The risk of a residual tumor can, therefore, be estimated based on the histopathology of endoscopic submucosal dissection samples. Lymphovascular invasion appears to be a pivotal predictor of lymph node metastasis.

To reduce the operation time in RDG, a smarter and simpler system for setup should be developed to reduce the junk time. Additionally, a system for swifter instrument changes and more sophisticated energy devices are warranted to reduce the effective time.

BACKGROUND The clinical significance of intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity is unclear for HER2-positive gastric cancer, although it has been reported to be a significant prognosticator for HER2-positive breast cancer, which has received trastuzumab-based chemotherapy. AIM To clarify the clinical significance of intratumoral HER2 heterogeneity for HER2-positive gastric cancer, which has received trastuzumab-based chemotherapy. METHODS Patients with HER2-positive unresectable or metastatic gastric cancer who received trastuzumab-based chemotherapy as a first line treatment were included. The patients were classified into two groups according to their intratumoral HER2 heterogeneity status examined by immunohistochemistry (IHC) on endoscopic biopsy specimens before treatment, and their clinical response to chemotherapy and survival were compared. RESULTS A total of 88 patients were included in this study, and HER2 heterogeneity was observed in 23 (26%) patients (Hetero group). The overall response rate was significantly better in patients without HER2 heterogeneity (Homo group) (Homo vs Hetero: 79.5% vs 35.7%, P = 0.002). Progression-free survival of trastuzumab-based chemotherapy was significantly better in the Homo group (median, 7.9 vs 2.5 mo, HR: 1.905, 95%CI: 1.109-3.268). Overall survival was also significantly better in the Homo group (median survival time, 25.7 vs 12.5 mo, HR: 2.430, 95%CI: 1.389-4.273). Multivariate analysis revealed IHC HER2 heterogeneity as one of the independent poor prognostic factors (HR: 3.115, 95%CI: 1.610-6.024). CONCLUSION IHC of HER2 heterogeneity is the pivotal predictor for trastuzumab-based chemotherapy. Thus, HER2 heterogeneity should be considered during the assessment of HER2 expression.

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Laparoscopic transhiatal resection for Siewert type II AEG is technically challenging, but appears feasible and safe in technical or short-term oncological aspects when performed by an experienced surgical team. A large-scale prospective study is needed to evaluate long-term outcomes.

Background Traumatic esophageal injury leads to severe complications such as mediastinitis, pyothorax, and tracheoesophageal fistula. Although prompt diagnosis and treatment are required, there are no established protocols to guide diagnosis or treatment. In particular, thoracic esophageal injury tends to be diagnosed later than cervical esophageal injury because it has few specific symptoms. We report a case of thoracic esophageal injury caused by a cervical stab wound; the patient was stabbed with a sharp blade. Case presentation A 74-year-old woman was attacked with a knife while sleeping at home. The patient was taken to the emergency room with an injury localized to the left section of her neck. She was suspected of a left jugular vein and recurrent laryngeal nerve injury from cervical hematoma and hoarseness. On the day following the injury, computed tomography revealed a thoracic esophageal injury. Emergency surgery was performed for an esophageal perforation and mediastinal abscesses. Although delayed diagnosis resulted in suture failure, the patient was able to resume oral intake of food a month later following enteral feeding with a gastrostomy. Esophageal injuries due to sharp trauma are rare, and most are cervical esophageal injuries. There are very few reports on thoracic esophageal injuries. Conclusions The possibility of thoracic esophageal injury should always be considered when dealing with neck stab wounds, particularly those caused by an attack.

Laparoscopic radical gastrectomy with lymph node dissection has widely penetrated to East Asian countries, where incidence of gastric cancer occurrence is higher than the rest of the world. Laparoscopic distal gastrectomy for cStageI disease is regarded as one of the option in daily practice in the latest Japanese guidelines; however its applicability to more advanced disease (Stage II/III) is still under debate. Actually, operative techniques of laparoscopic D2 dissection is being matured, but still, necessity of total omentectomy, splenic hilar dissection, management of bulky nodes or large primary tumor, high-level anastomosis in esophageal invasion cases, and extensive peritoneal lavage can be raised as technical limitations. In the future perspective, further technological innovation, including next generation surgical robot, may help surgeons overcome these difficulties. Currently, three large-scaled randomized phase-III clinical trials are ongoing in East Asia, in which patients' accruals have been already completed. With coming long-term outcomes of these well-designed studies, oncological validity of laparoscopic approach will be adequately elucidated.

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