1 year of follow-up after curative resection survived without any evidence of local or distant recurrences over a median follow-up period of 36 months. The OS, DSS, and RFS rates of patients with curative ESD were 93.8, 100, and 100%, respectively.

CONCLUSIONS

ESD may have favorable long-term outcomes in patients with undifferentiated-type EGC after curative resection.

Endoscopic resection versus radical gastrectomy for early gastric cancer in Asia: A meta-analysis

BACKGROUND

To compare the efficacy and safety of endoscopic resection (ER) and radical gastrectomy (RG) for early gastric cancer (EGC) in Asia.

MATERIALS AND METHODS

We systematically searched relevant articles published before September 1, 2017. We evaluated the quality of the included non-randomized studies using the Newcastle-Ottawa Scale (NOS). Meta-analysis was carried out using RevMan 5.3 software. The odds ratio (OR) with 95% confidence intervals (CI) were used for the dichotomous data.

RESULTS

Fifteen retrospective studies were included in this analysis (3737 patients in the ER group and 4246 patients in RG group). No significant differences in the three-year survival rate (OR, 0.87; 95%CI, 0.50-1.53) and five-year survival rate (OR, 0.81; 95%CI, 0.58-1.13) between the ER and RG groups were observed. Although patients undergoing ER had a higher risk of recurrence (OR, 6.07; 95%CI 4.17-8.84) and the occurrence of metachronous cancer (OR, 8.35; 95%CI, 5.48-12.75), recurrent or metachronous gastric cancers following ER were successfully detected and removed using the endoscopic technique. Higher recurrence in the ER group may be associated with its lower en bloc resection rate (OR, 0.05; 95%CI, 0.02-0.14) and complete resection rate (OR, 0.03; 95%CI, 0.01-0.08). Importantly, although the three-year survival and five-year survival were similar in the two groups, the complication rate in the ER group was significantly lower than that in the RG group.

CONCLUSION

ER is a good choice for patients with small EGC lesions (≤2 cm) without lymph node metastasis, especially in elderly patients with various medical comorbidities and in patients who cannot tolerate abdominal surgery or who meet the criteria but decline surgery. In contrast, RG is recommended when the diameter of the tumor is large (>2 cm) and preoperative examination suggests the possible presence of lymph node metastasis.

Evaluation of Slug expression is useful for predicting lymph node metastasis and survival in patients with gastric cancer

BACKGROUND

Slug is a transcription factor that activates the epithelial-mesenchymal transition (EMT) process in cancer progression. The aim of our study was to evaluate the clinical significance of Slug expression in gastric cancer.

METHODS

The expression of Slug in gastric cancer tissues of 456 patients who underwent gastrectomy was evaluated by immunohistochemistry using tissue microarrays. Slug expression level was defined by the composite score determined by multiplying the tumor staining scores for intensity and extent. The associations of Slug expression with clinicopathological characteristics and overall and recurrence-free survival were analyzed.

RESULTS

Patients were divided into three groups according to Slug composite score (≤4, 6, and 9). Low, mid, and high expression of Slug was observed in 104 (22.7%), 130 (28.3%), and 225 (49.0%) of cases, respectively. Overall survival and recurrence-free survival progressively increased from high to low Slug expression. In terms of lymph node metastasis, the rate of positive lymph node metastasis was 38/104 (36.5%), 79/130 (60.8%), and 178/225 (79.1%) in low, mid, and high Slug expression groups, respectively, displaying a tendency to increase with higher Slug expression. In a multivariate analysis adjusting for patient age, tumor size, tumor depth, and histology, high Slug expression was associated with a high rate of positive lymph node metastasis compared with low Slug expression (odds ratio 3.42; 95% confidence interval, 1.74-6.69). In a subgroup analysis of T1 cancer, patients with negative Slug expression (defined as <5% positive tumor cells or no/weak staining) showed no lymph node metastasis (0/13), whereas those with positive Slug expression showed 15.9% (17/107) lymph node metastasis, with a negative predictive value of 100%.

CONCLUSIONS

High expression of Slug in gastric cancer tissue was associated with lymph node metastasis and poor survival. Evaluation of Slug would be useful for discriminating patients at high risk of lymph node metastasis in early gastric cancer.

Clinicopathological Characteristics and Prognostic Value of Signet Ring Cells in Gastric Carcinoma: A Meta-Analysis

Background and Objectives: Previous studies of the prognostic value of the signet ring cell (SRC) type have yielded inconsistent results. Therefore, the aim of the present meta-analysis is to explore the clinicopathological characteristics and prognostic value of SRCs.

Methods: Relevant articles that compared SRC and non-SRC type in PubMed and Web of Science were comprehensively searched. Then, a meta-analysis was performed.

Results: A total of 19 studies including 35947 cases were analyzed. Compared with non-SRC patients, SRC patients tended to be younger (WMD: -3.88, P=0.001) and predominantly female (OR: 1.60, P<0.001). Additionally, SRC patients exhibited less upper third tumor location (OR: 0.62, P<0.001) and less frequent hematogenous metastasis (OR: 0.41, P<0.001). There was no difference in overall survival (OS) between SRC and non-SRC patients in the total population (HR: 1.02, P=0.830). Early gastric cancer with SRCs was associated with better OS (HR: 0.57, P=0.002), while advanced gastric cancer with non-SRCs was associated with a worse prognosis (HR: 1.17, P<0.001).

Conclusions: This meta-analysis revealed that SRC tends to affect young females and tends to be located in the middle and lower third of the stomach. Early SRCs are associated with better prognoses, while advanced SRCs are associated with worse prognoses.

Metachronous Gastric Cancer Following Curative Endoscopic Resection of Early Gastric Cancer

This review article summarizes knowledge about metachronous gastric cancer (MGC) occurring after curative endoscopic resection (ER) of early gastric cancer (EGC), treatment outcomes of patients who developed MGC, and efficacy of Helicobacter pylori eradication to prevent MGC. The incidence of MGC following curative ER increases over time and is higher than in patients undergoing gastrectomy. Increasing age and multifocal EGC are independent risk factors for developing MGC. An MGC following curative ER is usually a small (<20 mm) and differentiated intramucosal cancer. Most MGC lesions are found at an early stage on semiannual or annual surveillance endoscopy and are successfully treated by further ER, with excellent long-term outcomes. Eradication of H. pylori may reduce the risk of MGC following ER of EGC, but further prospective studies with long-term outcomes are required. Surveillance endoscopy following gastric ER should be continued indefinitely, due to the risk of MGC even after successful H. pylori eradication. Risk stratification and tailored endoscopic surveillance schedules need to be developed.

Gastric cancer treated by endoscopic submucosal dissection or endoscopic mucosal resection in Japan from 2004 through 2006: JGCA nationwide registry conducted in 2013

BACKGROUND

The Japanese Gastric Cancer Association (JGCA) initiated a new nationwide gastric cancer registry in 2008 and reported the treatment outcomes of patients with primary gastric cancer who underwent surgical therapy in 2001 and 2003. However, the outcomes of endoscopic therapy have not been reported yet.

METHODS

The JGCA conducted a retrospective nationwide registry in 2013 to investigate the short-term and long-term outcomes of endoscopic mucosal resection or endoscopic submucosal dissection in patients with gastric cancer treated from January 2004 through December 2006. This registry used a computerized database with terminology in accordance with the JGCA classification (13th and 14th editions) and the Japanese Gastric Cancer Treatment Guidelines from 2010.

RESULTS

Accurate data on 12,647 patients were collected from 126 participating hospitals and analyzed. The treatment procedure was endoscopic submucosal dissection in 81% of the patients and endoscopic mucosal resection in 19%. En bloc and R0 resections were achieved in 89% and 79% of the patients respectively. The total proportion of patients who underwent curative resection was 69.2%; 43.8% of patients underwent curative resection for absolute indication lesions, and 25.4% underwent curative resection for expanded indication lesions. Emergency surgery was performed to treat bleeding or perforation in very few patients (0.3% and 0.4% respectively). The 5-year follow-up rate after endoscopic resection was 70%. The 5-year overall survival rate was 91.6% in patients with absolute indications and 90.3% in patients with expanded indications after curative resection and 86.5% in patients who underwent noncurative resection. The 5-year disease-specific survival rates were 99.9%, 99.7%, and 98.7% in patients with absolute indications who underwent curative resection, patients with expanded indications who underwent curative resection, and patients who underwent noncurative resection respectively.

CONCLUSION

Endoscopic resection of gastric cancer resulted in favorable short-term and long-term outcomes nationwide in Japan. Further efforts to increase the follow-up rate are needed.

Simultaneous endoscopic submucosal dissection for multiple early gastric cancers in a low volume center

The aim of the study is to evaluate the safety and efficacy of simultaneous endoscopic submucosal dissection (ESD) for multiple early gastric cancers.A total of 70 solitary early gastric cancers from 70 patients and 20 multiple early gastric cancers from 10 patients were included in this retrospective study. The curative resection rate, en bloc resection rate, procedure-related complications, and local recurrence were compared between the 2 groups.There was no statistical difference in the rate of complete resection, en bloc resection, and curative resection between the 2 groups (P > .05). No significant difference was found with respect to the occurrence of postoperative bleeding (P > .05). Procedure time was significantly longer in the simultaneous group than that in the single group (87.6 ± 25.1 min vs 54.6 ± 22.0 min, P = .004). The overall incidence of synchronous early gastric cancer was 7.5%.Simultaneous ESD for multiple early gastric cancers is a safe and feasible choice in low-volume hospital. The entire stomach should be examined meticulously during and after ESD. Larger randomized studies are needed to validate our results.

Expression of coproporphyrinogen oxidase is associated with detection of upper gastrointestinal carcinomas by 5-aminolevulinic acid-mediated photodynamic diagnosis

BACKGROUND

5-Aminolevulinic acid is a precursor of photosensitizing protoporphyrin IX and has been applied for photodynamic diagnosis of brain and bladder tumors with few side effects. Although most upper gastrointestinal tumors can be detected during photodynamic diagnosis, some tumors containing signet-ring cells cannot be visualized. Here, we aimed to assess whether proteins involved in the absorbance, activation, and turnover of protoporphyrin IX altered the fluorescence signal in gastric cancer.

METHODS

Aminolevulinic acid-mediated photodynamic diagnosis was performed in 23 lesions from 20 patients using an endoscope equipped with a blue laser light that caused red fluorescence emission of photosensitizing protoporphyrin IX. Red fluorescence signal and intensity was assessed during photodynamic diagnosis procedures. Lesions were resected by endoscopic and/or laparoscopic surgery, and specimens were immunostained and assessed for the expression of ATP-binding cassette sub-family G member 2, oligopeptide transporter-1, and coproporphyrinogen oxidase.

RESULTS

Photodynamic diagnosis was negative in four cases (17.4%). Three cases of photodynamic diagnosis-negative lesions were signet-ring cell carcinomas, and only one case was differentiated adenocarcinoma (intestinal type). Twenty intestinal type, photodynamic diagnosis-positive lesions showed high expression of coproporphyrinogen oxidase, whereas signet-ring cell carcinomas were all negative. Oligopeptide transporter-1 immunoreactivity was significantly higher in tumors of intestinal type. ATP-binding cassette sub-family G member 2 expression tended to be higher in luminal surface tumors than in intestinal type tumors.

CONCLUSION

Aminolevulinic acid-mediated photodynamic diagnosis provided good detection of upper gastrointestinal tumors of intestinal type but not diffuse type tumors, such as signet-ring cell carcinomas, possibly owing to coproporphyrinogen oxidase expression.

Pattern of extragastric recurrence and the role of abdominal computed tomography in surveillance after endoscopic resection of early gastric cancer: Korean experiences

BACKGROUND

Although extragastric recurrence after endoscopic resection of early gastric cancer is rare, it is important because of its potentially fatal outcomes. We investigated the patterns of extragastric recurrence after endoscopic resection and evaluated the role of abdominal computed tomography in surveillance.

METHODS

Between July 1994 and June 2014, 4915 patients underwent endoscopic resection of early gastric cancer. Because of follow-up periods of less than 6 months and consecutive surgery within 1 year, 810 patients were excluded. Thus, 4105 patients were retrospectively reviewed.

RESULTS

The median follow-up period was 37 months (interquartile range 20-59.6 months). The overall incidence of extragastric recurrence was 0.37% (n = 15). In patients who underwent curative resection, the incidence was 0.14% (n = 5). There were three recurrences in the absolute indication group, six in the expanded indication group, and six in the beyond expanded indication group. The median time to extragastric recurrence was 17 months (interquartile range 16.5-43.2 months). Of the 15 extragastric recurrences, 11 were in the regional lymph nodes and 4 were in the liver, adrenal gland, and peritoneum. Sixty percent (9/15) of the extragastric recurrences occurred without intragastric lesions. Eleven recurrences were detected by abdominal computed tomography, and eight patients underwent curative surgery.

CONCLUSIONS

After endoscopic resection of early gastric cancer, regional lymph node recurrence is the predominant extragastric recurrence pattern, which can be detected via abdominal computed tomography and cured by rescue surgery. Abdominal computed tomography should be considered as a surveillance method, especially in patients with an expanded indication.

Long-term outcomes of patients with early gastric cancer found to have lesions for which endoscopic treatment is not indicated on histopathological evaluation after endoscopic submucosal dissection

BACKGROUND

Gastric cancer treatment guidelines recommend additional surgery as the standard treatment for lesions for which endoscopic submucosal dissection (ESD) is not indicated. However, the incidence of lymph-node metastasis is low in most patients.

METHODS AND MATERIALS

The study comprised 231 patients (231 lesions) who underwent ESD for early gastric cancer (EGC) in our hospital from September 2002 through March 2015 and were found to have lesions for which endoscopic treatment is not indicated on histopathological evaluation after ESD. The patients were divided into the additional operation group and the follow-up group, and long-term outcomes were studied retrospectively. Risk factors for metastasis and recurrence were also studied (capture rate, 98.7%).

RESULTS

The median follow-up was 48 months. There were 174 men and 57 women with a median age of 72 years. The additional operation group comprised 118 patients, and the follow-up group comprised 113 patients. The rates of 5-year cause-specific survival and 5-year overall survival were significantly higher in the additional operation group (100 and 96.0%, respectively) than in the follow-up group (92.6 and 73.3%, respectively; p = 0.010, p < 0.001). In the follow-up group, 5 patients (4.4%) died of gastric cancer (p = 0.021). Among elderly patients 75 years or older, long-term outcomes did not differ significantly between the groups. Sixteen patients had metastasis or recurrence, and the presence of lymphatic involvement was an independent risk factor for metastasis, recurrence, or both (p = 0.003; odds ratio 10.594; 95% confidence interval 2.294-48.927).

CONCLUSIONS

In patients with EGC who are confirmed to have lesions for which endoscopic treatment is not indicated on histopathological evaluation after ESD, additional surgery should be aggressively performed if the patient can tolerate such treatment. In elderly patients aged 75 years or older and patients with serious underlying diseases, follow-up observation was suggested to be one option in patients who give informed consent after receiving an explanation of the risk of recurrence.