Feasibility of further expansion of the indications for endoscopic submucosal dissection in undifferentiated-type early gastric cancer

Nomogram for pre-procedural prediction of lymph node metastasis in patients with submucosal early gastric cancer

BACKGROUND

The treatment of early gastric cancer (EGC) is contingent upon the status of lymph node metastasis (LNM). Accurate preoperative prediction of LNM is critical for reducing unnecessary surgeries. This study seeks to evaluate the risk factors for LNM in submucosal EGC and develop a predictive model to optimize therapeutic decision-making.

METHODS

A retrospective analysis was performed on clinical data from 389 patients with T1b-stage EGC who underwent radical gastrectomy. Univariate and multivariate analyses were conducted to identify independent risk factors, followed by the development of a nomogram to predict LNM. The model's efficacy was validated through receiver operating characteristic curves, calibration curves, and decision curve analysis.

RESULTS

Of the 389 patients, 77 had LNM. Logistic regression analysis identified gender, CA199 levels, tumor location, degree of differentiation, presence of ulcers, and lymph node enlargement on CT as independent risk factors for LNM. A nomogram was constructed to assess the risk of LNM, demonstrating strong predictive accuracy with an area under the curve of 0.82 in the training set and 0.74 in the validation set, along with good sensitivity and positive predictive value.

CONCLUSIONS

This study presents a reliable preoperative nomogram to estimate the likelihood of LNM in submucosal EGC, providing valuable guidance for determining the most effective treatment strategies for patients.

Endoscopic Submucosal Dissection Criteria for Differentiated-type Early Gastric Cancer Are Applicable to Mixed-type Differentiated Predominant

BACKGROUND

There is a lack of sufficient evidence on whether mixed-type differentiated predominant early gastric cancer (MD-EGC) can be treated endoscopically by referring to the criteria for differentiated-type early gastric cancer (EGC). This study aims to evaluate the efficacy of endoscopic submucosal dissection (ESD) in MD-EGC.

METHODS

Patients with differentiated-type EGC treated with ESD first from January 2015 to June 2021 were reviewed, including MD-EGC and pure differentiated-type EGC (PD-EGC). Clinical data, including the clinicopathological characteristics, resection outcomes of ESD, and recurrence and survival time, were collected, and the difference between MD-EGC and PD-EGC was tested.

RESULTS

A total of 48 patients (48 lesions) with MD-EGC and 850 patients (890 lesions) with PD-EGC were included. Compared with PD-EGC, MD-EGC had a higher submucosal invasion rate (37.5% vs. 13.7%, P <0.001) and lymphatic invasion rate (10.4% vs. 0.4%, P <0.001). The rates of complete resection (70.8% vs. 92.5%, P <0.001) and curative resection (54.2% vs. 87.4%, P <0.001) in MD-EGC were lower than those of PD-EGC. Multivariate analysis revealed that MD-EGC (OR 4.26, 95% CI, 2.22-8.17, P <0.001) was an independent risk factor for noncurative resection. However, when curative resection was achieved, there was no significant difference in the rates of recurrence ( P =0.424) between the 2 groups, whether local or metachronous recurrence. Similarly, the rates of survival( P =0.168) were no significant difference.

CONCLUSIONS

Despite the greater malignancy and lower endoscopic curative resection rate of MD-EGC, patients who met curative resection had a favorable long-term prognosis.

Risk Prediction Models for Gastric Cancer: A Scoping Review

Background

Gastric cancer is a significant contributor to the global cancer burden. Risk prediction models aim to estimate future risk based on current and past information, and can be utilized for risk stratification in population screening programs for gastric cancer. This review aims to explore the research design of existing models, as well as the methods, variables, and performance of model construction.

Methods

Six databases were searched through to November 4, 2023 to identify appropriate studies. PRISMA extension for scoping reviews and the Arksey and O'Malley framework were followed. Data sources included PubMed, Embase, Web of Science, CNKI, Wanfang, and VIP, focusing on gastric cancer risk prediction model studies.

Results

A total of 29 articles met the inclusion criteria, from which 28 original risk prediction models were identified that met the analysis criteria. The risk prediction model is screened, and the data extracted includes research characteristics, prediction variables selection, model construction methods and evaluation indicators. The area under the curve (AUC) of the models ranged from 0.560 to 0.989, while the C-statistics varied between 0.684 and 0.940. The number of predictor variables is mainly concentrated between 5 to 11. The top 5 most frequently included variables were age, helicobacter pylori (Hp), precancerous lesion, pepsinogen (PG), sex, and smoking. Age and Hp were the most consistently included variables.

Conclusion

This review enhances understanding of current gastric cancer risk prediction research and its future directions. The findings provide a strong scientific basis and technical support for developing more accurate gastric cancer risk models. We expect that these conclusions will point the way for future research and clinical practice in this area to assist in the early prevention and treatment of gastric cancer.

Endoscopic Features of Undifferentiated-Type Early Gastric Cancer in Patients with Helicobacter pylori-Uninfected or -Eradicated Stomachs: A Comprehensive Review

Since the indications for endoscopic submucosal dissection have been expanded to include undifferentiated-type early gastric cancers, improvements in preoperative diagnostic ability have been an area of research. There are also concerns about the impact on the diagnosis of Helicobacter pylori infection. Based on our previous studies, in undifferentiated-type early gastric cancers, magnifying endoscopy with narrow-band imaging is useful for delineating the demarcation regardless of the tumor size. Additionally, inflammatory cell infiltration appears to be a cause of misdiagnosis, suggesting that the resolution of inflammation could contribute to the accurate diagnosis of demarcations. As such, the accuracy of demarcation in eradicated and uninfected cases is higher than that in non-eradicated cases. The common features of the endoscopic findings were discoloration under white-light imaging and a predominance of sites in the lower and middle regions. The uninfected group was characterized by smaller tumor size, flat type, more extended intervening parts in magnifying endoscopy with narrow-band imaging, and pure signet ring cell carcinoma. In contrast, the eradication and non-eradication groups were characterized by larger tumor size, depressed type, and wavy microvessels in magnifying endoscopy with narrow-band imaging. In this comprehensive review, as described above, we discuss the diagnosis of demarcation of undifferentiated-type early gastric cancers, undifferentiated-type early gastric cancers that developed following H. pylori eradication, and H. pylori-uninfected undifferentiated-type early gastric cancers, with a focus on studies with self-examination and endoscopic findings and describe the future direction.

Risk of lymph node metastasis and feasibility of endoscopic submucosal dissection in undifferentiated-type early gastric cancer

BACKGROUND

Whether endoscopic submucosal dissection (ESD) applies to undifferentiated-type early gastric cancer (UEGC) remains controversial. We aimed to analyze the risk factors for lymph node metastasis (LNM) in UEGC and evaluate the feasibility of ESD.

METHODS

This study included 346 patients with UEGC who underwent curative gastrectomy between January 2014 and December 2021. Univariate and multivariate analyses of the correlation between clinicopathological features and LNM were conducted, and the risk factors for exceeding the expanded ESD indications were evaluated.

RESULTS

The overall LNM rate in UEGC was 19.94%. Among the preoperatively assessable factors, submucosal invasion (odds ratio [OR] = 4.77, 95% confidence interval [CI]: 2.14-10.66) and > 2 cm(OR = 2.49, 95% CI: 1.20-5.15) were independent risk factors for LNM, while postoperative independent risk factors were > 2 cm (OR = 3.35, 95% CI: 1.02-5.40) and lymphovascular invasion(OR = 13.21, 95% CI: 5.18-33.70). Patients who met the expanded indications had a low LNM risk (4.1%). Additionally, tumors located in the cardia (P = 0.03), non-elevated type (P < 0.01) were independent risk factors for exceeding the expanded indications in UEGC.

CONCLUSIONS

ESD may be applicable for UEGC meeting the expanded indications, and preoperative evaluation should be cautious when the lesion is non-elevated type or located in the cardia.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (12/05/2022 ChiCTR2200059841 ).

Update on diagnosis and treatment of early signet-ring cell gastric carcinoma: A literature review

Gastric signet-ring cell gastric carcinoma (GSRC) is an unfavorable subtype of gastric cancer (GC) that presents with greater invasiveness and poorer prognosis in advanced stage than other types of GC. However, GSRC in early stage is often considered an indicator of less lymph node metastasis and more satisfying clinical outcome compared to poorly differentiated GC. Therefore, the detection and diagnosis of GSRC at early stage undoubtedly play a crucial role in the management of GSRC patients. In recent years, technological advancement in endoscopy including narrow-band imaging and magnifying endoscopy has significantly improved the accuracy and sensitivity of the diagnosis under endoscopy for GSRC patients. Researches have confirmed that early stage GSRC that meets the expanded criteria of endoscopic resection showed comparable outcomes to surgery after receiving endoscopic submucosal dissection (ESD), indicating that ESD could be considered standard treatment for GSRC after thorough selection and evaluation. This article summarizes the current knowledge and updates pertaining to the endoscopic diagnosis and treatment of early stage signet-ring cell gastric carcinoma.

Endoscopic Resection of Undifferentiated Early Gastric Cancer

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Risk assessment of lymph node metastasis in early gastric cancer: Establishment and validation of a Seven-point scoring model

BACKGROUND

Treatment options for early gastric cancer have evolved toward achieving accurate evaluation of lymph node metastasis. This study aimed to investigate risk factors of lymph node metastasis in patients with early gastric cancer and establish a risk score model to guide the selection of optimal treatment.

METHODS

The clinicopathological characteristics of 351 patients with early gastric cancer from January 2016 to December 2018 were reviewed retrospectively. On the basis of the independent risk factors determined by multivariate binary logistic regression analysis, we established a risk score model for predicting lymph node metastasis and then verified it. The receiver operating characteristic curves were plotted using the test and validation sets. The area under the receiver operating characteristic curve was used to assess the discriminant ability of the model.

RESULTS

Lymph node metastasis was observed in 10.5% (37/351) of early gastric cancer cases. Patients with early gastric cancer were grouped based on the independent risk factors for lymph node metastasis (tumor size, depth, histological type, and lymphovascular involvement) determined by multivariate analysis. A 7-point risk score model was established to predict the risk of lymph node metastasis. The area under the receiver operating characteristic curve in the development and validation sets were 0.839 (95% confidence interval, 0.769%-0.910%) and 0.820 (95% confidence interval, 0.711%-0.930%), respectively.

CONCLUSION

A feasible risk score model for lymph node metastasis was established to guide the optimal treatment of patients with early gastric cancer early gastric cancer.

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

The clinicopathological features of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) are incompletely understood, and the capacity of endoscopic submucosal dissection (ESD) to treat mixed-type cancer remains controversial. This systematic review analyzed the rate of lymph node metastasis (LNM) in mixed-type EGC. We gathered articles published up to February 21, 2021, that analyzed the relationship between LNM and mixed-type EGC from Embase, PubMed, and Web of Science. The primary outcome was the LNM rate associated with different histological types of EGC, and the secondary outcomes were the odds ratios (ORs) for LNM risk factors among EGC patients. From the 24 studies included in this meta-analysis, the overall rate of LNM in predominantly differentiated mixed-type (MD) EGC was 12%, whereas the LNM rate in predominantly undifferentiated mixed-type (MU) EGC was 22%. We further divided these studies into 2 groups according to the depth of invasion. In mixed-type mucosal EGC, the pooled LNM rate was 15%; in submucosal EGC, the rate was 33% for MU, which was higher than the rates for pure types (pure differentiated type, 13%; pure undifferentiated type, 21%; p<0.05). The LNM rate of MD was 20%, it was higher than those of the pure differentiated type and nearly the same as pure undifferentiated type. Other pooled statistics showed that submucosal invasion, pure undifferentiated EGC, and mixed-type EGC were independent risk factors for LNM. This meta-analysis showed that MD submucosal EGC has a high rate of LNM and is highly correlated with LNM; thus, the management of MD EGC as purely differentiated EGC according to the indications for ESD is inappropriate, and the mixed type should be added as a parameter in these indications.

Undifferentiated-predominant mixed-type early gastric cancer is more aggressive than pure undifferentiated type: a systematic review and meta-analysis

BACKGROUND

Studies have shown that differentiated-predominant mixed-type early gastric cancer (EGC) is more aggressive than pure differentiated-type EGC. However, the biological behaviour of undifferentiated-predominant mixed-type (MU) EGC and pure undifferentiated-type (PU) EGC are controversial. This study was conducted to compare the biological behaviour of MU EGC and PU EGC.

METHODS

A systematic review and meta-analysis of observational studies was conducted using literature published through PubMed and Embase from inception to 9 November 2021. Inclusion criteria were: (1) a direct or indirect comparison of MU and PU; (2) patients with EGC; (3) a specified outcome of lymph node metastasis (LNM), lymphovascular invasion, submucosal invasion and/or ulcer findings; and (4) the primary lesion was obtained. The literature search, data extraction and quality assessment were performed by two independent reviewers. The meta-analysis was conducted with a random-effect model using the Mantel-Haenszel method.

RESULTS

Twelve publications with 5644 patients were included. Patients with MU EGC had significantly higher risk of LNM (OR 2.28; 95% CI 1.72 to 3.03) and submucosal invasion (OR 2.19; 95% CI 1.90 to 2.52) compared with patients with PU EGC. No difference was found between patients with MU and PU EGC with respect to lymphovascular invasion risk (OR 1.81; 95% CI 0.84 to 3.87). After stratifying the data according to depth of tumour invasion, a significantly higher risk for LNM was associated with intramucosal MU EGC (OR 2.56; 95% CI 1.66 to 3.95) and submucosal MU EGC (OR 2.63; 95% CI 2.06 to 3.06). Submucosal MU EGC also had a significantly higher risk of lymphovascular invasion (OR 2.40; 95% CI 1.79 to 3.21) compared with submucosal PU EGC.

DISCUSSION

Patients with MU EGC had an increased risk of submucosal invasion and LNM compared with patients with PU EGC . MU patients with submucosal EGC also had an increased lymphovascular invasion risk compared with PU patients. Therefore, attention should be focused on the clinical management of patients with MU EGC.

Impact of preceding noncurative endoscopic submucosal dissection on patients with early gastric cancer who undergo subsequent surgery: a meta-analysis

BACKGROUND

The influence of preceding noncurative endoscopic submucosal dissection (ESD) on the efficacy of subsequent surgery is still controversial among early gastric cancer (EGC), especially for laparoscopic gastrectomy. The present meta-analysis was conducted to compare clinical outcomes between patients with EGC who underwent noncurative ESD before surgery (ESD group) and those who underwent direct surgery (non-ESD group).

METHODS

Related databases were searched, and articles comparing differences between ESD and non-ESD groups were included for meta-analysis.

RESULTS

Ten retrospective studies with 3465 participants were included in this meta-analysis. Compared with the non-ESD group, the ESD group was older and had more males, smaller tumors, more differentiated tumors and a higher proportion of pT1b, a shorter operation time, fewer dissected lymph nodes, a lower rate of positive lymph nodes and a lower rate of D2 dissection. There was no significant difference in intraoperative blood loss, postoperative complication rate, postoperative hospital stay or long-term prognosis, etc.

CONCLUSION

Preceding noncurative ESD has no negative impact on the short- and long-term results of additional gastrectomy (open surgery or laparoscopic surgery).

Long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated intramucosal gastric cancer regardless of size

BACKGROUND

The clinical outcomes of endoscopic submucosal dissection (ESD) for undifferentiated (UD) intramucosal early gastric cancer (EGC) compared with those of surgery, regardless of lesion size, are not well known. Furthermore, there is a concern regarding the treatment plan before and after ESD in cases of UD intramucosal EGC within expanded indications.

AIM

To evaluate clinical outcomes of ESD compared with those of surgery in UD intramucosal EGC patients regardless of tumor size.

METHODS

We enrolled patients with UD intramucosal EGC after ESD with complete resection or surgery from January 2005 to August 2020 who met the within or beyond expanded indications with lesion size > 2 cm (the only non-curative factor). Overall, 123 and 562 patients underwent ESD and surgery, respectively. After propensity-score matching, clinical and long-term outcomes, i.e., recurrence-free survival (RFS) and overall survival (OS), were analyzed. The multivariable Cox proportional hazard model with treatment modality and ESD indication was used to evaluate the recurrence risk.

RESULTS

After matching, 119 patients each were finally enrolled in the ESD and surgery groups. The median length of hospital stay was shorter in the ESD group than surgery group (4.0 vs 9.0 days, P < 0.001). Four cases of recurrence after ESD were local recurrences, all of which occurred within 1 year. Total recurrence was seven (5.9%) and two (1.7%) in the ESD and surgery groups, respectively. No difference was observed between the two groups with respect to OS (P = 0.948). However, the ESD group had inferior RFS compared with the surgery group (P = 0.031). ESD was associated with the risk of recurrence after initial treatment in all enrolled patients (hazard ratio, 5.2; 95% confidence interval: 1.0-25.8, P = 0.045).

CONCLUSION

Although OS was similar between the two groups, surveillance endoscopy was important for the ESD than for the surgery group because RFS was inferior and local recurrence was an issue.

Indications of Endoscopic Submucosal Dissection for Undifferentiated Early Gastric Cancer: Current Status and Future Perspectives for Further Expansion

BACKGROUND

Endoscopic submucosal dissection (ESD) is a widely accepted and minimally invasive treatment for early gastric cancer (EGC) without the risk of lymph node metastasis (LNM). However, undifferentiated-type EGC (UD-EGC) is considered to have a relatively high risk of LNM. Recently, the Japan Clinical Oncology Group conducted a nonrandomized confirmatory trial (JCOG1009/1010) to evaluate the efficacy and safety of ESD for UD-EGC. Herein, we review the results of JCOG1009/1010 and the possibility of further expanding the indications for ESD.

SUMMARY

JCOG1009/1010 showed excellent technical results and 5-year overall survival in patients with UD-EGC. Based on the results, ESD for UD-EGC (cT1a) of ≤2 cm without ulceration was technically feasible and acceptable for standard treatment instead of gastrectomy with lymph node dissection. A review of the EGC of mixed histological type (mixed EGC) suggested that the mixed EGC might have worse biological behavior than the pure histological type. In cases of intramucosal EGC with pure signet-ring cell carcinoma or presenting a double-layer structure, the risk of LNM might be relatively low. Thus, there is a possibility of further expanding the indications or curative evaluations. In the case of UD-EGC after noncurative resection, the data suggest that the eCura system may be applicable to UD-EGC; however, due to the small number of cases, further study is warranted. Key Message: This review summarizes the present knowledge regarding indications for UD-EGC and the possibility of further expanding them.

Current indications for endoscopic submucosal dissection of early gastric cancer

The development of endoscopic treatment technology has further promoted the minimally invasive treatment of early gastric cancer (EGC). Endoscopic treatment has achieved better therapeutic effects in terms of safety and prognosis and is the preferred treatment method for patients who meet the indications for endoscopic treatment. However, the consequent problem is that some patients receiving endoscopic treatment may undergo non-curative resection, and the principle of follow-up management for non-curative resection patients deserves further attention. In addition, there are still debates on how to improve the accuracy of clinical staging, select a reasonable treatment method for patients who meet the expanded indications for endoscopic treatment, manage patients with positive endoscopic surgical margins, conduct research on function-preserving surgery, and manage the treatment of EGC under the current situation in China. Consequently, we aim to review current indications for endoscopic submucosal dissection of EGC in order to better inform treatment options.

Long-term Outcomes of Undifferentiated-Type Early Gastric Cancer with Positive Horizontal Margins after Endoscopic Resection

Background/Aims

This study examined the long-term outcomes of undifferentiated-type early gastric cancer (UD EGC) with positive horizontal margins (HMs) after endoscopic resection (ER) and compared them between additional surgery and nonsurgical management.

Methods

From 2005 to 2015, a total of 1,124 patients with UD EGC underwent ER at 18 tertiary hospitals in Korea. Of them, 92 patients with positive HMs as the only noncurative factor (n=25) or with both positive HMs and tumor size >2 cm (n=67) were included. These patients underwent additional surgery (n=40), underwent additional endoscopic treatment (n=6), or were followed up without further treatment (n=46).

Results

No lymph node (LN) metastasis was found in patients who underwent additional surgery. During a median follow-up of 57.7 months (interquartile range, 27.6 to 68.8 months), no LN or distant metastases or gastric cancer-related deaths occurred in the overall cohort. At baseline, the residual cancer rate was 57.8% (26/45) after additional surgery or ER. The 5-year local recurrence rate was 33.6% among patients who were followed up without additional treatment. The 5-year overall survival rates were 95.0% and 87.8% after additional surgery and nonsurgical management (endoscopic treatment or close follow-up), respectively (log-rank p=0.224). In the multivariate Cox regression analysis, nonsurgical management was not associated with an increased risk of mortality.

Conclusions

UD EGC with positive HMs after ER may have favorable long-term outcomes and a very low risk of LN metastasis. Nonsurgical management may be suggested as an alternative, particularly for patients with old age or chronic illness. (Gut Liver 2021;15-731)

Clinical outcomes of endoscopic resection for undifferentiated intramucosal early gastric cancer larger than 2 cm

BACKGROUND

This study investigated the long-term clinical outcomes of endoscopic resection (ER) for undifferentiated-type (UD) early gastric cancer (EGC), with tumor size > 2 cm as the only non-curative factor.

METHODS

From among 1123 patients who underwent ER for UD EGC at 18 tertiary hospitals in Korea between 2005 and 2014, we identified 216 patients with UD intramucosal EGC > 2 cm, which was completely resected, with negative resection margins, and absence of ulceration and lymphovascular invasion. The patients were divided into the additional surgery (n = 40) or observation (n = 176) groups, according to post-ER management and were followed up for a median duration of 59 months for recurrence and 90 months for overall survival.

RESULTS

Lymph node (LN) or distant metastasis or cancer-related mortality was not observed in the surgery group. In the observation group, two (1.1%) patients developed LN or distant metastasis with a 5-year cumulative risk of 0.7%, and one (0.6%) patient died of gastric cancer. The 5- and 8-year overall survival rates were 94.1% and 89.9%, respectively, in the observation group and 100.0% and 95.2%, respectively, in the surgery group (log-rank P = 0.159). Cox regression analysis did not reveal an association between the observation group and increased mortality.

CONCLUSION

The risk of LN or distant metastasis was not negligible, but as low as 1% for patients undergoing non-curative ER for UD EGC, with tumor size > 2 cm as the only non-curative factor. Close observation may be an alternative to surgery, especially for older patients or those with poor physical status.

Incidence of metachronous cancer after endoscopic submucosal dissection: a comparison between undifferentiated-type and differentiated-type early gastric cancer

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has become an important and minimally invasive treatment for early gastric cancer (EGC) with a negligible risk of metastasis not only for differentiated-type (D-type) cancer but also for undifferentiated-type (UD-type) cancer. We aimed to investigate the incidence and characteristics of metachronous cancer after ESD for UD-type cancer, which has not yet been elucidated.

METHODS

In total, 175 patients who underwent ESD for UD-type EGC were enrolled. For comparison, 350 patients who underwent ESD for D-type EGC during the same period were randomly selected. These patients underwent a follow-up EGD annually. The median observation period was 6.0 years and 5.4 years, respectively.

RESULTS

The annual incidence of metachronous cancer after ESD for UD-type and D-type cancer was .9% and 5.3%, respectively. Among the patients who underwent ESD for UD-type cancer, 30.9% of patients were uninfected with Helicobacter pylori, whereas all patients who underwent ESD for D-type cancer were infected with H pylori. All patients who developed metachronous cancer were infected with H pylori. UD-type metachronous cancer developed more frequently in patients after ESD for UD-type cancer than after ESD for D-type cancer, and the curative resection rate of ESD was significantly lower in these cases.

CONCLUSIONS

Metachronous cancers developed only in H pylori-infected patients in this cohort. Although metachronous cancer incidence was significantly less frequent in patients after ESD for UD-type cancer, the curative resection rate of ESD was significantly lower. Routine surveillance should be conducted more carefully after ESD for UD-type cancer, especially in H pylori-infected patients.

Endoscopic full-thickness resection using an over-the-scope device: A prospective study

BACKGROUND

Endoscopic submucosal dissection to treat mucosal and submucosal lesions sometimes results in low rates of microscopically margin-negative (R0) resection. Endoscopic full-thickness resection (EFTR) has a high R0 resection rate and allows for the definitive diagnosis and treatment of selected mucosal and submucosal lesions that are not suitable for conventional resection techniques.

AIM

To evaluate the efficacy and safety of EFTR using an over-the-scope clip (OTSC).

METHODS

This prospective, single-center, non-randomized clinical trial was conducted at the endoscopy center of Shengjing Hospital of China Medical University. The study included patients aged 18-70 years who had gastric or colorectal submucosal tumors (SMTs) (≤ 20 mm in diameter) originating from the muscularis propria based on endoscopic ultrasound (EUS) and patients who had early-stage gastric or colorectal cancer (≤ 20 mm in diameter) based on EUS and computed tomography. All lesions were treated by EFTR combined with an OTSC for wound closure between November 2014 and October 2016. We analyzed patient demographics, lesion features, histopathological diagnoses, R0 resection (negative margins) status, adverse events, and follow-up results.

RESULTS

A total of 68 patients (17 men and 51 women) with an average age of 52.0 ± 10.5 years (32-71 years) were enrolled in this study, which included 66 gastric or colorectal SMTs and 2 early-stage colorectal cancers. The mean tumor diameter was 12.6 ± 4.3 mm. The EFTR procedure was successful in all cases. The mean EFTR procedure time was 39.6 ± 38.0 min. The mean OTSC defect closure time was 5.0 ± 3.8 min, and the success rate of closure for defects was 100%. Histologically complete resection (R0) was achieved in 67 (98.5%) patients. Procedure-related adverse events were observed in 11 (16.2%) patients. The average post-procedure length of follow-up was 48.2 ± 15.7 mo. There was no recurrence during follow-up.

CONCLUSION

EFTR combined with an OTSC is an effective and safe technique for the removal of select subepithelial and epithelial lesions that are not amenable to conventional endoscopic resection techniques.

Undifferentiated-type predominant mixed-type early gastric cancer is a significant risk factor for requiring additional surgeries after endoscopic submucosal dissection

We aimed to clarify the differences in therapeutic outcomes of patients with pure undifferentiated-type and mixed undifferentiated-type cancers who underwent endoscopic submucosal dissection (ESD), and whether pre-treatment diagnosis of mixed undifferentiated-type cancer is associated with requiring additional surgery after ESD. Patients subjected to ESD as initial treatment between May 2005 and March 2017 were enrolled. There were 277 undifferentiated-type cancers (265 patients). Histologically, 258 lesions were pure-type and 19 were mixed-type. We compared therapeutic outcomes and pre-treatment factors (tumour diameter, tumour depth, ulcerative findings, tumour location, and the macroscopic, and histological type of the biopsy specimen) between pure-type and mixed-type lesions, and between cases not requiring additional surgeries and cases requiring additional surgeries. Tumour diameter >20 mm, submucosal invasion, and the presence of ulcerative findings made pre-treatment diagnosis more difficult for mixed-type than for pure-type lesions. In cases requiring additional surgery, pre-treatment diagnosis of mixed-type lesions was significantly more likely than pre-treatment diagnosis of pure-type lesions. For mixed-type lesions, pre-treatment histological diagnosis and careful consideration are necessary to determine indications for ESD to avoid additional surgery after ESD.