Ho Suk Kang

Lymphovascular invasion in more than one-quarter of small rectal neuroendocrine tumors

AIM To identify the frequency, clinicopathological risk factors, and prognostic significance of lymphovascular invasion (LVI) in endoscopically resected small rectal neuroendocrine tumors (NETs). METHODS Between June 2005 and December 2015, 104 cases of endoscopically resected small (≤ 1 cm) rectal NET specimens at Hallym University Sacred Heart Hospital in Korea were retrospectively evaluated. We compared the detected rate of LVI in small rectal NET specimens by two methods: hematoxylin and eosin (H&E) and ancillary immunohistochemical staining (D2-40 and Elastica van Gieson); in addition, LVI detection rate difference between endoscopic procedures were also evaluated. Patient characteristics, prognosis and endoscopic resection results were reviewed by medical charts. RESULTS We observed LVI rates of 25.0% and 27.9% through H&E and ancillary immunohistochemical staining. The concordance rate between H&E and ancillary studies was 81.7% for detection of LVI, which showed statistically strong agreement between two methods (κ = 0.531, P < 0.001). Two endoscopic methods were studied, including endoscopic submucosal resection with a ligation device and endoscopic submucosal dissection, and no statistically significant difference in the LVI detection rate was detected between the two (26.3% and 26.8%, P = 0.955). LVI was associated with large tumor size (> 5 mm, P = 0.007), tumor grade 2 (P = 0.006). Among those factors, tumor grade 2 was the only independent predictive factor for the presence of LVI (HR = 4.195, 95%CI: 1.321-12.692, P = 0.015). No recurrence was observed over 28.8 mo regardless of the presence of LVI. CONCLUSION LVI may be present in a high percentage of small rectal NETs, which may not be associated with short-term prognosis.

Effect of low-dose proton pump inhibitor on preventing upper gastrointestinal bleeding in chronic kidney disease patients receiving aspirin.

Upper gastrointestinal bleeding (UGIB) leads to significant morbidity and mortality in chronic kidney disease (CKD) patients. This study determined the efficacy of using a low‐dose proton pump inhibitor (PPI) to reduce the risk of non‐variceal UGIB in CKD patients receiving aspirin.

Corrosive Esophagitis Caused by Ingestion of Picosulfate

Corrosive esophagitis is characterized by caustic injury due to the ingestion of chemical agents, mainly alkaline substances such as detergents. Esophageal bleeding, perforation, or stricture can be worsened by high-degree corrosive esophagitis. Picosulfate is a commonly used laxative frequently administered for bowel preparation before colonoscopy or colon surgery. Picosulfate powder should be completely dissolved in water before ingestion because the powder itself may cause chemical burning of the esophagus and stomach. Here, we report a case of corrosive esophagitis due to the ingestion of picosulfate powder that was not completely dissolved in water.

Signet-ring cell carcinoma arising from a fundic gland polyp in the stomach

Fundic gland polyps (FGPs) are currently the most common type of gastric polyps and are usually benign. However, although rare, gastric adenocarcinoma of FGP has been recently proposed as a new variant of gastric adenocarcinoma. Here we report the first case of a 49-year-old woman with focal signet ring cell carcinoma that arose from an FGP of the stomach. The tumor was completely excised by endoscopic snare polypectomy. FGPs should therefore be evaluated for malignant changes although they occur rarely, if the FGP has an erosive or irregular surface.

Programmed death ligand-1 and MET co-expression is a poor prognostic factor in gastric cancers after resection

Programmed death-ligand 1 (PD-L1) plays an essential protein for immune evasion, contributing to tumor development and progression. Recent studies have reported MET as an upregulator for PD-L1 overexpression through an oncogenic pathway. However, an association between PD-L1 expression with MET has not been reported in gastric cancer.The prognostic significance of PD-L1 and its association with Epstein-Barr virus (EBV), microsatellite instability (MSI), and mucin phenotype remain controversial. We performed in situ hybridization for EBV-encoded RNA and immunohistochemistry in tissue microarrays for 394 gastric cancers. A multiplex polymerase chain reaction with five quasimonomorphic markers was performed for MSI. PD-L1 expression was observed in 123 cases (31.2%), and clinicopathological features such as MET overexpression, high pT stage, and a lack of lymphatic invasion represent significant risk factors associated with PD-L1 overexpression in gastric cancers. No associations of EBV, MSI, or mucin phenotype with PD-L1 expression were statistically significant. PD-L1 expression was a strong indicator for worse overall survival (OS) but borderline significant in disease-free survival (DFS). A combined analysis of PD-L1 and MET expression indicated that the PD-L1+/MET+ subgroup showed the worst prognosis when compared to the PD-L1-/MET- subgroup, which had the best clinical outcome. Furthermore, PD-L1 overexpression exhibited poor prognosis in terms of both OS and DFS in EBV-negative, microsatellite stable, and intestinal mucin phenotype tumors. In conclusion, this is the first study to evaluate the overexpression of MET as a risk factor for PD-L1 positivity in gastric cancer tissue as well as the reliability and prognostic relevance of PD-L1/MET co-expression after surgery.Programmed death-ligand 1 (PD-L1) plays an essential protein for immune evasion, contributing to tumor development and progression. Recent studies have reported MET as an upregulator for PD-L1 overexpression through an oncogenic pathway. However, an association between PD-L1 expression with MET has not been reported in gastric cancer.The prognostic significance of PD-L1 and its association with Epstein-Barr virus (EBV), microsatellite instability (MSI), and mucin phenotype remain controversial.We performed in situ hybridization for EBV-encoded RNA and immunohistochemistry in tissue microarrays for 394 gastric cancers. A multiplex polymerase chain reaction with five quasimonomorphic markers was performed for MSI.PD-L1 expression was observed in 123 cases (31.2%), and clinicopathological features such as MET overexpression, high pT stage, and a lack of lymphatic invasion represent significant risk factors associated with PD-L1 overexpression in gastric cancers. No associations of EBV, MSI, or mucin phenotype with PD-L1 expression were statistically significant. PD-L1 expression was a strong indicator for worse overall survival (OS) but borderline significant in disease-free survival (DFS). A combined analysis of PD-L1 and MET expression indicated that the PD-L1+/MET+ subgroup showed the worst prognosis when compared to the PD-L1-/MET- subgroup, which had the best clinical outcome. Furthermore, PD-L1 overexpression exhibited poor prognosis in terms of both OS and DFS in EBV-negative, microsatellite stable, and intestinal mucin phenotype tumors. In conclusion, this is the first study to evaluate the overexpression of MET as a risk factor for PD-L1 positivity in gastric cancer tissue as well as the reliability and prognostic relevance of PD-L1/MET co-expression after surgery.

Second-Line Irinotecan, Leucovorin, and 5-Fluorouracil for Gastric Cancer Patients after Failed Docetaxel and S-1.

Background. This retrospective study aimed to assess the efficacy and toxicities of second-line chemotherapy with irinotecan, leucovorin, and 5-fluorouracil (5-FU) in metastatic gastric cancer (MGC) patients previously treated with docetaxel and S-1 with or without oxaliplatin (DS/DOS). Patients and Methods. We reviewed the data of patients who had previously been treated with first-line DS/DOS and received biweekly irinotecan-based chemotherapy (FOLFIRI/IFL) between October 2004 and November 2011. Results. A total of 209 cycles were administered to 35 patients, with a median of 4 (range, 1–22) cycles each. The overall response rate in 29 response-assessable patients was 17.2%, including 2 complete and 3 partial responses. The median progression-free and overall survivals were 3.81 (95% confidence interval [CI], 1.82–5.80) months and 6.24 (95% CI, 1.44–11.04) months, respectively. The major grade 3/4 toxicity was neutropenia (8.6%). Conclusion. FOLFIRI/IFL chemotherapy showed modest antitumour activity and tolerable toxicities in DS/DOS-treated MGC patients.

Does the discrepancy in histologic differentiation between a forceps biopsy and an endoscopic specimen necessitate additional surgery in early gastric cancer

AIM To investigate the clinicopathological variables in early gastric cancer (EGC) patients in relation to differentiation discrepancy. METHODS The data of 265 specimens from 240 patients with EGC, who had undergone radical operation at Hallym University Sacred Heart Hospital from 2010 to 2015, were retrospectively analyzed. We evaluated clinical, endoscopic, and histopathological data according to histological discrepancy. RESULTS Clinically significant discrepancy rate showed the difference in differentiated type (well and moderately differentiated) and undifferentiated type (poorly differentiated and signet ring cell) between endoscopic biopsies and postoperative specimens was 9.4% (25/265). There were no differences in tumor location, size, gross pattern, and number of biopsies. Specimens having histological discrepancy showed more submucosal invasion (72.0% vs 49.6%, P = 0.033) and lymph node involvement (24.0% vs 7.9%, P = 0.009) than specimens having non-discrepancy. The rate of a positive epidermal growth factor receptor status was higher in specimens having discrepancy than in specimens having non-discrepancy (81.0% vs 55.4%, P = 0.035). CONCLUSION The discordance of histologic differentiation is associated with higher submucosal invasion and lymph node metastases in EGC. Patients have histological discrepancy may require additional surgical treatments.

Baseline Renal Function Predicts Hyponatremia in Liver Cirrhosis Patients Treated with Terlipressin for Variceal Bleeding

Objectives Terlipressin is safely used for acute variceal bleeding. However, side effects, such as hyponatremia, although very rare, can occur. We investigated the development of hyponatremia in cirrhotic patients who had acute variceal bleeding treated with terlipressin and the identification of the risk factors associated with the development of hyponatremia. Design and Methods This retrospective, case-control study investigated 88 cirrhotic patients who developed hyponatremia and 176 controls that did not develop hyponatremia and were matched in terms of age and gender during the same period following terlipressin administration. Results The overall change in serum sodium concentration and the mean lowest serum sodium concentration were 3.44 ± 9.55 and 132.44 ± 8.78 mEq/L during treatment, respectively. Multivariate analysis revealed that baseline serum sodium was an independent positive predictor, and the presence of baseline serum creatinine, HBV, DM, creatinine, and shock on admission was independent negative predictors of hyponatremia (P < 0.05). Conclusion The presence of HBV, DM, the baseline serum sodium, shock on admission, and especially baseline creatinine may be predictive of the development of hyponatremia after terlipressin treatment. Therefore, physicians conduct vigilant monitoring associated with severe hyponatremia when cirrhotic patients with preserved renal function are treated with terlipressin for variceal bleeding.