Analysis of prognostic factors in patients with self-expandable metallic stents for treatment of malignant gastric outlet obstruction.

BACKGROUND AND AIM: Self-expandable metallic stents (SEMSs) are widely accepted as a less-invasive treatment for malignant gastric outlet obstruction (GOO). However, the factors related to prognosis and stent dysfunction after SEMS placement are not well known, and we aimed to investigate them. METHODS: This was a single-center retrospective cohort study of 212 malignant strictures in 207 patients. Factors related to prolonged overall survival (OS) and time to recurrent GOO (TRGOO) after SEMS placement were evaluated. RESULTS: Improvement of oral intake was confirmed in 179 patients (86%). The median OS was 65 days. A Cox proportional hazards model revealed that lower cancer stage, lower performance status score at the time of SEMS placement, and administration of chemotherapy after SEMS placement were significant predictive factors for prolonged OS. The median OS was 182 days in the group of SEMS followed by chemotherapy (group A) and 43 days in the group of SEMS alone (group B) (p< .0001). Chemotherapy after SEMS implantation contributed to the prolongation of survival in gastric cancer (hazard ratio (HR), 0.12) and pancreatic cancer (HR, 0.41). Furthermore, the cumulative incidence rates of stent dysfunction on day 120 after SEMS placement were 30% in group A and 61% in group B (p=.03). Notably, the preventive effect of chemotherapy on stent dysfunction was significant in pancreatic cancer. CONCLUSIONS: SEMS is a treatment with high technical and clinical success rate for malignant GOO. Furthermore, subsequent chemotherapy prolongs OS especially in gastric cancer, and TRGOO in pancreatic cancer.

Incidence of Delayed Bleeding among Patients Continuing Antithrombotics during Gastric Endoscopic Submucosal Dissection.

objective In patients continuing antithrombotics, delayed bleeding after gastric endoscopic submucosal dissection (ESD) is a severe complication. Vonoprazan (VPZ) exerts a rapid, potent, and long-lasting antacid effect compared with traditional proton-pump inhibitors (PPIs). This study aimed to compare the incidence of delayed bleeding after gastric ESD between the use of VPZ and PPIs in patients continuing antithrombotics. Methods In this retrospective analysis, we examined 71 patients with 101 lesions treated with traditional PPIs (PPI group) and 59 patients with 90 lesions treated with VPZ (VPZ group). After 2 days (day 0 and 1) of intravenous PPI administration, either an oral PPI or VPZ was administered from postoperative day 2 to 8 weeks after ESD. We assessed the incidence of overall delayed bleeding as well as bleeding that occurred from day 2 until 8 weeks after ESD. Results There was no significant difference in the use of antithrombotic agents between the groups. Overall delayed bleeding occurred 13 times (18%) in 9 patients in the PPI group and 18 times (31%) in 17 patients in the VPZ group (p=0.10). Bleeding from day 2 until 8 weeks after ESD occurred 12 times (17%) in 9 patients in the PPI group and 8 times (14%) in 8 patients in the VPZ group. Conclusion Even with a potent antacid agent, such as VPZ, the incidence of delayed bleeding was high in patients undergoing ESD with continuous antithrombotic agents.

Risk stratification for lymph node metastasis using Epstein-Barr virus status in submucosal invasive (pT1) gastric cancer without lymphovascular invasion: a multicenter observational study.

BACKGROUND: Lymphovascular invasion (LVI) is a strong predictive factor for lymph node metastasis (LNM) in early gastric cancer (GC). This study investigated the risk for LNM in pT1b GC without LVI based on Epstein-Barr virus (EBV) status in addition to conventional clinicopathological parameters. METHODS: In total, 847 consecutive patients of pT1b GC without LVI who underwent surgery at three high-volume centers between 2005 and 2014 were retrospectively analyzed. Clinicopathological parameters and EBV status were evaluated, and univariate and multivariate analyses were performed to estimate LNM risk. With regard to the presence of those three parameters, risk stratification for LNM was performed and compared with a previously proposed risk classification that included low-risk (LNM < 3.0%), intermediate-risk (LNM ≥ 3.0 and < 19.6%), and high-risk (LNM ≥ 19.6%) groups. RESULTS: EBV-positive GC (EBVGC) accounted for 11.3% (96 of 847) of cases; LNM was lower in EBVGC than in non-EBVGC (1 of 96, 1.0% vs. 71/751, 9.5%). In the multivariate analysis, non-EBVGC [odds ratio (OR) 10.8, 95% confidence interval (CI) 1.48-78.9], age < 65 years (OR 2.13, 95% CI 1.30-3.48), and tumor diameter > 3 cm (OR 2.26, 95% CI 1.36-3.74) were independent risk factors for LNM. Patients with EBVGC were at low risk for LNM whereas those with all of three independent risk factors were at high risk (36 of 168, 21.4%, 95% CI 15.5-28.4). CONCLUSION: LNM risk stratification that includes EBV status is useful for clinical decision-making in pT1b GC cases without LVI.

Effect of double-layer structure in intramucosal gastric signet-ring cell carcinoma on lymph node metastasis: a retrospective, single-center study.

BACKGROUND: Among all types of gastric cancer (GC), signet-ring cell carcinoma (sig-GC) accounts for 4-17% of cases. The prognosis of early sig-GC is relatively good, with the 5-year survival rate at 99.7%. However, the correlation between histological features and lymph node metastasis (LNM) among pT1a (M) sig-GC remains unclear. Sig-GC often exhibits a double-layer structure (DLS) in the intramucosal layer, demonstrating functional differentiation into the normal gastric gland. Assumedly, the loss of the differentiation makes the DLS deranged, accounting for the occurrence of submucosal invasion and LNM. This study aimed to assess the proportion of DLS, to elucidate the correlation between histological features (including DLS) and LNM status, and to determine the LNM-negative condition in pT1a (M) sig-GC. METHODS: We reviewed the pathological data of 310 patients with 310 intramucosal sig-GCs who received gastrectomy with lymph node dissection. Immunohistochemistry was performed on all specimens to evaluate the presence of DLS. Furthermore, we review the clinicopathological features, including tumor size, lymphovascular invasion (LVI), ulceration (UL), and DLS results, and then statistically analyze the correlation between these features and LNM status. RESULTS: Overall, 129 pT1a (M) sig-GCs (42%) were DLS present. The univariate analysis revealed that "Tumor size > 20 mm", "UL present", and "DLS absent" were significant risk factors of LNM. The multivariate logistic regression analysis revealed only "DLS absent" as statistically significant. CONCLUSIONS: "DLS absent" is a risk factor of LNM detected by the multivariate analysis. In pT1a (M), LVI absent, UL absent, tumor size > 20 mm, sig-GC, no LNM occurred in "DLS present" cases.

Epstein-Barr virus positivity among surgically resected intramucosal gastric cancer.

Epstein-Barr virus-associated gastric cancer (EBV-GC) accounts for approximately 8% of gastric cancers. However, little is known regarding intramucosal EBV-GC. The present study aimed to evaluate endoscopic and clinicopathological characteristics of intramucosal EBV-GC. Pathological data of 172 patients with 173 intramucosal gastric cancers who received gastrectomy with lymph node dissection were obtained for review. EBV-encoded small RNA in situ hybridization (EBER-ISH) was carried out using a tissue microarray block. Eight intramucosal early gastric cancers (4.6%) were EBER-ISH positive in which no cases had any lymph node metastasis. Macroscopic types were either depressed or flat, dominant histology was mixed type of moderate and poorly differentiated adenocarcinoma. In detail, histological features of "lace pattern" or "lymphocyte infiltration into the stroma or cancer nests" were observed.

A 10-year History of a Diminutive Rectal Neuroendocrine Tumor.

A 39-year-old woman underwent a preoperative diagnostic colonoscopy for cervical cancer. A 3-mm neuroendocrine tumor (NET) was incidentally detected in the rectum. The NET was observed via 7 colonoscopies over 10 years while giving priority to treating the cervical cancer. Complete cervical cancer remission was confirmed at the 10-year follow-up examination; therefore, endoscopic treatment for the NET was subsequently performed. The NET showed almost no change in either size or morphology over the 10-year period. This case illustrates the possible very-slow progression of a small NET, suggesting its benign behavior.

Transpapillary biliary stenting is a risk factor for pancreatic stones in patients with autoimmune pancreatitis.

BACKGROUND AND STUDY AIM: Pancreatic stones occasionally develop in autoimmune pancreatitis (AIP), often worsen endocrine and exocrine functions, and occasionally cause pain attacks. However, the risks of pancreatic stones in AIP have been poorly studied. The aim of this study was to analyze the risk factors associated with pancreatic stone formation in cases of AIP. PATIENTS AND METHODS: In total, 50 patients with AIP (39 males, 11 females; mean age 64.0 years), followed up for at least a year, were analyzed for their demographic and clinical findings and pancreatic stone occurrence. RESULTS: In total, 50 patients were followed up for an average of 59.7 (12 - 120) months, with steroid treatment in 44 patients (88 %); pancreatic stones occurred in 14 (28 %) patients after the diagnosis of AIP and endoscopic treatment was needed in one patient with pain attack. The pancreatic stones appeared only in patients with long follow-up period (P < 0.001, 83.9 months vs. 49.6 months), biliary stenting (odds ratio [OR]: 8.40, P = 0.010), relapse (OR: 6.20, P = 0.023), jaundice (OR: 5.40, P = 0.019), and swelling of the duodenal major papilla (OR: 4.67, P = 0.040). Biliary stenting was placed for an average of 9.9 months in 27 patients. Multivariate analysis revealed a significant association only with biliary stenting (P = 0.011). The stones appeared relatively earlier in patients with stones in the main pancreatic duct or Santorini duct (22.1 months) than in patients where pancreatic stones developed elsewhere (53.4 months) (P = 0.018). CONCLUSIONS: The risk of pancreatic stone development should be taken into account when a biliary stent is placed in patients with AIP.

[Locally Advanced Gastric Cancer Treated with Curative Gastrectomy and Showing Pathological Complete Response after Chemotherapy with S-1].

A 77-year-old man presented with epigastralgia. Gastrointestinal endoscopic examination showed advanced gastric cancer, type 3, in the distal antrum. The patient refused surgery and preferred chemotherapy. The regimen consisted of 80 mg/body/day of S-1, continuously administered from day 1-14, followed by discontinuation for 2 weeks. After 2 courses, the patient experienced fatigue and recurrent vomiting. Laboratory studies revealed severe anemia; the hemoglobin level was 5.5 g/dL. An upper gastrointestinal endoscopy revealed pyloric stenosis and significant tumor reduction. Therefore, distal gastrectomy was performed. Histological examination did not reveal any viable cancer cells in the stomach and lymph nodes. Thus, a Grade 3 postchemotherapeutic effect was revealed.

Characteristics of sugar surfactants in stabilizing proteins during freeze-thawing and freeze-drying.

Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 µM, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced.