Size discrepancy between endoscopic size and pathologic size is not negligible in endoscopic resection for early gastric cancer

Endoscopic and Surgical Treatment in Early Gastric Cancer: The Gray Zone in Treatment Decision-Making from the Perspectives of Endoscopists

To treat early gastric cancer, one must choose between endoscopic treatment and surgical treatment. Endoscopic treatment has been developing significantly since the late 1990s and has made great progress up to the present. However, many patients with early gastric cancer still undergo unnecessary surgery or endoscopic procedures. This is due to the existence of a "gray zone" of ambiguities between endoscopic and surgical treatment. These ambiguities arise because the important factors in determining the treatment for early gastric cancer can only be fully understood after endoscopic or surgical resection or because of discrepancies between the factors identifiable before treatment and those identifiable after treatment. This article aims to explore these ambiguous factors and discuss methods and efforts to reduce them.

Lymph node metastasis prediction model for each lymph node station in gastric cancer patients

BACKGROUND

Lymph node metastasis (LNM) prediction for each LN station is required for tailored surgery for patient safety or improving quality of life in gastric cancer. This retrospective review was performed to develop a prediction program for calculating the probability of LNM according to LN stations in patients with gastric cancer.

METHOD

Among patients who underwent gastrectomy for primary gastric cancer between 2003 and 2017 at Seoul National University Hospital, 4660 patients up to 2013 were used as the development set, and 2564 patients after 2013 were used as the validation set. Not only the center of tumor but also all locations of stomach by tumor were included in the analysis. A multiple logistic regression analysis was used to develop an LNM prediction program for each LN station in development set. The program was validated using C-statistics and a calibration plot of the validation set.

RESULTS

Multivariate analysis identified tumor depth, gross type, and involved locations as covariates associated with LNM. However, the significant factors differed slightly according to the LN station. The prediction equations were developed for each LN station. In the validation set, the prediction equation exhibited good discriminant C-statistics of over 0.8 for all stations. The calibration plot of the prediction equation predicted the LNM rate, which corresponded closely to the actual rate.

CONCLUSIONS

A program was developed to predict LNM at LN stations. Predictive power was confirmed via internal validation. Predicting the LN metastatic rate for each LN station could help in planning more customized surgery.

Enhancing endoscopic measurement: validating a quantitative method for polyp size and location estimation in upper gastrointestinal endoscopy

BACKGROUND

Accurate measurement of polyps size is crucial in predicting malignancy, planning relevant intervention strategies and surveillance schedules. Endoscopists' visual estimations can lack precision. This study builds on our prior research, with the aim to evaluate a recently developed quantitative method to measure the polyp size and location accurately during a simulated endoscopy session.

METHODS

The quantitative method merges information about endoscopic positions obtained from an electromagnetic tracking sensor, with corresponding points on the images of the segmented polyp border. This yields real-scale 3D coordinates of the border of the polyp. By utilising the sensor, positions of any anatomical landmarks are attainable, enabling the estimation of a polyp's location relative to them. To verify the method's reliability and accuracy, simulated endoscopies were conducted in pig stomachs, where polyps were artificially created and assessed in a test-retest manner. The polyp measurements were subsequently compared against clipper measurements.

RESULTS

The average size of the fifteen polyps evaluated was approximately 12 ± 4.3 mm, ranging from 5 to 20 mm. The test-retest reliability, measured by the Intraclass Correlation Coefficient (ICC) for polyp size estimation, demonstrated an absolute agreement of 0.991 (95% CI 0.973-0.997, p < 0.05). Bland & Altman analysis revealed a mean estimation difference of - 0.17 mm (- 2.03%) for polyp size and, a mean difference of - 0.4 mm (- 0.21%) for polyp location. Both differences were statistically non-significant (p > 0.05). When comparing the proposed method with calliper measurements, the Bland & Altman plots showed 95% of size estimation differences between - 1.4 and 1.8 mm (- 13 to 17.4%) which was not significant (p > 0.05).

CONCLUSIONS

The proposed method of measurements of polyp size and location was found to be highly accurate, offering great potential for clinical implementation to improve polyp assessment. This level of performance represents a notable improvement over visual estimation technique used in clinical practice.

Endoscopic measurement of the size of gastrointestinal polyps using an electromagnetic tracking system and computer vision-based algorithm

PURPOSE

Polyp size is an important factor that may influence diagnosis and clinical management decision, but estimation by visual inspection during endoscopy is often difficult and subject to error. The purpose of this study is to develop a quantitative approach that enables an accurate and objective measurement of polyp size and to study the feasibility of the method.

METHODS

We attempted to estimate polyp size and location relative to the gastro-oesophageal junction by integrating data from an electromagnetic tracking sensor and endoscopic images. This method is based on estimation of the three-dimensional coordinates of the borders of the polyp by combining the endoscope camera position and the corresponding points along the polyp border in endoscopic images using a computer vision-based algorithm. We evaluated the proposed method using a simulated upper gastrointestinal endoscopy model.

RESULTS

The difference between the mean of ten measurements of one artificial polyp and its actual size (10 mm in diameter) was 0.86 mm. Similarly, the difference between the mean of ten measurements of the polyp distance from the gastroesophageal junction and its actual distance (~ 22 cm) was 1.28 mm. Our results show that the changes in camera positions in which the images were taken and the quality of the polyp segmentation have the most impact on the accuracy of polyp size estimation.

CONCLUSION

This study demonstrated an innovative approach to endoscopic measurements using motion tracking technologies and computer vision and demonstrated its accuracy in determining the size and location of the polyp. The observed magnitude of error is clinically acceptable, and the measurements are available immediately after the images captured. To enhance accuracy, it is recommended to avoid identical images and instead utilise control wheels on the endoscope for capturing different views. Future work should further evaluate this innovative method during clinical endoscopic procedures.

Underestimation of endoscopic size in large gastric epithelial neoplasms

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is an effective method for resecting gastric adenomas and adenocarcinomas. A significant discrepancy was observed between endoscopic and pathological sizes in samples obtained from patients undergoing ESD. This study elucidates the factors affecting size discrepancy after formalin fixation.

METHODS

The records of 64 patients with 69 lesions were analyzed, including 50 adenomas and 19 adenocarcinomas. Data on location, gross shape, histology, and size after fixation in formalin were collected.

RESULTS

The mean size of the resected specimen appeared to decrease after formalin fixation (37.5 mm prefixation vs. 35.8 mm postfixation, p<0.05). The mean long axis diameter of the lesions was 20.3±7.9 mm prefixation and 13.4±7.9 mm postfixation. Size differences in lesions smaller than 20 mm were significantly greater than those in lesions larger than 20 mm (7.6±5.6 mm vs. 2.5±5.8 mm, p<0.01). In multivariate analysis, a tumor size of ≥20 mm was found to be an independent factor affecting size postformalin fixation (p<0.05).

CONCLUSION

The endoscopic size of lesions before ESD may be underestimated in tumors larger than 20 mm in size. Therefore, increased attention must be paid during ESD to avoid instances of incomplete resection.

Applicability of endoscopic submucosal dissection for patients with early gastric cancer beyond the expanded indication for endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) application for patients with tumors beyond the expanded indication for ESD is inconclusive. This study aimed to identify the preoperative clinical features that can be curatively treated with ESD in patients with early gastric cancer (EGC) beyond the indication of ESD.

METHODS

From 2006 to 2016, 673 patients who underwent gastrectomy for EGC beyond the expanded indication for ESD based on preoperative assessments were retrospectively reviewed. We identified tumors curatively resected by ESD based on the postoperative pathologic findings. We also analyzed the clinical and pre-treatment features to determine the risk factors associated with curative resection of ESD.

RESULTS

39% of the patients (263/673) who had undergone gastrectomy had tumors of endoscopic curability A or B (eCuraA/B) that could be treated by ESD alone. In multivariate analysis, tumor size ≤ 10 mm (OR 0.240; 95% CI = 0.12-0.46), no ulceration (OR 0.500; 95% CI = 0.29-0.87), differentiated histology (OR 0.599; 95% CI = 0.43-0.84), and location in the distal two-thirds of the stomach (OR 0.499; 95% CI = 0.28-0.88) in pre-treatment assessment were identified as independent predictors of eCuraA/B. Considering the risk factors, 63.6% (7/11)/61.3% (19/31) of patients with a differentiated/undifferentiated tumor size ≤ 10 mm located in distal two-third of the stomach without ulceration were deemed as eCuraA/B.

CONCLUSIONS

This study suggests that patients with EGC indicated for surgery can be treated by ESD by adding tumor locations in the indication for ESD. Thus, ESD can be applied for patients with a tumor size ≤ 10 mm located in the lower/middle stomach without ulceration.

Clinical factors associated with noncurative endoscopic submucosal dissection for the expanded indication of intestinal-type early gastric cancer: Post hoc analysis of a multi-institutional, single-arm, confirmatory trial (JCOG0607)

OBJECTIVES

The multi-institutional, single-arm, confirmatory trial JCOG0607 showed excellent efficacy of endoscopic submucosal dissection (ESD) for the expanded indication of intramucosal intestinal-type early gastric cancer (EGC), which consists of two groups: lesions >2 cm if clinical finding of ulcer (cUL)-negative, or those ≤3 cm if cUL-positive because of the expected low risk of lymph node metastasis. However, the proportion of noncurative resections (NCR) requiring additional surgery was high (32.4%). This post hoc analysis aimed to explore the clinical factors associated with NCR.

METHODS

As the expanded indication includes two different groups, we explored the clinical factors associated with NCR separately in cUL-negative (>2 cm) and cUL-positive (≤3 cm) groups using the log-linear model.

RESULTS

Two hundred and sixty cUL-negative and 206 cUL-positive EGCs were analyzed. The proportions of NCR were 33.8% in the cUL-negative group and 29.6% in the cUL-positive group. A multivariable analysis demonstrated that moderately differentiated predominant histology diagnosed in pretreatment biopsy (risk ratio [RR] 1.93, 95% confidence interval [CI] 1.34-2.77, P < 0.001) and lesion in the upper stomach (RR 1.75, 95% CI 1.03-2.96, P = 0.038) in the cUL-negative EGCs, and tumor size >2 cm (RR 1.78, 95% CI 1.22-2.58, P = 0.003) and female sex (RR 1.62, 95% CI 1.07-2.44, P = 0.021) in the cUL-positive EGCs were independent factors associated with NCR.

CONCLUSIONS

Clinical risk factors associated with NCR were different between cUL-negative and cUL-positive EGCs. To avoid NCR, we need to take these factors into account when deciding expanded indications for ESD.

Impact of non-curative endoscopic submucosal dissection on short- and long-term outcome of subsequent laparoscopic gastrectomy for pT1 gastric cancer

BACKGROUND

The feasibility and oncological safety of non-curative endoscopic submucosal dissection (ESD) prior to additional gastrectomy for early gastric cancer (EGC) are still unclear. The aim of this study was to evaluate the impact of non-curative ESD on short- and long-term outcomes of subsequent laparoscopic gastrectomy (LG) for pathological T1 (pT1) EGC.

METHODS

We retrospectively investigated 422 patients who underwent LG for pT1 EGC between January 2007 and December 2017 at our center. Eighty-five of these patients underwent ESD with curative intent before surgery. Using propensity-score matching for sex, age, body mass index, American society of anesthesiologists score, history of previous abdominal surgery, tumor location, mucosal/submucosal infiltration, histology, lymph node metastasis, extent of lymph node dissection, operative method, lymphatic invasion, and venous invasion, the clinicopathologic and survival data of these patients were compared.

RESULTS

The median follow-up period was 60 (range 2-168) months. Using propensity-score matching from a total of 422 patients, 75 patients were selected in the Non-ESD and the ESD cohorts each. There were no significant differences in terms of characteristics and clinicopathological findings between the two groups. Furthermore, there were no significant differences in postoperative morbidity (13.3% vs. 17.3%; P = 0.497) and mortality (1.3% vs. 0%; P = 0.316). Both the 5-year overall survival ratio (88.8% vs. 86.9%; P = 0.757) and 5-year disease-specific survival ratio (97.1% vs. 98.4%; P = 0.333) were similar in the two groups.

CONCLUSION

Short- and long-term outcomes of LG in patients with pT1 EGC are not related to preoperative ESD history. Even for non-curative resections, ESD prior to surgery is feasible in terms of oncological and surgical outcomes in pT1 EGC.

Discrepancy between endoscopic and pathological ulcerative findings in clinical intramucosal early gastric cancer

BACKGROUND

Ulcerative finding (UL) is one of the factors that define the indication and curability of endoscopic resection (ER) in early gastric cancer (EGC). Discrepancies between endoscopic UL (cUL) and pathological UL (pUL) sometimes occur in clinical practice. The aim of this study was to investigate the discrepancy rate in UL diagnosis and the risk factors associated with such discrepancies.

METHODS

Patients with clinical intramucosal (cT1a) EGC who underwent ER or surgery between September 2002 and December 2017 were analyzed. The proportion of cUL-negative (cUL0) lesions that were identified as pUL-positive (pUL1) and that of cUL-positive (cUL1) lesions that were identified as pUL-negative (pUL0) were calculated. Logistic regression analysis was performed to estimate the associations between discrepancy in UL diagnosis and clinical variables of the lesion, such as the size, histology, location, and macroscopic type.

RESULTS

In total, 5382 lesions were evaluated; 5.5% of cUL0 lesions (256/4619) were identified as pUL1, while 38.7% of cUL1 lesions (295/763) were pUL0. Multivariate analysis indicated that in cUL1 lesions, tumor location in the lower third of the stomach (odds ratio 3.11, 95% confidence interval 1.90-5.08) was identified as an independent risk factor for overestimation.

CONCLUSIONS

Endoscopic diagnosis of UL in cT1a EGC was overestimated in 38.7% of lesions, especially for lesions located in the lower third of the stomach. This discrepancy should be considered in the management of cT1a EGC with UL.

Prediction model for curative endoscopic submucosal dissection of undifferentiated-type early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is an effective treatment for early gastric cancer (EGC); however, its curative resection rate is low for undifferentiated-type EGC. We developed and externally validated a prediction model for curative ESD of undifferentiated-type EGC.

METHODS

In this cross-sectional study, we included 448 patients who underwent ESD for undifferentiated-type EGC at 18 hospitals in Korea between 2005 and 2015 in the development cohort and 1342 patients who underwent surgery at two hospitals in the validation cohort. A prediction model was developed using the logistic regression model.

RESULTS

Endoscopic tumor size 1-2 cm (odds ratio [OR], 2.40; 95% confidence interval [CI] 1.54-3.73), tumor size > 2 cm (OR, 14.00; 95% CI 6.81-28.77), and proximal tumor location from the lower to upper third of the stomach (OR, 1.45; 95% CI 1.03-2.04) were independent predictors of non-curative ESD. A six-score prediction model was developed by assigning points to endoscopic tumor size > 2 cm (five points), tumor size 1-2 cm (two points), upper third location (two points), and middle third location (one point). The rate of curative ESD ranged from 70.6% (score 0) to 11.6% (score 5) with an area under the receiver operating characteristic curve (AUC) of 0.720 (95% CI 0.673-0.766). The model also showed good performance in the validation cohort (AUC, 0.775; 95% CI 0.748-0.803).

CONCLUSIONS

This six-score prediction model may help in predicting curative ESD and making informed decisions about the treatment selection between ESD and surgery for undifferentiated-type EGC.

Endoscopic Indication of Endoscopic Submucosal Dissection for Early Gastric Cancer Is Not Compatible with Pathologic Criteria in Clinical Practice

BACKGROUND

The inappropriate selection of patients with early gastric cancer (EGC) for endoscopic submucosal dissection (ESD) may lead to additional surgery because of a non-curative resection. This study was performed to assess the accuracy of clinical decisions in ESD for EGC.

METHODS

A total of 607 cases of EGC treated by ESD were prospectively enrolled from January 2011 to June 2014 at a single academic hospital. The 607 EGCs were divided into three groups (overestimated, same-estimated, and underestimated) based on pre-procedure endoscopic findings (indication) and pathological diagnosis after ESD (criteria). We evaluated the discrepancy rates between pre-procedure indication and pathological criteria, and then analyzed the pre-procedure factors that could influence the occurrence of the discrepancies.

RESULTS

The absolute, expanded, and beyond the expanded indication has its accuracy on curability criteria in 87%, 77.6%, and 55.6% of cases, respectively. The ratio of overall indication-criteria discrepancies was 250/607 (41.2%). The curability was significantly lower in the underestimated group compared to the overestimated and same-estimated groups (41.6% vs. 94.6%, 94.4%, p < 0.001). In multivariate analysis examining the predictive factors for discrepancies in the 598 EGCs with absolute/expanded indications, the endoscopic size ≥ 20 mm [odds ratio (OR) 2.493, confidence interval (CI) 1.546-4.022, p < 0.001], presence of ulcers (OR 1.712, CI 1.070-2.738, p = 0.025), patient age < 60 years (OR 1.689, CI 1.044-2.733, p = 0.033), and undifferentiated type EGC on forceps biopsy (OR 5.397, CI 2.027-14.369, p = 0.001) were all associated with discrepancies.

CONCLUSIONS

Indication judged by pre-procedural endoscopy is not sufficiently accurate to be used as a good measurement for post-procedural criteria.

Cost-effectiveness and short-term clinical outcomes of argon plasma coagulation compared with endoscopic submucosal dissection in the treatment of gastric low-grade dysplasia

Endoscopic treatment such as endoscopic submucosal dissection (ESD) or argon plasma coagulation (APC) is widely performed to treat gastric low-grade dysplasia (LGD). We aimed to evaluate the clinical efficacy of APC versus ESD for gastric LGD in terms of cost-effectiveness. This was a retrospective review of patients with gastric LGD who were treated with endoscopic intervention (APC or ESD) between March 2011 to December 2015. Fifty-nine patients treated with APC and 124 patients treated with ESD were included. Patients in the APC group were significantly older (mean age, 67.68 vs 63.90 years, respectively, P < .01), had an increased rate of Helicobacter pylori infection (27.1 vs 10.5%, respectively, P < .01), and had a higher mean Charlson Comorbidity Index score (2.32 vs 0.38, respectively, P < .01) than those in the ESD group. The 2 groups did not differ in tumor size, location, macroscopic morphology, or surface configuration. The procedure time (11.31 vs56.44 minutes, respectively, P < .01), and hospital stay (3.2 vs 5.6 days, respectively, P < .01) were significantly, shorter in the APC group than in the ESD group. Additionally, the cost incurred was significantly, lower in the APC group than in the ESD group (962.03 vs 2,534.80 dollars, respectively, P < .01). APC has many advantages related to safety, and cost-effectiveness compared with ESD. Therefore, APC can be considered an alternative treatment option for gastric LGD.

Clinical predictors of histologic type of gastric cancer

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The value of diagnostic endoscopic submucosal dissection for patients with clinical submucosal invasive early gastric cancer

BACKGROUND

The standard treatment for clinical submucosal invasive (cT1b) early gastric cancer is gastrectomy. However, Japanese gastric cancer treatment guidelines list endoscopic submucosal dissection (ESD) as an option for treating limited early gastric cancer cases. ESD can be curative depending on the pathological characteristics of resected specimens. Thus, we aimed to clarify the benefits and disadvantages of preceding ESD for early gastric cancer.

METHODS

We retrospectively analyzed patients who underwent ESD or curative gastrectomy for cT1b gastric cancer with differentiated adenocarcinoma 30 mm or less in diameter. Patients who underwent ESD irrespective of undergoing gastrectomy were assigned to the ESD group (n = 107), and those who underwent gastrectomy without undergoing ESD were assigned to the non-ESD group (n = 181). Clinicopathological characteristics were assessed, and the short-term and long-term outcomes of patients were compared.

RESULTS

The criteria for curative resection were satisfied by 83 patients (28.8%), and preceding ESD did not affect the surgical outcomes of gastrectomy. Two patients (1.9%) who underwent ESD had an unscheduled total gastrectomy. The en bloc and complete resection rates of ESD were 99.0% and 84.1% respectively. Nine patients (8.4%) experienced intraprocedure perforation and postprocedure bleeding caused by ESD. Overall survival (hazard ratio 1.38; P = 0.302) and cause-specific survival (hazard ratio 0.96; P = 0.944) were comparable between groups.

CONCLUSIONS

The stomach was preserved in 28.8% of patients, and preceding ESD did not show obvious disadvantages. Therefore, diagnostic ESD should be considered as an initial treatment for limited cT1b gastric cancer cases.

A Risk-prediction Model Based on Lymph-node Metastasis for Incorporation Into a Treatment Algorithm for Signet Ring Cell-type Intramucosal Gastric Cancer

OBJECTIVE

The aim of the study was to develop a reliable and easy-to-use risk-scoring system (RSS) to predict lymph-node metastasis (LNM) and determine the feasibility of endoscopic submucosal dissection for mucosa-confined signet ring cell carcinomas (SRCs).

BACKGROUND

Fewer LNM and better survival rates have been reported for early gastric SRCs compared with other undifferentiated early gastric cancers (EGCs).

METHODS

Data from 1544 patients with mucosa-confined SRCs were reviewed. Stepwise logistic regression analysis determined the independent predictors of LNM. Risk scores were based on the final predictive factors for LNM, and performance was internally validated using a split-sample approach. External validation was also performed in an independent dataset (n = 208) to assess the discriminatory power of the RSS.

RESULTS

The overall LNM incidence was 3.8% (57/1544). Three risk factors (tumor size ≥1.7 cm, tumors of elevated type, and lymphatic-vascular involvement) were significantly associated with LNM. These factors were incorporated into the RSS, and were assigned scores ranging from 0 to 4. The area under the receiver-operating characteristic curve for predicting LNM after internal and external validation was 0.68 (95% confidence interval, 0.0793-0.2865) and 0.686 (95% confidence interval, 0.618-0.748), respectively. A score of 2 points was the optimal cut-off value for LNM prediction, and the overall diagnostic accuracy was 96%. LNM were found in 2.9% and 23.8% of the low and high-risk groups of the RSS, respectively.

CONCLUSIONS

A RSS may help to predict LNM and evaluate endoscopic submucosal dissection feasibility in patients with intramucosal SRC.

Prediction model for non-curative resection of endoscopic submucosal dissection in patients with early gastric cancer

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a useful method for complete resection of early gastric cancer (EGC). However, there are still some patients who undergo additional gastrectomy after ESD because of non-curative resection. There is no model that can accurately predict non-curative resection of ESD. We aimed to create a model for predicting non-curative resection of ESD in patients with EGC.

PATIENTS AND METHODS

We reviewed the medical records, including all gross findings of EGC, of patients who underwent ESD for EGCs. We divided the patients into a non-curative resection group and a curative resection group. The clinicopathologic characteristics were compared between the groups to identify the risk factors for non-curative resection of ESD. We created a scoring system based on logistic regression modeling and bootstrap validation.

RESULTS

Of 1639 patients who had undergone ESD for EGCs, 272 were identified as being treated non-curatively with ESD. A large tumor size (≥20 mm), tumor location in the upper body of the stomach, the presence of ulcer, fusion of gastric folds, the absence of mucosal nodularity, spontaneous bleeding, and undifferentiated tumor histology were associated with non-curative resection of ESD. Points of risk scores were assigned for these variables based on the β coefficient as follows: tumor size (≥20 mm), 2 points; tumor location in the upper body of the stomach, 1 point; ulcer, 2 points; fusion of gastric folds, 2 points; absence of mucosal nodularity, 1 point; spontaneous bleeding, 1 point; and undifferentiated histology, 2 points. Our risk scoring model showed good discriminatory performance on internal validation (bootstrap-corrected area under the receiver operating characteristic curve, 0.7004; 95% confidence interval, 0.6655-0.7353).

CONCLUSIONS

We developed a validated prediction model that can be used to identify patients who will undergo non-curative resection of ESD. Our prediction model can provide useful information for making decisions about the treatment of EGC before performing ESD.

A Risk Prediction Model Based on Lymph-Node Metastasis in Poorly Differentiated-Type Intramucosal Gastric Cancer

Background and Aim

Endoscopic submucosal dissection (ESD) for undifferentiated type early gastric cancer is regarded as an investigational treatment. Few studies have tried to identify the risk factors that predict lymph-node metastasis (LNM) in intramucosal poorly differentiated adenocarcinomas (PDC). This study was designed to develop a risk scoring system (RSS) for predicting LNM in intramucosal PDC.

Methods

From January 2002 to July 2015, patients diagnosed with mucosa-confined PDC, among those who underwent curative gastrectomy with lymph node dissection were reviewed. A risk model based on independent predicting factors of LNM was developed, and its performance was internally validated using a split sample approach.

Results

Overall, LNM was observed in 5.2% (61) of 1169 patients. Four risk factors [Female sex, tumor size ≥ 3.2 cm, muscularis mucosa (M3) invasion, and lymphatic-vascular involvement] were significantly associated with LNM, which were incorporated into the RSS. The area under the receiver operating characteristic curve for predicting LNM after internal validation was 0.69 [95% confidence interval (CI), 0.59–0.79]. A total score of 2 points corresponded to the optimal RSS threshold with a discrimination of 0.75 (95% CI 0.69–0.81). The LNM rates were 1.6% for low risk (<2 points) and 8.9% for high-risk (≥2 points) patients, with a negative predictive value of 98.6% (95% CI 0.98–1.00).

Conclusions

A RSS could be useful in clinical practice to determine which patients with intramucosal PDC have low risk of LNM.

Discrepancy between Clinical and Final Pathological Evaluation Findings in Early Gastric Cancer Patients Treated with Endoscopic Submucosal Dissection

PURPOSE

Early gastric cancer cases that are estimated to meet indications for treatment before endoscopic submucosal resection are often revealed to be out-of-indication after the treatment. We investigated the short-term treatment outcomes in patients with early gastric cancer according to the pretreatment clinical endoscopic submucosal resection indications.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of patients with early gastric cancer that met the pretreatment endoscopic submucosal resection indications, from 2004 to 2011. Curative resection rate and proportion of out-of-indication cases were compared according to the pre-endoscopic submucosal resection indications. Pre-endoscopic submucosal resection factors associated with out-of-indication in the final pathological examination were analyzed.

RESULTS

Of 756 cases, 660 had absolute and 96 had expanded pre-endoscopic submucosal resection indications. The curative resection rate was significantly lower in the patients with expanded indications (64.6%) than in those with absolute indications (81.7%; P<0.001). The cases with expanded indications (30.2%) were revealed to be out-of-indication more frequently than the cases with absolute indications (13.8%; P<0.001). Age of >65 years, tumor size of >2 cm, tumor location in the upper-third segment of the stomach, and undifferentiated histological type in pre-endoscopic submucosal resection evaluations were significant risk factors for out-of-indication after endoscopic submucosal resection.

CONCLUSIONS

Non-curative resection due to out-of-indication occurred in approximately one-third of the early gastric cancer cases that clinically met the expanded indications before endoscopic submucosal resection. The possibility of additional surgery should be emphasized for patients with early gastric cancers that clinically meet the expanded indications.

Predicting pre- and post-resectional histologic discrepancies in gastric low-grade dysplasia: A comparison of white-light and magnifying endoscopy

BACKGROUND AND AIM

The aim of this study was to evaluate the validity of the parameters of conventional white-light endoscopy and magnifying endoscopy with narrow-band imaging (MENBI) for the prediction of discrepancies between pre- and post-resectional histology in cases of gastric adenoma with low-grade dysplasia (LGD) that were diagnosed based on endoscopically biopsied specimens.

METHODS

The medical records of 266 lesions with gastric LGD that were diagnosed by endoscopic forceps biopsies were retrospectively reviewed. The Vienna classification was used for histologic diagnosis. These patients all underwent MENBI examinations followed by analyses of the incidence of histologic discrepancies and histologic heterogeneity. The relationship between white-light endoscopic/MENBI parameters and the presence of histologic discrepancies was also analyzed.

RESULTS

Discrepancies between the pre- and post-resectional histologies were found in 74 cases (27.9%). Among those cases, the histology was upgraded in 71 cases, whereas the histology was downgraded in three cases. The presence of erythema and positive MENBI findings were independent factors for the prediction of upgraded histologic discrepancies (P-values = 0.008, < 0.001, respectively). A positive MENBI finding yielded the highest predictive value, with a multivariate adjusted odds ratio of 42.46. Histologic heterogeneity in post-resectional specimens was found in 40.8% of cases with upgraded histologic discrepancies.

CONCLUSIONS

MENBI can provide more accurate information than white-light endoscopy for the prediction of pre- and post-resectional histologic discrepancies in biopsy-proven gastric LGD. Endoscopic resection is strongly recommended in cases with surface erythema on conventional white-light endoscopy or positive MENBI, irrespective of the lesion size.

Pre- and post-ESD discrepancies in clinicopathologic criteria in early gastric cancer: the NECA-Korea ESD for Early Gastric Cancer Prospective Study (N-Keep)

BACKGROUND

Discrepancies in the clinicopathologic parameters pre- and post-endoscopic submucosal dissection (ESD) sometimes necessitate additional surgical resection. The aim of this study was to assess such discrepancies in clinicopathologic parameters before and after ESD in the context of reducing the risk of failure of curative ESD.

METHODS

Data on 712 early gastric cancer patients were prospectively collected from 12 university hospitals nationwide. The inclusion criteria were differentiated carcinoma <3 cm in size, no ulceration, submucosal invasion <500 μm, and no metastasis. Clinicopathologic factors were compared retrospectively.

RESULTS

The discrepancy rate was 20.1 % (148/737) and the most common cause of discrepancy was tumor size (64 cases, 8.7 %). Ulceration, undifferentiated histology, and SM2 invasion were found in 34 (4.6 %), 18 (2.4 %), and 51 cases (6.9 %), respectively. Lymphovascular invasion (LVI) was observed in 34 cases (4.6 %). Cases with lesions exceeding 3 cm in size showed more frequent submucosal invasion, an elevated gross morphology, and upper and middle locations (p < 0.05). In the cases with ulceration, depth of invasion (DOI) was deeper than in the cases without ulceration (p = 0.005). Differentiation was correlated with DOI and LVI (p = 0.021 and 0.007). DOI was correlated with tumor size, ulceration, differentiation, LVI, gross type, and location. There were statistically significant differences between mucosal cancer cases and submucosal cancer cases in tumor size, differentiation, ulceration, LVI, and location.

CONCLUSIONS

The overall discrepancy rate was 20.1 %. To reduce this rate, it is necessary to evaluate the DOI very cautiously, because it is correlated with other parameters. In particular, careful checking for SM-invasive cancer is required due to the high incidence of LVI irrespective of the depth of submucosal invasion.

Diagnostic group classifications of gastric neoplasms by endoscopic resection criteria before and after treatment: real-world experience

BACKGROUND AND STUDY AIMS

There are often discrepancies between the pretreatment evaluation of gastric neoplasms by endoscopy with biopsy and the final diagnosis of resected specimen in terms of pathology and depth of invasion. We evaluated the spectrum of discrepancies between pretreatment and posttreatment diagnosis which may deliver significant differences on clinical practice.

PATIENTS AND METHODS

A total of 2041 patients with gastric dysplasia or cancer who underwent curative endoscopic resections or surgeries in 2012 were enrolled. Patients were classified into five different diagnostic groups: low-grade dysplasia (LGD), high-grade dysplasia (HGD), absolute indication early gastric cancer (AI-EGC), beyond absolute indication early gastric cancer (BAI-EGC), and advanced gastric cancer (AGC). The choice of initial treatment and final pathologic diagnosis was analyzed.

RESULTS

The study patients belonged to the following pretreatment diagnostic groups: LGDs in 162, HGDs in 164, AI-EGCs in 396, BAI-EGCs in 824, and AGCs in 495 cases. Posttreatment diagnostic groups were LGDs in 140, HGDs in 121, AI-EGCs in 322, BAI-EGCs in 947, AGCs in 505, and no residual tumor in 6 cases. In general, 6.9 % (141/2041) of cases were downgraded and 15.9 % (324/2041) were upgraded. Thirty-four percent of pretreatment HGDs (56/164) were changed to cancers after endoscopic resection. Thirty-three percent of pretreatment AI-EGCs (131/396) were regrouped as posttreatment BAI-EGCs. The additional surgery rate in each pretreatment group was 0.6 % in LGD, 4.3 % in HGD, 15.7 % in AI-EGC, 23.6 % in BAI-EGC among the patients with initial endoscopic resection (p < 0.01).

CONCLUSIONS

Twenty-three percent of gastric neoplasms changed in their final diagnostic group after endoscopic resection or surgery. This discrepancy should be considered when the initial treatment strategy is being selected.

Difficulty of predicting the presence of lymph node metastases in patients with clinical early stage gastric cancer: a case control study

BACKGROUND

The relationship between pathological factors and lymph node metastasis of pathological stage early gastric cancer has been extensively investigated. By contrast, the relationship between preoperative factors and lymph node metastasis of clinical stage early gastric cancer has not been investigated. The present study was to investigate discrepancies between preoperative and postoperative values.

METHODS

From January 2011 to December 2013, 1042 patients with clinical stage early gastric cancer who underwent gastrectomy with lymphadenectomy were enrolled. Preoperative and postoperative values were collected for subsequent analysis. Receiver operating characteristics curves were computed using independent predictive factors.

RESULTS

Several discrepancies were observed between preoperative and postoperative values, including existence of ulcer, gross type, and histology (all McNemar p-values were <0.001). Multivariate analyses identified the following independent predictive factors for lymph node metastasis: postoperative values including age (p = 0.002), tumor size (p < 0.001), and tumor depth (p < 0.001); preoperative values including age (p = 0.017), existence of ulcer (p = 0.037), tumor size (p = 0.009), and prediction of the presence of lymph node metastasis in computed tomography scans (p = 0.002). These postoperative and preoperative independent predictive factors produced areas under the receiver operating characteristics curves of 0.824 and 0.660, respectively.

CONCLUSIONS

Surgeons need to be aware of limitations in preoperative predictions of the presence of lymph node metastasis for clinical stage early gastric cancer.

Tumour size is related to the curability of signet ring cell early gastric cancer with endoscopic submucosal dissection: a retrospective single centre study

BACKGROUND

Endoscopic submucosal dissection is applied in selected cases of signet ring cell early gastric cancer. However, factors related to curability of signet ring cell early gastric cancer with this method have not been fully evaluated. Our aim was to evaluate factors related to incomplete resection in signet ring cell early gastric cancer with endoscopic submucosal dissection.

METHODS

A retrospective analysis was performed on a total of 126 consecutive patients with signet ring cell early gastric cancer who had undergone endoscopic submucosal dissection at the Severance Hospital in Korea, between March 2007 and March 2012. The clinical outcomes were reviewed and factors related to incomplete resection were analysed.

RESULTS

Multivariate analysis showed that large tumour size was the only significant factor related to incomplete resection (P=0.006; hazard ratio, 1.040; 95% confidence interval, 1.101-1.084). In addition, large tumour size was the only significant factor related to endoscopic size underestimation (P<0.001; hazard ratio, 1.391; 95% confidence interval, 1.221-1.586). The rate of endoscopic size underestimation was significantly higher in tumours with a size ≥20mm (P<0.001).

CONCLUSIONS

To improve the curability of signet ring cell early gastric cancer with endoscopic submucosal dissection, larger tumours (especially tumour with a size ≥20mm) should be resected with a larger margin.