How can we predict the presence of missed synchronous lesions after endoscopic submucosal dissection for early gastric cancers or gastric adenomas?

The correlation between the main and minor lesions of synchronous multiple gastric neoplasms assessed gastroscopically and microscopically

BACKGROUND

Patients with early gastric cancer (EGC) are at high risk of developing synchronous multiple gastric neoplasms (SMGNs) after undergoing endoscopic submucosal dissection (ESD). However, most previous studies have had small sample sizes, and few have focused on association studies.

AIMS

This study aimed to analyze the associations between SMGN lesion data from patients with EGC treated with ESD and their correlation coefficients.

METHODS

The clinical ESD data from two hospitals from January 2008 to January 2021 were retrospectively analyzed. The main lesions were defined as those with a significant depth of infiltration. The larger tumor diameter was considered the main lesion if the lesions had the same infiltration depth.

RESULTS

Of the 1013 post-ESD cases examined, 95 cases (223 lesions) had SMGN, and 25 patients had more than three lesions. For the correlation analysis, 190 lesions were included. The study revealed a similarity in pathological type between main and minor lesions (rs = 0.37) and a positive correlation in infiltration depth (rs = 0.58). The mean diameter sizes of the main and minor lesions were 20.7 ± 8.3 mm and 13.1 ± 6.4 mm, respectively, with statistically significant differences (P < 0.001). A linear correlation was observed between the diameter size and a linear regression model was constructed, producing r = 0.38 [95% confidence interval (CI) 0.19-0.54], b = 0.29 (95% CI 0.14-0.44), t = 3.94, P < 0.001]. A correlation was identified between the vertical distribution of the main and minor lesions, the horizontal distribution, and the gross endoscopic morphology (ϕc = 0.25, P = 0.02; ϕc = 0.32, P < 0.001; ϕc = 0.60, P < 0.001).

CONCLUSIONS

The correlation coefficients for microscopic characteristics were higher than those for gastroscopy. There is a significant positive correlation between the main and minor lesions regarding pathological stage and depth of infiltration, respectively. The spatial distribution of the lesions and the gastroscopic morphology were similar.

Susceptibility Genes Associated with Multiple Primary Cancers

With advancements in treatment and screening techniques, we have been witnessing an era where more cancer survivors harbor multiple primary cancers (MPCs), affecting approximately one in six patients. Identifying MPCs is crucial for tumor staging and subsequent treatment choices. However, the current clinicopathological criteria for clinical application are limited and insufficient, making it challenging to differentiate them from recurrences or metastases. The emergence of next-generation sequencing (NGS) technology has provided a genetic perspective for defining multiple primary cancers. Researchers have found that, when considering multiple tumor pairs, it is crucial not only to examine well-known essential mutations like MLH1/MSH2, EGFR, PTEN, BRCA1/2, CHEK2, and TP53 mutations but also to explore certain pleiotropic loci. Moreover, specific deleterious mutations may serve as regulatory factors in second cancer development following treatment. This review aims to discuss these susceptibility genes and provide an explanation of their functions based on the signaling pathway background. Additionally, the association network between genetic signatures and different tumor pairs will be summarized.

Endoscopic causes and characteristics of missed gastric cancers after endoscopic submucosal dissection

BACKGROUND AND AIMS

Because endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) preserves the entire stomach, missed gastric cancers (MGCs) are often found in the remaining gastric mucosa. However, the endoscopic causes of MGCs remain unclear. Therefore, we aimed to elucidate the endoscopic causes and characteristics of MGCs after ESD.

METHODS

From January 2009 to December 2018, all patients undergoing ESD for initially detected EGC were enrolled. According to a review of EGD images before ESD, we identified the endoscopic causes (perceptual, exposure, sampling errors, and inadequate preparation) and characteristics of MGC in each endoscopic cause.

RESULTS

Of 2208 patients who underwent ESD for initial EGC, 82 patients (3.7%) had 100 MGCs. The breakdown of endoscopic causes of MGCs was as follows: 69 (69%) perceptual errors, 23 (23%) exposure errors, 7 (7%) sampling errors, and 1 (1%) inadequate preparation. Logistic regression analysis showed that the risk factors for perceptual error were male sex (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.16-5.18), isochromatic coloration (OR, 3.17; 95% CI, 1.47-6.84), greater curvature (OR, 2.31; 95% CI, 1.121-4.40), and lesion size ≤12 mm (OR, 1.74; 95% CI, 1.07-2.84). The sites of exposure errors were around the incisura angularis (11 [48%]), posterior wall of the gastric body (6 [26%]), and antrum (5 [21%]).

CONCLUSIONS

We identified MGCs in 4 categories and clarified their characteristics. Quality improvements in EGD observation, with attention to the risks of perceptual and site of exposure errors, can potentially prevent missing EGCs.

Long-term outcomes and clinical safety of expanded indication early gastric cancer treated with endoscopic submucosal dissection versus surgical resection: a meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) remains an investigational issue for early gastric cancer (EGC) with expanded indications owing to the risk of lymph node metastasis. In this study, we aimed to evaluate the clinical outcomes and safety of ESD versus surgical resection (SR) for EGC with expanded indications.

METHODS

The systematic review selected studies from PubMed, Embase, Cochrane and Web of Science databases from 2010 to 2020, and compared survival and clinical safety data of ESD with those of surgical resection for EGC with expanded indications. The fixed-effects or random-effects model was used to calculate the differences between the two groups. To assess the validity of the eligible studies, risk of bias was measured using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Nine retrospective studies were used to calculate the differences in survival and clinical safety data between the two groups for EGC with expanded indications. Differences were not significant between the groups in terms of age, sex, tumour size, tumour histology or lesion morphology. Regarding tumour site, tumours located in the L area (the lower third of the stomach) were more likely to be found in the ESD group. With regard to metachronous and synchronous carcinomas, there was a significant difference favouring SR treatment (metachronous: OR=0.12, 95% CI=0.05 to 0.25, p<0.00001; synchronous: OR=0.11, 95% CI=0.02 to 0.46, p=0.003). Adverse event data were identified in six studies showing a significant difference favouring ESD treatment (ESD vs SR, OR=0.49, 95% CI=0.34 to 0.72. p=0.002). Additionally, six studies evaluating 5-year overall survival showed no significant differences between the two groups (HR=1.22, 95% CI=0.66 to 2.25, p=0.53). With regard to 5-year disease-free survival, patients with expanded indication EGC undergoing SR showed better survival (ESD vs SR, HR=3.29, 95% CI=1.60 to 6.76, p=0.001).

CONCLUSION

ESD provided favourable results for patients with EGC with expanded indications regarding clinical outcomes and safety in retrospective studies. Further, to detect synchronous or metachronous lesions, endoscopic surveillance should be performed following ESD. However, the included studies were observational, some did not have adequate adjustment for confounding factors and their results lacked generalisability due to their origin. Thus, further related randomised controlled trials are urgently encouraged.

PROSPERO REGISTRATION NUMBER

CRD42021251068.

Endoscopic, clinicopathological, and growth characteristics of minute gastric cancer

OBJECTIVE

To clarify the endoscopic, clinicopathological, and growth characteristics of minute gastric cancer (MGC) and to improve its detection rate.

METHODS

Patients with early gastric cancer who underwent endoscopic submucosal dissection from July 2012 to September 2021 were retrospectively reviewed. MGC was defined as gastric cancer of 5 mm or less in size. Preoperative and postoperative endoscopic and pathological data were collected and analyzed. Follow-up information was collected until 9 April 2022.

RESULTS

Eighty patients were enrolled, with 82 lesions observed under endoscopy and 87 diagnosed histopathologically. All patients received en bloc and curative resection. Compared with the time point when the last endoscopic examiniation prior to lesion deteciton was performed (t0), 64.29% of patients with MGC had disease progression at lesion detection (t1). However, 21.43% showed normal or only atrophic changes under white-light endoscopy, and their lesions were diagnosed accidentally by random biopsy. The majority of MGC lesions presented as type IIc and reddish, and 95.00% of cases had well-differentiated tubular adenocarcinoma. The mean growth rate of MGC was 0.0071 mm/day, and it took an average of 3.42 years to grow to 5 mm. There was no significant difference in the depth of invasion between the low cellular atypia group and the high cellular atypia group.

CONCLUSIONS

Type IIc and reddish appearance are main endoscopic features of MGC. For cases with no obvious endoscopic changes, multipoint biopsy is helpful. MGC is mostly well differentiated and grows relatively slowly; therefore, MGC can still have a chance to be identified and resected curatively if it is missed diagnosed.

Assessment of Outcomes From 1-Year Surveillance After Detection of Early Gastric Cancer Among Patients at High Risk in Japan

IMPORTANCE

Single endoscopic examination often misses early gastric cancer (GC), even when both high-definition white light imaging and narrow-band imaging are used. It is unknown whether new GC can be detected approximately 1 year after intensive index endoscopic examination.

OBJECTIVE

To examine whether new GC can be detected approximately 1 year after intensive index endoscopic examination using both white light and narrow-band imaging.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study was a preplanned secondary analysis of a randomized clinical trial involving 4523 patients with a high risk of GC who were enrolled between October 1, 2014, and September 22, 2017. Data were analyzed from December 26, 2019, to April 21, 2021. Participants in the clinical trial received index endoscopy to detect early GC via 2 examinations of the entire stomach using white light and narrow-band imaging. The duration of follow-up was 15 months. The secondary analysis included 107 patients with newly detected GC (case group) and 107 matched patients without newly detected GC (control group) within 15 months after index endoscopy.

INTERVENTIONS

Surveillance endoscopy was scheduled between 9 and 15 months after index endoscopy. If new lesions suspected of being early GC were detected during surveillance endoscopy, biopsies were obtained to confirm the presence of cancer.

MAIN OUTCOMES AND MEASURES

The primary end point was the rate of new GC detected within 15 months after index endoscopy. The main secondary end point was identification of risk factors associated with new GC detected within 15 months after index endoscopy.

RESULTS

Among 4523 patients (mean [SD] age, 70.6 [7.5] years; 3527 men [78.0%]; all of Japanese ethnicity) enrolled in the clinical trial, 4472 received index endoscopy; the rate of early GC detected on index endoscopy was 3.0% (133 patients). Surveillance endoscopy was performed in 4146 of 4472 patients (92.7%) who received an index endoscopy; the rate of new GC detected within 15 months after index endoscopy was 2.6% (107 patients). Among 133 patients for whom early GC was detected during index endoscopy, 110 patients (82.7%) received surveillance endoscopy within 15 months after index endoscopy; the rate of newly detected GC was 10.9% (12 patients). For the secondary analysis of risk factors associated with newly detected GC, characteristics were well balanced between the 107 patients included in the case group vs the 107 patients included in the matched control group (mean [SD] age, 71.7 [7.2] years vs 71.8 [7.0] years; 94 men [87.9%] in each group; 82 patients [76.6%] vs 87 patients [81.3%] with a history of gastric neoplasm). Multivariate analysis revealed that the presence of open-type atrophic gastritis (odds ratio, 6.00; 95% CI, 2.25-16.01; P < .001) and early GC detection by index endoscopy (odds ratio, 4.67; 95% CI, 1.08-20.21; P = .04) were independent risk factors associated with new GC detection.

CONCLUSIONS AND RELEVANCE

In this study, the rate of new GC detected by surveillance endoscopy approximately 1 year after index endoscopy was similar to that of early GC detected by index endoscopy. These findings suggest that 1-year surveillance is warranted for patients at high risk of GC.

Outcomes of simultaneous endoscopic submucosal dissection for synchronous multiple gastric neoplastic lesions: a retrospective comparative study

BACKGROUND AND AIMS

Simultaneous endoscopic submucosal dissection (ESD) is occasionally used in synchronous multiple gastric neoplastic lesions (SMGL). Therefore, we aim to evaluate the safety and efficacy of simultaneous ESD for SMGL compared with ESD for single lesions.

METHODS

A total of 1058 patients who received ESD from November 2006 to September 2019 were retrospectively evaluated in this study, including 997 single gastric epithelial lesions treated by single ESD (unifocal group) and 125 SMGL from 61 patients treated by simultaneous ESD (multifocal group).

RESULTS

The mean procedure time was 49.2 ± 41.30 min and 89.5 ± 66.33 min in unifocal group and multifocal group, respectively (p < 0.001). There was no significant difference in postoperative stenosis rate (1.0% vs. 0.0%, p = 1.000), intraoperative bleeding (endoscopic resection bleeding-c3 grade) rate (0.5% vs. 1.6%, p = 0.696), postoperative bleeding rate (1.3% vs. 0.0%, p = 0.461), and perforation rate (0.9% vs. 1.6%, p = 0.449) between the two groups. In addition, en block resection rate (p = 0.825), complete resection rate (p = 0.856) and curative resection rate (p = 0.709) were comparable between the two groups. During the follow-up, the local recurrence rate per patient: p = 0.363; per lesion: p = 0.235) was not significantly different between the two groups, however, the cumulative incidence of metachronous lesions after treatment was significantly higher in the multifocal group than the other group (10.0% vs. 3.2%, p = 0.004).

CONCLUSIONS

Simultaneous ESD is safe and effective in the treatment of SMGL. However, separate ESD is recommended for SMGL with longer procedure time. Besides, the metachronous gastric neoplastic lesions should be paid attention to during follow-up.

Sporadic foveolar-type gastric adenoma with a raspberry-like appearance in Helicobacter pylori-naïve patients

Sporadic foveolar-type gastric adenoma (FGA) has been described as an extremely rare polyp that is whitish and flatly elevated. However, we recently found that sporadic FGA with a raspberry-like appearance (FGA-RA) is not rare in Helicobacter pylori (H. pylori)-naïve gastric mucosa. We endoscopically or surgically treated 647 patients with gastric epithelial neoplasms in the last 5 years, with 7.7% (50/647) being H. pylori-naïve. Among these, 43 FGA-RAs were diagnosed based on histologic and endoscopic features in 34 patients, who were all enrolled in this retrospective study. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We subsequently analyzed their endoscopic and microscopic features and patient characteristics. The patients were 22 males and 12 females aged 57±23 years (mean±2SD). WLE showed raspberry-like small polyps mimicking gastric hyperplastic polyps in the oxyntic gastric compartment (body/fundus). Multiple growths were confirmed in 20.6% (7/34) of the patients. NBIME revealed irregularly shaped papillary/gyrus-like microstructures with abnormal capillaries. Histologically, all lesions were intraepithelial neoplasms, and most of lesions (62.8%, 27/43) exhibited low-grade dysplasia. Immunohistochemically, neoplastic cells featured strong and diffuse MUC5AC expression, negative or very low MUC6 expression, and negative MUC2/CD10 expression. They also showed Ki-67 hyperexpression with a mean labeling index of 59.4±48.7%. The coexistence of fundic gland polyps in the background mucosa was significantly higher in multiple FGA-RA cases than in solitary cases (100% vs. 55.5%, P< 0.05). FGA-RA is a newly suggested histologic variant of sporadic FGA whose occurrence is not rare in daily endoscopic practice.

Increased incidence of metachronous gastric neoplasm after endoscopic resection in patients with synchronous gastric neoplasm

Background

Recurrence risk is a major concern after endoscopic resection (ER) of gastric neoplasms. This study was to compare metachronous risk in patients with and without synchronous neoplasms after complete ER.

Methods

After ER for gastric neoplasms, patients were divided into those with and without synchronous neoplasm. The metachronous risk of gastric neoplasms was compared between the two groups.

Results

After ER of 678 cancers and 891 adenomas, synchronous neoplasm was found in 11.8% of cancers and 11.4% of adenomas. In the multiple (n = 182) and the single group (n = 1387), metachronous neoplasms occurred in 18.1 and 8.6%, respectively (HR 2.40; 95% CI, 1.62–3.34). When the pathology of the recurred lesion was limited to cancer, metachronous risk was also significantly higher in the multiple than in the single group (HR, 2.2; 95% CI, 1.17–3.85). In the recurred pathology of the multiple group, cancer development was frequently observed in patients with cancer compared to those with only adenomas in the synchronous lesion (67.0% vs. 13.0%, respectively; P = 0.023).

Conclusions

This study demonstrated that metachronous risk was significantly higher in patients with synchronous gastric neoplasms after ER. Therefore, meticulous examination is important in patients with synchronous neoplasm.

Molecular characteristics of synchronous multiple gastric cancer

Rationale: Multiple gastric cancer (MGC) is characterized by the presence of more than two different tumors in the stomach. However, the clonal relationship and carcinogenesis of MGC remain unclear. We investigated the clonal relationship and role of germline mutations in the carcinogenesis of MGC.

Methods: We gathered 16 multiple gastric cancer patients. Thirty-three tumor samples and sixteen normal gastric tissue or blood samples were obtained from January 2016 to December 2017. We also conducted analyses for 208 gastric cancer and 49 esophagogastric junction cancer (GC-EGJ) tumors from TCGA. DNA extraction from our samples was conducted for whole-exome sequencing (WES).

Results: Tumor mutation burden (TMB) was not statistically significant within database and our data in the GC-EGJ (P=0.0591) and GC groups (P=0.3113). The mutation spectrum and signatures also showed uniform distributions in GC and GC-EGJ groups within our data and TCGA database. Among sixteen patients, four were identified as monoclonal, in which 11, 10, 26 and 6 somatic mutations were shared within different tumors of P7, P8, P9 and P16, respectively. However, no common mutation between different tumors of the same patient was found among the other 12 patients. After identifying predisposing genes, we found that germline MSH2 and NCOR2 mutations were significantly dominant in 8/12 and 10/12 of genetic MGC patients. Additionally, all patients were identified with MSH2 mutations in cancer samples of those genetic MGC patients. Taking genetic MGCs as a whole, we identified that TP53 were significantly mutated in 14 of 25 tumor samples.

Main conclusions: WES analyses are suggestive of monoclonal and polyclonal origin of MGC, which may promote the classification of MGC into genetic and metastatic MGC. For patients with genetic MGC, germline MSH2 X314_splice variants may contribute to carcinogenesis, thus prompting the consideration of more radical surgery and/or anti-PD-1/PD-L1 therapy.

Common Locations of Gastric Cancer: Review of Research from the Endoscopic Submucosal Dissection Era

Detection of early-stage gastric cancer improves the prognosis of patients. Endoscopic submucosal dissection (ESD) is a curative and stomach-preserving treatment for early gastric cancer (EGC) associated with a low risk of lymph node metastasis. However, several studies have reported missed diagnosis of gastric cancer. Therefore, endoscopists are required to learn accurate diagnostic skills to eliminate endoscopic blind spots. A systematic screening protocol to map the entire stomach without blind spots reduces the risk of missed lesions. Knowledge of the features of EGC or dysplasia is essential to identify suspicious lesion. Information of the common sites of occurrence of EGC can also enable a detailed endoscopic examination to improve detection rates. Previous reports investigating the location of gastric cancers resected by ESD or surgery showed that the antrum and lesser curvature of stomach were predominantly affected. Helicobacter pylori-induced atrophic changes advance from the antrum to the corpus along the lesser curvature, predominantly affecting these areas. Gastric cancers in the antrum and the lower corpus are also commonly missed during screening examination. Therefore, a careful examination of the lower third stomach is warranted to avoid missing synchronous and metachronous gastric lesions. Knowledge of the location of EGC enables accurate endoscopic examination and detection of EGC in early stage.

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.

Occurrence of metachronous or synchronous lesions after endoscopic treatment of gastric epithelia dysplasia- impact of histologic features of background mucosa

AIMS

Endoscopic resection is a safe and effective method to treat gastric epithelia dysplasia (GED). However, the development of metachronous and synchronous lesions after treatment has become a major concern. In this study, we investigated clinicopathologic features of 105 GED lesions from endoscopic resections between January 2008 and December 2009. Our goal is to find histologic factors that predict synchronous and metachronous lesions after ESD treatment. We assessed the degree of intestinal metaplasia (IM) and atrophy, type of IM, presence of gastritis cystica profunda, and crypt dysplasia in the adjacent mucosa.

METHODS AND RESULTS

We divided 105 GED lesions into three groups: a single group without metachronous or synchronous GED or adenocarcinoma (n=35); a multiple synchronous group (n=30, group with synchronous occurrence of GED or adenocarcinoma after treatment); and a multiple metachronous group (n=40, group with metachronous occurrence of GED or adenocarcinoma after treatment). The multiple metachronous and synchronous groups showed larger sizes (p=0.003) and higher grades (p=0.021) as compared with the single group. Furthermore, marked IM and atrophy in adjacent mucosa were more easily seen in the multiple metachronous and synchronous groups as compared with the single group (p<0.0001). Interestingly, the presence of incomplete type of IM (p=0.025) and crypt dysplasia (p<0.0001) in background mucosa was associated with occurrence of metachronous and synchronous lesions following endoscopic resection of GED.

CONCLUSIONS

The histological features of background mucosa, such as intestinal metaplasia, atrophy, and crypt dysplasia could be used as indicators of occurrence of metachronous and synchronous lesions after endoscopic treatment of GED.

Predictive risk factors associated with synchronous multiple early gastric cancer

The aim of this study was to elucidate the predictive risk factors of synchronous multiple early gastric cancer regardless of the treatment modality.Patients who underwent early gastric cancer treatment between July 2005 and June 2015 were retrospectively reviewed. In total, 1529 patients who were treated for early gastric cancer were included. We analyzed the patient's data to find predictive factors of synchronous multiple early gastric cancer compared to solitary early gastric cancer. Further analysis was performed to verify the difference between endoscopic and surgical treatment groups.Among the 1529 patients, synchronous multiple early gastric cancer was diagnosed in 68 (4.4%) patients. Significant differences in sex (P = .004), gross appearance (P = .038), depth of invasion (P = .007), and lymphovascular invasion (P = .039) were found between patients with solitary early gastric cancer and synchronous multiple early gastric cancer by univariate analysis. In multivariate analysis, male sex (odds ratio, 2.475; P = .011) and submucosal invasion (odds ratio, 1.850; P = .033) were independent predictive risk factors of synchronous multiple early gastric cancer. In addition, in multivariate analysis, significant differences in age, tumor size, longitudinal location, depth of invasion, and histology were found between patients groups depending on the mode of treatment.Male sex and submucosal invasion were predictive risk factors of synchronous multiple early gastric cancer. Patients with these factors should undergo more meticulous endoscopic surveillance.

Missing rate for gastric cancer during upper gastrointestinal endoscopy: a systematic review and meta-analysis

OBJECTIVES

Esophagogastroduodenoscopy (EGD) is considered a very effective method to identify gastric cancer (GC). However, the existence of missed lesions has been frequently discussed. This systematic review and meta-analysis aimed at assessing the magnitude of missing GC diagnosis with EGD and its predictive factors.

METHODS

MEDLINE was searched to identify all studies assessing and reporting the proportion of missed GC diagnosis with EGD. Pooled proportion and negative predictive values were computed using the random-effects model and heterogeneity was assessed using the Cochrane Q-test and I.

RESULTS

The studies included (n=22) were grouped by study design. The pooled negative predictive value was 99.7% (95% confidence interval 99.6-99.9%). Missed GCs proportion was 9.4% (95% confidence interval 5.7-13.1%), being 10.0% in studies including patients with negative EGD followed over time, 8.3% in studies including patients with GC, and 23.3% in studies evaluating the proportion of missed synchronous lesions. Mainly, missed cancers were located in the gastric body both in Eastern and in Western studies (39 and 47%, respectively). The majority of missed GCs were adenocarcinomas. Younger age (<55 years), female sex, marked gastric atrophy, gastric adenoma or ulcer, and inadequate number of biopsy fragments were reported as predictive factors for diagnostic failure.

CONCLUSION

EGD is a very effective method to rule out GC. However, missing GC with EGD is not uncommon, with one out of 10 cancers being potentially missed. Interestingly, lesions were more often missed in the body and therefore a more rigorous protocol for endoscopy and biopsy should be implemented worldwide.

Characteristics of Missed Simultaneous Gastric Lesions Based on Double-Check Analysis of the Endoscopic Image

BACKGROUND/AIMS

The detection of multifocal lesions is important for the successful management of gastric neoplasms. We investigated the characteristics of missed simultaneous lesions and the reason for the missed diagnoses.

METHODS

A total of 140 patients who underwent repeat endoscopy before endoscopic resection between June 2013 and June 2014 were retrospectively reviewed. We classified simultaneous lesions into three groups based on a review of earlier images: group 1, no images of the location of simultaneous lesions were taken; group 2, no corresponding lesion was evident in the previous images; and group 3, simultaneous lesions were visible in the earlier images but a biopsy was not performed.

RESULTS

Simultaneous lesions were found in 12 patients (8.6%) with 13 lesions, comprising 10 dysplasia (76.9%) and three adenocarcinoma (23.1%). Regarding the reasons for missed diagnoses, seven lesions (53.8%) were classified as group 3, five (38.5%) as group 1, and the remaining lesion (7.7%) as group 2. There were no significant differences in the characteristics of the patients with and without simultaneous lesions.

CONCLUSIONS

Lesions disregarded or unnoticed during endoscopic examination were the main reason for missed diagnosis of simultaneous lesions. Endoscopists should consider the possibility of simultaneous lesions and attempt to meticulously evaluate the entire gastric mucosa.

Gastric adenomas in familial adenomatous polyposis are common, but subtle, and have a benign course

Background

Patients with familial adenomatous polyposis (FAP) are known to have an increased risk for gastric adenomas. The clinical features of gastric adenomas in FAP have not been well characterized, and there is a lack of standardized approaches to the management of these lesions.

Aims

To study the endoscopic appearance, risk factors, clinical course, and response to therapy of gastric adenomas in patients with FAP.

Methods

We retrospectively reviewed the records of 97 patients with FAP who underwent esophagogastroduodenoscopy (EGD) at Mayo Clinic (Florida, Rochester and Arizona) between 2004 and 2013.

Results

Nine patients (9%) had biopsy-proven gastric adenomas. Adenomas were located in the antrum (five patients), in the body and fundus in the setting of background fundic gland polyps (FGP) (three patients), and in the body not associated with FGP (one patient). Adenoma size was 3–40 mm and the number of adenomas per patient ranged from one to 20. Adenomas in the antrum were flat and subtle, whereas those in the gastric body or fundus were polypoid and difficult to differentiate from the cystic FGPs seen in patients with FAP. The performing endoscopists reported difficulty with identifying adenomas, and six patients had at least one EGD within the previous three years where gastric adenomas were not reported. Adenomas were classified as tubular in eight patients and tubulovillous in one patient. High grade dysplasia was noted in one patient. After a median follow-up of 63 months (interquartile range: 20–149 months), no patient in our entire cohort (with or without gastric adenomas) developed gastric cancer. The patients in whom gastric adenoma developed, compared to those without gastric adenoma, were more likely to be younger [36 ± 12 vs. 48 ± 15 years, p = 0.02], have concomitant chronic gastritis [22% vs. 0%, p = 0.008], and have desmoid tumors [5 (56%) vs. 19 (22%), p = 0.04].

Conclusions

Gastric adenomas are not uncommon in patients with FAP and are often difficult to identify endoscopically. Endoscopists should have a high degree of suspicion for gastric adenomas in these patients and a low threshold to biopsy. Given the benign clinical course, recommended initial management is conservative with endoscopic therapy and periodic surveillance.

Seven synchronous early gastric cancer with 28 lymph nodes metastasis

An 85 year male patient complaining epigastric discomfort was admitted. From the esophagogastroduodenoscopy, three early gastric cancer (EGCa) lesions had been identified and these were diagnosed as adenocarcinoma with poorly differentiated cell type. The patient underwent operation. From the post-operative mapping, however, additional 4 EGCa lesions were found, and the patient was diagnosed with 7 synchronous EGCa. Out of the 7 EGCa lesions, 6 had shown invasion only to the mucosal layer and one had shown invasion into the 1/3 layer of submucosa. In spite of such superficial invasions, 28 of 48 lymph nodes had been identified as metastases. The multiple lesions of EGCa do not increase the risk of lymph node metastasis, but if their differentiations are poor or if they have lympho-vascular invasion, multiple lymph node metastases could incur even if the depth of invasion is limited to the mucosal layer or the upper portion of the submucosal layer.

Clinicopathological characteristics of synchronous and metachronous gastric neoplasms after endoscopic submucosal dissection

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) has become accepted as a minimally invasive treatment for gastric neoplasms. However, the development of synchronous or metachronous gastric lesions after endoscopic resection has become a major problem. We investigated the characteristics of multiple gastric neoplasms in patients with early gastric cancer (EGC) or gastric adenoma after ESD.

METHODS

In total, 512 patients with EGC or gastric adenoma who had undergone ESD between January 2008 and December 2011 participated in this study. The incidence of and factors associated with synchronous and metachronous gastric tumors were investigated in this retrospective study.

RESULTS

In total, 66 patients (12.9%) had synchronous lesions, and 13 patients (2.5%) had metachronous lesions. Older (> 65 years) subjects had an increased risk of multiple gastric neoplasms (p = 0.012). About two-thirds of the multiple lesions were similar in macroscopic and histological type to the primary lesions. The median interval from the initial lesions to the diagnosis of metachronous lesions was 31 months. The annual incidence rate of metachronous lesions was approximately 3%.

CONCLUSIONS

We recommend careful follow-up in patients of advanced age (> 65 years) after initial ESD because multiple lesions could be detected in the remnant stomach. Annual surveillance might aid in the detection of metachronous lesions. Large-scale, multicenter, and longer prospective studies of appropriate surveillance programs are needed.