Risk factors for local recurrence in patients with positive lateral resection margins after endoscopic submucosal dissection for early gastric cancer

The staining results of early gastric cancer by indigo carmine chromoendoscopy associated with histological structure: a retrospective study

BACKGROUND

At present, conventional endoscopy and chromoendoscopy using indigo carmine (IC) is a very useful method to determine the demarcation line (DL) of early gastric cancer lesions, but it is not suitable for all lesions.

AIMS

This study aimed to determine the applicable conditions for IC chromoendoscopy.

METHODS

We retrospectively evaluated 187 lesions in 181 patients who had an endoscopic diagnosis of EGC and were treated with endoscopic submucosal dissection (ESD). According to the existence of the DL between the lesion mucosa and normal mucosa with IC chromoendoscopy, the lesions were divided into two groups: clear group and unclear group. Clinicopathological characteristics were evaluated in each group. From January 2022 to March 2023, the postoperative pathological sections of 19 lesions (81 slices) in the clear group and 19 lesions (80 slices) in unclear group were scanned with high definition, and the crypt structure between the two groups was evaluated.

RESULTS

There was no significant difference in clinical factors between the clear group and unclear group. There were significant differences in crypt area, crypt length, and crypt opening diameter between the two groups. In the clear group, there were significant differences in crypt area, crypt length, and crypt opening diameter between the normal area and cancer area, but there was no significant difference in the unclear group.

CONCLUSIONS

The margins of lesions with fused or absent crypt structures, a small crypt area, a short crypt length, and a short crypt opening diameter can be easily determined with IC chromoendoscopy.

Knowledge, attitude, and practice of monitoring early gastric cancer after endoscopic submucosal dissection

BACKGROUND

Early gastric cancer (EGC) is typically treated with endoscopic submucosal dissection (ESD). However, recurrence may occur after ESD, requiring surveillance.

AIM

To examine the knowledge, attitude, and practice (KAP) of EGC survivors following ESD regarding gastric cancer recurrence.

METHODS

This cross-sectional study was conducted between June 1, 2022 and October 1, 2022 in Zhejiang, China. A total of 400 EGC survivors who underwent ESD at the Affiliated Jinhua Hospital, Zhejiang University School of Medicine participated in this study. A self-administered questionnaire was developed to assess KAP monitoring gastric cancer after ESD.

RESULTS

The average scores for KAP were 3.34, 23.76, and 5.75 out of 5, 30, and 11, respectively. Pearson correlation analysis revealed positive and significant correlations between knowledge and attitude, knowledge and practice, and attitude and practice (r = 0.405, 0.511, and 0.458, respectively; all P < 0.001). Multivariate logistic regression analysis showed that knowledge, attitude, 13-24 mo since the last ESD (vs ≤ 12 mo since the last ESD), and ≥ 25 mo since the last ESD (vs ≤ 12 mo since the last ESD) were independent predictors of proactive practice (odds ratio = 1.916, 1.253, 3.296, and 5.768, respectively, all P < 0.0001).

CONCLUSION

EGC survivors showed inadequate knowledge, positive attitude, and poor practices in monitoring recurrences after ESD. Adequate knowledge, positive attitude, and a longer time since the last ESD were associated with practice.

Demarcation Line Determination for Diagnosis of Gastric Cancer Disease Range Using Unsupervised Machine Learning in Magnifying Narrow-Band Imaging

Background and Aims: It is important to determine an accurate demarcation line (DL) between the cancerous lesions and background mucosa in magnifying narrow-band imaging (M-NBI)-based diagnosis. However, it is difficult for novice endoscopists. We aimed to automatically determine the accurate DL using a machine learning method. Methods: We used an unsupervised machine learning approach to determine the DLs. Our method consists of the following four steps: (1) an M-NBI image is segmented into superpixels using simple linear iterative clustering; (2) the image features are extracted for each superpixel; (3) the superpixels are grouped into several clusters using the k-means method; and (4) the boundaries of the clusters are extracted as DL candidates. The 23 M-NBI images of 11 cases were used for performance evaluation. The evaluation investigated the similarity of the DLs identified by endoscopists and our method, and the Euclidean distance between the two DLs was calculated. For the single case of 11 cases, the histopathological examination was also conducted to evaluate the proposed system. Results: The average Euclidean distances for the 11 cases were 10.65, 11.97, 7.82, 8.46, 8.59, 9.72, 12.20, 9.06, 22.86, 8.45, and 25.36. The results indicated that the proposed method could identify similar DLs to those identified by experienced doctors. Additionally, it was confirmed that the proposed system could generate pathologically valid DLs by increasing the number of clusters. Conclusions: Our proposed system can support the training of inexperienced doctors as well as enrich the knowledge of experienced doctors in endoscopy.

Therapeutic approach to non-curative resection after endoscopic treatment in early gastric cancer

Background: Endoscopic resection is indicated for early or superficial gastrointestinal neoplasms with a negligible risk of lymph node metastasis. This procedure could preserve the organ while allowing en bloc resection of tumors, irrespective of the size and location of the lesion. Histological evaluation of the resected specimen determines whether curative resection, which implies a favorable long-term outcome, was achieved. If the resected specimen reveals non-curative, additional treatment is necessary as it is strongly associated with recurrence.Current Concepts: Surgical resection is recommended after non-curative resection of gastrointestinal neoplasms. However, rather than surgical resection, additional endoscopic treatment can be recommended if non-curative resection is solely because of the positive involvement at the horizontal resection margin without any other findings compatible with the non-curative resection criteria.Discussion and Conclusion: Adopting precise indications of endoscopic resection is important to reduce the risk of non-curative resection. If curative resection is not achieved after endoscopic resection, additional treatment should be considered to prevent local recurrence as well as lymph node metastasis.

The Modified eCura System for Identifying High-Risk Lymph Node Metastasis in Patients with Early Gastric Cancer Resected by Endoscopic Submucosal Dissection

Background: Endoscopic submucosal dissection (ESD) is widely used for early gastric cancer (EGC) in patients without lymph node metastasis (LNM). Prediction of LNM after ESD is important to determine prognosis in patients with EGC. In this regard, the eCura system was applied to predict LNM after noncurative ESD for EGC. This study aimed to identify risk factors for LNM and improve the accuracy of the eCura system for predicting the risk of LNM after ESD. Methods: A total of 150 patients who underwent noncurative resection of EGC by ESD were retrospectively enrolled at five institutions in Japan. All patients underwent additional surgery with lymph node resection after ESD. The risk factors for LNM among clinicopathological parameters were examined and receiver operating characteristic curve (ROC) analysis was used to determine the optimal cutoff point for predicting high LNM risk using the modified eCura system. Results: Of 150 patients, 19 (13%) had LNM. In the multivariate analysis, lymphatic invasion, and tumor size >30 mm were independent risk factors for LNM. Using a cutoff score of ≥4 for predicting high risk based on the eCura system, the rate of LNM was significantly higher in the high-risk group (4–7 points) than in the low-risk group (0–3 points) (odds ratio 12.0, 95% confidence interval 3.7–54.2, p < 0.0001). Conclusions: An eCura score ≥4 may improve the prediction of LNM risk after ESD in patients with EGC in the intermediate-risk group (2–4 points) of the eCura system, suggesting better treatment strategies for patients. Further prospective and long-term follow-up studies are needed to validate the efficacy of the modified system.

Long-term Outcomes of Additional Endoscopic Treatments for Patients with Positive Lateral Margins after Endoscopic Submucosal Dissection for Early Gastric Cancer

Background/Aims

It is uncertain whether additional endoscopic treatment may be chosen over surgery in patients with positive lateral margins (pLMs) as the only non-curative factor after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to compare the long-term outcomes of additional endoscopic treatments in such patients with those of surgery and elucidate the clinicopathological factors that could influence the treatment selection.

Methods

A total of 99 patients with 101 EGC lesions undergoing additional treatment after non-curative ESD with pLMs as the only non-curative factor were analyzed. Among them, 25 (27 lesions) underwent ESD, 29 (29 lesions) underwent argon plasma coagulation (APC), and 45 (45 lesions) underwent surgery. Clinicopathological characteristics and long-term outcomes were compared.

Results

Residual tumor was found in 73.6% of cases. The presence of multiple pLMs was associated with higher risk of residual tumor (p=0.046). During a median follow-up of 58.9 months, recurrent or residual lesions after additional ESD and APC were found in 4% (1/25) and 6.8% (2/29) of patients, respectively. However, all were completely cured with surgery or repeated ESD. There were no extragastric recurrences after additional endoscopic treatment. Lymph node metastasis was identified after additional surgery in one (2.2%) patient with an EGC showing histological heterogeneity.

Conclusions

Given the favorable long-term outcomes, additional ESD or APC may be an acceptable choice for patients with pLMs as the only non-curative factor after ESD for EGC. However, clincopathological characteristics such as multiple pLMs and histological heterogeneity should be considered in the treatment selection.

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)

Guidelines for endoscopic submucosal dissection and endoscopic mucosal resection for early gastric cancer (second edition)

In response to the rapid and wide acceptance and use of endoscopic treatments for early gastric cancer, the Japan Gastroenterological Endoscopy Society, in collaboration with the Japanese Gastric Cancer Association, produced "Guidelines for Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Early Gastric Cancer" in 2014, as a set of basic guidelines in accordance with the principles of evidence-based medicine. At the time, a number of statements had to be established by consensus (the lowest evidence level), as evidence levels remained low for many specific areas in this field. However, in recent years, the number of well-designed clinical studies has been increasing. Based on new findings, we have issued the revised second edition of the above guidelines that cover the present state of knowledge. These guidelines are divided into the following seven categories: indications, preoperative diagnosis, techniques, evaluation of curability, complications, long-term postoperative surveillance, and histology.

Long-term natural history after endoscopic resection for gastric dysplasia

BACKGROUND AND STUDY AIMS

Natural history after endoscopic resection (ER) for gastric dysplasia is still unclear. The aim of this study was to evaluate the long-term clinical outcomes and risk factors after ER for gastric dysplasia between control and cases with synchronous or metachronous gastric neoplasm.

METHODS

A total of 1090 patients who had undergone ER for gastric dysplasia and been followed up for at least one year from December 2002 to December 2013 were finally analyzed. Risk factors affecting the development of synchronous or metachronous neoplasm (SMN) and long-term clinical outcomes after ER for gastric dysplasia were evaluated.

RESULTS

Synchronous and metachronous neoplasms had developed in 126 (11.6%) and 133 patients (12.2%) during the mean follow-up duration of 63.6 months, respectively. Five-year and 10-year risk of metachronous neoplasm were 9.8% and 27.2%, respectively. Median duration to the development of metachronous neoplasm was 103.1 months. While age (P < 0.001) and mucosal atrophy (P = 0.09) of index cases were associated with the development of synchronous neoplasm, age (P = 0.017), incomplete resection (P = 0.025), and intestinal metaplasia (P = 0.017) of background mucosa of index cases were significantly related to the development of metachronous neoplasm in multivariate analysis. Cumulative incidence of SMN was not significantly different among H. pylori negative, eradicated, and persistent group.

CONCLUSIONS

Age, incomplete ER, and background intestinal metaplasia of index gastric dysplasia were significantly associated with metachronous recurrence. Endoscopic surveillance for metachronous recurrence after ER for gastric dysplasia is mandatory for longer than 10 years.

Risk Factors and Clinical Outcomes of Non-Curative Resection in Patients with Early Gastric Cancer Treated with Endoscopic Submucosal Dissection: A Retrospective Multicenter Study in Korea

BACKGROUND/AIMS

The purpose of this study was to investigate the risk factors and long-term clinical outcomes of non-curative resection (NCR) in a large-scale patient population.

METHODS

We retrospectively analyzed the clinical data of 3,094 patients who underwent endoscopic submucosal dissection (ESD) of early gastric cancer from March 2005 to March 2018 at 13 institutions in Korea. We analyzed the risk factors for NCR and the survival between patients with curative resection and those with NCR with no additional treatment.

RESULTS

The NCR rate was 21.4% (661/3,094). In multivariate regression analysis, the risk factors affecting NCR with ESD were old age, undifferentiated tumor, tumor location in the upper body, tumor size ≥2 cm, and presence of an ulcer. In Cox proportional hazard regression analysis, tumor size ≥2 cm, submucosal invasion, positive horizontal margin, and lymphovascular invasion were risk factors for local recurrence. In Kaplan-Meier analysis, there was no statistically significant difference in the overall survival between the two groups (log-rank p=0.788). However, disease-specific survival was significantly lower in the NCR group (log-rank p=0.038).

CONCLUSION

Clinicians should be aware of the risk factors for NCR and local recurrence after ESD for early gastric cancer, and should consider providing additional treatment after NCR.

Gastric endoscopic submucosal dissection: a systematic review and meta-analysis on risk factors for poor short-term outcomes

OBJECTIVE

Endoscopic submucosal dissection (ESD) is now established as the first option to manage early gastric neoplasms, but its efficacy may vary according to diverse factors. We aimed to systematically identify risk factors for poor short-term outcomes of gastric ESD with the purpose to improve patients' selection and management.

METHODS

Three online databases (MEDLINE, ISI Web of Knowledge and Scopus) were searched (last search on June 2018) for poor outcomes of gastric ESD (deep submucosal invasion, piecemeal/incomplete resection, noncurative resection and local recurrence).

RESULTS

One hundred five studies were included referring to 52.126 ESDs. Undifferentiated histology and upper location (vs lower) were associated with submucosal invasion [odds ratio (OR) = 2.42 [95% confidence interval (CI), 1.62-3.61] and OR = 3.20 (1.04-9.86), respectively] and deep submucosal invasion [OR = 2.98 (2.02-4.39) and OR = 2.35 (1.45-3.81), respectively]. Lesion size greater than 30 mm and ulceration were associated with piecemeal resection [OR = 2.78 (1.17-6.60) and OR = 2.76 (1.23, 6.20), respectively]. Lesion size greater than 30 mm, ulceration, upper location and fibrosis were risk factors for incomplete resection [OR = 3.83 (2.68-5.49), OR = 4.06 (1.62-10.16), OR = 3.71 (2.49-5.54) and OR = 4.46 (1.66-11.96), respectively]. A noncurative resection was more often observed for lesions located in the upper third of the stomach [OR = 1.49 (1.24-1.79)], depressed morphology [OR = 1.49 (1.04-2.12)] and those outside standard criteria [OR = 3.56 (2.31-5.48)]. Older age was significantly linked with local recurrence rates [OR = 3.08 (1.13-5.02)].

CONCLUSION

Several risk factors influence poor efficacy short-term outcomes of gastric ESD that may be used to inform both patients and health providers about the expected efficacy.

Risk Factors Associated with Lymph Node Metastasis for Early Gastric Cancer Patients Who Underwent Non-curative Endoscopic Resection: a Systematic Review and Meta-analysis

BACKGROUND

Recently, increased evidence indicated that additional surgery should be performed in highly selected patients with non-curative endoscopic resection. In this study, we performed a systematic review and meta-analysis to evaluate the risk factors associated with lymph node metastasis for the patients with non-curative endoscopic resection of early gastric cancer.

METHODS

The related studies were identified by searching PubMed and Embase databases. According to the status of lymph node metastasis, all patients were classified into node-negative group and node-positive group. The relevant clinicopathologic factors were extracted, and the pooled odds ratio (OR) and 95% confidence interval (CIs) were assessed using a fixed effects model or random effects model.

RESULTS

A total of nine relevant studies involving 1720 early gastric cancer patients who underwent additional surgery following the non-curative endoscopic resection were included in this meta-analysis. The results indicated that deeper submucosal invasion (SM2) (OR 3.44, 95% CI 1.94-6.10, P < 0.001; I² = 0%), positive vertical margin (OR 2.35, 95% CI 1.57-3.53, P < 0.001; I² = 0%), lymphatic invasion (OR 11.06, 95% CI 5.47-22.36, P < 0.001; I² = 0%), and vascular invasion (OR 2.79, 95% CI 1.68-4.64, P < 0.001; I² = 0%) were significantly associated with lymph node metastasis for these patients. However, horizontal margin, tumor size, differentiation type, and ulceration were not identified as risk factors associated with lymph node metastasis.

CONCLUSION

Lymphatic invasion, vascular invasion, deeper submucosal invasion (SM2), and positive vertical margin should be strongly considered in selecting the candidates for additional surgery treatment.

Is Radical Surgery Necessary for All Patients Diagnosed as Having Non-Curative Endoscopic Submucosal Dissection?

If a lesion does not meet the expanded indication criteria for treatment with endoscopic therapy for early gastric cancer or has a positive resection margin, it is regarded as suitable for non-curative resection. Non-curative resection is closely related to the risk of local recurrence, lymph node metastasis, and poor prognosis. If the result is confirmed as non-curative resection, additional treatment should be considered depending on the risks of residual tumor, local recurrence, and lymph node metastasis. As lymphatic invasion is the most important risk factor of recurrence and poor prognosis, surgical treatment should be considered if lymphatic invasion is present. If patients are not suitable for additional surgery owing to old age or coexisting severe disease, close surveillance can be an alternative treatment option.

Additive endoscopic resection may be sufficient for patients with a positive lateral margin after endoscopic resection of early gastric cancer

BACKGROUND AND AIMS

No well-established treatment strategies exist for lateral margin positivity (LM+) alone after endoscopic resection (ER) of early gastric cancer (EGC). Thus, we aimed to clarify a treatment strategy for non-curative resection (non-CR) with LM+ alone after ER in EGC.

METHODS

Among 2065 patients with EGC treated by ER, 76 (3.6%) with only LM+ after non-CR of EGC were reviewed retrospectively. Of these, 28 underwent gastrectomy, 25 underwent argon plasma coagulation (APC), and 23 underwent repeat ER (re-ER). We analyzed the clinicopathologic characteristics of all patients and compared those who underwent additive surgery, APC, or re-ER.

RESULTS

Of the 76 patients, 28 (36.8%) fulfilled the absolute criteria and 48 (63.2%) the expanded criteria for ER. Among the latter patients, the proportion undergoing additive surgery was 75.0%, higher than that of patients in the former group (P = .014). Residual cancer cells were observed in 70.6% of patients after additive surgery or re-ER. Residual cancer cells were observed significantly more often in patients with undifferentiated-type than in those with differentiated-type EGC (P = .02). However, no lymph node metastasis was observed in any patient after additive surgery.

CONCLUSIONS

Our results suggest that endoscopic treatment may be a sufficient additive therapy for patients with LM+ alone after ER, irrespective of whether the absolute or expanded ER criteria are used. However, as complete ablation of remnant cells cannot be guaranteed, re-ER is a better additive treatment than APC.

[Treatment Strategies after Non-curative Endoscopic Resection of Early Gastric Cancer]

The cases of non-curative endoscopic resection (NCR) of early gastric cancer have increased due to the widespread use of endoscopic submucosal dissection (ESD). NCR is associated with augmenting chances of local recurrence and lymph node metastasis (LNM). Therefore, some additional treatment strategies after NCR are needed. Treatment strategies for NCR should be determined by considering the risk of residual tumor or local recurrence and LNM. Additional surgical treatment such as gastrectomy and lymph node dissection are recommended in patients who have high-risk of LNM. Close observation without additional treatment is considered for selected patients with a less possibility of local recurrence or LNM. Also it may be suggested if there is no or less benefit from surgery in elderly patients or patients with underlying diseases. Additional endoscopic procedures including ESD, endoscopic mucosal resection or argon coagulation therapy are suggested alternatively for highly selected patients not at risk of LNM based on the absolute or expanded criteria of ESD.

Management of early gastric cancer with positive horizontal or indeterminable margins after endoscopic submucosal dissection: multicenter survey

Background and study aims Positive horizontal margins in resected specimens are sometimes encountered after endoscopic submucosal dissection (ESD) for early gastric cancers, and appropriate treatment strategies for these cases are not established. The aim of this study was to evaluate current empirical treatments for patients with positive horizontal or indeterminable margins after ESD. Patients and methods We performed a multicenter survey and data from 14 hospitals were collected. The pooled proportions of positive horizontal or indeterminable margins and those of patients followed up without early intervention were calculated using a logistic-normal random-effects model. For calculating pooled estimates, subgroup analyses of high- and non-high-volume centers were conducted. Results A total of 11,796 ESD cases were enrolled and 229 patients (2 %) had positive horizontal or indeterminable margins. Ninety-eight cases were treated within 30 days of ESD and 131 cases were followed up without early treatments. Pooled estimates of positive margins in high- and non-high-volume centers were 1 % (95 % CI: 1 % - 2 %) and 2 % (95 % CI: 1 % - 4 %), respectively, and were not heterogeneous (P = 0.191). The proportion of patients followed up without early intervention ranged from 30 % to 100 %. The pooled estimate was 68 % (95 % CI: 50 % - 83 %). The pooled estimates of high- and non-high-volume centers were 65 % (95 % CI: 38 % - 85 %) and 72 % (95 % CI: 44 % - 89 %), respectively, and were not heterogeneous (P = 0.692). Conclusion There was insufficient consensus regarding treatment strategies used for early gastric cancer with positive horizontal or indeterminable margins after ESD. Further studies are required to establish a consensus.

Treatment Strategy after Incomplete Endoscopic Resection of Early Gastric Cancer

Endoscopic resection of early gastric cancer is defined as incomplete when tumor cells are found at the resection margin upon histopathological examination. However, a tumor-positive resection margin does not always indicate residual tumor; it can also be caused by tissue contraction during fixation, by the cautery effect during endoscopic resection, or by incorrect histopathological mapping. Cases of highly suspicious residual tumor require additional endoscopic or surgical resection. For inoperable patients, argon plasma coagulation can be used as an alternative endoscopic treatment. Immediately after the incomplete resection or residual tumor has been confirmed by the pathologist, clinicians should also decide upon any additional treatment to be carried out during the follow-up period.

Factors associated with incomplete gastric endoscopic submucosal dissection due to misdiagnosis

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is widely accepted for treating early gastric cancer (EGC); however, there can be cases of incomplete resection due to not only technical problems, but also misdiagnosis. Our aim was to identify factors associated with incomplete gastric ESD due to misdiagnosis.

PATIENTS AND METHODS

A total of 2,268 patients with solitary EGCs at initial onset underwent ESD with curative intent at our hospital from 1999 to 2008. We retrospectively assessed the clinicopathological factors by comparing the two groups of incomplete ESD cases due to misdiagnosis (cases with a positive lateral margins [LM] [Group A] or those with a positive vertical margins [VM] [Group B]) with complete ESD cases using multivariable analysis.

RESULTS

Complete ESD was achieved in 2,097 patients. The 171 patients with incomplete ESDs were divided into 109 with a positive LM and 80 with a positive VM (overlapped). Except 49 cases with a positive LM due to technical problems, a positive LM due to misdiagnosis was identified in 60 cases (Group A). Excluding 32 cases with a positive VM due to technical problems, a positive VM due to misdiagnosis was found in 48 cases (Group B). Significant independent factors (odds ratios [OR]; 95 % confidence intervals [CI]) for each group were as follows: Group A: size > 20 mm (5.4; 3.0 - 9.9), undifferentiated-type (4.1; 1.8 - 9.0), submucosal invasion (2.0; 1.1 - 3.4) and location of upper/middle (1.9; 1.0 - 3.6); Group B: size > 20 mm (3.0; 1.6 - 5.5), undifferentiated-type (3.0; 1.1 - 8.0) and location of upper/middle (2.4; 1.2 - 4.8).

CONCLUSIONS

Endoscopists must be aware of these factors associated with incomplete gastric ESD due to misdiagnosis to further decrease their incidence.

Additional surgery for non-curative resection after endoscopic submucosal dissection for gastric cancer: a retrospective analysis of 200 cases

PURPOSE

Endoscopic submucosal dissection is recommended for early gastric cancer with a low risk of lymph node metastasis. When the pathological findings do not meet the curative criteria; then, an additional gastrectomy with lymph node dissection is recommended. However, most cases have neither lymph node metastasis nor a local residual tumor during an additional surgery.

METHODS

This was a single-institutional retrospective cohort study, analyzing 200 patients who underwent an additional gastrectomy after non-curative endoscopic submucosal dissection from January 2005 to October 2015. We reviewed the patients' clinicopathological data and evaluated the predictors for the presence of a residual tumor.

RESULTS

Histopathology revealed lymph node metastasis in 15 patients (7.5 %) and a local residual tumor in 23 (11.5 %). A multivariable analysis revealed macroscopic findings (flat/elevated type) (p = 0.011, odds ratio = 4.63), lymphatic invasion (p < 0.0001, odds ratio = 14.2), and vascular invasion (p = 0.04, odds ratio = 4.00) to be predictors for lymph node metastasis. A positive vertical margin (p = 0.0027, odds ratio = 3.26) and horizontal margin (p = 0.0008, odds ratio = 5.74) were predictors for a local residual tumor. All cases with lymph node metastasis had lymphovascular invasion with at least one other non-curative factor.

CONCLUSIONS

The risk of a residual tumor can, therefore, be estimated based on the histopathology of endoscopic submucosal dissection samples. Lymphovascular invasion appears to be a pivotal predictor of lymph node metastasis.