Clinical outcomes of early gastric cancer with lateral margin positivity after endoscopic submucosal dissection

Long-term Outcomes of Patients With Early Gastric Cancer Who Had Lateral Resection Margin-Positive Tumors Based on Pathology Following Endoscopic Submucosal Dissection

PURPOSE

Long-term outcomes of patients with positive lateral margins (pLMs) after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study aimed to evaluate the remnant cancer and survival rates of patients with pLMs compared with those who underwent curative resection.

MATERIALS AND METHODS

A retrospective analysis was performed on consecutive patients with pLMs as the only non-curative factor of expanded indication who underwent ESD for EGC with a follow-up duration of 5 years or more. The rates of remnant cancer, recurrence, and survival were analyzed and compared to those of control patients who underwent curative resection by propensity score matching.

RESULTS

Among 3,515 patients treated with ESD between 2005 and 2018, 123 non-curative EGCs were retrospectively analyzed. A total of 108 patients were followed up without endoscopic or surgical resection for 8.2 years. The control group was matched in a 1:1 ratio with patients with EGC who underwent curative resection after ESD. The observation group with pLMs had a higher incidence of remnant cancer (25.9%; 28/108) compared to that in the curative resection group (0/108; P=0.000). The remaining tumors were treated with surgical or endoscopic resection, and no additional recurrences were observed. The overall survival analysis demonstrated no significant difference between the observation and curative resection groups (P=0.577).

CONCLUSIONS

No difference was observed in the overall survival rate between observation and curative resection groups. Therefore, observation may be a possible option for incomplete ESD with pLMs if continuous follow-up is performed.

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.

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)

Risk-Scoring System for Prediction of Non-Curative Endoscopic Submucosal Dissection Requiring Additional Gastrectomy in Patients with Early Gastric Cancer

Purpose

When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required.

Materials and Methods

Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set.

Results

Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%.

Conclusions

We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

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.

A systematic review and meta-analysis on outcomes after Rx or R1 endoscopic resection of superficial gastric cancer

OBJECTIVE

Endoscopic resection is a standard treatment for gastric superficial lesions. A positive or a nonevaluable margin is considered a noncurative criterion. We aimed to systematically review recurrence, residual disease, lymph node metastasis (LNM) and cancer-related death following Rx/R1 resection of gastric lesions in the absence of other noncurative criteria.

MATERIALS AND METHODS

MEDLINE systematic review and meta-analysis by July 2014.

RESULTS

Data were extracted from 31 manuscripts. Definitions and results differed significantly. However, nonevaluable (HMx) and positive horizontal margins (HM1) were associated with 10% [95% confidence interval (CI) 5-15%] and 36% (95% CI 24-48%) rates of recurrence/residual disease, respectively, with an odds ratio of 2.85 (95% CI 1.6-5.8, P<0.01) for HM1 compared with HMx. Nonevaluable (VMx) or positive (VM1) vertical margin was associated with a 43% (95% CI 17-68%) rate of recurrence/residual. VMx/VM1 was associated with a higher risk of recurrence/residual compared with HMx/HM1 (odds ratio 3.76, 95% CI 1.71-6.82, P<0.01). The most common strategy after HMx/HM1 was endoscopic surveillance and retreatment, whereas surgery was recommended after VMx/VM1. No cases of LNM or cancer-related death were noticeable if neither submucosal invasion more than 500 µm nor lymphovascular infiltration was also reported.

CONCLUSION

Rx/R1 resection in the absence of other noncurative criteria does not appear to be a significant risk factor for LNM or cancer-related death. The risk of recurrence/residual disease is higher after HM1 than HMx and higher after VMx/VM1 than HMx/HM1. However, considerable heterogeneity was found in studies. Standard definitions should be created and applied in future studies.

Endoscopic prediction of tumor margin and invasive depth in early gastric cancer

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related deaths in the world. The prognosis of GC is clearly associated with the tumor stage, with a 5-year overall survival rate for early gastric cancer (EGC) exceeding 90%, which is significantly higher than that of advanced gastric cancer. Endoscopic resection, including endoscopic mucosal resection and endoscopic submucosal dissection, has been adopted in recent decades as the first treatment option of EGC in many countries for its minimal invasion and high curative rate. However, the horizontal and vertical margins are related to the curative resection of EGC and the prognosis of patients. Thus the accurate prediction of the tumor boundary and its invasive depth before treatment counts for much in planning the most appropriate treatment strategy and promising curative resection. To date, various endoscopic techniques have been identified to play a role in pretreatment evaluation, such as white light endoscopy, chromoendoscopy, narrow band imaging and endoscopic ultrasonography. This article aimed to summarize the diagnostic methods, applications and limitations of these different endoscopic techniques for identifying tumor horizontal and vertical margins in EGC, helping to increase preoperative evaluation of capabilities and to improve the curative resection rate of EGC.

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

BACKGROUND

With the widespread use of endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC), the number of cases with incomplete resection due to positive lateral resection margins (LM+) is increasing. Local recurrence, which occurs frequently in LM+ cases, is an important issue. This study aimed to clarify the clinicopathological factors related to tumor recurrence in LM+ cases after ESD for EGC.

METHODS

From January 2005 to December 2012, a total of 1,083 patients with EGC underwent ESD at our hospital. Of these, cases with a pathological diagnosis of LM+ were included in this study. Patients with positive vertical resection margins, those who underwent surgical resection immediately or were followed up for less than 6 months after ESD, were excluded.

RESULTS

A total of 55 LM+ cases after ESD for EGC were enrolled. Incorrect delineation of a lesion that extended pathologically beyond the ESD marking dots was the main cause of LM+. Local recurrence was found in 20 (36.4 %) patients (median follow-up period, 23 months). Local recurrence rates related to LM+ length were as follows: 7/29 (24.1 %) in 2 mm, 6/16 (37.5 %) in 4 mm, 1/3 (33.3 %) in 6 mm, 4/5 (80 %) in 8 mm, and 2/2 (100 %) in ≥ 10 mm. In multivariate analysis, tumor size > 2 cm (OR 4.48, 95 % CI 1.18-16.99, p = 0.027), and LM+ length > 6 mm (OR 7.65, 95 % CI 1.15-50.70, p = 0.035) were independent risk factors for tumor recurrence.

CONCLUSION

To decrease the risk of LM+, it is highly important to accurately delineate the lateral margins during ESD; when the final histopathological result is LM+, cases with LM+ length >6 mm or tumor size > 2 cm should be considered for additional surgical resection or re-ESD because of a high risk of tumor recurrence.

Clinical outcomes of early gastric cancer with lymphovascular invasion or positive vertical resection margin after endoscopic submucosal dissection

BACKGROUND

In early gastric cancer (EGC) cases with lymphovascular invasion or positive vertical margins after endoscopic submucosal dissection (ESD), additional radical gastrectomy is performed on principle. However, an additional surgery is often difficult to consider if the surgical approach itself is challenging or the patient refuses surgery. In such cases, only close surveillance is performed without additional surgical procedures. This study aimed to examine the difference in clinical prognosis of EGC cases with lymphovascular invasion or positive vertical margins after ESD either with or without surgery.

METHODS

We retrospectively studied 83 patients with lymphovascular invasion or positive vertical margins after ESD from July 2005 to November 2013.

RESULTS

Of the 83 patients, 45 (54.2%) underwent radical additional gastrectomy (surgical group) and 38 (45.8%) were under close surveillance without surgical or endoscopic treatments (close surveillance group.) The cancer-free survival period was 78.3 ± 3.4 months in the surgical group and 64.5 ± 4.6 months in the close surveillance group. The recurrence rates did not significantly differ between the 2 groups, at 7.9% in the surgical group and 6.7% in the non-surgical group.

CONCLUSIONS

Close surveillance may be suggested as an option for EGC patients for whom a surgical approach is difficult, who exhibit a positive vertical margin after ESD, and who have no lymphovascular or deep submucosa invasion after ESD.