Clinical Outcomes of Gastrectomy after Incomplete EMR/ESD

A Diagnostic Method for Gastric Cancer Using Two-Photon Microscopy With Enzyme-Selective Fluorescent Probes: A Pilot Study

BACKGROUND

Endoscopy is the most important tool for gastric cancer diagnosis. However, it relies on naked-eye evaluation by endoscopists, and the histopathologic confirmation is time-consuming. We aimed to visualize and measure the activity of various enzymes through two-photon microscopy (TPM) using fluorescent probes and assess its diagnostic potential in gastric cancer.

METHODS

β-Galactosidase (β-gal), carboxylesterase (CES), and human NAD(P)H: quinone oxidoreductase (hNQO1) enzyme activities in the normal mucosa, ulcer, adenoma, and gastric cancer biopsy samples were measured using two-photon enzyme probes. The fluorescence emission ratio at long and short wavelengths (Ch2/Ch1) for each probe was comparatively analyzed. Approximately 8,000 - 9,000 sectional images in each group were obtained by measuring the Ch2/Ch1 ratio according to the tissue depth. Each probe was cross-validated by measuring enzymatic activity from a solution containing lysed tissue.

RESULTS

Total of 76 subjects were enrolled in this pilot study (normal 21, ulcer 18, adenoma 17, and cancer 20 patients, respectively). There were significant differences in the mean ratio values of β-gal (0.656 ± 0.142 vs. 1.127 ± 0.109, P < 0.001) and CES (0.876 ± 0.049 vs. 0.579 ± 0.089, P < 0.001) between the normal and cancer, respectively. The mean ratio value of cancer tissues was different compared to ulcer and adenoma (P < 0.001). The hNQO1 activity showed no significant difference between cancer and other conditions. Normal mucosa and cancer were visually and quantitatively distinguished through β-gal and CES analyses using TPM images, and enzymatic activity according to depth, was determined using sectional TPM ratiometric images. The results obtained from lysis buffer-treated tissue were consistent with TPM results.

CONCLUSIONS

TPM imaging using ratiometric fluorescent probes enabled the discrimination of gastric cancer from normal, ulcer, and adenoma. This novel method can help in a visual differentiation and provide quantitative depth profiling in gastric cancer diagnosis.

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.

Comparing long-term outcomes between endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for type II esophagogastric junction neoplasm

Background

Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are used to remove esophagogastric junction (EGJ) neoplasm. This study aimed to compare feasibility, safety, and effectiveness between ESD and EMR to help endoscopists choose treatment methods.

Methods

A total of 130 patients with EGJ neoplasm underwent endoscopic resection, including 52 patients with EMR and 78 patients with ESD. Cap-assisted EMR (EMRC) was performed with typical sequences. Larger lesions required removal in multiple pieces (i.e., piecemeal EMR). The ESD procedures were included that marking the periphery of the lesion, submucosa injected, circumferentially cutting and submucosal dissection. Resection time, adverse events, en bloc resection rate, R0 resection rate and recurrence rate were compared between the two groups.

Results

There were no significant differences in demographic characteristics or histopathological features between the two groups. Resection time was longer in the ESD group than in the EMR group (64.4±33.9 vs. 22.1±8.0 minutes; P<0.01). Adverse events were more common in the ESD group than in the EMR group (16.7% vs. 3.8%; P=0.03), including bleeding (7.7% vs. 3.8%), perforation (5.1% vs. 0%) and stenosis (5.1% vs. 0%). The en bloc resection rate and R0 resection rate were much higher in the ESD group than in the EMR group (98.7% and 92.3% vs. 23.1% and 23.1%, respectively; P<0.01). The 5-year overall survival rate and disease-free survival rate were 100% vs. 92.0% and 100% vs. 90.1% between the ESD and EMR groups, respectively (P=0.01 and P=0.01). The 5-year cancer-specific survival rate was 100% vs. 96.0% between the ESD and EMR groups (P=0.08). The recurrence rate was lower in the ESD group than in the EMR group (0% vs. 9.6%; P=0.01).

Conclusions

ESD is an acceptable first-line endoscopic treatment for type II EGJ neoplasm, however, it is time-consuming and has a higher rate of adverse events. Furthermore, EMR is a safe and alternative technique, particularly when EMR could achieve en bloc resection.

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).

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.

Safety and effectiveness of endoscopic mucosal resection or endoscopic submucosal dissection for gastric neoplasia within 2 days' hospital stay

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been well-established methods of treating upper gastrointestinal neoplasia. The aim of this study was to identify the safety and effectiveness of endoscopic treatment for gastric neoplasia within a 2-day hospital stay.Between 2004 and 2015, a total of 914 patients with gastric neoplasia were treated with EMR or ESD within 2 days of hospitalization. The neoplasia sites, en bloc resection rates, pathology, local residual neoplasia rates, and major complications were evaluated retrospectively.The mean age was 63.4 years old, and 636 (69.6%) patients were male. Adenoma was the most common final diagnosis (60.9%), followed by adenocarcinoma (28.9%). The first follow-up endoscopy was performed 4.9 ± 1.1 months after the procedure, and an average of 4.4 endoscopic examinations were performed for 7.16 years (range, 2.1 to 10.2 years). Additional surgery was performed in 11 (1.2%) cases based on post-procedure pathology results. On follow-up endoscopy, a mean of 5.9 months after the procedure, there were 18 residual neoplasia cases (EMR = 13, ESD = 5). Only 4 (0.4%) patients returned to the emergency unit with delayed bleeding, but all 4 cases were successfully controlled with endoscopic treatment. There were no other complications such as delayed perforation or aspiration pneumonia during the 2 days in hospital.EMR and ESD within only 2 days in hospital showed safe and effective outcomes in terms of managing early gastric neoplasia with low complication and local residual rates.

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

BACKGROUND AND AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Aberrant metastatic behavior and particular features of early gastric cancer

In this paper, we have focused on the metastatic behavior of EGC and its particularities. The main factors that are currently considered as predictors of the metastatic behavior and that are used in the therapeutic decision (endoscopic resection vs surgical removal) are the tumor size (upper or bellow 2 cm), depth of infiltration, angiolymphatic invasion, the presence or absence of ulceration, and histologic type (undifferentiated vs differentiated carcinomas). However, most of the metastatic cases were published as case reports or case series. This is the reason why a proper estimation of metastatic risk in EGC is not well known. To date, 79 cases presenting bone metastases, three reports of brain metastases, and one EGC that was associated with skin metastasis were published. However, occult metastasis, lymph node micrometastasis, and skip metastasis can also occur and should be identified. Making a synthesis of the literature data that is correlated with our experience, we finally proposed the inclusion of the six Japanese subgrouping system, tumor size, angiolymphatic invasion, and micrometastasis as components of the pTNM staging system, which should be particularly adapted for EGC.

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.

A case of endoscopic full-thickness resection in a patient with gastric high-grade dysplasia unsuitable for endoscopic submucosal dissection

Gastric high-grade dysplasia is an important premalignant lesion in gastric epithelial cells and has a high possibility of transforming to adenocarcinoma. Therefore, biopsy-proven high-grade dysplasia should be treated with en bloc resection methods such as endoscopic mucosal resection or endoscopic submucosal dissection (ESD). We report the case of a 63-year-old male patient, diagnosed with gastric high-grade dysplasia at the angle and lesser curvature side of the lower body. The patient was initially treated with ESD, although histopathology subsequently showed horizontal margin involvement. Since the lesion was diffusely edematous and margins were uncertain because of the previous ESD treatment, we chose to treat the patient with laparoscopy-assisted endoscopic full-thickness resection (EFTR). EFTR is a recently developed procedure, which uses both endoscopic and laparoscopic techniques to resect the full-thickness of the tissue. The final pathologic report revealed high-grade dysplasia and a focal intramucosal carcinoma of 0.8×0.7 cm. We conclude that EFTR can be an effective alternative treatment in gastric high-grade dysplasia unsuitable for ESD.

Is there an optimal surgery time after endoscopic resection in early gastric cancer?

BACKGROUND

The patients with early gastric cancer who have undergone incomplete endoscopic resection (ER) generally need additional surgery because of the possibility of lymph node metastasis. The aim of study was to evaluate the optimal time interval from ER to additive surgery by evaluating the effect of time interval on the surgical and oncological outcomes.

METHODS

We analyzed 154 patients who underwent additive gastrectomy after incomplete ER at Severance and Gangnam Severance Hospitals. The time interval point, at which operative time and estimated intraoperative blood loss (EBL) of the earlier operation group and the later operation group showed the greatest disparities, was evaluated. The patients were divided into 2 groups according to the time interval point, as the earlier operation group (group A) and the later operation group (group B). We retrospectively evaluated the clinicopathological characteristics and surgical and oncological outcomes.

RESULTS

The greatest difference between operative time and EBL was in the groups who underwent operation before and after 29 days. Of the 154 patients, 78 were in group A (≤29 days) and 76 in group B (>29 days). There were no differences in the clinicopathological characteristics and oncological outcomes except for tumor size. The operative time and EBL were significantly longer and more in group A compared with group B.

CONCLUSIONS

The time interval between ER and additive surgery is associated with surgical outcomes. Additive surgery at about 1 month after ER may be optimal for better surgical outcomes without affecting the oncological outcomes.

Evidence-based review of the management of early gastric cancer

Although standard gastrectomy remains the most definitive locoregional treatment for early gastric cancer, it carries significant perioperative morbidities. Surgical gastrectomy for resection of lymph nodes is not always required and endoscopic resection may be a treatment option for patients at negligible risk of lymph node metastasis. Furthermore, the criteria for endoscopic resection are expanding, along with the development of new technology, in both Eastern and western countries with high prevalence of early gastric cancer, where studies for endoscopic treatment modalities have been conducted. Within such a trend, however, it should be emphasized that early gastric cancer needs to be treated cautiously, especially in western countries, as several studies suggest that there may be differences in tumor biology and aggressiveness between Asian and non-Asian populations.

Afferent loop obstruction following laparoscopic distal gastrectomy with Billroth-II gastrojejunostomy

Purpose

Afferent loop (A-loop) obstruction is an uncommon postgastrectomy complication following Billroth-II (B-II) or Roux-en-Y reconstruction. Moreover, its development after laparoscopic gastrectomy has not been reported. Here we report 4 cases of A-loop obstructions after laparoscopic distal gastrectomy (LDG) with B-II reconstruction.

Methods

Among the 396 patients who underwent LDG with a B-II anastomosis between April 2004 and December 2011, 4 patients had A-loop obstruction. Their data were obtained from a prospectively maintained institutional database and analyzed for outcomes.

Results

Four patients (1.01%) developed A-loop obstruction. All were male, and their median age was 52 years (range, 30 to 73 years). The interval between the initial gastrectomies and the operation for A-loop obstruction ranged from 4 to 540 days (median, 33 days). All 4 patients had symptoms of vomiting and abdominal pain and were diagnosed by abdominal computed tomographic (CT) scan. The causes of the A-loop obstructions were adhesions (2 cases) and internal herniations (2 cases) that were treated with Braun anastomoses and reduction of the herniated small bowels, respectively. All patients recovered following the emergency operations.

Conclusion

A-loop obstruction is a rare but serious complication following laparoscopic and open gastrectomy. It should be considered when a patient complains of continuous abdominal pain and/or vomiting after LDG with B-II reconstruction. Prompt CT scan may play an important role in diagnosis and treatment.

Tissue engineering of the stomach

Tissue engineering combines engineering principles with the biological sciences to create functional replacement tissues. The underlying principle of tissue engineering is that isolated cells combined with biomaterials can form new tissues and organs in vitro and in vivo. This review focuses on stomach tissue engineering, which is a promising approach to the treatment of gastric cancer, the fourth most common malignancy in the world and the second-leading cause of cancer mortality worldwide. Although gastrectomy is a reliable intervention to achieve complete removal of cancer lesions, the limited capacity for food intake after resection results in lower quality of life for patients. To address this issue, we have developed a tissue-engineered stomach to increase the capacity for food intake by creating a new food reservoir. We have transplanted this neo-stomach as a substitute for the original native stomach in a rat model and confirmed functional adaptation. Furthermore, we have demonstrated the feasibility of transplanting a tissue-engineered gastric wall patch in a rat model to alleviate the complications after resection of a large area of the gastric wall. Although progress has been achieved, significant challenges remain to bring this approach to clinical practice. Here, we summarize our work and present the state of the art in stomach tissue engineering.

Metachronous liver and bone metastasis from small early gastric carcinoma without lymph node involvement: A case report

A 65-year-old man was referred to our Hospital for examination of gastric cancer initially diagnosed by medical check-up. Esophagogastroduodenoscopy demonstrated a superficial depressed-type gastric cancer in the antrum, and abdominal computed tomography showed no evidence of distant metastases. A tumor measuring 11 mm in diameter was removed by endoscopic submucosal dissection (ESD). Since histological examinations of ESD specimens showed a well-differentiated adenocarcinoma invading the submucosal layer with lymphatic invasion, the patient subsequently underwent laparoscopy-assisted distal gastrectomy with regional lymph node dissection, resulting in no residual carcinoma and no lymph node metastasis. The patient developed solitary liver metastasis one year later and was treated with trastuzumab plus capecitabine/cisplatin since results of the immunohistochemical analysis of the resected specimens demonstrated overexpression of the human epidermal growth factor receptor 2 (HER2). The patient was alive 12 months after surgical resection of the liver metastasis and subsequently developed bone metastasis. Controversy remains over the role of HER2 status as a prognostic factor in gastric cancer. However, it has been generally reported that HER2 overexpression correlates with aggressive biological behavior and poor prognosis. HER2 overexpression is a potentially useful predictive factor for tumor recurrence and poor prognosis even in early gastric cancer cases.