Therapy For Early Gastric Cancer Research Articles

Venous Invasion Is a Risk Factor for Recurrence of pT1 Gastric Cancer with Lymph Node Metastasis

BackgroundPostoperative adjuvant therapy for early gastric cancer (EGC) has not been widely studied, and there are differing indications for postoperative adjuvant therapy between Western and Asian countries. Japanese gastric cancer treatment guidelines do not recommend adjuvant chemotherapy for EGC, but it is unclear whether surgery alone is the most appropriate treatment. MethodsThis is a single-center retrospective study of 1001 consecutive patients who underwent radical gastrectomy for pT1 gastric cancer between 1999 and 2013 at the Wakayama Medical University Hospital. ResultsRecurrence was observed in 12 patients, nine of whom as the result of hematogenous metastasis. In all patients with pT1 gastric cancer (n = 1001), lymph node metastasis was identified as an independent predictive factor for recurrence (hazard ratio [HR] = 10.910, P = 0.002). In patients with pT1N + gastric cancer, however, the 5-year disease-specific survival (DSS) rate was still high, 90.8%. In patients with pT1N + gastric cancer (n = 97), the presence of venous invasion (pT1N + v +) was identified by univariate and multivariate analyses as an independent risk factor for recurrence (HR = 4.791, P = 0.032). In patients with venous invasion, the 5-year DSS rate was significantly lower than that in those without venous invasion (79.3% vs. 95.2%, P = 0.018). ConclusionsLong-term prognosis of patients with EGC with lymph node metastasis is good, but venous invasion is associated with a higher risk of recurrence. Selective application of postoperative adjuvant chemotherapy for pT1N + v + gastric cancer may efficiently improve prognosis among patients with EGC.

Tumor-Associated Neutrophils Can Predict Lymph Node Metastasis in Early Gastric Cancer.

The consensus of endoscopic therapy for early gastric cancer (EGC) mainly depends on its clinicopathological features. However, the roles of tumor-associated neutrophils (TANs) in EGC remain uncertain. Here, we explored its predictive role for lymph node metastasis (LNM) in EGC. Three hundred twenty-two patients who underwent radical gastrectomy for EGC were enrolled. Preoperative peripheral blood was used to analyze the neutrophil-to-lymphocyte ratio (NLR), and the different status of TANs was determined by hematoxylin-and-eosin staining (H&E) and immunohistochemistry (IHC). TANs, rather than NLR, were positively associated with tumor size, Lauren classification, lymphovascular invasion (LVI), and LNM. Univariate analysis revealed that TANs were associated with LNM as well as tumor size, depth of invasion, Lauren classification, histological classification, LVI, and perineural invasion. In addition to histological classification and LVI, TANs were found to be an independent risk factor for LNM in EGC (P = 0.013). Stratification analysis by depth of invasion showed LVI in SM1 tumor, and both LVI and TANs (P = 0.042) in SM2 tumor were independent risk factors for LNM. In conclusion, TANs in EGC can predict LNM, and TANs may help to estimate LNM precisely in addition to the current criteria.

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.

The Expression of VEGFR2 and VEGFR3 in Early Gastric Cancer and Its Clinical Significance

Background: To explore the expression and its clinical significance of vascular endothelial growth factor receptor II and III (VEGFR2 and VEGFR3) in early gastric cancer.Methods: Immunohistochemical method is applied to detect 120 cases of early gastric cancer and normal gastric tissue of its cut edge in the expression of VEGFR2 and VEGFR3.Results: The positive expression rates of VEGFR2 and VEGFR3 in early gastric cancer are 75% and 60%, which are higher than in normal gastric tissues of cut edge (22.5%, 12.5%), respectively. The expression of VEGFR2 and VEGFR3 is associated with depth of invasion, lymph node metastasis (P 0.05).Conclusion: VEGFR2 and VEGFR3 play important roles in occurrence and development of early gastric cancer, which potentially provides a basis for targeted molecular therapy of early gastric cancer.

An update in the endoscopic management of gastric cancer.

Gastric cancer remains a leading cause of mortality worldwide and gastroenterologists are playing an increasingly larger role in its management. This article reviews the endoscopic management of gastric cancer, with emphasis on recent advances in the field. Long-term studies comparing surgery and endoscopic resection for early gastric cancer have shown no difference in 10-year survival rates. Second-look endoscopy, performed 2 days after endoscopic submucosal dissection (ESD) to address the concern of delayed bleeding, may not affect rebleeding rates. Magnesium, proton pump inhibitors, and bupivacaine may help reduce post-ESD pain. New devices such as the Clutch Cutter and EndoLifter may help make ESD easier and safer. Endoscopic therapy for early gastric cancer is becoming increasingly popular and innovations are constantly being made to improve technique and technology. This review focuses on the latest approaches to the endoscopic management of gastric cancer.

Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer.

ObjectiveHuman induced pluripotent stem (iPS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human iPS cells labeled with fluorescent magnetic nanoparticles (FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo.MethodsHuman iPS cells were prepared and cultured for 72 h. The culture medium was collected, and then was co-incubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human iPS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly.ResultsiPS cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iPS cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field.ConclusionFMNP-labeled human iPS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer.

Web Survey of Society Members' Recognition of Guidelines for the Diagnosis and Treatment ofHelicobacter pyloriInfection in Korea, 2013 Revised Edition

2 , Incheon, Korea Background/Aims: We aimed to evaluate recognition of the 2013 revised guidelines for diagnosis and treatment of Helicobacter py- lori infection in Korea by members of the society through a web survey. Materials and Methods: We analyzed the respondents' agreement with the 19 guidelines in terms of awareness and adherence. Among 718 physicians, 149 (20.8%) answered the questionnaire by e-mail between October and November 2013. Results: The mean age of the respondents was 40±7 years, and the ratio of men to women were 74.5:25.5. The respondents were as follows: professors (36.2%), fellows (31.5%), salaried doctors (17.4%), private practitioners (11.4%), and screening center clini- cians (3.4%). Among the 141 respondents, 69.1% had read, 17.3% agreed completely, and 77.3% agreed generally with the guidelines. The respondents indications for eradication were peptic ulcer disease (77.2%), MALT lymphoma (89.3%), and follow- ing endoscopic therapy for early gastric cancer (71.1%). However, 42.3% and 48.3% of the physicians administered H. pylori erad- ication treatment for patients with atrophic gastritis and a family history of gastric cancer, respectively. Triple therapy as first line regimens was administered by 81.2% of the respondents. The duration was one-week for 77.7% and two-weeks for 13.4%. A total of 55.7% prescribed a bismuth-based secondary treatment. When bismuth-based initial therapy failed, a combination of 2 anti- biotics that were not used as first-line therapy were used (37.6%). Conclusions: This web survey was very helpful for analyzing society members' recognition of 2013 revised guidelines. Generally, all the society members followed the guidelines. (Korean J Helicobacter Up Gastrointest Res 2015;15:95-102)

Endoscopic therapy for early gastric cancer: standard techniques and recent advances in ESD.

The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.

Metachronous gastric cancer after successful Helicobacter pylori eradication.

The high incidence of gastric cancer in Japan initially resulted in establishment of a country-wide gastric cancer screening program to detect early and treatable cancers. In 2013 countrywide Helicobacter pylori (H. pylori) eradication was approved coupled with endoscopy to assess for the presence of chronic gastritis. Current data support the notion that cure of the infection in those with non-atrophic gastritis will prevent development of gastric cancer. However, while progression to more severe damage is halted in those who have already developed, atrophic gastritis/gastric atrophy remain at risk for subsequent development of gastric cancer. That risk is directly related to the extent and severity of atrophic gastritis. Methods to stratify cancer risk include those based on endoscopic assessment of the atrophic border, histologic grading, and non-invasive methods based on serologic testing of pepsinogen levels. Continued surveillance is required because those with atrophic gastritis/gastric atrophy retain considerable gastric cancer risk even after H. pylori eradication. Those who have already experienced a resectable early gastric cancer are among those at highest risk as metachronous lesions are frequent even after H. pylori eradication. We review the role of H. pylori and effect of H. pylori eradication indicating the incidence and the predictive factors on development of metachronous cancer after endoscopic therapy of early gastric cancer. Studies to refine risk markers to stratify for risk, surveillance methods, intervals, and duration after successful H. pylori eradication, and whether adjuvant therapy would change risk are needed.

Predictive risk factors of perforation in gastric endoscopic submucosal dissection for early gastric cancer: a large, multicenter study

Although endoscopic submucosal dissection (ESD) is standard therapy for early gastric cancer, the complication rate is unsatisfactory, with perforation as the major complication during ESD. There have been several reports regarding the complications of ESD for gastric tumor especially perforation; however, little is known about the predictors for complications in patients undergoing ESD. The purpose of this retrospective study was to determine the risk factors for perforation in patients with early gastric cancer during ESD. Between February 2003 and May 2010, we performed ESD for 1,289 lesions in 1,246 patients at six tertiary academic hospitals in Daegu, Kyungpook, Korea. Patient-related variables (age, sex, and underlying disease), endoscopic-related variables (indication of ESD, lesion size, location, type, and mucosal ulceration), procedure-related variables (operation time, complete resection, and invasion of submucosa/vessel/lymph node), and the pathologic diagnosis were evaluated as potential risk factors. The mean age of the patients was 64 years. The mean size of the endoscopic lesion was 19.4 mm. The overall en bloc resection rate was 93.3 %. Perforation (microperforation and macroperforation) was seen in 35 lesions. The location of the lesion (long axis: body/short axis: greater and lesser curvature) and piecemeal resection were associated with perforation (p = 0.01/0.047 and p = 0.049). Upon multivariate analysis, the location (body vs. antrum) of the lesion (odds ratio (OR) 2.636; 95 % confidence interval (CI) 1.319-5.267; p = 0.006) and piecemeal resection (OR 2.651; 95 % CI 1.056-6.656; p = 0.038) were significant predictive factors for perforation. The result of this study demonstrated that the location of the lesion (body) and piecemeal resection were related to perforation during ESD.

Fluorescent magnetic nanoparticle-labeled mesenchymal stem cells for targeted imaging and hyperthermia therapy of in vivo gastric cancer

How to find early gastric cancer cells in vivo is a great challenge for the diagnosis and therapy of gastric cancer. This study is aimed at investigating the feasibility of using fluorescent magnetic nanoparticle (FMNP)-labeled mesenchymal stem cells (MSCs) to realize targeted imaging and hyperthermia therapy of in vivo gastric cancer. The primary cultured mouse marrow MSCs were labeled with amino-modified FMNPs then intravenously injected into mouse model with subcutaneous gastric tumor, and then, the in vivo distribution of FMNP-labeled MSCs was observed by using fluorescence imaging system and magnetic resonance imaging system. After FMNP-labeled MSCs arrived in local tumor tissues, subcutaneous tumor tissues in nude mice were treated under external alternating magnetic field. The possible mechanism of MSCs targeting gastric cancer was investigated by using a micro-multiwell chemotaxis chamber assay. Results show that MSCs were labeled with FMNPs efficiently and kept stable fluorescent signal and magnetic properties within 14 days, FMNP-labeled MSCs could target and image in vivo gastric cancer cells after being intravenously injected for 14 days, FMNP-labeled MSCs could significantly inhibit the growth of in vivo gastric cancer because of hyperthermia effects, and CCL19/CCR7 and CXCL12/CXCR4 axis loops may play key roles in the targeting of MSCs to in vivo gastric cancer. In conclusion, FMNP-labeled MSCs could target in vivo gastric cancer cells and have great potential in applications such as imaging, diagnosis, and hyperthermia therapy of early gastric cancer in the near future.

Risk Factors for Perforation with Endoscopic Mucosal Dissection

Endoscopic mucosal dissection (ESD) is now commonly used as therapy for early gastric cancers in countries with high prevalence. Bleeding and perforation are the most common potential complications. To identify predictors for perforation, investigators retrospectively studied ESD outcomes in 1500 patients in a single …

Endoskopische Therapie von Magenfrühkarzinomen

Endoscopic treatment of early gastric cancer has been shown to be effective and safe. It is a minimally invasive and organ-preserving treatment approach that can safely be used as an alternative to surgical resection. A prerequisite of any endoscopic treatment with a curative intent is a very low risk of lymph node metastasis of the lesion intended to be endoscopically resected. As in high-volume surgical centers all endoscopic procedures with a curative intent should also be carried out in centers with a high expertise in the different endoscopic resection (ER) techniques available, the major techniques being suck-and-cut ER and endoscopic submucosal dissection (ESD). Because of the risk of secondary neoplasia after curative endoscopic therapy, a standardized follow-up protocol is required. The majority of secondary neoplastic lesions can again be treated endoscopically. In the present article an overview of initial staging procedures, techniques, indications, as well as follow-up strategies after endoscopic therapy for early gastric cancer is given.

Risk for local recurrence of early gastric cancer treated with piecemeal endoscopic mucosal resection during a 10-year follow-up period

Endoscopic mucosal resection (EMR) is a therapy for early gastric cancer (EGC) that can be provided relatively easily and safely in any institution. Identification of the resection margin is a problem in EMR, especially in cases of piecemeal EMR. Despite the long-standing widespread use of piecemeal EMR for EGC, its limitation and long-term outcomes in clinical practice have not been fully evaluated. This study aimed to determine the risk factors of piecemeal EMR, the local recurrence rates, and the mortality rate. A cross-sectional, retrospective cohort study was performed to investigate the risks of piecemeal EMR for patients with the diagnosis of differentiated adenocarcinoma localized to the mucosa. Local recurrence of EGC was investigated by annual follow-up esophagogastroduodenoscopy (EGD) for 10years. EMR was performed with snare electrocautery using a two-channel scope. When a resection margin was clearly positive for cancer, additional surgery was performed soon after the initial EMR. For the 149 EGC patients (mean age, 68.8±9.8; male, 77%) who underwent EMR between 1995 and 2001, EMR was performed en bloc in 66 cases and piecemeal in 83 cases. The comorbid conditions existing in 34 of the 149 patients included other malignancies (n=12), heart failure (n=5), pulmonary disease (n=7), liver cirrhosis (n=4), and other illness (n=6). However, EMR was completed without complication. The mean area (length×width) of the lesions was 404±289mm(2) in the piecemeal group and 250±138mm(2) in the en bloc groups. The en bloc and piecemeal EMR groups differed significantly in terms of unclear horizontal margins but not in terms of unclear vertical margins. Multiple logistic regression suggested that the adjusted odds ratio for maximum diameters exceeding 20mm for piecemeal EMR was 2.71 (95% confidence interval [CI], 1.30-5.64). According to Kaplan-Meier estimates, the local recurrence rate was 30% (95% CI, 20-40%) at both 5 and 10years. No recurrence was observed in the en bloc group. The adjusted hazard ratio of unclear horizontal margins for local recurrence was 1.63 (95% CI, 1.12-2.36). A total of 24 patients died after EMR because of comorbid conditions, including other malignancies (n=11), cardiovascular disease (n=6), pulmonary disease (n=4), liver cirrhosis (n=2), and traffic accident (n=1). However, no patient died of gastric cancer during the 10-year follow-up period. An evaluation of horizontal margins in terms of local recurrence after piecemeal EMR is important, and en bloc resection is recommended. Close follow-up assessment is warranted, especially within 5years in cases of unclear margin resection after piecemeal EMR. The use of EMR is safe even for patients with severe comorbid conditions.

BRCAA1 monoclonal antibody conjugated fluorescent magnetic nanoparticles for in vivo targeted magnetofluorescent imaging of gastric cancer

BackgroundGastric cancer is 2th most common cancer in China, and is still the second most common cause of cancer-related death in the world. How to recognize early gastric cancer cells is still a great challenge for early diagnosis and therapy of patients with gastric cancer. This study is aimed to develop one kind of multifunctional nanoprobes for in vivo targeted magnetofluorescent imaging of gastric cancer.MethodsBRCAA1 monoclonal antibody was prepared, was used as first antibody to stain 50 pairs of specimens of gastric cancer and control normal gastric mucous tissues, and conjugated with fluorescent magnetic nanoparticles with 50 nm in diameter, the resultant BRCAA1-conjugated fluorescent magnetic nanoprobes were characterized by transmission electron microscopy and photoluminescence spectrometry, as-prepared nanoprobes were incubated with gastric cancer MGC803 cells, and were injected into mice model loaded with gastric cancer of 5 mm in diameter via tail vein, and then were imaged by fluorescence optical imaging and magnetic resonance imaging, their biodistribution was investigated. The tissue slices were observed by fluorescent microscopy, and the important organs such as heart, lung, kidney, brain and liver were analyzed by hematoxylin and eosin (HE) stain method.ResultsBRCAA1 monoclonal antibody was successfully prepared, BRCAA1 protein exhibited over-expression in 64% gastric cancer tissues, no expression in control normal gastric mucous tissues, there exists statistical difference between two groups (P < 0.01). The BRCAA1-conjugated fluorescent magnetic nanoprobes exhibit very low-toxicity, lower magnetic intensity and lower fluorescent intensity with peak-blue-shift than pure FMNPs, could be endocytosed by gastric cancer MGC803 cells, could target in vivo gastric cancer tissues loaded by mice, and could be used to image gastric cancer tissues by fluorescent imaging and magnetic resonance imaging, and mainly distributed in local gastric cancer tissues within 12 h post-injection. HE stain analysis showed that no obvious damages were observed in important organs.ConclusionsThe high-performance BRCAA1 monoclonal antibody-conjugated fluorescent magnetic nanoparticles can target in vivo gastric cancer cells, can be used for simultaneous magnetofluorescent imaging, and may have great potential in applications such as dual-model imaging and local thermal therapy of early gastric cancer in near future.

Abstract 3506: γ-secretase inhibitor enhances anti-cancer effects of 5-FU in gastric cancer

Abstract Surgery is the most effective therapy for early gastric cancers. In advanced gastric cancer (AGC), achievement of loco-regional control after tumor resection is less successful because of frequent recurrences after surgical and medical therapies. Combinations of 5-fluorouracil (5-FU) and platinum analogues or cytotoxic agents, such as capecitabine, cisplastin, oxaliplatin and S-1, are currently widely accepted as standard treatment for AGC. However, survival of AGC patients following sedative chemotherapy is poor. Therefore, the development of novel therapies has been needed, and some clinical studies already have been performed using novel molecular targeting agents have shown hopeful activity, particularly in combination with cytotoxic agents. Recently, the importance of Notch signal pathway has been reported in gastric cancer. Gamma-secretase inhibitors (GSI), a notch proteolytic activation blocker, can be considered as a novel target agent for gastric cancer. In this study, the anti-proliferation effects of GSI combined with 5-FU on gastric cancer cells in vitro and in vivo were studied. GSI combined with 5-FU was treated on gastric cancer cells, and then cell-proliferation by MTT assay, apoptosis by annexin V and expressions of protein level were determined by western blotting. Effects of GSI combined with 5-FU on tumor growth in vivo was assessed in an experimental model with orthotopically grown tumors. In gastric cancer cells, GSI combined with 5FU significantly inhibited cell proliferation and induced apoptosis. It was confirmed by expression changes of apoptosis related protein, such as caspase-3, caspase-8, caspase-9, PARP, BCL2, BID and BAX. GSI is also known to regulate PI3K/PTEN/AKT signaling pathway. After treatment with GSI plus 5-FU, this pathway was significantly down-regulated, and more, over-expression of constitutively activated AKT could prevent the apoptosis induction by combination treatment. This is suggested that the combination treatment with GSI plus 5-FU decreases the gastric cancer cell growth through inhibition of PI3K/PTEN/AKT signaling pathway. Moreover, administration of GSI in combination with 5-FU drastically reduced gastric tumor burdens in orthografted mice without prominent gastrointestinal toxicity. In conclusion, we present here that the combination treatment with GSI plus 5-FU has a potential for therapeutic activity in advanced gastric cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3506. doi:10.1158/1538-7445.AM2011-3506

Tu1444 How Many Days in Advance Should Proton Pump Inhibitor (PPI) Administration Be Started to Prevent Bleeding After Endoscopic Submucosal Dissection? Prospective Randomized Trial of PPI Administration

Tu1444 How Many Days in Advance Should Proton Pump Inhibitor (PPI) Administration Be Started to Prevent Bleeding After Endoscopic Submucosal Dissection? Prospective Randomized Trial of PPI Administration Takuto Hikichi, Masaki Sato, Atsushi Irisawa, Tadayuki Takagi, Tsunehiko Ikeda, Rei Suzuki, Kou Watanabe, Jun Nakamura, Hiromasa Ohira, Katsutoshi Obara Endoscopy, Fukushima Medical University Hospital, Fukushima, Japan; Gastroenterology and Rheumatology, Fukushima Medical University, Fukushima, Japan; Preparatory Office for Aizu Medical Center, Fukushima Medical University, Fukushima, Japan Background: Endoscopic submucosal dissection (ESD) is widely performed as a standard endoscopic therapy for early gastric cancer. However, post-procedural bleeding is a big problem. Although a proton pump inhibitor (PPI) is administered before ESD to prevent the bleeding by raising gastric pH (G-pH), there have been few assessment reports regarding its administration. Therefore, we attempted to establish an appropriate PPI administration schedule. Methods: The PPI used in this study was rabeprazole sodium (RPZ), which is well known for its rapid effect in raising G-pH. A total of 55 patients who underwent ESD for early gastric carcinoma or adenoma from November 2007 through November 2008 and gave informed consent to participate in this trial were enrolled. These patients were randomly divided into two groups: Group A consisting of 24 patients who took RPZ 20 mg/day from three days before the day of ESD through the morning of ESD, and Group B consisting of 31 patients who took RPZ 20 mg/day only on the morning of ESD. Administration of RPZ on the morning of ESD was made at least seven hours before the procedure so that its optimal effect was achieved. G-pH was measured three times: one month before ESD (pre-ESD pH), just before ESD (immediate pre-ESD pH), and one week after ESD (post-ESD pH). The frequency of post-procedural bleeding and G-pH were compared between Groups A and B. Results: Post-procedural bleeding occurred in no patients in Group A, but in one patient in Group B. The immediate preESD and post-ESD pHs were significantly higher than the pre-ESD pH in both Group A (7.20 0.58 and 6.92 1.45 vs. 4.99 2.03) and Group B (6.53 1.11 and 6.87 1.46 vs. 4.78 2.45) (P 0.001). The post-ESD pH was not significantly different between the two groups; however, the immediate pre-ESD pH was significantly higher in Group A (P 0.007), although that of Group B was above 5.4, the lowest level required to prevent and control post-procedural bleeding. Conclusion: These results suggest that the administration of PPI at least seven hours before ESD is effective enough to prevent bleeding after ESD, although its administration started three days before the day of ESD is more advisable.

Tu1411 The Preoperative Diagnostic Accuracy of Early Gastric Cancer for Suitable Treatment Choice

As minimally invasive therapy for early gastric cancer (EGC), endoscopic submucosal dissection (ESD) and laparoscopic gastrectomy (LG) is performed widely in Japan. ESD is applied to a lesion met the expanded-indication criteria of Japan Gastric Cancer Association (JGCA) as follows. 1;differentiated mucosal cancer without ulceration, regardless of size, or differentiated mucosal cancer with ulceration,≤30mm (D-type), 2; undifferentiated mucosal cancer without ulceration, ≤20mm (UD-type). On the other hand, a lesion is beyond the expanded-indication criteria (the JGCA criteria) preoperatively, LG is performed such lesion because of the risk of lymph node metastasis.If the histological finding of a lesion treated with ESD is beyond the JGCA criteria, additional surgical resection is required after ESD.

Mo1547 Usefulness of Narrow-Band Imaging in Delineating Early Gastric Cancer

Endoscopic submucosal dissection (ESD) has been widely accepted as an endoscopic therapy for early gastric cancer (EGC), to obtain a precise pathological diagnosis and promising curability for EGC. Appropriately margining resection at will is one of distinctive features of ESD, therefore, the precise estimation for the lateral extent of the lesion has an important role in successful ESD. The aim of this study is to investigate the usefulness in delineating the lateral extent of EGC using narrow-band imaging (NBI) endoscopy with magnification.

Sa1680 Predictive Factors Suggesting an Awkward Early Gastric Cancer Requiring a Deliberative Strategy for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) has been widely accepted as an endoscopic therapy for early gastric cancer (EGC), to obtain a precise pathological diagnosis and promising curability for EGC. As encountering the awkward lesion which is difficult to complete a procedure with single endoknife, the device should be changed out of necessity, supposing to change the strategy. Meanwhile there are few reports to examine the difficulty of gastric ESD in terms of a correlation between endoknife and the feature of the lesion.