A Modified eCura System to Stratify the Risk of Lymph Node Metastasis in Undifferentiated-Type Early Gastric Cancer After Endoscopic Resection

PURPOSE

The original eCura system was designed to stratify the risk of lymph node metastasis (LNM) after endoscopic resection (ER) in patients with early gastric cancer (EGC). We assessed the effectiveness of a modified eCura system for reflecting the characteristics of undifferentiated-type (UD)-EGC.

MATERIALS AND METHODS

Six hundred thirty-four patients who underwent non-curative ER for UD-EGC and received either additional surgery (radical surgery group; n=270) or no further treatment (no additional treatment group; n=364) from 18 institutions between 2005 and 2015 were retrospectively included in this study. The eCuraU system assigned 1 point each for tumors >20 mm in size, ulceration, positive vertical margin, and submucosal invasion <500 µm; 2 points for submucosal invasion ≥500 µm; and 3 points for lymphovascular invasion.

RESULTS

LNM rates in the radical surgery group were 1.1%, 5.4%, and 13.3% for the low- (0-1 point), intermediate- (2-3 points), and high-risk (4-8 points), respectively (P-for-trend<0.001). The eCuraU system showed a significantly higher probability of identifying patients with LNM as high-risk than the eCura system (66.7% vs. 22.2%; McNemar P<0.001). In the no additional treatment group, overall survival (93.4%, 87.2%, and 67.6% at 5 years) and cancer-specific survival (99.6%, 98.9%, and 92.9% at 5 years) differed significantly among the low-, intermediate-, and high-risk categories, respectively (both P<0.001). In the high-risk category, surgery outperformed no treatment in terms of overall mortality (hazard ratio, 3.26; P=0.015).

CONCLUSIONS

The eCuraU system stratified the risk of LNM in patients with UD-EGC after ER. It is strongly recommended that high-risk patients undergo additional surgery.

Functional Annotation and Gene Set Analysis of Gastric Cancer Risk Loci in a Korean Population

PURPOSE

We aimed to identify the associated single nucleotide polymorphisms (SNPs) with gastric cancer (GC) risk by genome-wide association study (GWAS) and to explore the pathway enrichment of implicated genes and gene-sets with expression patterns.

MATERIALS AND METHODS

The study population was comprised of 1,253 GC cases and 4,827 controls from National Cancer Center and an urban community of the Korean Genome Epidemiology Study and their genotyping was performed. SNPs were annotated, and mapped to genes to prioritize by three mapping approaches by functional mapping and annotation (FUMA). The gene-based analysis and gene-set analysis were conducted with full GWAS summary data using MAGMA. Gene-set pathway enrichment test with those prioritized genes were performed.

RESULTS

In GWAS, rs2303771, a nonsynonymous variant of KLHDC4 gene was top SNP associated significantly with GC (odds ratio, 2.59; p=1.32×10-83). In post-GWAS, 71 genes were prioritized. In gene-based GWAS, seven genes were under significant p < 3.80×10-6 (0.05/13,114); DEFB108B had the lowest p=5.94×10-15, followed by FAM86C1 (p=1.74×10-14), PSCA (p=1.81×10-14), and KLHDC4 (p=5.00×10-10). In gene prioritizing, KLDHC4 was the only gene mapped with all three gene-mapping approaches. In pathway enrichment test with prioritized genes, FOLR2, PSCA, LY6K, LYPD2, and LY6E showed strong enrichment related to cellular component of membrane; a post-translation modification by synthesis of glycosylphosphatidylinositol (GPI)-anchored proteins pathway.

CONCLUSION

While 37 SNPs were significantly associated with the risk of GC, genes involved in signaling pathways related to purine metabolism and GPI-anchored protein in cell membrane are pinpointed to be playing important role in GC.

Proton Single-Energy Bragg-Peak FLASH Using Clinical Systems Can Achieve IMPT-Equivalent Plan Quality for Breast and Prostate Cancers

PURPOSE/OBJECTIVE(S)

Most current proton FLASH-RT studies focus on transmission proton techniques. In this study, we propose a novel method for achieving FLASH dose rate in hypofractionated proton radiotherapy using the Bragg peak of a single-energy proton beam. The dosimetric characteristics using this novel technique for proton pencil beam scanning (PBS) stereotactic body radiation therapy (SBRT) of prostate and breast cancers were first investigated based on the clinically available cyclotron beam parameters.

MATERIALS/METHODS

This novel approach uses the distal tracking technique that enables PBS Bragg-peak of the highest proton energy to adapt to the target distally. Positioning of the Bragg peak at different depths is achieved using a universal range shifter and range compensator. To investigate the feasibility of this approach, we developed an in-house treatment planning platform for intensity-modulated proton therapy (IMPT) delivery and performed dosimetric studies on prostate and breast SBRT cases previously treated with conventional proton PBS technique. FLASH plans were generated using a similar clinical beam arrangement to deliver 40 Gy (RBE) in 5 fractions. Dose metrics were compared between the clinical and FLASH plans. Dose-rate volume histograms (DRVH) were also calculated to investigate the 40 Gy/s coverage (V40 Gy/s) of organs-at-risk (OARs) for FLASH plans.

RESULTS

The distal tracking can precisely stop the Bragg peak at the target distal edge, and Bragg peak plans achieved tumor coverage and dose conformality equivalent to IMPT plans. The clinical IMPT plans yielded slightly superior target dose uniformity -CTV Dmax of FLASH plans was 10% higher for prostate and 2% higher for breast. There was no significant difference between the clinical and FLASH plans in dose metrics for major OARs, including rectum, large bowel, heart, and lung. Higher maximal doses to femoral heads (∼2 Gy) and urethra (∼6 Gy) were observed in prostate FLASH plans than in the clinical plans but were still within clinically accepted dose limits. The V40 Gy/s for OARs were >90% for prostate FLASH plans and >76.5% for breast FLASH plans.

CONCLUSION

The proposed single-energy Bragg-peak FLASH technique eliminates exit dose associated with transmission proton FLASH and can still yield comparable plan quality and OAR sparing while preserve sufficient FLASH dose rate coverage for prostate and breast proton SBRT. This study demonstrates the potential application of Bragg peaks for highly conformal FLASH-RT using clinical cyclotron systems to treat prostate and breast cancer patients, which moves towards clinical application.

Pencil Beam Scanning Proton Stereotactic Body Radiation Therapy (SBRT): A Robust Single Institution Experience

PURPOSE/OBJECTIVE(S)

To describe the feasibility of treating a complex and diverse group of patients using pencil beam scanning (PBS) proton stereotactic body radiation therapy (SBRT: 5 or fewer fractions, with a fraction size of at least 5 Gy).

MATERIALS/METHODS

Our center treats on average 105-120 PBS proton treatments daily, of which 9.5% of treatment courses are proton SBRT. Statistics of disease sites, treatment planning parameters (target volume, prescriptions, number of fields, SFO vs. MFO), and treatment efficiencies (scheduled time slots, actual treatment time) are presented for 305 consecutive SBRT patients receiving 1507 fractions in the past three years. Thermoplastic masks or Vacuum-lock bags are used to immobilize SBRT patients and index the patients' treatment position. Imaging guidance of orthogonal kV images and volumetric cone-beam CT is routinely used for patient setup.

RESULTS

SBRT patients are grouped based on the target locations: pelvis (31%), liver (17%), thoracic (13%), spine (8%), abdominal (8%), brain (7%), non-spine bone (7%), ocular (6%), and head and neck (2%). Only 112 patients (37%) were receiving their 1st RT course, whereas 113 (37%) had one prior in-field RT course, and 80 (26%) had multiple prior in-field RT courses. The median [IQR] target volume was 65.4 [29.3, 168] cc (range: 0.3-2475 cc). 72% of cases were planned with SFO and 28% with MFO. On average, 3.76 fields (range: 2 to 12) were planned for each treatment. 44% of the treatments were planned with three or fewer fields, and 10% received more than five fields, most of which involved repainting for moving targets. Over 97% of treatments were delivered in 5 fractions, with ∼3% delivered in 3 fractions. The median [IQR] prescription per treatment was 8 [7, 10] Gy (range: 5-18 Gy per treatment). 85% (84%) of the SBRT treatments were scheduled (delivered) in a 45-minute or shorter slot, and 6% (7%) of treatments were scheduled (delivered) in over a one-hour slot, most commonly for multiple isocenter treatments. 93% of treatments were delivered within 15 minutes of the planned treatment time or shorter. Deep-inspiration breath-hold (DIBH) was applied to 45% of liver SBRT cases, with the remaining 55% planned on 4D CT with (14%) or without (86%) abdominal compression. DIBH was applied in 13% of lung SBRT cases. The application of other motion mitigation approaches, such as volumetric repainting, was determined by the target motion amplitude and whether the patient could tolerate DIBH.

CONCLUSION

In the most diverse and largest proton SBRT experience delivered in the world over the past 3 years, over 300 patients were treated, demonstrating the feasibility and efficiency of delivering proton SBRT in a very busy center. The planning and treatment parameter statistics reported serve as a helpful reference for the proton community.

Practice Patterns and Disparities of Fractionation Schemes for Post-Mastectomy Comprehensive Nodal Irradiation

PURPOSE/OBJECTIVE(S)

Hypofractionated (HF) radiotherapy is the established standard of care for whole breast irradiation and is being investigated for comprehensive nodal irradiation, but appropriate patient selection for the latter is currently undefined. This study aims to report national practice patterns and patient selection for HF comprehensive nodal irradiation compared to conventional fractionation (CF). The hypothesis is that the rate of HF for comprehensive nodal irradiation in breast cancer has been increasing over time and is more likely to be offered to disparate demographic populations.

MATERIALS/METHODS

We queried the National Cancer Database and identified 128,693 patients who received comprehensive nodal irradiation between 2008-2016 in the United States. No patient who underwent lumpectomy received HF nodal irradiation; therefore, only post-mastectomy patients were included in this study. After the exclusion, 29,053 post-mastectomy patients with adjuvant comprehensive nodal irradiation remained. A multivariable binomial regression analysis between HF and CF patients was performed.

RESULTS

Of the patients identified, 1,910 received HF (6.57%), and 27,143 received CF (93.43%) radiotherapy. All patients had locally advanced breast cancer treated with mastectomy, lymph node dissection, adjuvant radiation, and +/- chemotherapy. The median dose in the HF group was 4,256 cGy in 16 fractions, and in the CF group was 6,040 cGy in 33 fractions. HF rate grew from 3.56% in 2004-2007, 5.29% in 2008-2011, 7.42% in 2012-2013, and 12.05% in 2014-2016. HF was favored in older patients (median age 66 vs. 51, OR = 1.16, 95% Cl 1.11-1.22) and those who lived in suburban or rural regions compared to urban or metropolitan regions (OR = 9.48, 95% CI 1.17-76.9). However, there was no correlation when distance from treatment site was evaluated as a continuous variable. A "boost" dose was used in only 10.58% of HF patients compared to 54.6% of CF patients (OR = 0.17, 95% Cl 0.14-0.21). Chemotherapy was delivered in 36.91% of HF patients compared to 78.14% of CF patients (OR = 0.77, 95% Cl 0.59-0.99). There were no statistically significant correlates of either fractionation scheme for breast laterality, stage, grade, or receptor status. Notably, other than population density and age, demographic factors including race, Hispanic origin, insurance type, median income, and education level demonstrated no correlation with radiation fractionation scheme.

CONCLUSION

HF for comprehensive nodal irradiation in breast cancer is still uncommon but growing in popularity. Currently, HF is more likely to be used in elderly patients and lower population density centers and less likely to be used in those determined to benefit from receipt of a boost or chemotherapy.

Treatment of Thymoma and Thymic Carcinoma with Proton Beam Therapy: Outcomes from the Proton Collaborative Group Prospective Registry

PURPOSE/OBJECTIVE(S)

Given the generally long natural history of thymic malignancies, proton beam therapy (PBT) is advocated to minimize the risk of long-term toxicities to mediastinal organs. Adverse events (AE) and long-term clinical outcomes for this population have not been well-characterized.

MATERIALS/METHODS

The Proton Collaborative Group registry (NCT01255748), a multi-institutional prospective database of academic and community proton centers in the US, was queried for patients with thymomas and thymic carcinomas treated with PBT. Patients with recurrent/metastatic disease, non-thymic histology, received either prior or palliative radiotherapy (dose < 40 Gy RBE) were excluded. Overall survival (OS) and local control (LC) were estimated using Kaplan-Meier methods.

RESULTS

A total of 97 patients were identified in the PCG registry. After applying relevant exclusion criteria, 70 patients from 12 proton centers treated from 2011-2021 were included for analysis. Median follow-up length was 16 months. Median age was 58.5 years (IQR 46-63), and 60% were female. 81.4% had a diagnosis of thymoma, and 18.6% thymic carcinoma. 59 patients underwent surgical resection. 11 were treated with definitive PBT, of which 5 received concurrent chemotherapy. Median dose was 54 Gy RBE (range 41.4 - 70 Gy RBE), median number of fractions was 30 (range 21 - 38). 73.4% received pencil beam scanning and 23% uniform scanning PBT. Treatment was overall well-tolerated: a single patient developed grade 4 pneumonitis. Grade 3 AEs were seen in 3 patients - dyspnea, anorexia, and heart failure. Highest grade toxicity experienced was grade 2 for 47.1% and grade 1 for 42.9% of patients. 3-year overall survival (OS) was 82.6% for the entire cohort. 3-year OS was 94% for resected/adjuvant cohort and 35.6% in the non-surgical/definitive cohort. 3-year local control (LC) was 91.7% for the entire cohort. By surgery/margin status, 3-year LC was 96.8% in patients with close or negative margins (a single failure in a patient with close margins), whereas 3-year LC was 55.1% for patients with positive margins/unresectable disease.

CONCLUSION

Thymic malignancies treated with PBT appear to have favorable outcomes, especially in the adjuvant setting, in this cohort representing the largest series of such patients.

Prospective Evaluation of Patient-Reported Outcomes of Invisible Ink Tattoos for the Delivery of External Beam Radiation Therapy: The PREFER Trial

PURPOSE/OBJECTIVE(S)

Invisible ink tattoos allow for setup accuracy while avoiding the cosmetic permanence of visible ink tattoos. The goal of this trial was to evaluate patient-reported preference for the use of invisible ink tattoos in a radiation oncology clinic.

MATERIALS/METHODS

In an IRB-approved, prospective, feasibility trial, patients at a single institution receiving pencil beam scanning proton therapy to the thorax, abdomen, or pelvis underwent invisible ink tattoo-based treatment setup. Patient preference surveys comparing visible and invisible ink tattoos were completed prior to simulation (17 questions), immediately following simulation (5 questions), and at the end of treatment (18 questions), with preference scored on a 5-point Likert scale from strongly disagree to strongly agree, and cosmesis scored on a 4-point Likert scale of excellent-good-fair-poor. Differences in distributions were examined using Wilcoxon rank-sum tests, Fisher's exact tests, or chi-square tests, where statistical significance was considered at p<0.05.

RESULTS

Of 107 patients screened, 102 were enrolled and 94 completed all surveys. Mean age was 55.0 years, and 58.5% were female. Most patients were white (79.1%) and non-Hispanic (92.6%). Patients most commonly had breast (34.0%), prostate (16.0%), and lung (9.6%) cancer. An average of 5 (range 3-8) invisible ink tattoos were placed per patient. Overall, 75.5% of patients reported that they would prefer to receive invisible tattoos vs. visible tattoos, and 88.3% rated the overall cosmetic outcome of invisible ink tattoo marks as excellent or good. Compared to males, females were more willing to travel farther from their home in order to avoid receiving visible tattoos (45.4% vs. 23.1%, p = 0.035) and would pay additional money to avoid receiving visible tattoos (34.5% vs. 5.1%, p = 0.002). Patients who had previously received any tattoo (cosmetic or visible RT tattoos) were more satisfied with the appearance of their invisible ink tattoos compared to those who had never previously received tattoos (82.9% vs. 61.5%, p = 0.022). Patients receiving definitive intent RT were more satisfied with the appearance of the tattoos compared to those receiving palliative intent RT (67.1% vs. 38.9%, p = 0.011). Patients with at least a college education were less satisfied with the appearance of tattoos compared to those without a college education (67.0% vs. 95.0% p = 0.018).

CONCLUSION

These findings demonstrate stronger avoidance of visible tattoos and patient preference for invisible tattoos. The standard incorporation of invisible ink tattoos for patient setup should be strongly considered.

A Dosimetric Assessment of Sexual Organ Sparing Proton Radiotherapy in Female Pelvic Cancer Patients

PURPOSE/OBJECTIVE(S)

Optimizing treatment techniques for female patients undergoing curative treatment for pelvic cancers requires incorporating the goals of maximizing cure while maintaining quality of life. Optimizing treatment to maintain sexual quality of life has received little attention in female patients despite the presence of and toxicity risks to functional anatomic organs and their associated neurovasculature, including the bulboclitoris, vagina, and ovaries. Recent dosimetric data without employing sexual organ sparing suggest that mean VMAT dose to the bulboclitoris in low rectal cancer is around 3300 cGy, and in anal cancer, mean dose is around 2000 cGy to the external genitalia and 4500-5000 cGy to the bulboclitoris, all of which would be expected to result in clinically significant toxicity. Therefore, investigation of the avoidance of these important organs is needed and we hypothesize that proton techniques may achieve greater sparing than photon techniques.

MATERIALS/METHODS

In this study, we dosimetrically compare proton- vs. photon-based techniques in sparing functional sexual organs. The cohort consisted of four consecutive female pelvic cancer cases that had received 5000 cGy or greater. All cases were re-planned with VMAT and protons while optimizing dose to functional sexual organs and maintaining target coverage. Sexual organ structures assessed include the genitalia, vagina, ovaries, bulboclitoris and internal pudendal arteries. Given the small number of patients included in this demonstration study, statistical tests were not performed.

RESULTS

MRI was required to appropriately delineate soft tissue. In all cases, dosimetric sparing of sexual organs was improved with proton therapy without compromising target coverage. Mean doses were marginally decreased for structures within the PTV, while structures such as the bulboclitoris were spared substantially. Mean dose to the external genitalia was low with sparing using both VMAT (Median [IQR] (cGy): 852 [811, 1090]) and Proton techniques (Median [IQR] (cGy): 39.4 [11.9, 78.5]). Similarly, mean dose with sparing to the external genitalia was lower than would be expected without sparing, using both VMAT and Proton techniques (Median (IQR) Dmean (cGy) VMAT 3100 [2890, 3580] vs. Proton 1530 [1100, 2090]), with protons demonstrating greater sparing. In one case of a sacral chordoma, ovaries were substantially spared to below ablative thresholds (Dmean (cGy) VMAT 3598.8 and 3548.0 vs Proton 34.1 and 103.3).

CONCLUSION

Magnetic resonance imaging at simulation combined with proton radiotherapy for female sexual organ sparing may provide a technically feasible route to more equitable sexual outcomes for female patients. These results will guide future studies to optimize proton treatment techniques for female sexual organ sparing for future trials.

External Validation of the eCura System for Undifferentiated-Type Early Gastric Cancer with Noncurative Endoscopic Resection

Background/Aims

The eCura system, a scoring model for stratifying the lymph node metastasis risk after noncurative endoscopic resection for early gastric cancer (EGC), has been internally validated, primarily for differentiated-type EGC. We aimed to externally validate this model for undifferentiated-type EGC.

Methods

This multicenter, retrospective cohort study included 634 patients who underwent additional surgery (radical surgery group, n=270) or were followed up without additional treatment (no additional treatment group, n=364) after noncurative endoscopic resection for undifferentiated-type EGC between 2005 and 2015. The lymph node metastasis and survival rates were compared according to the risk categories.

Results

For the radical surgery group, the lymph node metastasis rates were 2.6%, 10.9%, and 14.8% for the low-, intermediate-, and high-risk eCura categories, respectively (p for trend=0.003). For the low-, intermediate-, and high-risk categories in the no additional treatment group, the overall survival (92.7%, 68.9%, and 80.0% at 5 years, respectively, p<0.001) and cancer-specific survival rates (99.7%, 94.7%, and 80.0% at 5 years, respectively, p<0.001) differed significantly. In the multivariate analysis, the hazard ratios (95% confidence interval) in the no additional treatment group relative to the radical surgery group were 3.18 (1.41 to 7.17; p=0.005) for overall mortality and 2.60 (0.46 to 14.66; p=0.280) for cancer-specific mortality in the intermediate-to-high risk category. No such differences were noted in the low-risk category.

Conclusions

The eCura system can be applied to undifferentiated-type EGC. Close follow-up without additional treatment might be considered for low-risk patients, while additional surgery is recommended for intermediate- and high-risk patients.

Risk of upper gastrointestinal cancer and death in persons with negative screening results: results from the National Cancer Screening Program in South Korea

BACKGROUND

The Korea National Cancer Screening Program (KNCSP) offers upper endoscopy or upper gastrointestinal series (UGIS) biannually for people aged ≥ 40 years. This study aimed to assess the effect of negative screening results on the incidence of and mortality from upper gastrointestinal (GI) cancer.

METHODS

A population-based retrospective cohort of 15,850,288 men and women was constructed using data from 3 national databases. The participants were followed until the end of 2017 for data on cancer incidence and in 2019 for data on the vital status. Cox proportional hazard model with time-varying exposure was used to assess the association.

RESULTS

By the end of the follow-up period, 230,783 upper GI cancer cases and 99,348 upper GI cancer deaths were recorded. Negative gastric cancer screening was significantly associated with a lower risk of upper GI cancer in both UGIS (adjusted hazard ratio [aHR] = 0.81, 95% CI = 0.80-0.82) and upper endoscopy (aHR = 0.67, 95% CI = 0.67-0.68) groups. The HRs for upper GI mortality were 0.55 (95% CI = 0.54-0.56) and 0.21 (95% CI = 0.21-0.22) for the UGIS and upper endoscopy groups, respectively. The most significant reductions in the risk of upper GI cancer (UGIS: aHR = 0.76, 95% CI = 0.74-0.77; upper endoscopy: aHR = 0.60, 95% CI = 0.59-0.61) and death (UGIS: aHR = 0.54, 95% CI = 0.52-0.55; upper endoscopy: aHR = 0.19, 95% CI = 0.19-0.20) were observed among individual aged 60-69 years.

CONCLUSION

Negative screening cases, especially in upper endoscopy of the KNCSP, were associated with an overall reduction in the risk of and mortality from upper GI cancer.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Exploring Connections between Oral Microbiota, Short-Chain Fatty Acids, and Specific Cancer Types: A Study of Oral Cancer, Head and Neck Cancer, Pancreatic Cancer, and Gastric Cancer

The association between oral microbiota and cancer development has been a topic of intense research in recent years, with compelling evidence suggesting that the oral microbiome may play a significant role in cancer initiation and progression. However, the causal connections between the two remain a subject of debate, and the underlying mechanisms are not fully understood. In this case-control study, we aimed to identify common oral microbiota associated with several cancer types and investigate the potential mechanisms that may trigger immune responses and initiate cancer upon cytokine secretion. Saliva and blood samples were collected from 309 adult cancer patients and 745 healthy controls to analyze the oral microbiome and the mechanisms involved in cancer initiation. Machine learning techniques revealed that six bacterial genera were associated with cancer. The abundance of Leuconostoc, Streptococcus, Abiotrophia, and Prevotella was reduced in the cancer group, while abundance of Haemophilus and Neisseria enhanced. G protein-coupled receptor kinase, H+-transporting ATPase, and futalosine hydrolase were found significantly enriched in the cancer group. Total short-chain fatty acid (SCFAs) concentrations and free fatty acid receptor 2 (FFAR2) expression levels were greater in the control group when compared with the cancer group, while serum tumor necrosis factor alpha induced protein 8 (TNFAIP8), interleukin-6 (IL6), and signal transducer and activator of transcription 3 (STAT3) levels were higher in the cancer group when compared with the control group. These results suggested that the alterations in the composition of oral microbiota can contribute to a reduction in SCFAs and FFAR2 expression that may initiate an inflammatory response through the upregulation of TNFAIP8 and the IL-6/STAT3 pathway, which could ultimately increase the risk of cancer onset.

Endoscopic submucosal dissection for papillary early gastric carcinoma: Insights from a large-scale analysis of post-gastrectomy pathology specimens

Gastric papillary adenocarcinoma is considered a differentiated adenocarcinoma in the current endoscopic submucosal dissection indication guidelines. However, the safety of endoscopic submucosal dissection remains controversial. Currently, data regarding which papillary early gastric cancer should be considered for endoscopic submucosal dissection are unavailable. Thus, the aim of this study was to investigate lymph node metastasis and the safety of endoscopic submucosal dissection in patients with papillary early gastric cancer. This observational study recruited 4264 consecutive patients with early gastric cancer who underwent curative gastrectomy between October 2000 and December 2017 at the National Cancer Center, Korea. Of these, 45 had pathologically confirmed papillary early gastric cancer, 2106 had differentiated non-papillary early gastric cancer, and 2113 had undifferentiated early gastric cancer. Logistic regression analysis was performed to identify risk factors for lymph node metastasis. Mucosal tumors were less common in papillary early gastric cancer (37.9%) than in differentiated non-papillary early gastric cancer (48.8%) and undifferentiated early gastric cancer (60.4%) (both P < .001). Lymph node metastasis was more common in papillary early gastric cancer (20.0%) than in differentiated non-papillary early gastric cancer (9.2%) and undifferentiated early gastric cancer (11.7%; both P < .001). In multivariate analysis, non-mixed-type papillary early gastric cancer showed marginally increased odds of lymph node metastasis than differentiated early gastric cancer (odds ratio [OR]: 2.5, 95% confidence interval [CI]: 1.0-6.3). Rates of lymph node metastasis (1/10, 10%) and angiolymphatic invasion (2/10, 20%) for papillary early gastric cancer meeting expanded criteria were higher than those for other histology types meeting endoscopic submucosal dissection absolute or expanded criteria (P = .03 and P < .001, respectively). Endoscopic submucosal dissection should be considered carefully for papillary early gastric cancer, especially if it meets expanded endoscopic submucosal dissection indications since it is associated with high rates of submucosal invasion and lymph node metastasis.

Heart failure with improved ejection fraction (HFimpEF) in patients treated with sacubitril/valsartan (SV)

Introduction

Several studies demonstrated that patients with improvement of left ventricular ejection fraction (LVEF) and symptoms had good prognosis in heart failure with reduced ejection fraction (HFrEF). Based on these results, new classification of HF according to LVEF was currently proposed. Sacubitril/valsartan (SV) is recommended as one of the first-line therapy of HFrEF patients. SV reduced hospitalization for HF and cardiovascular mortality compared to enalapril in PARADIGM-HF trial. However, it is unclear that patients with improvement of LVEF also have better prognosis compared to patients without LVEF improvement among patients treated with SV.

Purpose

We aimed to evaluate the clinical characteristics and outcomes of heart failure with improved ejection fraction (HFimpEF) in heart failure with reduced ejection fraction (HFrEF) patients treated with SV.

Methods

We analyzed 230 patients with HFrEF taking SV in a multicenter retrospective cohort (RECORD-SV registry) from 2017 to 2019. Enrolled 230 patients were performed baseline and 1-year follow-up echocardiography. Based on 2 echocardiographic results, we defined “HFimpEF” as HF with a baseline LVEF ≤40%, ≥10% increase from baseline LVEF and a follow-up measurement of LVEF &gt;40%. Others were defined as “Persistent HFrEF”. We analyzed and compared clinical characteristics and outcomes between two groups. Primary endpoint was a composite outcome of all-cause death and hospitalization for HF (HHF).

Results

From 230 patients, 65 patients with HFimpEF and 165 patients with Persistent HFrEF were analyzed. The median follow-up duration was 557 days (interquartile range 364 to 727 days). Patients with HFimpEF had a higher prevalence of female gender (50.8% vs. 30.3%) and de novo HF (44.6% vs. 21.2%). There were no significant differences for age, etiology (ischemic vs. non-ischemic), diabetes, atrial fibrillation, hypertension, and HF medications including SV dose between two groups. Patients with HFimpEF showed lower rate of all-cause death or HHF as a primary endpoint compared to patients with persistent HFrEF (6.2% vs. 22.4%; IPTW adjusted HR 0.24; 95% CI 0.13–0.46; p&lt;0.001) (Table 1). It was also shown that HFimpEF patients had a reduced risk of primary endpoint in the Kaplan-Meier curves compared with persistent HFrEF (Log-rank p=0.045) (Figure 1). We demonstrated that Non-prior MI (adjusted OR 7.29; 95% CI 1.50–35.36; p=0.014) and de novo HF (adjusted OR 4.33; 95% CI 1.70–11.04; p=0.002) were independent prognostic factors of HFimpEF in HFrEF patients treated with SV.

Conclusions

HFimpEF patients had better clinical outcomes compared to those with persistent HFrEF in HFrEF patients treated with SV. Non-prior MI and de novo HF were independent predictors of HFimpEF in patients treated with SV.

Funding Acknowledgement

Type of funding sources: None.

An Approach to the Primary and Secondary Prevention of Gastric Cancer in the United States

BACKGROUND & AIMS

Gastric cancer (GC) remains a leading cause of mortality among certain racial, ethnic, and immigrant groups in the United States (US). The majority of GCs are diagnosed at advanced stages, and overall survival remains poor. There exist no structured national strategies for GC prevention in the US.

METHODS

On March 5-6, 2020 a summit of researchers, policy makers, public funders, and advocacy leaders was convened at Stanford University to address this critical healthcare disparity. After this summit, a writing group was formed to critically evaluate the effectiveness, potential benefits, and potential harms of methods of primary and secondary prevention through structured literature review. This article represents a consensus statement prepared by the writing group.

RESULTS

The burden of GC is highly inequitably distributed in the US and disproportionately falls on Asian, African American, Hispanic, and American Indian/Alaskan Native populations. In randomized controlled trials, strategies of Helicobacter pylori testing and treatment have been demonstrated to reduce GC-specific mortality. In well-conducted observational and ecologic studies, strategies of endoscopic screening have been associated with reduced GC-specific mortality. Notably however, all randomized controlled trial data (for primary prevention) and the majority of observational data (for secondary prevention) are derived from non-US sources.

CONCLUSIONS

There exist substantial, high-quality data supporting GC prevention derived from international studies. There is an urgent need for cancer prevention trials focused on high-risk immigrant and minority populations in the US. The authors offer recommendations on how strategies of primary and secondary prevention can be applied to the heterogeneous US population.

Current status of the gastric cancer screening program in Korea

Background: In 2019, gastric cancer was one of the most common cancers in Korea. As a secondary prevention strategy for gastric cancer, the cancer screening has been provided since 1999 by the National Cancer Screening Program every 2 years for adults aged ≥40 years.Current Concepts: The participation rates for gastric cancer screening program have increased from 7.4% in 2002 to 62.9% in 2019. Until 2017, either upper gastrointestinal series or endoscopy were recommended for screening method. Since 2018, endoscopy has become the preferred screening method and 89.1% of the participants underwent endoscopy in 2019. After the introduction of the screening program, the 5-year relative survival rates have markedly improved (43.9% between 1993 and 1995 vs. 77.5% between 2015 and 2019), and the proportion of early gastric cancer detection has increased (28.6% in 1995 vs. 63.6% in 2019). The risk of death from gastric cancer decreased by 47% in participants who had undergone endoscopy screening. Additionally, the gastric cancer screening program is cost-effective, and endoscopy-associated adverse events rarely occur.Discussion and Conclusion: With the implementation of the screening program, mortality due to gastric cancer has decreased owing to early detection. After the completion of ongoing clinical trials in the general population, the primary prevention strategy of Helicobacter pylori eradication should be considered to effectively reduce the incidence of gastric cancer. Further studies are also required to provide optimal screening interval according to the presence of risk factors including H. pylori infection and presence of gastric mucosal atrophy.

Gastric cancer risk is reduced by a predominance of antioxidant factors in the oxidative balance: a hospital-based case-control study in Korea

OBJECTIVES

Gastric carcinogenesis is linked to oxidative stress from both exogenous and endogenous exposures. This study aimed to determine the association between the risk of gastric cancer and the oxidative balance score (OBS), which comprises antioxidant and pro-oxidant factors, including diet and lifestyle.

METHODS

For this hospital-based case-control study, 808 controls and 404 patients with gastric cancer who had clinical records indicating Helicobacter pylori infection and the histological subtype of cancer were recruited. The OBS was determined based on diet and lifestyle factors obtained from a 106-item semiquantitative food frequency questionnaire and a constructed questionnaire. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A higher OBS was associated with a reduced gastric cancer risk (OR, 0.49; 95% CI <sub.T3 vs. T1, 0.33 to 0.71; p for trend <0.001). In a subgroup analysis, antioxidant factors showed inverse associations with gastric cancer risk (OR, 0.53; 95% CI T3 vs. T1, 0.35 to 0.79; p for trend=0.003). A stronger association with antioxidant factors was observed in patients with intestinal gastric cancer (OR, 0.34; 95% CI T3 vs. T1, 0.19 to 0.62; p for trend<0.001) and those with H. pylori infection (OR, 0.57; 95% CI T3 vs. T1, 0.37 to 0.88; p for trend=0.014).

CONCLUSIONS

A predominance of antioxidant factors compared to pro-oxidant factors from diet and lifestyle reduced the risk of gastric cancer. The combined effect of oxidative stress, which involves an altered balance between antioxidants and pro-oxidants, is important for modulating the risk of gastric cancer.

A Comprehensive and Comparative Review of Global Gastric Cancer Treatment Guidelines

Countries differ in their treatment expertise and research results regarding gastric cancer; hence, treatment guidelines are diverse based on evidence and medical situations. A comprehensive and comparative review of each country’s guidelines is imperative to understand the similarities and differences among countries. We reviewed and compared five gastric cancer treatment guidelines in terms of endoscopic, surgical, perioperative, and palliative systemic treatment based on evidence levels and recommendation grades, as well as the postoperative follow-up strategies for each guideline. The Korean, Chinese, and European guidelines provided evidence and grading of the recommendations. The United States guidelines suggested categories for evidence and consensus. The Japanese guidelines suggested evidence and recommendations only for systemic treatment. The Korean and Japanese guidelines described endoscopic treatment, surgery, and lymphadenectomy in detail. The Chinese, United States, and European guidelines more intensively considered perioperative chemotherapy. In particular, the indications for chemotherapy and the regimens recommended by each guideline differed slightly. Considering their medical situations, each guideline had some diversity in terms of adopting evidence, which resulted in heterogeneous recommendations. This review will help medical personnel to comprehensively understand the diversity in gastric cancer treatment guidelines for each country in terms of evidence and recommendations.

Comparison of long-term outcomes of endoscopic submucosal dissection and surgery for undifferentiated-type early gastric cancer meeting the expanded criteria: a systematic review and meta-analysis

BACKGROUND

There have been concerns over the long-term outcomes of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancer (UD EGC). We aimed to compare the long-term outcomes of ESD and surgery for patients with UD EGC.

METHODS

We searched PubMed, Embase, and Cochrane Library databases through March 2021 to identify studies that compared the long-term outcomes of ESD and surgery for UD EGC meeting expanded criteria for curative resection. The risk of bias was assessed with the Cochrane tool for non-randomized studies. The risk ratio (RR) was estimated using a fixed-effect model.

RESULTS

Overall, 1863 patients from five retrospective cohort studies, including 908 patients with propensity score matching (PSM), were eligible for meta-analysis. ESD was associated with inferior overall survival (OS) compared to surgery in the overall cohort (RR 2.11; 95% CI 1.26-3.55) but not in the PSM cohort (RR 1.18; 95% CI 0.60-2.32). In the PSM cohort, ESD had a lower disease-free survival (DFS) (RR 2.49; 95% CI 1.42-4.35) and higher recurrence (RR 12.61; 95% CI 3.43-46.37), gastric recurrence (RR 11.25; 95% CI 3.06-41.40), and extragastric recurrence (RR 4.23; 95% CI 0.47-37.93). Recurrence outcomes were similar between the overall and PSM cohorts. Disease-specific survival was not significantly different between the two groups in both the overall and PSM cohorts.

CONCLUSION

Although OS after curative ESD for UD EGC was not different from that after surgery in the PSM cohort, DFS and recurrence were inferior after ESD. Limitations included a lack of randomized trials. Further prospective studies comparing the long-term outcomes of ESD and surgery for UD EGC are needed (PROSPERO CRD 42021237097).

Current Evidence for a Paradigm Shift in Gastric Cancer Prevention From Endoscopic Screening to Helicobacter pylori Eradication in Korea

Gastric cancer is prevalent in Korea and ranked as the third most common cancer in 2019, followed by lung and thyroid cancers. The National Cancer Screening Program (NCSP) for gastric cancer has been implemented in adults aged ≥40 since 1999 and involves endoscopic screening every 2 years. The beneficial effects of the current NCSP on early cancer detection, cost-effectiveness, and mortality reduction are evident. However, the screening program results in a large socioeconomic burden and the consumption of medical resources, as it focuses solely on secondary prevention (early detection) rather than primary prevention of cancer. Helicobacter pylori is defined as a group I carcinogen by the International Agency for Research on Cancer. Hence, its eradication has been suggested as an important primary gastric cancer prevention strategy. Well-designed randomized controlled trials involving high-risk groups (post-endoscopic resection of early gastric cancer and family history of gastric cancer) and long-term follow-up studies in the general population have provided high-quality evidence regarding the effects of H. pylori eradication on gastric cancer prevention. In this review, we discussed the evidences for a possible modification of the current gastric cancer secondary prevention strategy by introducing primary prevention through H. pylori eradication. Areas for future research to optimize primary prevention strategies were also suggested.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Association between bacteria other than Helicobacter pylori and the risk of gastric cancer

BACKGROUND

The gastric microbiota, including Helicobacter pylori (HP), has a remarkable role in gastric cancer (GC) occurrence. Evidence for the role of non-HP bacteria in GC risk is limited. We aimed to observe the association between bacteria other than HP and risk of GC in a Korean population.

METHODS

In this study, 268 GC cases and 288 healthy controls were included. Demographic data and total energy intake data were collected using a general questionnaire and a semiquantitative food frequency questionnaire, respectively. 16S rRNA gene sequencing was performed using DNA extracted from gastric biopsy samples.

RESULTS

Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and non-HP Proteobacteria were the five main phyla in the gastric environment. The five phyla were negatively related to the relative abundance of Helicobacter species (all p < 0.001). The Shannon index, richness, and Pilou-evenness were negatively correlated with Helicobacter species (all p < 0.001), while the microbial dysbiosis index was positively correlated with Helicobacter species (p < 0.001). Participants with a higher relative abundance of Actinobacteria species showed a significantly increased risk of GC (OR: 3.16, 95% CI = 1.92-5.19, p-trend<0.001). The non-HP microbiota composition among the four groups (HP+cases, HP- cases, HP+controls, and HP- controls) was significantly different (ANOSIM R = 0.10, p = 0.001).

CONCLUSION

Other than HP, several bacterial species might be associated with GC risk. HP status and GC status could determine the differences in microbial compositions. Further large prospective studies are warranted to confirm our findings.

Metabolic Effects of Gastrectomy and Duodenal Bypass in Early Gastric Cancer Patients with T2DM: A Prospective Single-Center Cohort Study

We evaluated the metabolic effects of gastrectomies and endoscopic submucosal dissections (ESDs) in early gastric cancer (EGC) patients with type 2 diabetes mellitus (T2DM). Forty-one EGC patients with T2DM undergoing gastrectomy or ESD were prospectively evaluated. Metabolic parameters in the patients who underwent gastrectomy with and without a duodenal bypass (groups 1 and 2, n = 24 and n = 5, respectively) were compared with those in patients who underwent ESD (control, n = 12). After 1 year, the proportions of improved/equivocal/worsened glycemic control were 62.5%/29.2%/8.3% in group 1, 40.0%/60.0%/0.0% in group 2, and 16.7%/50.0%/33.3% in the controls, respectively (p = 0.046). The multivariable ordered logistic regression analysis results showed that both groups had better 1-year glycemic control. Groups 1 and 2 showed a significant reduction in postprandial glucose (−97.9 and −67.8 mg/dL), body mass index (−2.1 and −2.3 kg/m²), and glycosylated hemoglobin (group 1 only, −0.5% point) (all p < 0.05). Furthermore, improvements in group 1 were more prominent when preoperative leptin levels were high (p for interaction < 0.05). Metabolic improvements in both groups were also observed for insulin resistance, leptin, plasminogen activator inhibitor-1, and resistin. Gastrectomy improved glycemic control and various metabolic parameters in EGC patients with T2DM. Patients with high leptin levels may experience greater metabolic benefits from gastrectomy with duodenal bypass.

Efficacy of endoscopic management for anastomotic leakage after gastrectomy in patients with gastric cancer

Background

Anastomotic leakage (AL) after gastrectomy in gastric cancer patients is associated with high mortality rates. Various endoscopic procedures are available to manage this postoperative complication. The aim of study was to evaluate the outcome of two endoscopic modalities, clippings and stents, for the treatment of AL.

Patients and methods

There were 4916 gastric cancer patients who underwent gastrectomy between December 2007 and January 2016 at the National Cancer Center, Korea. A total of 115 patients (2.3%) developed AL. Of these, 85 patients (1.7%) received endoscopic therapy for AL and were included in this retrospective study. The endpoints were the complete leakage closure rates and risk factors associated with failure of endoscopic therapy.

Results

Of the 85 patients, 62 received endoscopic clippings (with or without detachable snares), and 23 received a stent insertion. Overall, the complete leakage closure rate was 80%, and no significant difference was found between the clipping and stent groups (79.0% vs. 82.6%, respectively; P = 0.89). The complete leakage closure rate was significantly lower in the duodenal and jejunal stump sites (60%) than esophageal sites (86.1%) and gastric sites (94.1%; P = 0.026). The multivariate analysis showed that stump leakage sites (adjusted odds ratio [aOR], 4.51; P = 0.031) and the presence of intra-abdominal abscess (aOR, 4.92; P = -0.025) were associated with unsuccessful leakage closures.

Conclusions

Endoscopic therapy using clippings or stents is an effective method for the postoperative management of AL in gastric cancer patients. This therapy can be considered a primary treatment option due to its demonstrated efficacy, safety, and minimally invasive nature.

Evidence based guidelines for the treatment of Helicobacter pylori infection in Korea 2020

Helicobacter pylori infection is one of the most common infectious diseases worldwide. H. pylori is responsible for substantial gastrointestinal morbidity with a high disease burden. Since the revision of the H. pylori Clinical Practice Guidelines in 2013 in Korea, the eradication rate of H. pylori has gradually decreased with the use of a clarithromycin based triple therapy. According to a nationwide randomized controlled study by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was mostly due to increased antimicrobial resistance to clarithromycin. The clinical practice guidelines for treatment of H. pylori were updated based on evidence-based medicine from a meta-analysis conducted on a target group receiving the latest level of eradication therapy. The draft recommendations developed based on the meta-analysis were finalized after expert consensus on three recommendations regarding the indication for treatment and eight recommendations on the treatment itself. These guidelines were designed to provide clinical evidence for the treatment of H. pylori to patients, nurses, medical school students, policymakers, and clinicians. These may differ from current medical insurance standards, and will be revised if more evidence emerges in the future.

Effect of Helicobacter pylori treatment on the long-term mortality in patients with type 2 diabetes

BACKGROUND/AIMS

Meta-analyses of randomized trials reported a non-significant increase in overall mortality risk after Helicobacter pylori eradication. In this study, we investigated whether H. pylori treatment is associated with increased risk of overall mortality in patients with type 2 diabetes.

METHODS

In this retrospective population-based cohort study, we identified 66,706 patients treated for type 2 diabetes between 2002 and 2010 from the Korean National Health Insurance Service-National Sample Cohort. Patients who received H. pylori treatment (Hp-treatment cohort, 1,727 patients) were matched to those who did not (non-treatment cohort, 3,454 patients) at a 1:2 ratio. The primary outcome was overall mortality. The secondary outcomes were mortalities due to cardiovascular disease, cerebrovascular disease, or cancers. To estimate hazard ratio (HR) with confidential interval (CI), we used the Cox proportional-hazard model.

RESULTS

During a median follow-up of 4.7 years, the overall mortality was 5.9% (101/1,727 patients) among patients in the Hp-treatment cohort and 7.6% (364/3,454 patients) among patients in the non-treatment cohort. Adjusted HR (aHR) for overall mortality in the Hp-treatment cohort was 0.74 (95% CI, 0.59 to 0.93; p = 0.011). The mortality risks due to cardiovascular disease (aHR, 1.34; 95% CI, 0.54 to 3.30; p = 0.529), cerebrovascular disease (aHR, 0.97; 95% CI, 0.37 to 2.55; p = 0.947), and cancer (aHR, 1.08; 95% CI, 0.68 to 1.72; p = 0.742) were not significantly different between the groups.

CONCLUSION

In type 2 diabetes patients, overall mortality did not increase after H. pylori treatment.

Risk factors for lymph node metastasis in early gastric cancer without lymphatic invasion after endoscopic submucosal dissection

BACKGROUND

Lymphatic invasion (LI) is a potent risk factor for lymph node metastasis (LNM) in early gastric cancer (EGC) after endoscopic submucosal dissection (ESD). However, there are also other risk factors for LNM. Hence, to identify the need for additional surgery in some case of EGC without LI, the present study aimed to identify the risk factors for LNM in patients with EGC without LI.

METHODS

Data from 2284 patients diagnosed with EGC who underwent curative surgery at National Cancer Center in Korea from January 2012 to May 2019 were collected. The clinicopathological characteristics of patients with EGC without LI were compared on the basis of LNM status.

RESULTS

There were 339 (17.1%) and 1648 (82.9%) patients with and without LI respectively. Among these patients with and without LI, 118 (34.8%) and 91 (5.5%) patients presented with LNM, respectively. In patients with EGC without LI, tumor size larger than 3 cm (OR = 2.12, 95% CI = 1.22-3.68; p = 0.007), submucosal invasion (OR = 4.14, 95% CI = 2.57-6.65; p < 0.001), and undifferentiated histologic type (OR = 2.33, 95% CI = 1.45-3.76; p < 0.001) were significant risk factors for LNM. Rates of LNM in patients meeting absolute, expanded, and beyond expanded criteria without LI were 0%, 1.5% (OR = 3.27, 95% CI = 0.18-59.41; p = 0.423), and 7.3% respectively. When the expanded criteria were divided into four subtypes patients with EGC, without LI within each subtype did not show significant risk of incidence of LNM compared to the absolute criteria.

CONCLUSIONS

The current expanded criteria for endoscopic resection (ER) are tolerable in cases without LI, even though minimal risk LNM exists. Therefore, additional surgery may not be needed for patients meeting expanded criteria for ER.

Establishing Machine Learning Models to Predict Curative Resection in Early Gastric Cancer with Undifferentiated Histology: Development and Usability Study

Background

Undifferentiated type of early gastric cancer (U-EGC) is included among the expanded indications of endoscopic submucosal dissection (ESD); however, the rate of curative resection remains unsatisfactory. Endoscopists predict the probability of curative resection by considering the size and shape of the lesion and whether ulcers are present or not. The location of the lesion, indicating the likely technical difficulty, is also considered.

Objective

The aim of this study was to establish machine learning (ML) models to better predict the possibility of curative resection in U-EGC prior to ESD.

Methods

A nationwide cohort of 2703 U-EGCs treated by ESD or surgery were adopted for the training and internal validation cohorts. Separately, an independent data set of the Korean ESD registry (n=275) and an Asan medical center data set (n=127) treated by ESD were chosen for external validation. Eighteen ML classifiers were selected to establish prediction models of curative resection with the following variables: age; sex; location, size, and shape of the lesion; and whether ulcers were present or not.

Results

Among the 18 models, the extreme gradient boosting classifier showed the best performance (internal validation accuracy 93.4%, 95% CI 90.4%-96.4%; precision 92.6%, 95% CI 89.5%-95.7%; recall 99.0%, 95% CI 97.8%-99.9%; and F1 score 95.7%, 95% CI 93.3%-98.1%). Attempts at external validation showed substantial accuracy (first external validation 81.5%, 95% CI 76.9%-86.1% and second external validation 89.8%, 95% CI 84.5%-95.1%). Lesion size was the most important feature in each explainable artificial intelligence analysis.

Conclusions

We established an ML model capable of accurately predicting the curative resection of U-EGC before ESD by considering the morphological and ecological characteristics of the lesions.

Long-term Outcomes of Undifferentiated-Type Early Gastric Cancer with Positive Horizontal Margins after Endoscopic Resection

Background/Aims

This study examined the long-term outcomes of undifferentiated-type early gastric cancer (UD EGC) with positive horizontal margins (HMs) after endoscopic resection (ER) and compared them between additional surgery and nonsurgical management.

Methods

From 2005 to 2015, a total of 1,124 patients with UD EGC underwent ER at 18 tertiary hospitals in Korea. Of them, 92 patients with positive HMs as the only noncurative factor (n=25) or with both positive HMs and tumor size >2 cm (n=67) were included. These patients underwent additional surgery (n=40), underwent additional endoscopic treatment (n=6), or were followed up without further treatment (n=46).

Results

No lymph node (LN) metastasis was found in patients who underwent additional surgery. During a median follow-up of 57.7 months (interquartile range, 27.6 to 68.8 months), no LN or distant metastases or gastric cancer-related deaths occurred in the overall cohort. At baseline, the residual cancer rate was 57.8% (26/45) after additional surgery or ER. The 5-year local recurrence rate was 33.6% among patients who were followed up without additional treatment. The 5-year overall survival rates were 95.0% and 87.8% after additional surgery and nonsurgical management (endoscopic treatment or close follow-up), respectively (log-rank p=0.224). In the multivariate Cox regression analysis, nonsurgical management was not associated with an increased risk of mortality.

Conclusions

UD EGC with positive HMs after ER may have favorable long-term outcomes and a very low risk of LN metastasis. Nonsurgical management may be suggested as an alternative, particularly for patients with old age or chronic illness. (Gut Liver 2021;15-731)

Evidence-Based Guidelines for the Treatment of Helicobacter pylori Infection in Korea 2020

Helicobacter pylori infection is one of the most common infectious diseases worldwide. Although the prevalence of H. pylori is gradually decreasing, approximately half of the world&#039;s population still becomes infected with this disease. H. pylori is responsible for substantial gastrointestinal morbidity worldwide, with a high disease burden. It is the most common cause of gastric and duodenal ulcers and gastric cancer. Since the revision of the H. pylori clinical practice guidelines in 2013 in Korea, the eradication rate of H. pylori has gradually decreased with the use of a clarithromycin-based triple therapy for 7 days. According to a nationwide randomized controlled study conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was mostly due to increased antimicrobial resistance, especially from clarithromycin. The clinical practice guidelines for the treatment of H. pylori were updated according to evidence-based medicine from a meta-analysis conducted on a target group receiving the latest level of eradication therapy. The draft recommendations developed based on the meta-analysis were finalized after an expert consensus on three recommendations regarding the indication for treatment and eight recommendations for the treatment itself. These guidelines were designed to provide clinical evidence for the treatment (including primary care treatment) of H. pylori infection to patients, nurses, medical school students, policymakers, and clinicians. These may differ from current medical insurance standards and will be revised if more evidence emerges in the future.

Eradication Rates of Clarithromycin Triple Therapy in Korea: A Systematic Review and Meta-analysis

Background/Aims: Standard triple therapy, including a proton pump inhibitor, clarithromycin, and amoxicillin, has been recommended as the first-line for <i>Helicobacter pylori</i> infection. However, the eradication rate of standard triple therapy has declined over the past years because of the increasing resistance to clarithromycin in Korea. We analyzed the eradication rates and the 10-year change in the eradication rates in Korea.Methods: PubMed, EMBASE, the Cochrane Library, and KoreaMed were searched for studies published between January 2007 and June 2018. The pooled eradication rates and their 95% CIs were estimated using a random-effect logistic regression model.Results: Twenty-six randomized controlled studies on standard triple therapy conducted in Korea were selected. The intention-to-treat (ITT) and per protocol analyses showed pooled eradication rates of standard triple therapy of 71.6% (95% CI, 69.9~73.3%) and 79.6% (95% CI, 76.6~82.2%), respectively. The eradication rate decreased with time. The ITT analysis showed that the 14-day therapy (78.1% [95% CI, 75.2~80.7%]) had significantly higher eradication rates than the 7-day therapy (70.0% [95% CI, 68.5~71.4%]) (<i>P</i><0.01).Conclusions: These results suggest that the eradication rate of standard triple therapy, as the first-line therapy, has shown an unacceptable decrease. The eradication rate increased when the duration of therapy was increased to 14 days, but it was not satisfactory. Therefore, other treatment regimens or therapies based on susceptibility tests should be considered for the first-line therapy.

Salvage Regimens after Failure of Previous Helicobacter pylori Eradication Therapy: A Systematic Review and Meta-analysis

Background/Aims: As antibiotic resistance increases and new first-line therapies emerge, salvage therapies for <i>Helicobacter pylori</i> (<i>H. pylori</i>) eradication failures are becoming more common and complicated. This study aimed to systematically review overall salvage regimens after previous failure of <i>H. pylori</i> eradication.Materials and Methods: A systematic review of randomized clinical trials evaluating salvage therapies after previous <i>H. pylori</i> eradication failure was performed. A meta-analysis was conducted when an adequate number of studies suitable for grouping was found.Results: Overall, 36 studies with 77 treatment arms were identified, and they were highly heterogeneous regarding previously failed regimens and salvage regimens under comparison. Bismuth quadruple therapy after failure of standard triple therapy showed a pooled intention-to-treat (ITT) eradication rate of 75.5% (95% CI, 71.6~79.1%), and the rates were significantly higher with 14-day therapy than 7-day therapy by 9% (95% CI, 2~15%). Levofloxacin triple therapy after failure of standard triple therapy demonstrated a pooled ITT eradication rate of 73.3% (95% CI, 68.4~77.3%). In direct comparison, the two regimens were not significantly different in eradication rates. No study evaluated salvage regimens after the failure of bismuth or non-bismuth quadruple therapy.Conclusions: The current studies regarding salvage regimens are highly heterogeneous. Bismuth quadruple therapy and levofloxacin triple therapy may be a reliable option after failure of standard triple therapy, but the regional profile of antibiotic resistance should be considered. Further studies are needed for salvage regimens after failure of non-bismuth or bismuth quadruple therapy.

Ten-day bismuth-containing quadruple therapy versus 7-day proton pump inhibitor-clarithromycin containing triple therapy as first-line empirical therapy for the Helicobacter pylori infection in Korea: a randomized open-label trial

BACKGROUND

This randomized, open-label trial aimed to compare the efficacy of 10-day bismuth-containing quadruple therapy (BQT) with 7-day proton-pump inhibitor-clarithromycin containing standard triple therapy (STT) as an empirical first-line Helicobacter pylori therapy.

METHODS

Participants with H. pylori infection were randomly assigned to either 10-day BQT (daily doses of bismuth 300 mg, four times; lansoprazole 30 mg, twice; metronidazole 500 mg, three times; and tetracycline 500 mg, four times) or 7-day STT (lansoprazole 30 mg; amoxicillin 1,000 mg; and clarithromycin 500 mg; each given twice daily). Participants who failed initial therapy were crossed over to the alternative treatment regimen. Primary outcome was the eradication rates of first-line treatment by intention-to-treat analysis.

RESULTS

Study participants (n = 352) were randomized to receive either 10-day BQT (n = 175) or 7-day STT (n = 177). The BQT-group achieved a significantly higher eradication rate than the STT-group in the intention-to-treat analysis (74.3% vs 57.1%, respectively; P = 0.001), modified intention-to-analysis (87.2% [130/149] vs 68.7% [101/147], respectively; P < 0.001) and per-protocol analysis (92.9% [105/113] vs 70.1% [94/134], respectively; P < 0.001). Although there was no serious adverse event, the compliance was lower with BQT than STT as a higher proportion of participants in the BQT-group discontinued therapy because of adverse events than those in the STT-group (23.1% vs 9.1%, respectively; P = 0.001) CONCLUSIONS: Ten-day BQT had higher eradication rates compared to that of the 7-day STT as an empirical first-line treatment for H. pylori eradication in Korea.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02557932. Registered 23 September 2015, https://clinicaltrials.gov/ct2/show/NCT02557932?term=NCT02557932&draw=2&rank=1 .

Gastric Cancer Risk Prediction Using an Epidemiological Risk Assessment Model and Polygenic Risk Score

Simple Summary

Risk prediction models incorporate various established risk factors to estimate individual risk specifically in cancer. These models additionally include biological or genetic risk factors to assess cancer risk more accurately. The polygenic risk score (PRS) combines the effects of multiple single-nucleotide polymorphisms (SNPs) that are associated with disease; its discrimination ability was assessed both alone and when used in combination with conventional risk prediction models. As few studies have evaluated the combination of genetic variants to identify high risk population of gastric cancer (GC), and we examined the performance of a GC risk assessment model in combination with SNPs as a PRS in consideration of Helicobacter pylori (H. pylori) infection status. Such a combination improves the identification of a GC-susceptible population among people with H. pylori infection.

Abstract

We investigated the performance of a gastric cancer (GC) risk assessment model in combination with single-nucleotide polymorphisms (SNPs) as a polygenic risk score (PRS) in consideration of Helicobacter pylori (H. pylori) infection status. Six SNPs identified from genome-wide association studies and a marginal association with GC in the study population were included in the PRS. Discrimination of the GC risk assessment model, PRS, and the combination of the two (PRS-GCS) were examined regarding incremental risk and the area under the receiver operating characteristic curve (AUC), with grouping according to H. pylori infection status. The GC risk assessment model score showed an association with GC, irrespective of H. pylori infection. Conversely, the PRS exhibited an association only for those with H. pylori infection. The PRS did not discriminate GC in those without H. pylori infection, whereas the GC risk assessment model showed a modest discrimination. Among individuals with H. pylori infection, discrimination by the GC risk assessment model and the PRS were comparable, with the PRS-GCS combination resulting in an increase in the AUC of 3%. In addition, the PRS-GCS classified more patients and fewer controls at the highest score quintile in those with H. pylori infection. Overall, the PRS-GCS improved the identification of a GC-susceptible population of people with H. pylori infection. In those without H. pylori infection, the GC risk assessment model was better at identifying the high-risk group.

Antioxidant-Rich Diet, GSTP1 rs1871042 Polymorphism, and Gastric Cancer Risk in a Hospital-Based Case-Control Study

Background

Chronic gastritis along with Helicobacter pylori (H. pylori) infection has been implicated in inflammatory response-related genes linked to the causation of gastric cancer. Glutathione S-transferase Pi (GSTP1) plays a role in regulating oxidative stress and detoxification against carcinogenesis. In this study, we aimed to determine whether an antioxidant-rich diet is associated with gastric cancer risk and identify how this association could be altered by GSTP1 genetic variants.

Methods

This study included 1,245 participants (415 cases and 830 controls) matched for age and sex. The dietary antioxidant capacity was estimated based on the oxygen radical absorbance capacity (ORAC) incorporated with a semiquantitative food frequency questionnaire. Five single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695, rs749174, rs1871042, rs4891, and rs947895) were selected among the exome array genotype data.

Results

High dietary ORAC was inversely associated with gastric cancer (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.57, 0.39–0.82, P = 0.004; lipophilic ORAC = 0.66, 0.45–0.95, P = 0.021; total phenolics = 0.57, 0.39–0.83, P = 0.005). The polymorphism rs1871042 increased the risk of gastric cancer (OR, 95% CI = 1.55, 1.10–2.16, P = 0.01, CT+TT vs. CC). A remarkably reduced risk of gastric cancer was observed among those who had a high dietary ORAC according to rs1871042 polymorphism (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.36, 0.17–0.78, P for trend = 0.013; lipophilic ORAC = 0.58, 0.37–0.93, P for trend = 0.021; total phenolics = 0.38, 0.17–0.83, P for trend = 0.019).

Conclusions

Our findings indicate that dietary ORAC intake may be inversely associated with the risk of gastric cancer altered by genetic variants of GSTP1, providing new intervention strategies for gastric cancer patients.

Clinicopathologic Features of Submucosal Papillary Gastric Cancer Differ from Those of Other Differentiated-Type Histologies

Background/Aims

Papillary gastric cancer (GC) is classified as differentiated adenocarcinoma, together with well-differentiated (WD) and moderately differentiated (MD) adenocarcinoma. This study evaluated the risk of lymph node metastasis (LNM) in submucosal (SM) invasive papillary GC compared with other differentiated early GC types.

Methods

This retrospective study involved three tertiary hospitals and enrolled 1,798 lesions with differentiated SM invasive GC treated with curative gastrectomy between March 2001 and December 2012. All pathology slides were reviewed, and clinicopathologic findings associated with LNM, including tumor size, location, gross type, ulceration, depth and width of SM invasion, and lymphovascular invasion (LVI), were analyzed.

Results

The proportion of SM papillary GC was 2.8% (n=51). SM papillary GC was associated with larger tumor size and deeper and wider SM invasion than other differentiated GC types. LNM was significantly higher in the papillary type than in the MD and WD types. LNM was found in 27.5% of SM papillary GC patients (WD 9.0%, MD 21.2%). LVI was the only significant risk factor for LNM in SM papillary GC. The depth or width of SM invasion was not associated with LNM in papillary GC. Lower third location or elevated gross appearance was significantly associated with LVI.

Conclusions

SM papillary GC had the highest LNM rate, with features different from those of other differentiated SM invasive GCs. The treatment strategy for SM papillary GC should be carefully approached, especially for lesions located in the lower third or of the elevated gross type.

Risk factors of lymph node metastasis after non-curative endoscopic resection of undifferentiated-type early gastric cancer

BACKGROUND

This study aimed to investigate risk factors for lymph node (LN) or distant metastasis after non-curative endoscopic resection (ER) of undifferentiated-type early gastric cancer (EGC).

METHODS

Of 1124 patients who underwent ER for undifferentiated-type gastric cancer at 18 tertiary hospitals across six geographic areas in Korea between 2005 and 2014, 634 with non-curative ER beyond the expanded criteria were retrospectively enrolled. According to the treatment after ER, patients were divided into additional surgery (n = 270) and follow-up (n = 364) groups. The median follow-up duration was 59 months for recurrence and 84 months for mortality.

RESULTS

LN metastasis was found in 6.7% (18/270) of patients at surgery. Ulcer [odds ratio (OR) 3.83; 95% confidence interval (CI) 1.21-12.13; p = 0.022] and submucosal invasion (OR 10.35; 95% CI 1.35-79.48; p = 0.025) were independent risk factors. In the follow-up group, seven patients (1.9%) developed LN or distant recurrence. Ulcer [hazard ratio (HR) 7.60; 95% CI 1.39-35.74; p = 0.018], LVI (HR 6.80; 95% CI 1.07-42.99; p = 0.042), and positive vertical margin (HR 6.71; 95% CI 1.28-35.19; p = 0.024) were independent risk factors. In the overall cohort, LN metastasis rates were 9.6% in patients with two or more risk factors and 1.2% in those with no or one risk factor.

CONCLUSIONS

LVI, ulcer, submucosal invasion, and positive vertical margin are independently associated with LN or distant metastasis after non-curative ER of undifferentiated-type EGC. Surgical resection is strongly recommended for patients with two or more risk factors.

Evidence-based Guidelines for the Treatment of Helicobacter pylori Infection in Korea: 2020 Revised Edition

Helicobacter pylori (H. pylori) infection is one of the most common infectious diseases worldwide. Although its incidence is gradually decreasing, about half of the world's population still get infected. H. pylori infection is responsible for substantial gastrointestinal morbidity worldwide. It is the most common cause of gastric and duodenal ulcers as well as gastric cancer. Since the revision of the H. pylori Clinical Practice Guidelines in 2013, the eradication rate of H. pylori has gradually decreased with the use of classical triple therapy, wherein amoxicillin, clarithromycin, and proton pump inhibitors are administered, for 7 days. According to a nationwide randomized controlled study conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research released in 2018, the intention-to-treat eradication rate was only 63.9%, which was due to increased antimicrobial resistance induced by the use of antibiotics, especially clarithromycin. The update of clinical practice guideline for treatment of H. pylori was developed based on evidence-based medicine by conducting a meta-analysis. The draft recommendations were finalized after expert consensus on three recommendations regarding the indication for treatment and eight recommendations on the treatment itself. These guidelines are designed to provide patients, nurses, medical school students, policymakers, and clinicians with clinical evidence to guide primary care and treatment of H. pylori infection. These may differ from current medical insurance standards and will be revised further, if necessary, based on research-based evidence.

Effect of <i>Helicobacter pylori</i> Treatment on Long-term Mortality in Patients with Hypertension

Background/Aims

A meta-analysis of randomized trials performed in healthy asymptomatic individuals suggested that overall mortality may increase after Helicobacter pylori eradication despite a significant decrease in the gastric cancer incidence and mortality rates. This retrospective population-based cohort study investigated if H. pylori treatment is associated with an increase in overall mortality in patients with hypertension.

Methods

From the database of the Korean National Health Insurance Sample Cohort, we selected 198,487 patients treated for hypertension between 2002 and 2010. Those who received H. pylori treatment (H. pylori treatment cohort, 5,541 patients) were matched to those who did not (nontreatment cohort, 11,082 patients) at the ratio of 1 to 2. The primary outcome was the risk of overall mortality. The secondary outcomes were the risks of mortality due to cardiovascular disease, cerebrovascular disease, and cancer. The outcomes were evaluated from 6 months after H. pylori treatment to December 2013. A Cox proportional hazard model was used to estimate the hazard ratios (HRs).

Results

During a median follow-up period of 4.8 years, death from any cause was reported in 4.1% of the patients in the H. pylori treatment cohort and 5.5% of the patients in the nontreatment cohort. The adjusted HR (aHR) for overall mortality in the H. pylori treatment cohort was 0.70 (95% confidence interval [CI], 0.60 to 0.82; p<0.001). With regard to cause-specific mortality, compared with the nontreatment cohort, the H. pylori treatment cohort had a lower risk of mortality due to cerebrovascular disease (aHR, 0.46; 95% CI, 0.26 to 0.81; p=0.007). The risks of mortality due to cancer and cardiovascular disease were not different between the cohorts.

Conclusions

H. pylori treatment is not associated with an increase in overall mortality in patients treated for hypertension.

An unusual anatomical variant of the left phrenic nerve encircling the transverse cervical artery

During educational dissection of cadavers, we encountered anatomical variability of the left phrenic nerve (PN). In this cadaver, nerve fibres from C3 and C4 descended and crossed behind the transverse cervical artery (TCA), a branch of the thyrocervical trunk, at the level of the anterior scalene muscle. On the other hand, nerve fibres from C5 descended obliquely above the TCA and then joined the fibres from C3-C4 on the medial side of the anterior scalene muscle to form the PN. To our knowledge, the encircling of the TCA by the left PN in the neck has not yet been reported and may pose a potential risk for nerve compression during movement of the neck. We discuss several types of anatomical variants of the PN and the associated risk during thorax and neck dissection procedures.

A Summary of the 2020 Gastric Cancer Summit at Stanford University

There exists no coherent national strategy for the early detection or prevention of gastric cancer in the United States (US), even among identified high-risk groups such as Asian Americans, African Americans, Hispanic Americans, and Alaska Native/American Indian peoples. As a result, patients with gastric cancer in the US are diagnosed at later stages and demonstrate worse overall survival compared to nations of East Asia with established screening programs (Table 1). The under-recognition of gastric cancer risk within minority communities is a significant unaddressed healthcare disparity.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Non-exposure Simple Suturing Endoscopic Full-thickness Resection with Sentinel Basin Dissection in Patients with Early Gastric Cancer: the SENORITA 3 Pilot Study

Purpose

Recently, non-exposure simple suturing endoscopic full-thickness resection (NESS-EFTR) was developed to prevent tumor exposure to the peritoneal cavity. This study aimed to evaluate the feasibility of NESS-EFTR with sentinel basin dissection for early gastric cancer (EGC).

Materials and Methods

This was the prospective SENORITA 3 pilot. From July 2017 to January 2018, 20 patients with EGC smaller than 3 cm without an absolute indication for endoscopic submucosal dissection were enrolled. The sentinel basin was detected using Tc^99m-phytate and indocyanine green, and the NESS-EFTR procedure was performed when all sentinel basin nodes were tumor-free on frozen pathologic examination. We evaluated the complete resection and intraoperative perforation rates as well as the incidence of postoperative complications.

Results

Among the 20 enrolled patients, one dropped out due to large tumor size, while another underwent conventional laparoscopic gastrectomy due to metastatic sentinel lymph nodes. All NESS-EFTR procedures were performed in 17 of the 18 other patients (94.4%) without conversion, and the complete resection rate was 83.3% (15/18). The intraoperative perforation rate was 27.8% (5/18), and endoscopic clipping or laparoscopic suturing or stapling was performed at the perforation site. There was one case of postoperative complications treated with endoscopic clipping; the others were discharged without any event.

Conclusions

NESS-EFTR with sentinel basin dissection is a technically challenging procedure that obtains safe margins, prevents intraoperative perforation, and may be a treatment option for EGC after additional experience.

Trial Registration

ClinicalTrials.gov Identifier: NCT03216174

Evaluation of Submucosal or Lymphovascular Invasion Detection Rates in Early Gastric Cancer Based on Pathology Section Interval

PURPOSE

The guidelines for pathological evaluation of early gastric cancer (EGC) recommend wider section intervals for surgical specimens (5-7 mm) than those for endoscopically resected specimens (2-3 mm). Studies in surgically resected EGC specimens showed not negligible lymph node metastasis risks in EGCs meeting the expanded criteria for endoscopic submucosal dissection (ESD).

MATERIALS AND METHODS

This retrospective study included 401 EGC lesions with an endoscopic size of ≤ 30 mm detected in 386 patients. Pathological specimens obtained by ESD or surgery were cut into 2-mm section intervals for reference. Submucosal or lymphovascular invasion (LVI) was evaluated arbitrarily in 4- or 6-mm section intervals. McNemar's tests compared the differences between submucosal and LVI.

RESULTS

Submucosal invasion was detected in 29.2% (117/401) and LVI in 9.5% (38/401) at 2-mm interval. The submucosal invasion detection rates in 4-mm intervals decreased to 88.0% or 90.6% (both P<0.001), while the LVI detection rates decreased to 86.8% or 57.9% (P=0.025 and P<0.001, respectively). In 6-mm intervals, the submucosal and LVI detection rates decreased further to 72.7-80.3% (P<0.001 for all three sets) and 55.3-63.2% (P<0.001 for all three sets), respectively. Among 150 out-of-indication cases at 2-mm interval, 4-10 (2.7%-6.7%) at 4-mm intervals, and 10-17 (6.7%-11.3%) at 6-mm intervals were misclassified as lesions meeting the curative resection criteria due to the underestimation of submucosal or LVI.

CONCLUSIONS

After ESD, the 2-mm wide section interval was suitable for the pathological evaluation of focal submucosal or LVI. Thus, if an EGC lesion meets the expanded criteria for the ESD specimen pathological evaluation, it could be safely followed up.

Comparison of the performance of risk scoring systems for tumor bleeding in patients with inoperable gastric cancer

BACKGROUND

The Glasgow - Blatchford bleeding score (GBS) and admission and full Rockall scores are widely used risk scoring systems to stratify risk and determine the need for intervention in patients with upper gastrointestinal bleeding. We evaluated the performance of these risk scoring systems in patients with gastric cancer and tumor bleeding.

METHODS

This retrospective study included patients with inoperable gastric cancer who presented with tumor bleeding at the National Cancer Center, Korea, between 2001 and 2015. The GBS, and admission and full Rockall scores were calculated. Primary outcome was the performance of the risk scoring systems in predicting the need for urgent interventions (endoscopic therapy, transarterial embolization, and surgery). The risk factors associated with urgent intervention were analyzed.

RESULTS

Of 357 patients with tumor bleeding, 118 (33.1 %; 116 endoscopic therapy, 2 trans-arterial embolization) required urgent intervention. The full Rockall score was better at predicting the need for urgent intervention (area under the receiver operating characteristic curve = 0.78; P < 0.001) than the GBS (0.56) and admission Rockall score (0.56). Hemostatic intervention was not performed in patients with a full Rockall score ≤ 6 (103 patients, 28.9 %). On multivariate analysis, endoscopic stigmata of recent hemorrhage of Forrest classes Ia - IIb were significant factors associated with urgent intervention.

CONCLUSIONS

The full Rockall score was superior to the GBS and admission Rockall score in predicting the need for urgent intervention for tumor bleeding. Thus, endoscopic evaluation is required to determine the need for urgent intervention in patients with gastric cancer and tumor bleeding.

Identification of Dietary Pattern Networks Associated with Gastric Cancer Using Gaussian Graphical Models: A Case-Control Study

Gaussian graphical models (GGMs) are novel approaches to deriving dietary patterns that assess how foods are consumed in relation to one another. We aimed to apply GGMs to identify dietary patterns and to investigate the associations between dietary patterns and gastric cancer (GC) risk in a Korean population. In this case-control study of 415 GC cases and 830 controls, food intake was assessed using a 106-item semiquantitative food frequency questionnaire that captured 33 food groups. The dietary pattern networks corresponding to the total population contained a main network and four subnetworks. For the vegetable and seafood network, those who were in the highest tertile of the network-specific score showed a significantly reduced risk of GC both in the total population (OR = 0.66, 95% CI = 0.47-0.93, p for trend = 0.018) and in males (OR = 0.55, 95% CI = 0.34-0.89, p for trend = 0.012). Most importantly, the fruit pattern network was inversely associated with the risk of GC for the highest tertile (OR = 0.56, 95% CI = 0.38-0.81, p for trend = 0.002). The identified vegetable and seafood network and the fruit network showed a protective effect against GC development in Koreans.

Ten-Day Concomitant, 10-Day Sequential, and 7-Day Triple Therapy as First-Line Treatment for Helicobacter pylori Infection: A Nationwide Randomized Trial in Korea

Background/Aims

This nationwide, multicenter prospective randomized controlled trial aimed to compare the efficacy and safety of 10-day concomitant therapy (CT) and 10-day sequential therapy (ST) with 7-day clarithromycin-containing triple therapy (TT) as first-line treatment for Helicobacter pylori infection in the Korean population.

Methods

Patients with H. pylori infection were assigned randomly to 7d-TT (lansoprazole 30 mg, amoxicillin 1 g, and clarithromycin 500 mg twice daily for 7 days), 10d-ST (lansoprazole 30 mg and amoxicillin 1 g twice daily for the first 5 days, followed by lansoprazole 30 mg, clarithromycin 500 mg, and metronidazole 500 mg twice daily for the remaining 5 days), or 10d-CT (lansoprazole 30 mg, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg twice daily for 10 days). The primary endpoint was eradication rate by intention-to-treat (ITT) and per-protocol (PP) analyses.

Results

A total of 1,141 patients were included. The 10d-CT protocol achieved a markedly higher eradication rate than the 7d-TT protocol in both the ITT (81.2% vs 63.9%) and PP analyses (90.6% vs 71.4%). The eradication rate of the 10d-ST protocol was superior to that of the 7d-TT protocol (76.3% vs 63.9%, ITT analysis; 85.0% vs 71.4%, PP analysis). No significant differences in adherence or serious side effects were found among the three treatment arms.

Conclusions

The 10d-CT and 10d-ST regimens were superior to the 7d-TT regimen as standard first-line treatment in Korea.

Family History of Gastric Cancer and Helicobacter pylori Treatment

BACKGROUND

Helicobacter pylori infection and a family history of gastric cancer are the main risk factors for gastric cancer. Whether treatment to eradicate H. pylori can reduce the risk of gastric cancer in persons with a family history of gastric cancer in first-degree relatives is unknown.

METHODS

In this single-center, double-blind, placebo-controlled trial, we screened 3100 first-degree relatives of patients with gastric cancer. We randomly assigned 1838 participants with H. pylori infection to receive either eradication therapy (lansoprazole [30 mg], amoxicillin [1000 mg], and clarithromycin [500 mg], each taken twice daily for 7 days) or placebo. The primary outcome was development of gastric cancer. A prespecified secondary outcome was development of gastric cancer according to H. pylori eradication status, assessed during the follow-up period.

RESULTS

A total of 1676 participants were included in the modified intention-to-treat population for the analysis of the primary outcome (832 in the treatment group and 844 in the placebo group). During a median follow-up of 9.2 years, gastric cancer developed in 10 participants (1.2%) in the treatment group and in 23 (2.7%) in the placebo group (hazard ratio, 0.45; 95% confidence interval [CI], 0.21 to 0.94; P = 0.03 by log-rank test). Among the 10 participants in the treatment group in whom gastric cancer developed, 5 (50.0%) had persistent H. pylori infection. Gastric cancer developed in 0.8% of participants (5 of 608) in whom H. pylori infection was eradicated and in 2.9% of participants (28 of 979) who had persistent infection (hazard ratio, 0.27; 95% CI, 0.10 to 0.70). Adverse events were mild and were more common in the treatment group than in the placebo group (53.0% vs. 19.1%; P<0.001).

CONCLUSIONS

Among persons with H. pylori infection who had a family history of gastric cancer in first-degree relatives, H. pylori eradication treatment reduced the risk of gastric cancer. (Funded by the National Cancer Center, South Korea; ClinicalTrials.gov number, NCT01678027.).

The Suggestion of Revised Criteria for Endoscopic Resection of Differentiated-Type Submucosal Gastric Cancer

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.