Updated evidence on endoscopic resection of early gastric cancer from Japan

Background

Endoscopic resection for early gastric cancer (EGC) plays a central role in the treatment of EGC in Japan. However, there is still room for improvement, and it is necessary to summarize the recently obtained knowledge from Japan for further improvement.

Methods

We conducted a PubMed search to select relevant articles in the 5 years until September 18, 2016, using the keywords “gastric cancer” and “endoscopic treatment,” “endoscopic submucosal dissection,” “endoscopic mucosal resection,” or “polypectomy” and filtering article types as “clinical study” or “clinical trial.”

Results

Among the 329 articles selected automatically from the keywords “polypectomy” (1 article), “endoscopic mucosal resection” (29 articles), “endoscopic submucosal dissection” (77 articles), and “endoscopic treatment” (222 articles) in combination with “gastric cancer,” 32 relevant articles from Japanese investigators were chosen. Seven articles were categorized into “equipment,” 4 into “preparation and sedation,” 17 into “complications and their prevention,” and 4 into “therapeutic outcomes.” Among them, CO₂ insufflation, propofol sedation, and how to prevent post-endoscopic submucosal dissection (ESD) ulcer bleeding and achieve post-ESD ulcer healing were intensively investigated. Long-term outcomes of endoscopic mucosal resection and ESD were also reported as favorable outcomes.

Conclusions

Endoscopic resection for EGC is still developing toward an ideal form, pursuing a more reliable, safer, and faster minimally invasive treatment.

     

Longterm outcomes after endoscopic mucosal resection for early gastric cancer

Background Despite the widespread use of endoscopic mucosal resection (EMR) in patients with early gastric cancer (EGC), its longterm outcomes have not been fully evaluated. Our aim was to evaluate longterm survival after complete EMR for EGC. Methods From patients who underwent EMR between 1978 and 1996 at our center, we enrolled 131 patients with differentiated mucosal EGCs less than 2 cm (without ulcerative change) that had been completely removed by EMR. The vital status of the patients at the end of December 1998 was confirmed by the hospital cancer registry, which is linked to the Osaka Cancer Registry. Results A total of 124 patients (95%) were completely followed-up. Two patients (1.5%) died of gastric cancer and 26 died of other causes during the mean observation period of 58 months. The overall 5- and 10-year survival rates were 84% and 64%, respectively. The disease-specific 5- and 10-year survival rates were 99% and 99%. Conclusion En bloc EMR ensured an excellent prognosis, and should be the first choice of treatment in patients with small differentiated mucosal EGC. Careful histological examination and longterm endoscopic surveillance are important.     

A multicenter retrospective study of endoscopic resection for early gastric cancer

Background The reported outcomes of endoscopic resection (ER) for early gastric cancer (EGC) remain limited to several single-institution studies. Methods A multicenter retrospective study was conducted at 11 Japanese institutions concerning their results for ER, including conventional endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Results A total of 714 EGCs (EMR, 411; ESD, 303) in 655 consecutive patients were treated from January to December 2001. Technically, 511 of the 714 (71.6%) lesions were resected in one piece. The rate of one-piece resection with ESD (92.7%; 281/303) was significantly higher compared with that for EMR (56.0%; 230/411). Histologically, curative resection was found in 474 (66.3%) lesions. The rate of curative resection with ESD (73.6%; 223/303) was significantly higher compared with that for EMR (61.1%; 251/411). Blood transfusion because of bleeding was required in only 1 patient (0.1%) with EMR of 714 lesions. Perforation was found in 16 (2.2%). The incidence of perforation with ESD (3.6%; 11/303) was significantly higher than that with EMR (1.2%; 5/411). All complications were managed endoscopically, and there was no procedure-related mortality. The median follow-up period was 3.2 years (range, 0.5–5.0 years). In total, the 3-year cumulative residual-free/recurrence-free rate and the 3-year overall survival rate were 94.4% and 99.2%, respectively. The 3-year cumulative residual-free/recurrence-free rate in the ESD group (97.6%) was significantly higher than that in the EMR group (92.5%). Conclusion ER leads to an excellent 3-year survival in clinical practice and could be a possible standard treatment for EGC. ESD has the advantage of achieving one-piece resection and reducing local residual or recurrent tumor.     

早期胃癌内窥镜下切除能否根治

如何判断是否存在淋巴结转移及术前正确选择病例是内窥镜下胃粘膜切除术(EMR)成功的关键.本文围绕早期胃癌(EGC)的病理特征、淋巴结转移规律及EMR的适应范围进行综述.     

Mixed poorly differentiated adenocarcinoma in undifferentiated-type early gastric cancer predicts endoscopic noncurative resection

Background

Comparisons between surgical cases of mixed poorly differentiated adenocarcinoma and pure signet ring cell carcinoma have revealed higher frequencies of lymph node metastasis and submucosal invasion in the former. However, this comparison has not been reported for endoscopically treated cases. Therefore, we compared cases of curative and noncurative resection in patients who underwent endoscopic submucosal dissection to determine what factors could influence the curative resection rate.

Methods

We analyzed 268 undifferentiated-type early gastric cancers in 264 patients treated with endoscopic submucosal dissection in our hospital between March 2005 and March 2017, involving 229 and 39 cases of curative and noncurative resection, respectively. Treatment results were compared between 129 lesions of pure signet ring cell carcinoma and 139 lesions of mixed poorly differentiated adenocarcinoma.

Results

The overall curative resection rate was 85.4% (229/268). On comparing noncurative and curative resection cases, after excluding factors that determine curative resection (e.g., tumor diameter), we found that the former was associated with older age and significantly more mixed poorly differentiated adenocarcinomas, with odds ratios of 1.052 [95% confidence interval (CI), 1.017–1.089] and 2.746 (95% CI, 1.162–6.485), respectively, on multivariate analysis. The curative resection rate was significantly higher in pure signet ring cell carcinoma than in mixed poorly differentiated adenocarcinoma (93.8% vs. 77.7%, respectively).

Conclusion

Advanced age and mixed poorly differentiated adenocarcinoma predicted endoscopic noncurative resection.

     

Endoscopic resection of early gastric cancer

The purpose of this review is to examine recent advances in the techniques and technologies of endoscopic resection of early gastric cancer (EGC). Endoscopic mucosal resection (EMR) of EGC, with negligible risk of lymph node metastasis, is a standard technique in Japan and is increasingly becoming accepted and regularly used in Western countries. EMR is a minimally invasive technique which is safe, convenient, and efficacious; however, it is insufficient when treating larger lesions. The evidence suggests that difficulties with the correct assessment of depth of tumor invasion lead to an increase in local recurrence with standard EMR when lesions are larger than 15 mm. A major factor contributing to this increase in local recurrence relates to lesions being excised piecemeal due to the technical limitations of standard EMR. A new development in endoscopic techniques is to dissect directly along the submucosal layer — a procedure called endoscopic submucosal dissection (ESD). This allows the en-bloc resection of larger lesions. ESD is not necessarily limited by lesion size and it is predicted to replace conventional surgery in dealing with certain stages of ECG. However, it still has a higher complication rate when compared to standard EMR, and it requires high levels of endoscopic skill and experience. Endoscopic techniques, indications, pathological assessment, and methods of endoscopic resection of EGC need to be established for carrying out appropriate treatment and for the collation of long-term outcome data.     

内镜下黏膜剥离术与内镜黏膜下切除术治疗早期胃癌的疗效比较

目的 比较内镜下黏膜剥离术(ESD)与内镜黏膜下切除术(EMR)治疗早期胃癌的疗效.方法 根据治疗方法将90例早期胃癌患者分为对照组和观察组,每组45例,对照组患者给予EMR治疗,观察组患者给予ESD治疗.比较两组患者肿瘤切除情况、围手术期相关指标、血清胃蛋白酶原(PG)水平(包括PGⅠ、PGⅡ,计算PGⅠ/PGⅡ)、...     

术前细致化干预在内镜下早期胃癌切除术患者中的应用效果

目的 探讨术前细致化干预在内镜下早期胃癌切除术患者中的应用效果.方法 根据干预方式的不同将76例行内镜下切除术的早期胃癌患者分为对照组和观察组,每组38例.对照组患者术后进行常规干预,观察组患者在常规干预的基础上给予术前细致化干预.比较两组患者的住院费用、住院时间、视觉模拟评分法(VAS)评分、负性情绪、术后并发症发生...     

Adequate endoscopic mucosal resection for early gastric cancer obtained from the dissecting microscopic features of the resected specimens

Background. We have employed endoscopic mucosal resection (EMR), using a cap-fitted panendoscope (EMRC), for early gastric cancer since 1992. The presence of an adequate surgical margin is a requirement because of the radicality of EMR, and dissecting microscopic examination is useful in regard to the diagnosis of spread of the disease. Methods. To devise an adequate method of EMR that allows no lateral residue, we examined gastric mucosal specimens obtained by EMRC. One hundred and sixty-seven specimens from 97 lesions in 85 patients treated by EMRC were examined in regard to characteristic features, the recovery of marks made around the lesion, and the frequency of residue, and comparisons were made between the dissecting microscopic and histopathological findings. Results. The first specimen obtained with a large cap under full suction was a circular shape measuring 21 × 19 mm. The second specimen from fractionated resection was a half-moon or crescent shape, and the third specimen had a ginkgo leaf-like or irregular shape. In the elevated lesions, coincidence regarding the spread, as determined by dissecting microscopy and histopathology, was present in 62 (93%) of the 67 lesions. In 16 (53%) of 30 flat or depressed lesions, there was a difference of 2 to 5 mm between the spread determined by these two examinations. Conclusion. It is important to place an adequate number of marks around the lesion and recover all marks by resection. When an elevated lesion measures 15 mm or more, and a flat or depressed lesion is not clearly demarcated, aggressive use of planned fractionated resection seems to be the best way to prevent a lateral residue in EMR. Received: February 1, 2001 / Accepted: July 3, 2001     

早期胃癌内镜下黏膜切除术后创面闭合中金属钛夹的应用

目的 探讨金属钛夹在早期胃癌内镜下黏膜切除术(endoscopic mucosal resection,EMR)后创面闭合中的应用价值.方法 选取经胃镜检查发现的早期胃癌患者110例,采用随机数字表法分为观察组与对照组各55例.观察组采用EMR联合金属钛夹闭合术治疗,对照组采用EMR治疗.门诊随访3个月,比较两组EMR术后创面闭合情况、临床指标(手术时间、住院时间、住院费用)与术后随访情况.结果 观察组EMR术后迟发性出血发生率低于对照组(0.0％ vs 10.9％,P＜0.05).两组EMR术后迟发性穿孔发生率比较,差异无统计学意义(1.8％vs 7.3％,P＞0.05).两组手术时间、住院时间和住院费用比较,差异均无统计学意义(均P＞0.05).术后随访3个月两组患者均无腹痛和发热等不良反应,创面完整愈合.结论 金属钛夹在早期胃癌EMR后创面闭合中具有应用价值.     

Past and current trends in endoscopic diagnosis for early stage gastric cancer in Japan

Methodology for the diagnosis and staging of early gastric cancer (EGC) has improved in Japan since the development of the gastro-camera and determination of a definition of EGC. Imaging technology has been steadily evolving in the endoscopy field. Improvements in the resolution of standard endoscopy images used in screening and surveillance provide greater opportunities to find gastric cancer earlier. Image enhancement endoscopy (IEE), such as narrow band imaging (NBI), highlights mucosal structures and vascularity. In particular, when NBI is used with magnifying endoscopy, it reveals fine details of subtle superficial abnormalities of EGC that are difficult to recognize using standard white light endoscopy. IEE-assisted magnifying endoscopy has improved the accuracy of the differentiation of superficial gastric cancer as well as delineation of the diseased mucosa. The advanced imaging technology enables precise assessment of the risk of lymph node metastasis of EGC and is widely used to determine indications for endoscopic treatment. It is not an overstatement to say that this has become the basis for the current development and dissemination of endoscopic treatments. Moreover, the resolution of endoscopic imaging has been upgraded to the microscopy level by the development of endomicroscopy, including endocytoscopy and confocal laser endomicroscopy. Endomicroscopy allows real-time histological analysis of living tissue during routine endoscopy and may reduce the number of biopsies needed to reach the correct diagnosis, minimizing the risk of sampling errors.

     

Discrepancies in histologic diagnoses of early gastric cancer between biopsy and endoscopic mucosal resection specimens

Background  

A preoperative histologic diagnosis of neoplasia is a requirement for endoscopic resection (ER). However, discrepancies may occur between histologic diagnoses based on biopsy specimens versus ER specimens. The aim of this study was to assess the rate of discrepancy between histologic diagnoses from biopsy specimens and ER specimens.     

Possibility of endoscopic treatment for early gastric cancer

Endoscopic therapy has been aggressively used for radical treatment of early gastric cancer, because endoscopic resection allows us to collect the removed tissue and to determine histopathologically whether the cancer lesion has been completely resected. In order to succeed in radical treatment, the complete resection of lesion and no lymph node metastasis are necessary. On the basis of thorough histopathological investigations into operated cases with early gastric cancer, the types of early gastric cancer which have no lymph node metastasis are considered to be as follows: 1) Intramucosal carcinoma type I type II a, measuring 30 mm or less type II b type II c, measuring 10 mm or less 2) carcinoma invading up to submucosal layer type II a + II c, measuring 10 mm or less type II a, measuring 20 mm or less type II b type II c, measuring 10 mm or less type II a + II c, measuring 10 mm or less However, indications of endoscopic resection should be more strictly decided due to diagnostic and technical problems. Eventually, it will be important to detect and resect intramucosal gastric carcinoma as small as possible in order that the lesion be completely resected. The success of curative treatment is evaluated by not only histopathological examination of resected tissue, but also through follow-up study. Therefore, various problems remain to be resolved in this treatment. A larger case sampling will serve to confirm the reliability of this form of therapy for early gastric cancer.     

Incidence of lymph node metastasis and the feasibility of endoscopic resection for undifferentiated-type early gastric cancer

Background  

Endoscopic resection (ER) has been accepted as minimally invasive treatment in patients with early gastric cancer (EGC) who have a negligible risk of lymph node metastasis. It has already been determined which lesions in differentiated-type EGC present a negligible risk of lymph node metastasis, and ER is being performed for these lesions. In contrast, no consensus has been reached on which lesions in undifferentiated-type (UD-type) EGC present a negligible risk for lymph node metastasis, nor have indications for ER for UD-type EGC been established.     

Detection of resection line in early gastric cancer

In patients with multiple gastric cancer and superficial spreading type gastric carcinoma (abbreviated as S.S.C.) accompanied by IIb, the remnant stomach is sometimes cancer positive. Our study population consisted of 44 patients with multiple early gastric cancer and 63 patients with depressed type S.S.C. The gastric mucosa was classified into 3 types according to the surrounding mucosal atrophy, 1) pyloric gland zone, 2) intermediate zone, 3) fundic gland zone. All lesions of multiple early gastric cancer and S.S.C. were located in the pyloric gland zone or the intermediate zone. The depressed type S.S.C. did not invade the fundic gland zone. Therefore, knowledge about the extend++ of surrounding mucosal atrophy is required for the proper diagnosis of early gastric cancer and the surgeon must recognize the relationship between the glandular border line and resection line.     

Endoscopic mucosal resection for early gastric cancer.

Progress in the detection of early gastric cancer has made endoscopic mucosal resection (EMR) possible for the treatment of gastric cancer instead of only conventional surgical resection. The most commonly employed modalities include strip biopsy, double snare polypectomy, and resection with combined use of highly concentrated saline and epinephrine, and resection using a cap. The indications should be strictly limited to the differentiated IIa type (the slightly elevated type) that is smaller than 2 cm, or the differentiated IIc type (slightly depressed type) without ulcer formation and smaller than 1 cm. Both of these entities are thought to have a negligible risk of lymph node metastasis. Prognosis after this treatment is comparable that of surgical resection for early gastric cancer in completely resected cases. EMR also permits local resection in elderly patients with various complications who would be at risk for conventional surgical operations. EMR should be encouraged for treatment of gastric cancer if the indications are strictly chosen.     

胃部分切除术治疗早期胃癌的临床疗效

目的探讨胃部分切除术治疗早期胃癌的临床疗效。方法收集2008年1月至2011年1月间收治的早期胃癌患者124例,其中行胃部分切除术的62例作为观察组,行常规远端胃切除术的62例作为对照组,比较两组患者的疗效。结果观察组患者术后15、30、60 min的胃排空功能均显著优于对照组(P<0.05),术后60 min胆囊收缩功能显著优于对照组(P<0.05)。术后6个月,观察组的身体质量指数(BMI)显著高于对照组(P<0.05);观察组患者术后远期并发症显著低于对照组(P<0.05)。两组患者的3年复发率和生存率的差异无统计学意义(P>0.05)。结论胃部分切除术治疗早期胃癌可有效改善患者的胃排空和胆囊收缩功能,保留BMI水平,减少远期并发症和复发率,值得推广应用。