Background
The effects of obesity on prognosis in gastric cancer are controversial.
Aims
To evaluate the association between body mass index (BMI) and mortality in patients with gastric cancer.
...Methods
A single-institution cohort of 7765 patients with gastric cancer undergoing curative gastrectomy between October 2000 and June 2016 was categorized into six groups based on BMI: underweight (< 18.5 kg/m
2
), normal (18.5 to < 23 kg/m
2
), overweight (23 to < 25 kg/m
2
), mildly obese (25 to < 28 kg/m
2
), moderately obese (28 to < 30 kg/m
2
), and severely obese (≥ 30 kg/m
2
). Hazard ratios (HRs) for overall survival (OS) and disease-specific survival (DSS) were calculated using Cox proportional hazard models.
Results
We identified 1279 (16.5%) all-cause and 763 (9.8%) disease-specific deaths among 7765 patients over 83.05 months (range 1.02–186.97) median follow-up. In multivariable analyses adjusted for statistically significant clinicopathological characteristics, preoperative BMI was associated with OS in a non-linear pattern. Compared with normal-weight patients, underweight patients had worse OS HR 1.42; 95% confidence interval (CI) 1.15–1.77, whereas overweight (HR 0.84; 95% CI 0.73–0.97), mildly obese (HR 0.77; 95% CI 0.66–0.90), and moderately obese (HR 0.77; 95% CI 0.59–1.01) patients had better OS. DSS exhibited a similar pattern, with lowest mortality in moderately obese patients (HR 0.58; 95% CI 0.39–0.85). Spline analysis showed the lowest all-cause mortality risk at a BMI of 26.67 kg/m
2
.
Conclusion
In patients undergoing curative gastric cancer surgery, those who were overweight or mildly-to-moderately obese (BMI 23 to < 30 kg/m
2
) preoperatively had better OS and DSS than normal-weight patients.
Background Extended lymph node dissection in gastric cancer (D3) was proven to have no survival benefit compared with a D2 dissection, but whether adding the superior mesenteric nodes (No. 14v) to ...the dissection provides survival benefit for gastric cancer patients remains controversial. Methods From April 2001 to June 2007, 1,661 patients underwent curative resection for middle or lower third gastric cancer. Patients were grouped according to No. 14v lymphadenectomy (14vD+/14vD-). Clinicopathologic characteristics and treatment-related factors were compared between the groups. Overall survival according to the clinical stage (Union for International Cancer Control tumor–node–metastasis staging 6th edition) was analyzed using the Cox proportional hazard model. Results The incidence of No. 14v lymph node metastasis was 5.0%. There was no difference in morbidity or mortality between the 14vD+ and the 14vD- groups. The proportion of locoregional recurrence was greater in 14vD- group ( P = .018). In clinical stages I and II, 14v lymph node dissection did not affect overall survival; in contrast, 14v lymph node dissection was an independent prognostic factor in patients with clinical stage III/IV gastric cancer (hazard ratio, 0.58; 95% confidence interval, 0.38–0.88; P = .01). Conclusion Extended D2 gastrectomy including No. 14v lymph node dissection seems to be associated with improved overall survival of patients with clinical stage III/IV gastric cancer in the middle or lower third of the stomach.
Background and objectives
Determination of stomach tumor location and invasion depth requires delineation of gastric histological structure, which has hitherto been widely accomplished by ...histochemical staining. In recent years, alternative histochemical evaluation methods have been pursued to accelerate intraoperative diagnosis, often by bypassing the time-consuming step of dyeing. Owing to strong endogenous signals from coenzymes, metabolites, and proteins, autofluorescence spectroscopy is a favorable candidate technique to achieve this aim.
Materials and methods
We investigated stomach tissue slices and block specimens using a fast fluorescence imaging scanner. To obtain histological information from broad and structureless fluorescence spectra, we analyzed tens of thousands of spectra with multiple machine-learning algorithms and built a tissue classification model trained with dissected gastric tissues.
Results
A machine-learning-based spectro-histological model was built based on the autofluorescence spectra measured from stomach tissue samples with delineated and validated histological structures. The scores from a principal components analysis were employed as input features, and prediction accuracy was confirmed to be 92.0%, 90.1%, and 91.4% for mucosa, submucosa, and muscularis propria, respectively. We investigated the tissue samples in both sliced and block forms using a fast fluorescence imaging scanner.
Conclusion
We successfully demonstrated differentiation of multiple tissue layers of well-defined specimens with the guidance of a histologist. Our spectro-histology classification model is applicable to histological prediction for both tissue blocks and slices, even though only sliced samples were trained.
Gastritis is a disease characterized by inflammation of the gastric mucosa. It is very common and has various classification systems such as the updated Sydney system. As there is a lot of evidence ...that
infection is associated with the development of gastric cancer and that gastric cancer can be prevented by eradication,
gastritis has been emphasized recently. The incidence rate of gastric cancer in Korea is the highest in the world, and due to the spread of screening endoscopy, atrophic gastritis and intestinal metaplasia are commonly diagnosed in the general population. However, there have been no clinical guidelines developed in Korea for these lesions. Therefore, this clinical guideline has been developed by the Korean College of
and Upper Gastrointestinal Research for important topics that are frequently encountered in clinical situations related to gastritis. Evidence-based guidelines were developed through systematic review and de novo processes, and eight recommendations were made for eight key questions. This guideline needs to be periodically revised according to the needs of clinical practice or as important evidence about this issue is published in the future.
Background
The long‐term effect of Helicobacter pylori eradication in preventing metachronous gastric cancer (GC) development after endoscopic resection (ER) of early gastric cancer (EGC) remains ...controversial. The aim of this study was to investigate the effect of H. pylori status on the incidence of metachronous GC after ER during long‐term follow‐up.
Patients and methods
We retrospectively reviewed the medical records of 374 patients who underwent ER for EGC. Helicobacter pylori status was assessed by histology, rapid urease test, and serology. According to the H. pylori status after ER, included patients were classified into H. pylori‐negative group (n = 218), H. pylori‐eradicated group (n = 49), and H. pylori‐persistent group (n = 107). Metachronous GC incidence and risk factors according to H. pylori status were analyzed.
Results
Median follow‐up duration after ER was 4.3 years (range 1.0–11.3 years). During the follow‐up period, metachronous GC had developed in 13 patients (6.0% 13/218) in the H. pylori‐negative group, 2 patients (4.1% 2/49) in the H. pylori‐eradicated group, and 16 patients (15.0% 16/107) in the H. pylori‐persistent group. Cumulative incidence of metachronous GC was significantly higher in patients with H. pylori‐persistent group than in those with H. pylori‐negative (p = .011, log‐rank test) and H. pylori‐eradicated group (p = .006, log‐rank test). In a multivariate Cox proportional hazard model, age ≥65 years (hazard ratio HR 2.29, p = .038), family history of GC (HR 2.60, p = .014), and H. pylori‐persistent status (HR 2.42, p = .019) were associated with metachronous GC development.
Conclusions
Persistent H. pylori infection after ER may increase risk of metachronous GC development.
Background and Aims Excellent long-term outcome is expected for early gastric cancers (EGCs) after endoscopic submucosal dissection (ESD). However, if ESD is considered noncurative at the pathologic ...evaluation, additional surgery is recommended. We evaluated whether long-term outcome is compromised if additional surgery is not performed for EGCs that are out-of-indication. Methods We retrospectively analyzed a cohort of patients with EGC not meeting ESD indications whose initial treatment was either ESD (n = 219) or surgery (n = 1799). Among them, 127 patients who underwent additional surgery after initial ESD and 67 patients who did not were matched using propensity scores to patients who initially underwent standard surgery, at a 1:1 ratio. Overall mortality and gastric cancer recurrence were compared. Results The overall mortality and gastric cancer recurrence rates were not significantly different between the 127 patients who underwent initial ESD with additional surgery and the corresponding initial standard surgery patients. However, the overall mortality of the 67 patients who underwent ESD without additional surgery (5-year mortality, 26.0%; 95% CI, 13.5%-49.9%) was higher than that of the matched initial standard surgery patients (5-year mortality, 14.5%; 95% CI, 6.3%-33.6%; P = .04). Gastric cancer recurrence was also higher in ESD patients without additional surgery (5-year recurrence, 17.0%; 95% CI, 7.6%-37.8%) than in the matched initial surgery group (0%; P = .002). In multivariate analyses, ESD without additional surgery was a significant risk factor for overall mortality and gastric cancer recurrence. Conclusions Additional surgery should be encouraged after non-curative ESD to obtain long-term outcomes comparable with those of initial standard surgery. (Clinical trial registration number: NCC2015-0093.)
We conducted an RNA sequencing study to identify novel gene fusions in 80 discovery dataset tumors collected from young patients with diffuse gastric cancer (DGC). Twenty-five in-frame fusions are ...associated with DGC, three of which (CLDN18-ARHGAP26, CTNND1-ARHGAP26, and ANXA2-MYO9A) are recurrent in 384 DGCs based on RT-PCR. All three fusions contain a RhoGAP domain in their 3' partner genes. Patients with one of these three fusions have a significantly worse prognosis than those without. Ectopic expression of CLDN18-ARHGAP26 promotes the migration and invasion capacities of DGC cells. Parallel targeted RNA sequencing analysis additionally identifies TACC2-PPAPDC1A as a recurrent and poor prognostic in-frame fusion. Overall, PPAPDC1A fusions and in-frame fusions containing a RhoGAP domain clearly define the aggressive subset (7.5%) of DGCs, and their prognostic impact is greater than, and independent of, chromosomal instability and CDH1 mutations. Our study may provide novel genomic insights guiding future strategies for managing DGCs.
Aims
Intestinal metaplasia and atrophy of the gastric mucosa are associated with Helicobacter pylori infection and are considered premalignant lesions. The updated Sydney system is used for these ...parameters, but experienced pathologists and consensus processes are required for interobserver agreement. We sought to determine the influence of the consensus process on the assessment of intestinal metaplasia and atrophy.
Methods and results
Two study sets were used: consensus and validation. The consensus set was circulated and five gastrointestinal pathologists evaluated them independently using the updated Sydney system. The consensus of the definitions was then determined at the first consensus meeting. The same set was recirculated to determine the effect of the consensus. The second consensus meeting was held to standardise the grading criteria and the validation set was circulated to determine the influence. Two additional circulations were performed to assess the maintainance of consensus and intraobserver variability. Interobserver agreement of intestinal metaplasia and atrophy was improved through the consensus process (intestinal metaplasia: baseline κ = 0.52 versus final κ = 0.68, P = 0.006; atrophy: baseline κ = 0.19 versus final κ = 0.43, P < 0.001). Higher interobserver agreement in atrophy was observed after consensus regarding the definition (pre‐consensus: κ = 0.19 versus post‐consensus: κ = 0.34, P = 0.001). There was improved interobserver agreement in intestinal metaplasia after standardisation of the grading criteria (pre‐standardisation: κ = 0.56 versus post‐standardisation: κ = 0.71, P = 0.010).
Conclusions
This study suggests that interobserver variability regarding intestinal metaplasia and atrophy may result from lack of a precise definition and fine criteria, and can be reduced by consensus of definition and standardisation of grading criteria.
Background
Early gastric cancer that meets the expanded criteria for endoscopic resection (ER) is expected to be associated with a negligible risk for lymph node metastasis (LNM); however, recent ...studies have reported LNM in submucosal gastric cancer patients who met the existing criteria. In this study, we develop the revised criteria for ER of submucosal gastric cancer with the aim of minimizing LNM.
Methods
We analyzed the clinicopathological data of 2461 patients diagnosed with differentiated, submucosal gastric cancer who underwent surgery at three tertiary hospitals between March 2001 and December 2012, and re-analyzed the pathological slides of all patients. The depth of submucosal invasion was measured histopathologically in two different ways (the classic and alternative methods) to obtain accurate data.
Results
Of the enrolled subjects, 306 (17.0%) had LNM. The width of submucosal invasion correlated well with the LNM. We defined the depth and width of submucosal infiltration associated with the lowest incidence of LNM. None of the 254 subjects developed LNM when the following criteria were met: tumor diameter ≤ 3 cm, submucosal invasion depth < 1000 μm (as measured using the alternative method), submucosal invasion width < 4 mm, no lymphovascular invasion, and no perineural invasion; however, LNM was observed in 2.7% of subjects (6/218) who met the existing criteria.
Conclusions
We revised the criteria for ER by adopting the alternative method to measure the depth of submucosal invasion and adding the width of such invasion. Our criteria better predicted LNM than the current criteria used to select ER to treat submucosal gastric cancer.
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