Background Current guidelines for endoscopic management such as EMR and endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) are in evolution, with broader indication criteria. ...Objective To determine the clinical outcomes of endoscopic treatment, based on absolute indication and extended indication criteria and endoscopic methods. Design Retrospective study. Setting Tertiary-care, academic medical center. Patients EMR or ESD was performed on 1627 cases of EGC in 1447 patients from July 1994 to January 2009. Intervention EMR and ESD. Main Outcome Measurements Clinical outcomes of EGC after EMR or ESD, based on the indication criteria. Results Although the complete resection rate was higher (95.9% vs 88.4%; P < .001), and the complication rate was lower (6.8% vs 9.8%; P = .054) in the absolute than in the extended indication group, there was no between-group difference in the local recurrence rate (0.9% vs 1.1%; P = .783) at a median follow-up period of 32 months (interquartile range 22-48 months). In the extended indication group, ESD resulted in a significantly higher complete resection rate than EMR (83.0% vs 91.1%; P = .006). Limitations Retrospective study. Conclusion ESD in the extended indication group showed acceptable clinical outcomes with a relatively high complete resection rate and a low local recurrence rate.
A technology to extract lignin oil from pretreated biomass has been developed for a cosmetic additive application (i.e., UV protection) through isopropyl alcohol without any catalyst. It was used for ...co-product lignin oil with XOS from a biorefinery process in this study. One of the key factors impacting economic feasibility is extraction solvent recovery, and it is important to design the process details based on techno-economic analysis. Therefore, this study has integrated lab experiments, process designs with Aspen Plus process simulations, and Excel-based techno-economic analysis to investigate the effect of solvent recovery on overall economics. Three options for solvent recovery (e.g., distillation, salting-out, and molecular sieve) have been explored. The salting-out method showed the best economic performance with an IRR of 33.6%, while the distillation method was 21.7% and the molecular sieve method was 16.7%. Key parameters are also identified by sensitivity analyses, which indicate the improvement potential for each case. This study has laid a foundation for lignin oil production studies, but its concept and approach can be applied to any solvent recycling in a biorefinery process, which is often neglected in lab-scale biorefinery studies.
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Background
Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) meeting the expanded indication is considered investigational. We aimed to compare long-term outcomes of ESD and ...surgery for EGC in the expanded indication based on each criterion.
Methods
This study included 1823 consecutive EGC patients meeting expanded indication conditions and treated at a tertiary referral center: 916 and 907 patients underwent surgery or ESD, respectively. The expanded indication included four discrete criteria: (I) intramucosal differentiated tumor, without ulcers, size >2 cm; (II) intramucosal differentiated tumor, with ulcers, size ≤3 cm; (III) intramucosal undifferentiated tumor, without ulcers, size ≤2 cm; and (IV) submucosal invasion <500 μm (sm1), differentiated tumor, size ≤3 cm. We selected 522 patients in each group by propensity score matching and retrospectively evaluated each group. The primary outcome was overall survival (OS); the secondary outcomes were disease-specific survival (DSS), recurrence-free survival (RFS), and treatment-related complications.
Results
In all patients and subgroups meeting each criterion, OS and DSS were not significantly different between groups (OS and DSS, all patients:
p
= 0.354 and
p
= 0.930; criteria I:
p
= 0.558 and
p
= 0.688; criterion II:
p
= 1.000 and
p
= 1.000; criterion III:
p
= 0.750 and
p
= 0.799; and criterion IV:
p
= 0.599 and
p
= 0.871). RFS, in all patients and criterion I, was significantly shorter in the ESD group than in the surgery group (
p
< 0.001 and
p
< 0.003, respectively). The surgery group showed higher rates of late and severe treatment-related complications than the ESD group.
Conclusions
ESD may be an alternative treatment option to surgery for EGCs meeting expanded indications, including undifferentiated-type tumors.
Although many epidemiologic studies have shown that Helicobacter pylori (H. pylori) eradication has prophylactic effects on gastric cancer, their results are less clear in high-risk populations. We ...conducted this study to examine whether H. pylori eradication would affect the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.
We retrospectively analyzed 2,089 adults who underwent endoscopic resection of gastric low-grade neoplasia, high-grade neoplasia, or differentiated invasive neoplasia from 2004 to 2008 at Asan Medical Center. Of these, a total of 1,007 patients with early gastric cancer were enrolled in this study. We evaluated the demographic data, the pathology, and the incidence of metachronous recurrence by dividing them into three groups: those without active H. pylori infection (Hp negative group, n=340), those who successfully underwent H. pylori eradication (eradicated group, n=485), and those who failed or did not undergo H. pylori eradication (noneradicated group, n=182).
Metachronous recurrence was diagnosed in 75 patients, including 17 in the Hp, 34 in the eradicated, and 24 in the noneradicated groups. Median time to metachronous recurrence was 18 months (range, 7-75 months). The incidence of metachronous gastric cancer was 10.9 cases per 1,000 person-years in the Hp negative group, 14.7 cases per 1,000 person-years in the eradicated group, and 29.7 cases per 1,000 person-years in the noneradicated group. The hazard ratios in the noneradicated group compared with the Hp negative and eradicated groups were 2.5 (P<0.01) and 1.9 (P=0.02), respectively. H. pylori eradication reduced metachronous recurrence of gastric neoplasm, which was also shown in the secondary analysis of 1,487 patients with low-grade neoplasia and early gastric cancer.
Successful H. pylori eradication may reduce the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.
Ferroelectric photovoltaics (FPVs) are being extensively studied owing to their anomalously high photovoltages, coupled with reversibly switchable photocurrents. However, FPVs suffer from their ...extremely low photocurrents, which is primarily due to their wide band gaps. Herein, we present a new class of FPV by demonstrating (i) a nearly optimum band gap of ∼1.55 eV and (ii) the ferroelectric polarization switching in the epitaxial hexagonal manganite thin films, h-RMnO3, where R = Lu and Y. According to the thickness-dependent photovoltaic measurements, the ITO/h-LuMnO3/Pt solar cell shows a power conversion efficiency of ∼0.11% when the thickness of the h-LuMnO3 layer is ∼150 nm. We have shown that the PCE is 1–3 orders higher than those of classical FPVs such as undoped Pb(Zr,Ti)O3 and BiFeO3 under the standard AM 1.5G illumination. We have further elucidated that the switchable photovoltaic effect dominates over the nonferroelectric internal field effect.
We propose a closed-loop pretreatment process, wherein volatiles produced during steam explosion pretreatment were recovered and reintroduced as acid catalysts into the pretreatment system. The ...volatiles were separated through a drastic decompression process followed by a steam explosion process and recovered as a liquified catalyst (LFC) through a heat exchanger. The LFC effectively served as an acid catalyst for hemicellulose hydrolysis, significantly decreasing residence time from 90 min to 30 min to achieve 80 % conversion yield at 170 °C. Hydrolysates with high content of lower molecular weight oligomeric sugars were obtained using LFC, and were considered advantageous for application as prebiotics. These results are attributed to the complementary features of acetic acid and furfural contained within the LFC. Computational simulation using Aspen Plus was used to investigate the effects of recycling on LFC, and it demonstrated the feasibility of the catalyst-recirculating system. A validation study was conducted based on simulation results to predict the actual performance of the proposed pretreatment system. Based on these results, the recirculating system was predicted to improve the conversion yield and low-molecular weight oligomers yield by 1.5-fold and 1.6-fold, respectively.
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Background
There is little known about the clinicopathological features and the predictors of survival in extremely young adult patients aged 18–30 years. The aim of this study was to identify ...clinicopathological features and clinical outcomes for the overall population and for a resectable subgroup of gastric cancer patients aged 18–30 years.
Methods
From January 2004 to December 2010, 207 patients aged between 18 and 30 years old were diagnosed with gastric cancer and treated at the Asan Medical Center. Clinical findings, histopathological parameters and outcomes were reviewed retrospectively. Patients were further divided into 2 groups according to tumor resectability and then clinicopathological factors that affect tumor resectability and clinical outcomes were analyzed.
Results
Clinicopathological characteristics of study population showed a predominance of females, undifferentiated tumors, diffuse-type cancers, and advanced gastric cancer. The overall resectability rate was 70.0 % and the median follow-up period was significantly longer in the resectable tumor group (
P
< 0.001). Significant prognostic predictors for overall survival in overall patients were higher CEA levels (
P
= 0.016), larger tumor size (
P
< 0.001), unresectability (
P
= 0.006), and presence of lymphovascular invasion (
P
= 0.012) in a multivariate analysis. Significant prognostic factors for overall survival in patients with resectable disease included larger tumor size (>4 cm), lymphovascular invasion and higher CEA level in the multivariate analysis.
Conclusions
Gastric adenocarcinomas in young adult patients aged 18–30 years have unique clinicopathological features. Early detection in a resectable state and subsequent complete resection could increase survival period in young patients with gastric cancer.
Background Endoscopic submucosal dissection (ESD) is curative treatment for patients with early gastric cancer (EGC). Because of the technical difficulties, however, these procedures may take a long ...time, which can increase the rate of procedure-related complications. Objective To investigate the procedure time of ESD performed by 4 experts according to the location and size of the EGC. Design Retrospectively analyzed study of prospectively collected data. Setting Tertiary care, academic medical center. Patients Complete ESDs were performed by 4 experts, primarily using an insulated-tip knife, for 916 EGCs. Intervention ESD. Main Outcome Measurement Procedure time relative to the location and size of tumors was analyzed along with other predictive factors. Results ESD procedure time was increased as tumor size increased and for tumors in the middle and lower thirds of the stomach. Univariate analysis showed that tumor size, location, depth, submucosal fibrosis, and perforation during the procedure were significant predictors of procedure time. Multivariate analysis showed that proximal location, tumor size greater than 20 mm, submucosal fibrosis, and perforation during the procedure were independent predictors of a longer procedure time. Limitation Single-center, retrospective study design. Conclusions Procedure time became longer as tumor location became higher and as tumor size increased, except for tumors in the upper third of the stomach. These findings suggest that tumor size and location may be useful in predicting the time required to perform ESD.
Summary Granular cell tumors (GCTs) are uncommon benign neoplasms in the gastrointestinal (GI) tract, and our current understanding of GCT in GI tract is limited. A total of 98 GCTs were retrieved ...from 95 patients, and the clinicopathological and immunohistochemical features were compared. The male-to-female ratio was 2.2:1 and with a mean age of 49 years. The mean tumor size was 0.37 cm. Seventy-three esophageal (75%), 21 colorectal (21%), and 4 gastric (4%) GCTs were included. Gastric (mean, 0.75 cm) and colorectal (0.6 cm) GCTs were significantly larger than esophageal tumors (0.27 cm; P < .001). Colonic and gastric GCTs showed a more infiltrative growth pattern ( P < .001) and peritumoral lymphoid cuffs ( P < .001) than esophageal tumors. Involvement of mucosa, submucosa, and both were noted in 58 cases (59%), 11 cases (11%), and 28 cases (29%), respectively. One GCT from the sigmoid colon (1%) had infiltration to pericolic soft tissue and with lymph node metastasis. High frequency of immunolabeling for S-100 protein (81/81, 100%), CD56 (55/58, 95%), CD68 (58/61, 95%), SOX-10 (54/58, 93%), and inhibin- α (30/58, 52%) were observed. In summary, GCTs in the GI tract were observed with the following frequency: esophagus, colorectum, and stomach. Colorectal and gastric GCTs were larger and had infiltrative growth and more lymphoid cuffs than esophageal GCTs. Although invasive GCT was rare, it could be observed in the GI tract. Inhibin- α expression were more common in colonic GCTs than esophageal tumors. High S-100 protein, CD56, CD68, and SOX-10 expression rates were observed in GCTs from GI tracts.
Background Limited data exist regarding the long-term outcomes of EMR compared with gastrectomy. Objective To compare the long-term outcomes after EMR and surgery. Design Retrospective analysis with ...propensity-score matching. Setting Tertiary care center. Patients This study involved 215 patients with intramucosal gastric cancer completely removed by EMR and 843 patients who underwent curative surgical resection between January 1997 and August 2002. Propensity-score matching yielded 551 matched patients. Interventions EMR versus surgery. Main Outcome Measurements Death and recurrence. Results In the matched cohort, there were no significant between-group differences in the risk of death (hazard ratio HR for the EMR group 1.39; 95% CI, 0.87-2.23) or recurrence (HR 1.18; 95% CI, 0.22-6.35). Although patients who underwent EMR had higher risk of metachronous gastric cancers (HR 6.72; 95% CI, 2.00-22.58), all recurrent or metachronous gastric cancers after EMR were successfully re-treated without affecting overall survival. Although complication rates were similar (odds ratio 0.84; 95% CI, 0.41-1.70), there were no mortalities in the EMR group compared with 2 in the surgery group. The EMR group had a significantly shorter hospital stay (median 8 days, interquartile range IQR 6-11 days vs 15 days, IQR 12-19 days; P < .001) and lower cost of care ($2049, IQR $1586-2425 vs $4042, IQR $3458-4959; P < .001). Limitations Retrospective, nonrandomized study. Conclusions EMR was comparable to surgery in terms of risk of death and recurrence. Because of its lower medical costs and shorter duration of hospital stay, EMR has advantages over surgery.
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