Surgical outcomes and clinicopathological characteristics of patients who underwent potentially noncurative endoscopic resection for gastric cancer: a report of a single-center experience

Management Strategy of Non-curative ESD in Gastric Cancer: Curative Criteria, and the Critical Building Block for Determining Beyond It

Endoscopic submucosal dissection is performed in cases of early gastric cancer, where the risk of lymph node metastasis (LNM) is expected to be negligible, and 12%-21% of these patients are deemed to have undergone non-curative resections based on pathological criteria. In such cases, decisions regarding additional treatments must be made to maximize curability, depending on the anticipated LNM risk. Well-established risk factors for LNM include lymphatic invasion, vascular invasion, deep submucosal invasion, positive vertical margins, and larger tumor size. When pathological factors associated with a clear LNM risk, such as lymphatic or deep submucosal invasion, are present, additional gastrectomy with lymph node dissection should be considered. Conversely, in cases involving only a positive horizontal margin, additional endoscopic treatment may be an effective therapeutic option as opposed to gastrectomy because of the negligible risk of LNM despite the potential risk of residual tumors. Endoscopic resection is particularly advantageous for determining complete resection. In addition to pathological curability, patient-specific factors, such as age and comorbidities, must be considered. Several retrospective cohort studies have shown that the cause of mortality among patients placed only on observation without additional treatment after non-curative resection is generally related to underlying conditions irrelevant to gastric cancer. Thus, it is crucial to assess both GC-specific mortality and all-cause mortality to finalize treatment decisions that help minimize such mortality. Therefore, new treatment algorithms that integrate pathological curability with patient-specific factors must be developed.

Lymph Node Metastasis and Its Risk Factors for Early Gastritis Individuals Who Underwent Noncurative Endoscopic Resection: A Systematic Review and Meta-Analysis

Background

In the present review, we carried out a systematic review and meta-analysis to analyze possible lymph node metastasis (LNM) hazards in individuals with endoscopic resection of gastric cancer.

Methods

Relevant literature was selected by evaluating the PubMed, Cochrane Library, and Google Scholar electronic databases since from inception to March 2022. Corresponding clinicopathological outcomes were summarized, and pooled log odds ratios and 95% confidence intervals were assessed. The random effect model was preferred if variations among studies is high otherwise fixed effect model was preferred.

Results

Overall, 12 associated papers, including 4808 early gastric cancer individuals who endured more surgery after noncurative endoscopic resection, were entered into this analysis. The outcomes showed that submucosal invasion (log odd ratio 1.75, 95% (CI): 0.77-3.95, I2 = 80.0%); vertical margin (log odd ratio 6.53, 95% (CI): 2.81-15.17, I2 = 65%); horizontal margin (log Odd ratio 0.69 95% (CI): 0.22-2.14, I2 = 52%), lymphatic invasion (Odd ratio 6.33 95% (CI): 1.98-20.24, I2 = 91%), and vascular invasion (Odd ratio 3.55, 95% (CI): 1.31-9.58, I2 = 92%) was significantly related to metastasis of lymph node for these patients.

Conclusion

There was a significant association of LNM hazards in individuals with endoscopic resection of gastric cancer. Therefore, invasion to lymph, vascular, submucosa and positive vertical margin should be strongly noticed when selecting surgical treatment factors.

Clinical outcomes and risk factors of non-curative endoscopic submucosal dissection for early gastric cancer: a retrospective multicenter study in Zhejiang, China

Background

Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) does not always lead to curative resection. Risk factors of lymph node metastasis (LNM)/local cancer residue after non-curative ESD for EGC have not been fully elucidated. We therefore aimed to clarify them and evaluate whether the "eCura system" is reliable for the risk stratification of LNM after non-curative ESD.

Methods

We conducted a multicenter retrospective study at seven institutions in Zhejiang, China, on 128 patients who underwent non-curative ESD for EGC. We divided the patients into two groups according to their therapeutic regimen after non-curative ESD. We analyzed the risk factors for LNM, local cancer residue, cancer recurrence, and cancer-specific mortality. Furthermore, we compared the outcomes in each risk category after applying the "eCura system".

Results

Among 68 patients undergoing additional surgery, LNM was found in three (4.41%) patients, while local cancer residue was found in eight (11.76%) patients. Multivariate analysis showed that upper third location and deep submucosal invasion were independent risk factors of LNM and local cancer residue. Among 60 patients who underwent simple follow-up, local cancer recurrence was found in four (6.67%) patients and cancer-specific mortality was found in one (1.67%) patient. There were no independent risk factors of cancer recurrence and cancer-specific mortality in our study. During the follow-up period, 5-year overall survival (OS) and disease-free survival (DFS) were 93.8% and 88.9%, respectively. Additionally, LNM and cancer recurrence were significantly associated with the eCura scoring system (p = 0.044 and p = 0.017, respectively), while local cancer residue and cancer-specific mortality were not (p = 0.478 and p = 0.131, respectively).

Conclusion

Clinicians should be aware of the risk factors for the prognosis of patients with non-curative ESD to determine subsequent treatment. Through the application of the "eCura system", additional surgery should be performed in patients with intermediate/high risk of LNM.

[Endoscopic Resection of Early Gastric Cancer in Elderly]

With the aging of the society, the proportion of elderly patients with gastric cancer is increasing and the chances of encountering elderly patients with early gastric cancer (EGC) are increasing. Because elderly patients have more comorbidities, and lower life expectancy than younger patients, the treatment strategy for elderly patients with EGC is not standardized. Therefore, it is necessary to identify risk factors related to survival of elderly patients with EGC and to establish treatment strategies according to prognosis in elderly patients with EGC.

Endoscopic instruments and techniques in endoscopic submucosal dissection for early gastric cancer

Introduction: Endoscopic submucosal dissection (ESD) is a less invasive local treatment for early gastric cancer (EGC).Areas covered: Japanese guidelines have recently expanded the endoscopic treatment indications for EGC. ESD is sometimes performed for lesions with a relative indication that has not previously been considered for ESD. ESD procedures are technically difficult, especially for larger and more invasive lesions. Complete resection and accurate histological assessment of EGC lesions are essential to evaluate endoscopic curability. Various endoscopic instruments, including three types of endoscopic knives and specific hemostatic forceps, have been developed, and endoscopic techniques, including the traction method, have been modified to simplify the procedure.Expert opinion: An insulated-tip knife with large tissue contact allows us to perform faster incisions, while a needle-type knife with minimal tissue contact allows us to perform precise incisions. Furthermore, a scissor-type knife with grasping tissues allows us to perform more secure incision. The traction method enables the operator to proceed with submucosal dissection procedures. In cases with small lesions, snaring can be used, as well as knife dissection. Understanding the features of each endoscopic instrument and technique is essential because appropriate selection and usage contribute to successful and safe ESD procedures.

Recurrence rate of intramucosal gastric cancer with positive vertical margin due to lesion damage during endoscopic submucosal dissection

BACKGROUND AND STUDY AIM

In principle, additional surgery is performed after endoscopic submucosal dissection for early gastric cancer if the vertical margin is positive, regardless of lesion damage. The recurrence rate of vertical margin-positive lesions due to lesion damage after endoscopic submucosal dissection is unknown, and unnecessary surgeries may be performed. In this study, we investigated whether there was a difference in the recurrence rate between vertical margin-positive lesions due to lesion damage and vertical margin-negative lesions.

PATIENTS AND METHODS

We included 1,294 intramucosal gastric cancer lesions that were resected by endoscopic submucosal dissection between January 2008 and December 2016, without additional surgery. The lesions were divided into the Damage and No damage groups based on vertical margin status. The Damage group had only one non-curative indication: a positive vertical margin due to lesion damage. The No damage group had no non curative indications. We compared the recurrence rate between the Damage and No damage groups.

RESULTS

The recurrence rates of the Damage and No damage groups were 0% (0/23; 95% confidence interval: 0-14.8%) and 0% (0/1,271; 95% confidence interval: 0-0.003%), respectively, with no statistically significant difference.

CONCLUSIONS

In intramucosal gastric cancer, the recurrence rate of vertical margin-positive lesions due to lesion damage was 0%, which did not differ from that of vertical margin-negative lesions with curative resection. Follow-up, instead of additional surgery, may be an option for patients with non-curative resection when the only non-curative indication is a positive vertical margin due to lesion damage.

Preceding endoscopic submucosal dissection in submucosal invasive gastric cancer patients does not impact clinical outcomes

Submucosal deep invasion of gastric cancer (T1b2; depth of submucosal invasion ≥ 500 μm) is a risk factor for lymph node metastasis and, thus, is one of the criteria for curative treatment. Our aim was to evaluate the specific influence of endoscopic submucosal dissection (ESD) on the prognosis of patients with T1b2 gastric cancer. This was a retrospective analysis of 248 consecutive patients, with 252 pT1b2 gastric cancer lesions, who underwent ESD prior to additional surgery (Group A, n = 101) or surgery only (Group B, n = 147). After propensity score-matching (for sex, age, tumor diameter and gross type), we compared pathological characteristics between the 2 groups and the prognosis over a follow-up period ≥ 60 months. Compared to Group B, patients in Group A were older, with a higher proportion of men. The proportion of depressed and undifferentiated type tumors was greater in Group B than A, with larger tumor size and depth of submucosal invasion as well. There was no incidence of local recurrence, but distant metastasis was identified in 5% of cases in Group A and 3% in Group B. After propensity score-matching, there were no difference in the 5-year overall survival rate between Group A and B (87.5% vs. 91.2%, respectively), nor in the 5-year disease-specific survival rate (96.3% vs. 96.4%, respectively). ESD prior to surgery for T1b2 gastric cancer did not adversely affect clinical outcomes after additional surgery.

Management following endoscopic resection in elderly patients with early-stage upper gastrointestinal neoplasia

With the ongoing increase in the aging population in Japan, the number of elderly patients among the total population with upper gastrointestinal (GI) neoplasia has also been increasing. As elderly patients present unique age-related variations in their physical condition, the therapeutic approach for upper GI neoplasia should be differentiated between elderly and nonelderly patients. According to the existing guidelines, additional treatment is the standard therapy in patients who undergo endoscopic resection (ER) with a possible risk of lymph node metastasis (LNM) for upper GI neoplasia. However, due to the relatively low rate of LNM, applying additional treatment in all elderly patients may be excessive. Although additional treatment has the advantage of reducing cancer-specific mortality, its disadvantages include deteriorated quality of life, complications, and mortality in surgery. In patients with early gastric cancer, we propose treatment decisions be made using a risk-scoring system for LNM and upon considering the physical condition of the patient after ER with curability C-2. In those with superficial esophageal squamous cell carcinoma with a possible risk of LNM after ER, selective chemoradiotherapy may be a less-invasive treatment option, although the present standard treatment is esophagectomy. When considering the treatment decision, achieving a "cure" of the tumor has been regarded as critical. However, as the main cause of mortality in elderly patients with ER for upper GI neoplasia is noncancer-related death, both achieving a "cure" and also a good level of "care" is important in the management of elderly patients.

Prevalence and risk factors for lymph node metastasis after noncurative endoscopic resection for early gastric cancer: a systematic review and meta-analysis

BACKGROUND

Additional surgery for all patients with noncurative resection after endoscopic resection (ER) for early gastric cancer (EGC) may be excessive due to the relatively low rate of lymph node metastasis (LNM) in such patients. However, the prevalence and risk factors for LNM after noncurative ER have not been consistent across studies.

METHODS

We performed a systematic review of electronic databases through August 10, 2018 to identify cohort studies with patients who underwent additional surgery after noncurative ER for EGC. The prevalence of LNM in such patients was extracted for all studies. Odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of LNM, when possible.

RESULTS

We identified 24 studies comprising 3877 patients with 311 having LNM (pooled prevalence, 8.1%). The risk of LNM was significantly increased in lymphatic invasion (OR [95% confidence interval] = 4.22 [2.88-6.19]), lymphovascular invasion (LVI) (4.17 [2.90-5.99]), vascular invasion (2.38 [1.65-3.44]), positive vertical margin (2.16 [1.59-2.93]), submucosal invasion depth of ≥ 500 μm (2.14 [1.48-3.09]), and tumor size > 30 mm (1.77 [1.31-2.40]). In contrast, there was no significant association between undifferentiated-type or ulceration (scar) and LNM. When studies were restricted to those that evaluated the adjusted OR, the risk of vascular invasion for LNM did not reach statistical significance.

CONCLUSIONS

Several pathological factors, most notably lymphatic invasion and LVI, were associated with LNM in patients with noncurative resection after ER for EGC. Lymphatic and vascular invasion should be assessed separately instead of LVI (PROSPERO CRD42018109996).

A Recent Argument for the Use of Endoscopic Submucosal Dissection for Early Gastric Cancers

Endoscopic submucosal dissection (ESD) has become the standard treatment method for early gastric cancers (EGCs) due to the negligible risk for lymph node metastasis (LNM) in Eastern Asian countries. According to the guidelines, the curability of EGC after endoscopic resection was classified into three groups: curative resection, expanded curative resection, and noncurative resection. In Eastern Asian countries, a structured follow-up schedule is needed for patients undergoing curative resection and expanded curative resection. Conversely, in Western countries, additional surgery may be recommended for some patients undergoing expanded curative resection (ulcerated, undifferentiated, or slight submucosal invasion) due to the potential risk for LNM, even though specimens of ESD and surgery may not be handled with the same methodology as that used in Japan, which may lead to this slightly higher risk. In noncurative resection, additional surgery is the standard method after ESD because of the risk for LNM. However, in elderly patients and/or those with severe underlying diseases, the advantages and disadvantages of additional surgery should be considered when selecting a post-ESD treatment strategy for patients undergoing noncurative resection. Risk-scoring systems for LNM may facilitate clinical decisions for these patients. However, it should be noted that when recurrence was detected in patients who were followed up with no additional treatment after ESD with noncurative resection, most of them had a poor prognosis. To select an appropriate treatment method, especially in elderly patients undergoing ESD with noncurative resection, a new tool for evaluating the condition of patients should be established.

High-Risk Comorbidity Influences Prognosis in Early Gastric Cancer after Noncurative Endoscopic Submucosal Dissection: A Retrospective Study

BACKGROUND

There are few studies reporting the clinical outcomes of noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) from the perspective of patient health condition/status. Thus, the aim of this study was to investigate clinical outcomes of noncurative ESD considering not only curability but also patient factors such as advanced age, comorbidities, and nutritional status.

METHODS

Between April 2007 and March 2012, 95 patients who underwent noncurative ESD for EGC were enrolled in the study. Patients were categorized by treatment after ESD: additional gastrectomy (49 patients) and follow-up (46 patients). Clinical outcomes were evaluated between the 2 groups for overall survival (OS).

RESULTS

The absence of lymphovascular involvement and age ≥80 years were significantly associated with decision-making for observation after noncurative ESD. The OS rates were higher in female patients, patients with better Eastern Cooperative Oncology Group performance status (≤1) or low-risk comorbidity (Charlson Comorbidity Index [CCI ≤ 2]), patients with ulcerative findings, and those who underwent radical gastrectomy. Multivariate Cox proportional hazards analysis indicated that presence of a high-risk comorbidity (CCI ≥ 3) was a significant prognostic factor (hazard ratio: 16.43, p = 0.024) in patients who underwent noncurative ESD for EGC.

CONCLUSION

High-risk comorbidity is the primary prognostic parameter in terms of patient factors after noncurative ESD for EGC. The CCI should be considered as a prognostic factor in patients who underwent noncurative ESD for EGC.

Predictors of lymph node metastasis and residual tumor in early gastric cancer patients after noncurative endoscopic resection: a systematic review and meta-analysis

BACKGROUND

It is challenging to identify the prevalence of lymph node metastasis (LNM) and residual tumor in patients with early gastric cancer (EGC) who underwent noncurative endoscopic resection (ER). This present meta-analysis was aimed to establish imperative potential predictive factors in order to select the optimal treatment method.

METHODS

A systematic literature search of PubMed, Embase, and Cochrane Library databases was performed through 1 February 2019 to identify relevant studies, which investigated risk factors for LNM and residual tumor in patients with EGC who underwent noncurative ER. Eligible data were systematically reviewed through a meta-analysis.

RESULTS

Overall, 12 studies investigating the risk factor of LNM were included, totaling 3015 patients, 7 of which also involved cancer residues. After the present meta-analysis, six predictors, including tumor size >30 mm, tumor invasion depth (⩾500 μm from the muscularis mucosae), macroscopic appearance, undifferentiated histopathological type, positive vertical margin, and presence of lymphovascular invasion (including lymphatic invasion and vascular invasion) were significantly associated with LNM, whereas tumor size >30 mm, positive horizontal margin, and positive vertical margin were identified as significant predictors for the risk of residual tumor. No evidence of publication bias was observed.

CONCLUSIONS

Six and three variables were established as significant risk factors for LNM and residual tumor in patients with EGC who underwent noncurative ER, respectively. Patients with EGC who present these risk factors after noncurative ER are strongly suggested to receive additional surgery, while others might be suitable for strict follow-up. This might shed some new light on the selection of follow-up treatment for noncurative ER.

History and future perspectives in Japanese guidelines for endoscopic resection of early gastric cancer

Japanese guidelines for gastric cancer treatment were first published in 2001 for the purpose of showing the appropriate indication for each treatment method, thereby reducing differences in the therapeutic approach among institutions, and so on. With the accumulation of evidence and the development and prevalence of endoscopic submucosal dissection (ESD), the criteria for the indication and curability of endoscopic resection (ER) for early gastric cancer (EGC) have expanded. However, several problems still remain. Although a risk-scoring system (eCura system) for predicting lymph node metastasis (LNM) may help treatment decision in patients who do not meet the curative criteria for ER of EGC, which is referred to as eCura C-2 in the latest guidelines, additional gastrectomy with lymphadenectomy may be excessive for many patients, even those at high risk for LNM. Less-invasive function-preserving surgery, such as non-exposed endoscopic wall-inversion surgery with laparoscopic sentinel node sampling, may overcome this problem. In addition, further less-invasive treatment, such as ER with chemotherapy, should be established for patients who prefer not to undergo additional gastrectomy.

Additional laparoscopic gastrectomy after noncurative endoscopic submucosal dissection for early gastric cancer: A single-center experience

BACKGROUND

The necessity of additional gastrectomy for early gastric cancer (EGC) patients who do not meet curative criteria after endoscopic submucosal dissection (ESD) is controversial.

AIM

To examine the clinicopathologic characteristics of patients who underwent additional laparoscopic gastrectomy after ESD and to determine the appropriate strategy for treating those after noncurative ESD.

METHODS

We retrospectively studied 45 patients with EGC who underwent additional laparoscopic gastrectomy after noncurative ESD from January 2013 to January 2019 at the Cancer Hospital of the Chinese Academy of Medical Sciences. We analyzed the patients’ clinicopathological data and identified the predictors of residual cancer (RC) and lymph node metastasis (LNM).

RESULTS

Surgical specimens showed RC in ten (22.2%) patients and LNM in five (11.1%). Multivariate analysis revealed that positive horizontal margin [odds ratio (OR) = 13.393, 95% confidence interval (CI): 1.435-125, P = 0.023] and neural invasion (OR = 14.714, 95%CI: 1.087-199, P = 0.043) were independent risk factors for RC. Undifferentiated type was an independent risk factor for LNM (OR = 12.000, 95%CI: 1.197-120, P = 0.035). Tumors in all patients with LNM showed submucosal invasion more than 500 µm. Postoperative complications after additional laparoscopic gastrectomy occurred in five (11.1%) patients, and no deaths occurred among patients with complications.

CONCLUSION

Gastrectomy is necessary not only for patients who have a positive margin after ESD, but also for cases with neural invasion, undifferentiated type, and submucosal invasion more than 500 µm. Laparoscopic gastrectomy is a safe, minimally invasive, and feasible procedure for additional surgery after noncurative ESD. However, further studies are needed to apply these results to clinical practice.

Is Additional Surgery Always Sufficient for Preventing Recurrence After Endoscopic Submucosal Dissection with Curability C-2 for Early Gastric Cancer?

BACKGROUND

When a lesion does not meet the curative criteria of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), referred to as non-curative resection or curability C-2 in the guidelines, an additional surgery is the standard therapy because of the risk of lymph node metastasis (LNM).

OBJECTIVE

This study aimed to identify high-risk patients for recurrence after additional surgery for curability C-2 ESD of EGC.

METHODS

This multicenter retrospective cohort study enrolled 1064 patients who underwent additional surgery after curability C-2 ESD for EGC. We evaluated the recurrence rate and the risk factors for recurrence after additional surgery in these patients.

RESULTS

The 5-year recurrence rate after additional surgery was 1.3%. Multivariate Cox analysis revealed that the independent risk factors for recurrence after additional surgery were LNM (hazard ratio [HR] 32.47; p < 0.001) and vascular invasion (HR 4.75; p = 0.014). Moreover, patients with both LNM and vascular invasion had a high rate of recurrence after additional surgery (24.6% in 5 years), with a high HR (119.32) compared with those with neither LNM nor vascular invasion. Among patients with no vascular invasion, a high rate of recurrence was observed in those with N2/N3 disease according to the American Joint Committee on Cancer TNM staging system (27.3% in 5 years), in contrast with no recurrence in those with N1 disease.

CONCLUSIONS

Patients with both LNM (N1-N3) and vascular invasion, as well as those with N2/N3 disease but no vascular invasion, would be candidates for adjuvant chemotherapy after additional surgery for curability C-2 ESD of EGC.

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.

Different risk factors between early and late cancer recurrences in patients without additional surgery after noncurative endoscopic submucosal dissection for early gastric cancer

BACKGROUND AND AIMS

Cancer recurrence is observed in some patients without additional radical surgery after endoscopic submucosal dissection (ESD) that does not fulfill the curability criteria for early gastric cancer (EGC), categorized as "noncurative resection" or "curability C-2" in the guidelines. However, time to cancer recurrence is different in such patients. Thus, we aimed to identify the risk factors of early and late cancer recurrences in these patients.

METHODS

Between 2000 and 2011, this multicenter study analyzed 905 patients who were followed up without additional radical surgery after ESD for EGC categorized as curability C-2. We evaluated the risk factors for early and late cancer recurrences, separately, after ESD. The cut-off value was defined at 2 years.

RESULTS

Time to cancer recurrence in the enrolled patients showed a bimodal pattern, and the 5-year cancer recurrence rate was 3.2%. Multivariate Cox analyses revealed that lymphatic invasion (hazard ratio [HR], 8.56; P = .003) was the sole independent risk factor for early cancer recurrence. Regarding late cancer recurrence, vascular invasion (HR, 4.50; P = .039) was an independent risk factor, and lymphatic invasion tended to be a risk factor (HR, 3.63; P = .069).

CONCLUSIONS

This multicenter study with a large cohort demonstrated that lymphatic invasion is mainly associated with early cancer recurrence; however, vascular invasion was a risk factor only for late recurrence in patients without additional treatment after ESD for EGC categorized as curability C-2. This finding may contribute to decision making for treatment strategies after ESD, especially for patients with a relatively short life expectancy.

Additional gastrectomy in early-stage gastric cancer after non-curative endoscopic resection: a meta-analysis

Background and objective

The role of additional gastrectomy after non-curative endoscopic resection remains uncertain. The present meta-analysis aimed to explore the risk factors for early-stage gastric-cancer patients after non-curative endoscopic resection and evaluate the efficacy of additional gastrectomy.

Methods

Relevant studies that reported additional gastrectomy after non-curative endoscopic resection were comprehensively searched in MedLine, Web of Science and EMBASE. We first investigated the risk factors for residual tumor and lymph-node metastasis after non-curative endoscopic resection and then analysed the survival outcome, including 5-year overall survival (OS) and 5-year disease-free survival, of additional gastrectomy.

Results

Twenty-one studies comprising 4870 cases were included in the present study. We found that residual tumor was associated with larger tumor size (>3 cm) (odds ratio [OR] = 2.81, P < 0.001), undifferentiated tumor type (OR = 1.78, P = 0.011) and positive horizontal margin (OR = 9.78, P < 0.001). Lymph-node metastasis was associated with larger tumor size (>3 cm) (OR = 1.73, P < 0.001), elevated tumor type (OR = 1.60, P = 0.035), deeper tumor invasion (>SM1) (OR = 2.68, P < 0.001), lymphatic invasion (OR = 4.65, P < 0.001) and positive vertical margin (OR = 2.30, P < 0.001). Patients who underwent additional gastrectomy had longer 5-year OS (hazard ratio [HR] = 0.34, P < 0.001), 5-year disease-free survival (HR = 0.52, P = 0.001) and 5-year disease-specific survival (HR = 0.50, P < 0.001) than those who did not. Moreover, elderly patients also benefited from additional gastrectomy regarding 5-year OS (HR = 0.41, P = 0.001).

Conclusions

Additional gastrectomy with lymph-node dissection might improve the survival of early-stage gastric-cancer patients after non-curative endoscopic resection. However, risk stratification should be performed to avoid excessive treatment.

The incidence of lymph node metastasis in submucosal early gastric cancer according to the expanded criteria: a systematic review

BACKGROUND

For successful endoscopic treatment of early gastric cancer (EGC), absolute criteria for a curative en bloc resection were initially established to include predominantly differentiated mucosal lesions ≤ 2 cm in diameter without ulceration. These indications were subsequently expanded to include larger, ulcerated, and predominantly undifferentiated mucosal lesions. In addition, differentiated type adenocarcinomas ≤ 3 cm with slight submucosal invasion of < 500 µm (pT1b1) are regarded as "curative" under the expanded criteria. However, data derived from studies of surgical specimens in patients with pT1b1 EGC have yielded varying rates of lymph node metastasis (LNM).

METHOD

A systemic review was conducted using the pooled analysis to calculate the incidence of LNM in pT1b1 EGC, and to investigate whether using a cut-off value of < 300 µm would decrease the risk of LNM in patients with submucosal EGC.

RESULTS

Nineteen articles were included. 1507 patients with pT1b1 EGC met the expanded indications. The incidence of LNM was 3% (45 out of 1507 patients). In a subgroup analysis of three studies, there was no significant difference in the LNM between pT1b EGC < 300 µm and < 500 µm [3/121(2.5%) vs. 5/180 (2.8%)] (OR 0.89, 95% CI 0.22-3.54).

CONCLUSION

Overall, expanding the indications for endoscopic resection of EGC to include lesions ≤ 3 cm T1b1 is associated with a potential risk of LNM of 3%. In countries outside of Japan, we found a slightly higher risk of LNM (4.0%). These estimates of LNM should be incorporated into decisions regarding further management of patients with EGC ≤ 3 cm who are found to have slight submucosal invasion (< 500 µm) in an ESD specimen. Standardization of specimen handling and histological evaluation is essential if the Japanese results of endoscopic treatment for EGC are to be successfully applied in other parts of the world.

The incidence of lymph node metastasis in early gastric cancer according to the expanded criteria in comparison with the absolute criteria of the Japanese Gastric Cancer Association: a systematic review of the literature and meta-analysis

BACKGROUND AND AIMS

Japanese criteria for curative endoscopic resection of early gastric cancer initially included nonulcerated, well-differentiated mucosal lesions ≤2 cm in diameter, known as the absolute criteria. Subsequently, these indications were expanded to include larger, ulcerated, and undifferentiated mucosal lesions as well as differentiated lesions with slight submucosal invasion. Whether patients meeting the expanded criteria can be managed safely without gastrectomy and lymph node dissection has been controversial. The risk of lymph node metastasis (LNM) in patients who met the expanded criteria is a critical factor in determining the best course of management for these patients.

METHODS

We comprehensively searched main reference databases for studies that included patients who underwent gastrectomy and lymph node dissection for early gastric cancer. A meta-analysis was conducted by using the random effects model. Relative risk reduction was used to compare the incidence of LNM in patients meeting the absolute criteria as compared with those meeting the expanded criteria.

RESULTS

Twelve studies met the inclusion criteria, providing a total of 9798 patients. The incidence of LNM was 0.2% for patients who met the absolute criteria as compared with 0.7% for patients who met the expanded criteria. Analysis of the various components of the expanded criteria was conducted, revealing that the incidence of LNM for differentiated mucosal lesions ≤3 cm with ulceration and for differentiated mucosal lesions without ulceration, irrespective of size, was 16 of 2814 (0.57%), reference range (RR) 3.01; P = .02 and 8 of 3004 (0.27%), RR 1.69; P = .37, respectively, only marginally higher than the risk of LNM associated with the absolute criteria. In contrast, undifferentiated mucosal lesions ≤2 cm and differentiated lesions <3 cm with slight submucosal invasion had a significantly higher incidence of LNM in comparison with the absolute criteria (25/972 [2.6%], RR 6.79; P = .0004 and 8/315 [2.5%], RR 6.30; P = .004, respectively).

CONCLUSION

Overall, expanding the indication for endoscopic resection to include mucosal nonulcerated differentiated lesions irrespective of size and differentiated mucosal ulcerated lesions <3 cm is justified with minimal increased risk in comparison to the absolute criteria. However, expanding the indication for undifferentiated lesions ≤2 cm and differentiated lesions with slight submucosal invasion (T1b) should be balanced with the risks of surgery, given the increased risk of LNM in these patients.

Management of early gastric cancer that meet the indication for radical lymph node dissection following endoscopic resection: a retrospective cohort analysis

BACKGROUND

Endoscopic resection (ER) has been widely accepted as the standard treatment for early gastric cancer (EGC). However, in patients considered to have undergone non-curative ER due to their potential risk of lymph node metastasis (LNM), additional gastrectomy is recommended. The aim of the present study was to identify EGC patients after non-curative ER at high risk of LNM.

METHODS

A total of 150 patients who had undergone ER for EGC were diagnosed as non-curative ER due to their potential risk of LNM. Clinicopathological data and clinical outcomes were examined retrospectively.

RESULTS

Additional gastrectomy with lymph node dissection was performed in 73 patients, and the remaining 77 patients were followed-up without additional gastrectomy. In patients who underwent additional gastrectomy, 8 patients had local residual tumor, and 8 patients had LNM, which were limited in the peritumoral nodes. Only lymphatic invasion (p = 0.012) was a statistically significant factor for LNM. The 5-year overall survival and recurrence-free survival were not significantly different between patients with and without additional gastrectomy.

CONCLUSION

Additional gastrectomy with lymph node dissection is recommended for patients who were diagnosed as non-curative ER with lymphatic invasion, and minimizing the extent of lymph node dissection may be allowed for these patients.

A Scoring System to Stratify Curability after Endoscopic Submucosal Dissection for Early Gastric Cancer: "eCura system"

OBJECTIVES

Although radical surgery is recommended for patients not meeting the curative criteria for endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) because of the potential risk of lymph node metastasis (LNM), this recommendation may be overestimated and excessive. We aimed to establish a simple scoring system for decision making after ESD.

METHODS

This multicenter retrospective study consisted of two stages. First, the risk-scoring system for LNM was developed using multivariate logistic regression analysis in 1,101 patients who underwent radical surgery after having failed to meet the curative criteria for ESD of EGC. Next, the system was internally validated by survival analysis in another 905 patients who also did not meet the criteria and did not receive additional treatment after ESD.

RESULTS

In the development stage, based on accordant regression coefficients, five risk factors for LNM were weighted with point values: three points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. Then, the patients were categorized into three LNM risk groups: low (0-1 point: 2.5% risk), intermediate (2-4 points: 6.7%), and high (5-7 points: 22.7%). In the validation stage, cancer-specific survival differed significantly among these groups (99.6, 96.0, and 90.1%, respectively, at 5 years; P<0.001). The C statistic of the system for cancer-specific mortality was 0.78.

CONCLUSIONS

This scoring system predicted cancer-specific survival in patients who did not meet the curative criteria after ESD for EGC. ESD without additional treatment may be an acceptable option for patients at low risk.

Is radical surgery necessary in all patients who do not meet the curative criteria for endoscopic submucosal dissection in early gastric cancer? A multi-center retrospective study in Japan

BACKGROUND

Although radical surgery is routinely performed for patients who do not meet the curative criteria for endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) due to the risk of lymph node metastasis (LNM), this standard therapeutic option may be excessive given the lower number of patients with LNM. Therefore, we aimed to investigate long-term outcomes and validate risk factors predicting recurrence after ESD.

METHODS

Of 15,785 patients who underwent ESD for EGC at 19 institutions between 2000 and 2011, 1969 patients not meeting the curative criteria were included in this multi-center study. Based on the treatment strategy after ESD, patients were divided into radical surgery (n = 1064) and follow-up (no additional treatment, n = 905) groups.

RESULTS

Overall survival (OS) and disease-specific survival (DSS) were significantly higher in the radical surgery group than in the follow-up group (p < 0.001 and p = 0.012, respectively). However, the difference in 3-year DSS between the groups (99.4 vs. 98.7 %) was rather small compared with the difference in 3-year OS (96.7 vs. 84.0 %). LNM was found in 89 patients (8.4 %) in the radical surgery group. Lymphatic invasion was found to be an independent risk factor for recurrence in the follow-up group (hazard ratio 5.23; 95 % confidence interval 2.01-13.6; p = 0.001).

CONCLUSIONS

This multi-center study, representing the largest cohort to date, revealed a large discrepancy between OS and DSS in the two groups. Since follow-up with no additional treatment after ESD may be an acceptable option for patients at low risk, further risk stratification is needed for appropriate individualized treatment strategies.

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.

Predictive factors for lymph node metastasis in additional gastrectomy after endoscopic resection of cT1aN0 gastric cancer

PURPOSE

Endoscopic therapy for clinical T1aN0 (cT1aN0) gastric cancer is an excellent therapeutic strategy; however, pathological lymph node metastasis (LNM) occasionally occurs. Patients who have a potential for LNM are subject to additional gastrectomy. Our aim was to identify predictors of LNM in additional gastrectomy.

METHODS

One hundred and twelve cT1aN0 gastric cancer patients undergoing additional gastrectomy after endoscopic resection were identified between 1997 and 2013. Predictors for LNM were initially selected by a univariate analysis and applied to a multivariate analysis.

RESULTS

(1) Twelve patients (10.7 %) had LNM following additional gastrectomy. (2) Clinicopathological factors significantly associated with LNM were the depth of invasion (SM2 or deeper, designated as SM2) (p = 0.0018) and rigorous lymphatic invasion (ly2,3) (p < 0.001). (3) The univariate predictors for LNM were applied to the multivariate logistic regression model, and SM2 (p = 0.0027) and ly2,3 (p = 0.0028) remained significant predictors. (4) When classified into 2 × 2 subgroups, the predictability for LNM was as follows: SM2 plus ly2,3 (46.7 %), SM2 plus ly0,1 (10.0 %), M,SM1 plus ly2,3 (0 %), and M,SM1 plus ly0,1 (0 %).

CONCLUSIONS

In cT1aN0 gastric cancer patients, both SM2 and ly2,3 are significant predictors for LNM that may be important as references for additional gastrectomy after endoscopic resection.

Predictors of lymph node metastasis in patients with non-curative endoscopic resection of early gastric cancer

BACKGROUND

Although surgery is recommend for non-curative endoscopic resection of early gastric cancer (EGC), only a part of patients are found to have lymph node (LN) metastasis. This study aimed to identify the predictors of LN metastasis in patients with non-curative endoscopic resection.

METHODS

Between April 2005 and July 2013, consecutive patients who received non-curative endoscopic resection and then underwent gastrectomy with lymphadenectomy or followed at least 1 year with abdominal computed tomography were retrospectively enrolled at a single tertiary hospital. Non-curative resection was defined as a resection beyond the expanded criteria in pathologic mapping. The predictors for LN metastasis were identified by fitting a multivariate logistic regression model.

RESULTS

Among the 1783 consecutive patients who received endoscopic resection of EGC, non-curative resection was performed in 323 (18.1%) patients. Of these patients, a total of 267 patients were enrolled, and the rate of LN metastasis was 6.7% (18/267). In multivariate analysis, venous invasion [odds ratio (OR), 7.83; 95% confidence interval (CI) 2.20-27.86; p = 0.001], sm2 invasion (tumor invasion ≥500 µm into submucosa; OR 4.98; 95% CI 1.34-18.47; p = 0.016), or antral tumor location (OR 12.65; 95% CI 1.57-102.00; p = 0.017) were independent predictors for LN metastasis. The rates of LN metastasis were 1.1% (95% CI 0-2.7) for patients with one or no predictor and 17.8% (95% CI 9.7-25.8) for those with two or more predictors.

CONCLUSIONS

Additional gastrectomy with lymphadenectomy after non-curative endoscopic resection of EGC is recommended for the patients with two or more identified predictors. However, close follow-up without immediate surgery might be considered cautiously for those with only one or no predictor.

Sonic hedgehog pathway contributes to gastric cancer cell growth and proliferation

The Sonic Hedgehog (Shh) signaling pathway is commonly activated in gastrointestinal cancer. However, our understanding of the Shh pathway in gastric cancer remains limited. Here we examined the effects of cyclopamine, a specific inhibitor of the Shh signaling pathway, on cell growth and proliferation in gastric primary cancer cells GAM-016 and the MKN-45 cell line. The results showed that the Shh signaling molecules SHH, PTCH, SMO, GLI1, and GLI2 were intact and activated in both types of cells. Furthermore, we observed that cyclopamine inhibited gastric cancer cell proliferation through cell cycle arrest and apoptosis. An in vivo study using NOD/SCID mouse xenografts demonstrated that cyclopamine significantly prevented tumor growth and development. Our study indicated that Shh signaling pathway could promote gastric cancer cell proliferation and tumor development, and blocking this pathway may be a potential strategy in gastric cancer treatment.