Dynamics of perioperative pancreatic exocrine function in patients undergoing reconstruction after gastrectomy for gastric cancer

BACKGROUND

Each method of reconstruction after gastrectomy results in a change in the digestive and absorptive status. However, there are few reports on the changes in pancreatic exocrine function after gastrectomy. We conducted this study to investigate the dynamics of pancreatic exocrine function after gastrectomy according to the method of reconstruction performed.

METHODS

The subjects of this study were 45 patients who underwent pancreatic exocrine function tests preoperatively and postoperatively, from among all patients who underwent gastrectomy for gastric cancer at our hospital between September, 2020 and March, 2022. We assessed pancreatic exocrine function using the Pancreatic Function Diagnostant (PFD) test.

RESULT

The mean preoperative PFD test result values for the distal gastrectomy (DG) Billroth I reconstruction (B-I) group and the DG Roux-en-Y reconstruction (R-Y) group were 62.6 and 67.3 (p = 0.36), respectively, and the mean postoperative PFD test result values for each group were 65.8 and 46.9 (p = 0.0094), respectively. A significant decrease in postoperative pancreatic function was observed in the DG R-Y group but not in the DG B-I group. The logistic regression analysis identified that age and the R-Y group were significantly correlated with a 10% decrease in the PFD value after gastrectomy.

CONCLUSIONS

Our study suggests that R-Y reconstruction may result in more impaired pancreatic exocrine function than B-I reconstruction.

Racial disparities of gastric cancer in the USA: an overview of epidemiology, global screening guidelines, and targeted screening in a heterogeneous population

Gastric cancer is the fifth most common cancer diagnosis and fourth leading cause of cancer-related death globally. The incidence of gastric cancer in the USA shows significant racial and ethnic disparities with gastric cancer incidence in Korean Americans being over five times higher than in non-Hispanic whites. Since gastric cancer is not common in the USA, there are no current screening guidelines. In countries with higher incidences of gastric cancer, screening guidelines have been implemented for early detection and intervention and this has been associated with a reduction in mortality. Immigrants from high incidence countries develop gastric cancer at lower rates once outside of their country of origin, but continue to be at higher risk for developing gastric cancer. This risk does seem to decrease with subsequent generations. With increasing availability of endoscopy, initiating gastric cancer screening guidelines for high-risk groups can have the potential to improve survival by diagnosing and treating gastric cancer at an earlier stage. This article aims to provide context to gastric cancer epidemiology globally, review risk factors for developing gastric cancer, highlight racial and ethnic disparities in gastric cancer burden in the USA, examine current guidelines that exist in high incidence countries, and suggest future studies examining the efficacy of additional screening in high-risk populations to reduce gastric cancer mortality and disparate burden on ethnic minorities in the USA.

The Circular RNA Circ_0043947 Promoted Gastric Cancer Progression by Sponging miR-384 to Regulate CREB1 Expression

Background/Aims

: The occurrence and development of circular RNAs in gastric cancer (GC) has attracted increasing attention. This study focused on investigating the biological role and molecular mechanism of circ_0043947 in GC.

Methods

: The expression levels of circ_0043947, miR-384 and CAMP response element binding protein (CREB1) were determined by quantitative real-time polymerase chain reaction or Western blotting. Cell proliferation, migration, and invasion, the cell cycle and apoptosis were determined using a cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, colony formation assay, wound healing assay, transwell assay, and flow cytometry assay. The interaction between miR-384 and circ_0043947 or CREB1 was verified by dual-luciferase reporter assay and RNA pull-down assay. The in vivo assay was conducted using a xenograft mouse model.

Results

: Circ_0043947 and CREB1 expression levels were significantly upregulated, whereas miR-384 expression levels were downregulated in GC tissues and cells. Functionally, knockdown of circ_0043947 inhibited cell proliferation, migration and invasion and induced G0/G1 phase arrest and apoptosis in vitro. Circ_0043947 could upregulate CREB1 expression by directly sponging miR-384. Rescue experiments showed that a miR-384 inhibitor significantly reversed the inhibitory effect of si-circ_0043947 on GC progression, and CREB1 overexpression significantly reversed the inhibitory effect of miR-384 mimics on the progression of GC cells. Furthermore, silencing of circ_0043947 inhibited tumor growth in vivo.

Conclusions

: Circ_0043947 acted as an oncogenic factor in GC to mediate GC cell proliferation, migration, and invasion, the cell cycle and apoptosis by regulating the miR-384/CREB1 axis. Circ_0043947 may be a potential target for GC diagnosis and therapy.

Effector Function Characteristics of Exhausted CD8+ T-cell in Microsatellite Stable and Unstable Gastric Cancer

Purpose

Gastric cancer exhibits molecular heterogeneity, with the microsatellite instability high (MSI-H) subtype drawing attention for its distinct features. Despite a higher survival rate, MSI-H gastric cancer lack significant benefits from conventional chemotherapy. The immune checkpoint inhibitors (ICIs), presents a potential avenue, but a deeper understanding of the tumor immune microenvironment of MSI-H gastric cancer is essential.

Materials and Methods

We explored the molecular characteristics of CD8+ T cell subtypes in three MSI-H and three microsatellite stable (MSS) gastric cancer samples using single-cell RNA sequencing and spatial transcriptome analysis.

Results

In MSI-H gastric cancer, significantly higher proportions of effector memory T cell (Tem), exhausted T cell (Tex), proliferative exhausted T cell (pTex), and proliferative T cell were observed, while MSS gastric cancer exhibited significantly higher proportions of mucosal-associated invariant T (MAIT) cell and NKT cell. In MSI-H gastric cancer, Tex and pTex exhibited a significant upregulation of the exhaustion marker LAG3, as well as elevated expression of effector function markers such as IFNG, GZMB, GZMH, and GZMK, compared to those in MSS gastric cancer. The IFN-γ signaling pathway of Tex and pTex was retained compared to those of MSS gastric cancer. The spatial transcriptome analysis demonstrates the IFN-γ signaling pathway between neighboring Tex and malignant cell, showcasing a significantly elevated interaction in MSI-H gastric cancer.

Conclusion

Our study reveals novel finding indicating that IFN-γ signaling pathway is retained in Tex and pTex of MSI-H gastric cancer, offering a comprehensive perspective for future investigations into immunotherapy for gastric cancer.

NESC Multicenter Phase II Trial in the Preoperative Treatment of Gastric Adenocarcinoma with Chemotherapy (Docetaxel-Cisplatin-5FU+Lenograstim) Followed by Chemoradiation Based 5FU and Oxaliplatin and Surgery

PURPOSE

Preoperative chemoradiation (CRT) is expected to increase the rate of curative resection and complete histological response. In this trial, we investigated the efficacy of a neoadjuvant CRT regimen in gastric adenocarcinoma (NCT01565109 trial).

MATERIALS AND METHODS

Patients with stage IB to IIIC gastric adenocarcinoma, endoscopy ultrasound and computed tomography-scan diagnosed, were eligible for this phase II trial. Neoadjuvant treatment consisted of 2 cycles of chemotherapy with DCF (docetaxel, cisplatin, and 5-fluorouracil [5FU]) followed by preoperative CRT with oxaliplatin, continuous 5FU and radiotherapy (45 Gy in 25 fractions of 1.8 Gy, 5 fractions per week for 5 weeks) administered before surgery. R0-resection rate, pathological complete response (pathCR) rate, and survival (progression-free survival [PFS] and overall survival [OS]) were evaluated as primary endpoints.

RESULTS

Among 33 patients included, 32 patients (97%) received CRT and 26 (78.8%) were resected (R0 resection for all patients resected). Among resected patients, we report pathCR in 23,1% and pathologic major response (tumor regression grade 2 according to Mandard's classification) in 26,9%. With a median follow-up duration of 5.82 years (range, 0.4 to 9.24 years), the estimated median OS for all 33 patients was not reached; 1-, 3-, and 5-year OS rates were 85%, 61%, and 52%, respectively. Among resected patients, those whose histological response was tumor grade regression (TRG) 1-2 had significantly better OS and PFS rates than those with a TRG 3-4-5 response (p=0.019 and p=0.016, respectively).

CONCLUSION

Promising results from trials involving preoperative chemoradiation followed by surgery in gastric cancer need to be further evaluated in a phase III trial.

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.

Safety and efficacy of apatinib in combination with chemotherapy with or without immunotherapy versus chemotherapy alone as first-line treatment for advanced gastric cancer

The specific first-line regimen for advanced gastric cancer (GC) is still controversial. The benefit of apatinib for first-line treatment of advanced GC remains unknown and needs to be further explored. Eighty-two patients with advanced GC treated in our institution from October 2017 to March 2023 were retrospectively reviewed. All individuals had her-2 negative GC and had received at least two cycles of first-line treatment, including 44 patients in the combination treatment group (apatinib in combination with chemotherapy with or without immunotherapy) and 38 patients in the simple chemotherapy group. We evaluated the efficacy and safety of apatinib in combination with chemotherapy with or without immunotherapy in the first-line treatment of advanced GC by comparing the efficacy, progression-free survival (PFS), and adverse events in two groups of patients. The median PFS of the simple chemotherapy group was 9.25 months (95% confidence interval (CI), 6.1-11.2 months), and that of the combination treatment group was 10.9 months (95% CI, 7.9-15.8 months), which was 1.65 months longer than the simple chemotherapy group. Statistically significant differences are shown (P = 0.022). The objective response rate (ORR) of the combination treatment group was 65.9%, and 36.8% in the simple chemotherapy group. Statistically significant differences are shown (P = 0.014). No serious (Grade IV) adverse events occurred in either group. Our study indicates that apatinib in combination with chemotherapy with or without immunotherapy as first-line treatment for advanced GC exhibits good anti-tumor activity and is well tolerated by patients.

Comparison of the Prognosis of Upper-Third Gastric Cancer With That of Middle and Lower-Third Gastric Cancer

PURPOSE

Gastric cancer is one of the most common cancers in Korea, and the proportion of upper-third gastric cancers has been steadily increasing over the last two decades. This study aimed to evaluate the effect of tumor location on gastric cancer prognosis.

MATERIALS AND METHODS

We retrospectively reviewed 2,466 patients who underwent gastrectomy for pathologically proven gastric cancer between January 2011 and December 2016. The patients were divided into an upper-third group (U group; n=419, 17.0%) and a middle- and lower-third group (ML group; n=2,047, 83.0%). Clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) after surgery were compared.

RESULTS

The U group had more advanced disease than the ML group and a higher incidence of N3b disease for T3 (12.0% vs. 4.9%, p=0.023) and T4 tumors (33.3% vs. 17.5%, p=0.001). The 5-year RFS rate for stage III disease was marginally lower in the U group than that in the ML group (47.1% vs. 56.7%, p=0.082). The upper third location was an independent prognostic factor for both OS (hazard ratio [HR], 1.350; 95% confidence interval [CI], 1.065-1.711) and RFS (HR, 1.430; 95% CI, 1.080-1.823).

CONCLUSIONS

Upper-third gastric cancer shows extensive node metastasis compared to those located more distally in ≥T3 tumors. The upper third location is an independent prognostic factor for both OS and RFS and may have an adverse impact on RFS, particularly in patients with stage III gastric cancer.

Comparison of totally laparoscopic and laparoscopic-assisted approach in gastrectomy with D2 lymphadenectomy for advanced gastric cancer after neoadjuvant chemotherapy: a retrospective comparative study

Purpose

Neoadjuvant chemotherapy is strongly recommended for advanced gastric cancer due to good local control and a high rate of R0 dissection with this strategy. Minimally invasive techniques such as laparoscopy-assisted or total laparoscopic approaches is becoming more and more acceptable in the treatment for gastric cancer. However, the safety and efficiency of total laparoscopic D2 gastrectomy (TLG) for advanced gastric cancer after neoadjuvant chemotherapy have not been well evaluated.

Methods

A retrospective study in a single center from 2014 to 2016 was conducted. A total of 65 locally advanced gastric cancers were treated by laparoscopy-assisted gastrectomy (LAG) or TLG. Parameters which include operation time, blood loss, complications, hospital stay, 3-year overall survival, and 3-year disease-free survival were used for comparison.

Results

The time of operation in the TLG group was shorter than in the LAG group (P = 0.013), blood loss was less (P = 0.002) and time to first flatus was shorter (P = 0.039) in the TLG group than that in the LLG group. Intraoperative and postoperative complications were comparable in both groups. No significant difference was found in 3-year overall and disease-free survival.

Conclusion

For patients with locally advanced gastric cancer after neoadjuvant chemotherapy, laparoscopic D2 gastrectomy can be considered as a safe and efficient alternative. A further multicenter prospective randomized controlled study is needed to elucidate the applicability of this technique for advanced gastric cancer.

Predicting pathologic response to neoadjuvant chemotherapy in locally advanced gastric cancer: The establishment of a spectral CT-based nomogram from prospective datasets

BACKGROUND

To establish a spectral CT-based nomogram for predicting early neoadjuvant chemotherapy (NAC) response for locally advanced gastric cancer (LAGC).

METHODS

This study prospectively recruited 222 cases (177 male and 45 female patients, 9.59 ± 9.54 years) receiving NAC and radical gastrectomy. Triple enhanced spectral CT scans were performed before NAC initiation. According to post-operative tumor regression grade (TRG), patients were classified into responders (TRG = 0 + 1) or non-responders (TRG = 2 + 3), and split into a primary (156) and validation (66) dataset at 7:3 ratio chronologically. We compared clinicopathological data, follow-up information, iodine concentration (IC), normalized ICs (nICs) in arterial/venous/delayed phases (AP/VP/DP) between responders and non-responders. Independent risk factors of response were screened by multivariable logistic regression and adopted for model construction. Model was visualized by nomograms and its capability was determined through receiver operating characteristic (ROC) curves. Log-rank survival analysis was conducted to explore associations between TRG, nomogram and patients' survival.

RESULTS

This work identified Borrmann classification, ICDP, and nICDP were independent risk factors of response outcomes. A spectral CT-based nomogram was built accordingly and achieved an area under the curve (AUC) of 0.797 (0.692-0.879) and 0.741(0.661-0.811) for the primary and validation dataset, respectively, higher than AUC of individual parameters alone. The nomogram was related to disease-free survival in the validation dataset (Hazard ratio (HR): 5.19 [1.18-12.93], P = 0.02).

CONCLUSIONS

The spectral CT-based nomogram provides an efficient tool for predicting the pathologic response outcomes of GC after NAC and disease-free survival risk stratification.

Clinicopathological and endoscopic features of Helicobacter pylori infection-negative gastric cancer in Japan: a retrospective study

Background/Aims

Helicobacter pylori infection-negative gastric cancer (HPNGC) has not been systematically investigated in consecutive patients. Hence, this study aimed to investigate the clinicopathological and endoscopic features of HPNGC.

Methods

This single-center retrospective study selected participants from patients with gastric cancer who were treated at the Fukuoka University Chikushi Hospital between January 2013 and December 2021. Only patients diagnosed with HPNGC were enrolled, and their clinicopathological and endoscopic features were analyzed in detail.

Results

The prevalence of HPNGC in the present study was 2.6% (54/2112). The types of HPNGC observed in each gastric region were as follows: advanced gastric cancer was observed in the cardia; gastric adenocarcinoma of fundic-gland differentiation, gastric adenocarcinoma of foveolar-type presenting with whitish elevation and raspberry-like foveolar-type gastric adenocarcinoma, gastric adenocarcinoma arising in polyposis, and gastric adenocarcinoma with autoimmune gastritis were observed in the fundic gland region ranging from the gastric fornix to the gastric body; signet-ring cell carcinoma was observed in the gastric-pyloric transition region ranging from the lower gastric body to the gastric angle; and well-differentiated tubular adenocarcinoma with low-grade atypia was observed in the antrum.

Conclusions

This study revealed that tumors from each gastric region exhibited distinct macroscopic and histological types in HPNGC.

Combined DNA Methylation and Gastric Microbiome Marker Predicts Helicobacter pylori-Negative Gastric Cancer

Background/Aims

While DNA methylation and gastric microbiome are each associated with gastric cancer (GC), their combined role in predicting GC remains unclear. This study investigated the potential of a combined DNA methylation and gastric microbiome signature to predict Helicobacter pylori-negative GC.

Methods

In this case-control study, we conducted quantitative methylation-specific polymerase chain reaction to measure the methylation levels of DKK3, SFRP1, EMX1, NKX6-1, MIR124-3, and TWIST1 in the gastric mucosa from 75 H. pylori-negative patients, including chronic gastritis (CG), intestinal metaplasia (IM), and GC. A combined analysis of DNA methylation and gastric microbiome, using 16S rRNA gene sequencing, was performed in 30 of 75 patients.

Results

The methylation levels of DKK3, SFRP1, EMX1, MIR124-3, and TWIST1 were significantly higher in patients with GC than in controls (all q<0.05). MIR124-3 and TWIST1 methylation levels were higher in patients with IM than those with CG and also in those with GC than in those with IM (all q<0.05). A higher methylation level of TWIST1 was an independent predictor for H. pylori-negative GC after adjusting for age, sex, and atrophy (odds ratio [OR], 15.15; 95% confidence interval [CI], 1.58 to 145.46; p=0.018). The combination of TWIST1 methylation and GC microbiome index (a microbiome marker) was significantly associated with H. pylori-negative GC after adjusting for age, sex, and atrophy (OR, 50.00; 95% CI, 1.69 to 1,476; p=0.024).

Conclusions

The combination of TWIST1 methylation and GC microbiome index may offer potential as a biomarker for predicting H. pylori-negative GC.

Assessment of programmed death-ligand 1 expression in primary tumors and paired lymph node metastases of gastric adenocarcinoma

BACKGROUND

Anti-programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) immunotherapy has demonstrated promising results on gastric cancer (GC). However, PD-L1 can express differently between metastatic sites and primary tumors (PT).

AIM

To compare PD-L1 status in PT and matched lymph node metastases (LNM) of GC patients and to determine the correlation between the PD-L1 status and clinicopathological characteristics.

METHODS

We retrospectively reviewed 284 GC patients who underwent D2-gastrectomy. PD-L1 was evaluated by immunohistochemistry (clone SP142) using the combined positive score. All PD-L1+ PT staged as pN+ were also tested for PD-L1 expression in their LNM. PD-L1(-) GC with pN+ served as the comparison group.

RESULTS

Among 284 GC patients included, 45 had PD-L1+ PT and 24 of them had pN+. For comparison, 44 PD-L1(-) cases with pN+ were included (sample loss of 4 cases). Of the PD-L1+ PT, 54.2% (13/24 cases) were also PD-L1+ in the LNM. Regarding PD-L1(-) PT, 9.1% (4/44) had PD-L1+ in the LNM. The agreement between PT and LNM had a kappa value of 0.483. Larger tumor size and moderate/severe peritumoral inflammatory response were associated with PD-L1 positivity in both sites. There was no statistical difference in overall survival for PT and LNM according to the PD-L1 status (P = 0.166 and P = 0.837, respectively).

CONCLUSION

Intra-patient heterogeneity in PD-L1 expression was observed between the PT and matched LNM. This disagreement in PD-L1 status may emphasize the importance of considering different tumor sites for analyses to select patients for immunotherapy.

Analysis of Characteristics and Risk Factors of Patients with Single Gastric Cancer and Synchronous Multiple Gastric Cancer among 14,603 Patients

Background/Aims

Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC.

Methods

A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC.

Results

The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high.

Conclusions

SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).

The Impact of Sedation on Cardio-Cerebrovascular Adverse Events after Surveillance Esophagogastroduodenoscopy in Patients with Gastric Cancer: A Nationwide Population-Based Cohort Study

Background/Aims

The impact of sedation on cardio-cerebrovascular (CCV) adverse events after esophagogastroduodenoscopy (EGD) in patients with gastric cancer (GC) is unclear. We investigated the incidence rate and impact of sedation on CCV adverse events after surveillance EGD in patients with GC.

Methods

We performed a nationwide population-based cohort study using the Health Insurance Review and Assessment Service databases from January 1, 2018, to December 31, 2020. Using a propensity score-matched analysis, patients with GC were divided into two groups: sedative agent users and nonusers for surveillance EGD. We compared the occurrence of CCV adverse events within 14 days between the two groups.

Results

Of the 103,463 patients with GC, newly diagnosed CCV adverse events occurred in 2.57% of patients within 14 days after surveillance EGD. Sedative agents were used in 41.3% of the patients during EGD. The incidence rates of CCV adverse events with and without sedation were 173.6/10,000 and 315.4/10,000, respectively. Between sedative agent users and nonusers based on propensity score matching (28,008 pairs), there were no significant differences in the occurrence of 14-day CCV, cardiac, cerebral, and other vascular adverse events (2.28% vs 2.22%, p=0.69; 1.44% vs 1.31%, p=0.23; 0.74% vs 0.84%, p=0.20; 0.10% vs 0.07%, p=0.25, respectively).

Conclusions

Sedation during surveillance EGD was not associated with CCV adverse events in patients with GC. Therefore, the use of sedative agents may be considered in patients with GC during surveillance EGD without excessive concerns about CCV adverse events.

Endoscopic Features of Undifferentiated-Type Early Gastric Cancer in Patients with Helicobacter pylori-Uninfected or -Eradicated Stomachs: A Comprehensive Review

Since the indications for endoscopic submucosal dissection have been expanded to include undifferentiated-type early gastric cancers, improvements in preoperative diagnostic ability have been an area of research. There are also concerns about the impact on the diagnosis of Helicobacter pylori infection. Based on our previous studies, in undifferentiated-type early gastric cancers, magnifying endoscopy with narrow-band imaging is useful for delineating the demarcation regardless of the tumor size. Additionally, inflammatory cell infiltration appears to be a cause of misdiagnosis, suggesting that the resolution of inflammation could contribute to the accurate diagnosis of demarcations. As such, the accuracy of demarcation in eradicated and uninfected cases is higher than that in non-eradicated cases. The common features of the endoscopic findings were discoloration under white-light imaging and a predominance of sites in the lower and middle regions. The uninfected group was characterized by smaller tumor size, flat type, more extended intervening parts in magnifying endoscopy with narrow-band imaging, and pure signet ring cell carcinoma. In contrast, the eradication and non-eradication groups were characterized by larger tumor size, depressed type, and wavy microvessels in magnifying endoscopy with narrow-band imaging. In this comprehensive review, as described above, we discuss the diagnosis of demarcation of undifferentiated-type early gastric cancers, undifferentiated-type early gastric cancers that developed following H. pylori eradication, and H. pylori-uninfected undifferentiated-type early gastric cancers, with a focus on studies with self-examination and endoscopic findings and describe the future direction.

Staging laparoscopy with peritoneal lavage to identify peritoneal metastases and free intraperitoneal cancer cells in the management of locally advanced gastric cancer

INTRODUCTION

Gastric cancer often presents in advanced stage with a significant risk for peritoneal dissemination. Staging laparoscopy can be used to detect peritoneal carcinomatosis (PC+) and free cancer cells in peritoneal lavage cytology (CY+). The current study aimed to present the outcomes of staging laparoscopy and the prognosis of PC+ and CY+ in a Swedish high-volume center.

MATERIALS AND METHODS

A cohort study including all consecutive patients with locally advanced gastric cancer who underwent staging laparoscopy between February 2008 and October 2022. The laparoscopy findings were categorized as PC+, PC-CY+ (positive cytology without peritoneal carcinomatosis) or negative laparoscopy (PC-CY-). The primary endpoint was overall survival (OS) stratified by laparoscopy findings. The secondary endpoint was OS within each laparoscopy finding group stratified by subsequent treatment.

RESULTS

Among 168 patients who underwent staging laparoscopy, 78 patients (46%) had PC-CY-, 29 patients (17%) had PC-CY+ and 61 patients (36%) had PC+. Decreased OS was observed for both PC-CY+ patients (aHR 2.14, 95% CI 1.13-4.06) and PC+ patients (aHR 5.36, 95% CI 3.21-8.93), compared to PC-CY-. Patients with PC-CY+ who converted to PC-CY- after chemotherapy and underwent tumor resection seemed to have a better prognosis compared to patients with persisting PC-CY+.

CONCLUSIONS

Staging laparoscopy is an important tool in the staging of locally advanced gastric cancer. Tumor resection for patients with PC-CY+ who convert to PC-CY- may lead to improved survival for these patients.

Twenty-four-month Progression-free Survival in HER2-amplified Advanced Gastric Cancer with Brain Metastases after Trastuzumab Deruxtecan Treatment: A Case Report and Literature Review

BACKGROUND

Trastuzumab deruxtecan (T-DXd) has shown promising outcomes as a second or subsequent-line treatment for human epidermal growth factor-2 (HER2)-positive advanced gastric or gastroesophageal junction cancer.

CASE PRESENTATION

We reported a 49-year-old male patient with stage IV HER2-amplified gastric cancer. Despite extensive pretreatments, including first-line trastuzumab plus FOLFOX, second-- line trastuzumab plus FOLFOX, followed by traditional Chinese medicine, third-line nivolumab plus trastuzumab, fourth-line pyrotinib plus paclitaxel and five hepatic arterial chemoembolization procedures, and fifth-line pembrolizumab plus nab-paclitaxel and thoracic radiotherapy, the patient experienced disease progression. In April 2021, T-DXd was initiated as the sixth-line therapy in combination with radiotherapy for brain metastases. After one treatment cycle, the patient achieved a partial response. T-DXd was discontinued in August 2022 due to recurrent anemia attributed to cardiac stenosis-related bleeding.

CONCLUSION

The condition of the patient remained stable until May 2023, indicating a progression-free survival of over 24 months. This case suggests that T-DXd may offer long-term clinical benefits in patients with HER2-amplified advanced gastric cancer with brain metastases.

Rivoceranib, a VEGFR-2 inhibitor, monotherapy in previously treated patients with advanced or metastatic gastric or gastroesophageal junction cancer (ANGEL study): an international, randomized, placebo-controlled, phase 3 trial

BACKGROUND

Rivoceranib is an oral, selective tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2. ANGEL (NCT03042611) was a global, randomized, double-blinded, placebo-controlled, phase 3 study evaluating rivoceranib as 3rd-line or ≥4th-line therapy in patients with advanced/metastatic gastric or gastroesophageal junction (GEJ) cancer.

METHODS

Patients had failed ≥2 lines of chemotherapy and were randomized 2:1 to rivoceranib 700 mg once daily or placebo with best supportive care.

PRIMARY ENDPOINT

overall survival (OS) in the intention-to-treat population. Secondary endpoints: progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) by blinded independent central review (BICR).

RESULTS

In total, 460 patients (rivoceranib n = 308, placebo n = 152) were enrolled. OS was not statistically different for rivoceranib versus placebo (median 5.78 vs. 5.13 months; hazard ratio [HR] 0.93, 95% CI 0.74-1.15; p = 0.4724). PFS by BICR (median 2.83 vs. 1.77 months; HR 0.58, 95% CI 0.47-0.71; p < 0.0001), ORR (6.5% vs. 1.3%; p = 0.0119), and DCR (40.3 vs. 13.2%; p < 0.0001) were improved with rivoceranib versus placebo. In patients receiving ≥4th-line therapy, OS (median 6.34 vs. 4.73 months; p = 0.0192) and PFS by BICR (median 3.52 vs. 1.71 months; p < 0.0001) were improved with rivoceranib versus placebo. The most common grade ≥ 3 treatment-emergent adverse events with rivoceranib were hypertension (17.9%), anemia (10.4%), aspartate aminotransferase increased (9.4%), asthenia (8.5%), and proteinuria (7.5%).

CONCLUSIONS

This study did not meet its primary OS endpoint. Compared to placebo, rivoceranib improved PFS, ORR, and DCR. Rivoceranib also improved OS in a prespecified patient subgroup receiving ≥4th-line therapy.

Risk of tuberculosis after endoscopic resection and gastrectomy in gastric cancer: nationwide population-based matched cohort study

BACKGROUND

This study aimed to investigate the association between gastrectomy and endoscopic resection for gastric cancer and the subsequent tuberculosis incidence.

METHODS

We conducted a nationwide matched cohort study using data from the Korea National Health Insurance Service from 2013 to 2019. We created two cohorts: patients who underwent gastrectomy and those who had endoscopic resection. Each patient was matched 1:1 with an unexposed individual based on index year, age, sex, income, and various comorbidities. The primary outcome was the incidence of tuberculosis during the follow-up period.

RESULTS

Our study comprised 90,886 gastrectomy patients and 46,759 endoscopic resection patients. The tuberculosis incidence was significantly higher in the gastrectomy group compared to its matched non-gastrectomy group (IRR 1.69, 95% CI 1.43-1.99, p < .001). In contrast, there was no significant difference in tuberculosis incidence between the endoscopic resection group and its matched non-resection group (IRR 0.95, 95% CI 0.75-1.19, p = 0.627). The Kaplan-Meier cumulative incidence also did not differ between the two groups. However, tuberculosis incidence significantly increased in the first year after endoscopic resection.

CONCLUSION

Gastrectomy for gastric cancer is associated with a higher incidence of subsequent tuberculosis, while no significant association was observed for endoscopic resection. However, tuberculosis incidence increases significantly during the first year after endoscopic resection.

Risk factors for abdominal surgical infectious complications after distal gastrectomy for gastric cancer: A post-hoc analysis of a randomized controlled trial (JCOG0912)

BACKGROUND

Abdominal surgical infectious complications (ASIC) after gastrectomy for gastric cancer impair patients' survival and quality of life. JCOG0912 was conducted to compare laparoscopy-assisted distal gastrectomy with open distal gastrectomy for clinical stage IA or IB gastric cancer. The present study aimed to identify risk factors for ASIC using prospectively collected data.

METHODS

We performed a post-hoc analysis of the risk factors for ASIC using the dataset from JCOG0912. All complications were evaluated according to the Clavien-Dindo classification (CD). ASIC was defined as CD grade I or higher anastomotic leakage, pancreatic fistula, abdominal abscess, and wound infection. Analyses were performed using the logistic regression model for univariable and multivariable analyses.

RESULTS

A total of 910 patients were included (median age, 63 years; male sex, 61 %). Among them, ASIC occurred in 5.8 % of patients. In the univariable analysis, male sex (odds ratio [OR] 2.855, P = 0.003), diabetes (OR 2.565, P = 0.029), and Roux-en-Y (R-Y) reconstruction (vs. Billroth Ⅰ, OR 2.707, P = 0.002) were significant risk factors for ASIC. In the multivariable analysis, male sex (OR 2.364, P = 0.028) and R-Y reconstruction (vs. Billroth Ⅰ, OR 2.310, P = 0.015) were independent risk factors for ASIC.

CONCLUSIONS

Male sex and R-Y reconstruction were risk factors for ASIC after distal gastrectomy. Therefore, when performing surgery on male patients or when R-Y reconstruction is selected after gastrectomy for gastric cancer, surgeons should pay special attention to prevent ASIC.

Daily Diet and Nutrition Risk Factors for Gastric Cancer Incidence in a Japanese Population

Background/Aims

: Nutritional factors associated with gastric cancer (GC) are not completely understood. We aimed to determine the effect of nutrient intake on the incidence of GC.

Methods

: This was a post hoc analysis of a prospective trial that evaluated modalities for GC screening in participants aged 30 to 74 years living in high-risk areas for GC in Japan between June 2011 and March 2013. The patients were followed up for GC incidence for 6 years. All participants completed a self-administered food frequency questionnaire (FFQ) upon enrollment before GC screening. Daily nutrient intake was calculated from the FFQ and dichotomized at each cutoff value using receiver operating characteristic analysis. Risk factors associated with GC incidence were investigated in terms of nutrient intake and participant characteristics using Cox proportional hazards regression analysis.

Results

: Overall, 1,147 participants were included in this analysis. The median age was 62 years, and 50.7% of the participants were men. The median follow-up period was 2,184 days. GC was detected in 25 participants during the follow-up. Multivariate Cox proportional hazards regression analysis revealed that the intake of sodium (adjusted hazards ratio [aHR], 3.905; 95% confidence interval [CI], 1.520 to 10.035; p=0.005) and vitamin D (aHR, 2.747; 95% CI, 1.111 to 6.788, p=0.029) were positively associated with GC incidence, whereas the intake of soluble dietary fiber (aHR, 0.104; 95% CI, 0.012 to 0.905; p=0.040) was inversely associated with GC incidence.

Conclusions

: Daily high intake of sodium and vitamin D and low soluble dietary fiber intake are associated with GC incidence.

Retrograde drainage for duodenal stump leakage using ileal decompression tube guided by double-balloon endoscopy: a novel case report

BACKGROUND

Duodenal stump leakage is a serious post-gastrectomy complication, and there have been no reports on endoscopic drainage.

CASE PRESENTATION

We report a case of duodenal stump leakage after laparoscopic gastrectomy with Roux-en-Y reconstruction in a 68-year-old man. First-line conservative management was ineffective. Reoperation was performed because of severe abdominal pain and increased ascites. After reoperation, duodenal stump leakage recurred with bleeding from the anterior superior pancreaticoduodenal artery. Coil embolization and pigtail catheter insertion were performed. Furthermore, we retrogradely inserted an ileal tube for tube decompression near the duodenal stump using double-balloon endoscopy for effective drainage. After tube insertion, duodenal stump leakage decreased; on the 47th primary postoperative day, the patient was discharged. The primary postoperative course was uneventful after 1 year and 9 months of follow-up.

CONCLUSIONS

This is the first successful case of duodenal stump leakage treated with retrograde decompression tube insertion near the duodenal stump using double-balloon endoscopy.

Modern insights into the pathophysiology and treatment of pseudoachalasia

BACKGROUND

Secondary achalasia or pseudoachalasia is a clinical presentation undistinguishable from achalasia in terms of symptoms, manometric, and radiographic findings, but associated with different and identifiable underlying causes.

METHODS

A literature review was conducted on the PubMed database restricting results to the English language. Key terms used were "achalasia-like" with 63 results, "secondary achalasia" with 69 results, and "pseudoachalasia" with 141 results. References of the retrieved papers were also manually reviewed.

RESULTS

Etiology, diagnosis, and treatment were reviewed.

CONCLUSIONS

Pseudoachalasia is a rare disease. Most available evidence regarding this condition is based on case reports or small retrospective series. There are different causes but all culminating in outflow obstruction. Clinical presentation and image and functional tests overlap with primary achalasia or are inaccurate, thus the identification of secondary achalasia can be delayed. Inadequate diagnosis leads to futile therapies and could worsen prognosis, especially in neoplastic disease. Routine screening is not justifiable; good clinical judgment still remains the best tool. Therapy should be aimed at etiology. Even though Heller's myotomy brings the best results in non-malignant cases, good clinical judgment still remains the best tool as well.

Safety and feasibility of minimally invasive gastrectomy following preoperative chemotherapy for highly advanced gastric cancer

BACKGROUND

This study aimed to determine the safety and feasibility of minimally invasive gastrectomy in patients who underwent preoperative chemotherapy for highly advanced gastric cancer.

METHODS

Preoperative chemotherapy was indicated for patients with advanced large tumors (≥ cT3 and ≥ 5 cm) and/or bulky node metastasis (≥ 3 cm × 1 or ≥ 1.5 cm × 2). Between January 2009 and March 2022, 150 patients underwent preoperative chemotherapy followed by gastrectomy with R0 resection, including conversion surgery (robotic, 62; laparoscopic, 88). The outcomes of these patients were retrospectively examined.

RESULTS

Among them, 41 and 47 patients had stage IV disease and underwent splenectomy, respectively. Regarding operative outcomes, operative time was 475 min, blood loss was 72 g, morbidity (grade ≥ 3a) rate was 12%, local complication rate was 10.7%, and postoperative hospital stay was 14 days (Interquartile range: 11-18 days). Fifty patients (33.3%) achieved grade ≥ 2 histological responses. Regarding resection types, total/proximal gastrectomy plus splenectomy (29.8%) was associated with significantly higher morbidity than other types (distal gastrectomy, 3.2%; total/proximal gastrectomy, 4.9%; P < 0.001). Specifically, among splenectomy cases, the rate of postoperative complications associated with the laparoscopic approach was significantly higher than that associated with the robotic approach (40.0% vs. 0%, P = 0.009). In the multivariate analysis, splenectomy was an independent risk factor for postoperative complications [odds ratio, 8.574; 95% confidence interval (CI), 2.584-28.443; P < 0.001].

CONCLUSIONS

Minimally invasive gastrectomy following preoperative chemotherapy was feasible and safe for patients with highly advanced gastric cancer. Robotic gastrectomy may improve surgical safety, particularly in the case of total/proximal gastrectomy combined with splenectomy.

Chilean consensus by expert panel using the Delphi technique for primary and secondary prevention of gastric cancer

INTRODUCTION

Gastric cancer (GC) is the first cause of cancer-related death in Chile and 6th in Latin America and the Caribbean (LAC). Helicobacter pylori (H. pylori) is the main gastric carcinogen, and its treatment reduces GC incidence and mortality. Esophageal-gastro-duodenoscopy (EGD) allows for the detection of premalignant conditions and early-stage GC. Mass screening programs for H. pylori infection and screening for premalignant conditions and early-stage GC are not currently implemented in LAC. The aim of this study is to establish recommendations for primary and secondary prevention of GC in asymptomatic standard-risk populations in Chile.

METHODS

Two on-line synchronous workshops and a seminar were conducted with Chilean experts. A Delphi panel consensus was conducted over 2 rounds to achieve>80% agreement on proposed primary and secondary prevention strategies for the population stratified by age groups.

RESULTS

10, 12, and 12 experts participated in two workshops and a seminar, respectively. In the Delphi panel, 25 out of 37 experts (77.14%) and 28 out of 52 experts (53.85%) responded. For the population aged 16-34, there was no consensus on non-invasive testing and treatment for H. pylori, and the use of EGD was excluded. For the 35-44 age group, non-invasive testing and treatment for H. pylori is recommended, followed by subsequent test-of-cure using non-invasive tests (stool antigen test or urea breath test). In the ≥45 age group, a combined strategy is recommended, involving H. pylori testing and treatment plus non-invasive biomarkers (H. pylori IgG serology and serum pepsinogens I and II); subsequently, a selected group of subjects will undergo EGD with gastric biopsies (Sydney Protocol), which will be used to stratify surveillance according to the classification Operative Link for Gastritis Assessment (OLGA); every 3 years for OLGA III-IV and every 5 years for OLGA I-II.

CONCLUSION

A "test-and-treat" strategy for H. pylori infection based on non-invasive studies (primary prevention) is proposed in the 35-44 age group, and a combined strategy (serology and EGD) is recommended for the ≥45 age group (primary and secondary prevention). These strategies are potentially applicable to other countries in LAC.

Single-port intragastric wedge resection using the tunnel method: a novel surgical approach for treating endophytic gastric subepithelial tumors

BACKGROUND

Intragastric wedge resection is an effective method for treating endophytic gastric subepithelial tumors (SETs). However, retracting the stomach wall to the umbilicus is difficult in certain patients. In response, we developed a novel surgical technique for single-port intragastric wedge resection, which we termed the "tunnel method."

METHODS

A transumbilical incision is made, and a wound retractor is applied. After diagnostic laparoscopy, a gastrostomy is made on the greater curvature, lower body. Another small wound retractor is inserted into the gastrostomy, and extracted through the transumbilical incision, creating a tunnel from the gastrostomy site to the umbilicus. Articulating laparoscopic instruments are inserted via the tunnel, and intragastric wedge resection is performed. We collected and analyzed the clinicopathologic and operative data of patients who underwent intragastric wedge resection via the tunnel method.

RESULTS

Twenty-seven patients who underwent single-port intragastric wedge resection via the tunnel method in a single tertiary referral hospital were included in this study. The mean age of the patients was 54.6 ± 11.4 years, body mass index was 26.5 ± 3.4 kg/m2. Twenty-four (88.9%) patients had tumors located in the upper third of the stomach. The average operative time was 65.0 ± 24.2 min. None of the patients experienced Clavien-Dindo grade IIIa or higher postoperative complications. The average postoperative hospital stay length was 2.5 ± 0.8 days. Thirteen gastrointestinal stromal tumors, nine leiomyomas, and one neuroendocrine carcinoma, schwannoma, lipoma, spindle cell proliferative lesion, and fibrotic lesion were pathologically diagnosed. The average tumor size was 2.6 ± 1.3 cm. All cases had negative resection margins.

CONCLUSIONS

Single-port intragastric wedge resection by the tunnel method is a feasible and safe approach for treating endophytic gastric SETs.

Ex vivo treatment with poly (I:C) alleviates the exhausted phenotype of tumor-infiltrating TCD8+ cells of gastric cancer patients

Gastric cancer is associated with the phenotypic and functional exhaustion of TCD8+ cells. On the other hand, Toll-like receptor (TLR) agonists are known to reinforce immune responses when used as adjuvants in cancer immunotherapies. Since the compromised signaling of pro-inflammatory pathways is usually associated with T cell exhaustion, the aim of the present study was to evaluate the impact of polyinosinic-polycytidylic acid (poly (I:C))-mediated TLR3 activation in restoring the normal phenotype and function of tumor-infiltrating TCD8+ cells. Peripheral blood and tumor-infiltrating TCD8+ cells of 35 gastric cancer patients were in vitro treated with increasing concentrations of poly (I:C) and the expressions of programmed death-1 (PD-1) and lymphocyte-activation gene 3 (LAG3) on these cells were examined. The peripheral TCD8+ cells of gastric cancer patients showed higher expressions of PD-1 and LAG3 along with lower proliferation compared to TCD8+ cells of the age-matched healthy control individuals. The in vitro treatment of TCD8+ cells with 100 μg/mL concentration of poly (I:C) alleviated the expression of PD-1 and LAG3 inhibitory checkpoint molecules on both peripheral and tumor-infiltrating TCD8+ cells. The mentioned dose of poly (I:C) improved the proliferation of TCD8+ cells in response to a polyclonal activator. Besides, the releases of Interferon gamma (IFN-γ) and Tumor necrosis factor alpha (TNF-α) were increased in the poly (I:C)-treated TCD8+ cells. Poly (I:C) demonstrated a potential to reduce the phenotypic and functional exhaustion of the peripheral and tumor-infiltrating TCD8+ cells and caused them to undergo more proliferation and cytokine release.

Investigating FGFR2 gene as a blood-based epigenetic biomarker in gastric cancer

BACKGROUND

Gastric adenocarcinoma is a prevalent form of cancer that often remains undetected in its early stages due to the lack of specific symptoms. This delayed diagnosis leads to poor clinical outcomes, underscoring the need for an effective and non-invasive method for early detection. Recent advances in cancer epigenetics have led to the identification of biomarkers that have the potential to revolutionize the early detection and monitoring of this disease. One such promising biomarker is the methylation of the FGFR2 promoter. This study aims to measure the methylation levels of a specific CpG site in the FGFR2 promoter gene in DNA extracted from blood leukocytes from patients with intestinal metaplasia, gastric cancer, and healthy control.

MATERIAL AND METHODS

The CpG site of the FGFR2 gene promoter was identified in its control region. Methylation alteration of the selected FGFR2 CpG site was determined through the (methylation-sensitive restriction enzyme) MSRE-qPCR. Genomic DNA was extracted from one hundred twenty-five participants.

RESULTS

The normal group had mean methylation levels of 93.23 ± 4.929%, while the IM group had a level of 69.85 ± 27.15%. In GC patients, the levels varied, with 25.96 ± 18.98% in the intestinal type and 28.30 ± 16.07% in the diffuse type. The methylation levels in the IM and GC patients were significantly lower than those in the normal control group. However, no significant difference was observed between the methylation status of the intestinal type of GC and the diffuse type. The Receiver operating characteristic (ROC) curve analysis showed that FGFR2 CpG methylation levels in GC patients compared to normal controls had a high sensitivity of 100% and specificity of 100%, with a cut-off of < 74.25%; when GC patients were compared to IM patients, the sensitivity was 85%, and the specificity was 80%, with a cut-off < 44.45%.

CONCLUSIONS

The potential of the FGFR2 methylation status as a non-invasive biomarker lies in its ability to be detected in blood leukocytes, which makes it a promising tool for the early detection of intestinal metaplasia and gastric cancer. This could significantly improve the detection and management of these gastric conditions.

mRNA Expression and Methylation of the RAD51, ATM, ATR, BRCA1, and BRCA2 Genes in Gastric Adenocarcinoma

Background

Immunohistochemical prognostic significance of the homologous recombination-related proteins RAD51, ATM, BRCA1, and BRCA2 is known in gastric adenocarcinoma, one of the deadliest cancers.

Objective and design

This retrospective cohort study aimed to evaluate mRNA expression and promoter methylation of some homologous recombination-related genes in this neoplasm.

Methods

We evaluated mRNA expression and methylation of RAD51, ATM, ATR, BRCA1, and BRCA2 in tumor and non-tumor frozen samples from gastrectomy specimens by RT-qPCR and MS-HRM, correlating our results with previous immunohistochemistry data and prognostic features.

Results

RAD51, ATR, BRCA1, BRCA2, and ATM mRNA expression was detected in 93.75% (45/48), 93.75% (45/48), 91.67% (44/48), 83.33% (40/48), and 89.58% (43/48) of the tumors; partial or complete methylation, in 94.87% (37/39), 0 (0/42), 97.56% (40/41), 100% (41/41), and 0 (0/40), respectively. Most gene pairs showed significant weak to moderate positive correlations of tumoral mRNA expression with each other: RAD51 with ATR (P = .027), BRCA1 (P < .001), and BRCA2 (P < .001); ATR with BRCA1 (P = .007), and ATM (P = .001); BRCA1 with BRCA2 (P = 0.001). BRCA1 mRNA was reduced in tumors compared with non-neoplastic mucosa (0.345 vs 1.272, P = .015) and, excluding neoadjuvant therapy cases, in T3 to T4 tumors compared with T2 (0.414 vs 0.954, P = .035). Greater tumoral RAD51 mRNA levels correlated with perineural invasion (1.822 vs 0.725, P = .010) and death (1.664 vs 0.929, P = .036), but not with survival time. There was an inverse association between nuclear immunohistochemical positivity for ATR and its mRNA levels (0.487 vs 0.907, P = .032), and no significant correlation for the other markers.

Conclusions

Our results suggest RAD51, BRCA1, and BRCA2 methylation as a frequent epigenetic mechanism in gastric cancer, support the hypothesis that reduced BRCA1 expression participates in disease progression, and show an association between RAD51 mRNA and perineural invasion and mortality that may be considered unexpected, considering the former immunohistochemical studies. The lack of correlation between immunohistochemistry and mRNA, and even the inverse association, for ATR, can be seen as indicative of action of post-transcriptional or post-translational regulatory mechanisms, to be better investigated.

Phase 1/2a Study of Rivoceranib, a Selective VEGFR-2 Angiogenesis Inhibitor, in Patients with Advanced Solid Tumors

Purpose

To report the results from an early-phase study of rivoceranib, an oral tyrosine kinase inhibitor highly selective for vascular endothelial growth factor receptor 2, in patients with advanced solid tumors.

Materials and Methods

In this open-label, single-arm, dose-escalating, multicenter three-part phase 1/2a trial, patients had advanced solid tumors refractory to conventional therapy. Part 1 evaluated the safety and pharmacokinetics of five ascending once-daily doses of rivoceranib from 81 mg to 685 mg. Part 2 evaluated the safety and antitumor activity of once-daily rivoceranib 685 mg. Part 3 was conducted later, due to lack of MTD determination in part 1, to evaluate the safety and preliminary efficacy of once-daily rivoceranib 805 mg in patients with unresectable or advanced gastric cancer.

Results

A total of 61 patients were enrolled in parts 1 (n=25), 2 (n=30), and 3 (n=6). In parts 1 and 2, patients were white (45.5%) or Asian (54.5%), and 65.6% were male. The most common grade ≥3 adverse events (AEs) were hypertension (32.7%), hyponatremia (10.9%), and hypophosphatemia (10.9%). The overall response rate (ORR) was 15.2%. In part 3, dose-limiting toxicities occurred in 2 out of 6 patients: grade 3 febrile neutropenia decreased appetite, and fatigue. The ORR was 33%.

Conclusion

The recommended phase 2 dose of rivoceranib was determined to be 685 mg once daily, which showed adequate efficacy with a manageable safety profile. (NCT01497704 and NCT02711969).

Delayed Perforation Occurring after Gastric Endoscopic Submucosal Dissection: Clinical Features and Management Strategy

Background/Aims

Delayed perforation is a rare but serious adverse event of gastric endoscopic submucosal dissection (ESD). The aim of this study was to clarify the clinical features and appropriate management strategy of patients with delayed perforation.

Methods

Among 11,531 patients who underwent gastric ESD, the clinical features and outcomes of patients who experienced delayed perforation were retrospectively reviewed and compared with those of the control group.

Results

Delayed perforation occurred in 15 of 11,531 patients (0.13%). The patients with delayed perforation were significantly older than those without delayed perforation (p=0.027). The median time to diagnosis of delayed perforation was 28.8 hours (range, 14 to 71 hours). All 15 patients with delayed perforation complained of severe abdominal pain after gastric ESD and underwent subsequent chest X-rays (CXRs) for evaluation. In subsequent CXR, free air was found in 12 patients (80%). For three (20%) patients without free air in CXR, delayed perforation was finally diagnosed by computed tomography. Leukocytosis was significantly less frequent in the patients without free air in CXR (p=0.022). A perforation hole smaller than 1 cm in size was more frequently observed in the six patients who underwent successful non-surgical treatments than in the nine patients who underwent surgery (p<0.001). There was no mortality related to delayed perforation.

Conclusions

One-fifth of the patients with delayed perforation did not show free air in CXR and exhibited less leukocytosis than those with free air. Non-surgical treatments including endoscopic closure might be considered as an initial treatment modality for delayed perforation smaller than 1 cm.

Bone metastasis is a late-onset and unfavorable event in survivors of gastric cancer after radical gastrectomy: Results from a clinical observational cohort

Background

The timing and incidence of recurrent bone metastasis (BM) after radical gastrectomy in patients with gastric cancer (GC) as well as the survival of these patients were not fully understood. The aim of this study was to analyze the data of an observational GC cohort and identify patients who underwent curative gastrectomy and had recurrent BM to describe and clarify the pattern and profile of BM evolution after surgery.

Methods

Data were retrieved from a hospital-based GC cohort, and patients who underwent upfront radical gastrectomy were selected. The time points of specific organ metastatic events were recorded, and the person-year incidence rate of metastatic events was calculated. The latency period of BM events after gastrectomy was measured and compared with that of the other two most common metastatic events, liver metastasis (LM) and distant lymph node metastasis (LNM), using analysis of variance. Propensity score matching and subgroup analysis were used for sensitivity analysis.

Results

A total of 1324 GC cases underwent radical gastrectomy between January 2011 and December 2021. Of these, 67 BM, 218 LM, and 248 LNM occurred before the last follow-up. The incidence of BM events was 1.7/100 person-years, which was approximately 3-fold lower than that of LM and distant LNM events (5.5 and 6.3 per 100 person-years, respectively). BM events had a significantly longer latency (median time, 16.5 months) than LM and LNM events (11.1 and 12.0 months, respectively). Recurrent BM led to a worse prognosis (median survival, 4.5 months) than those of LM and LNM events (median survival, 7.7 and 7.1 months, respectively). However, no difference in overall survival after gastrectomy was observed among the groups.

Conclusions

Compared with other common metastatic events, BM in GC after gastrectomy is a late-onset event indicating poor survival.

Trial registration

No. ChiCTR1800019978; http://www.chictr.org.cn/.

Application of artificial intelligence for diagnosis of early gastric cancer based on magnifying endoscopy with narrow-band imaging

Although magnifying endoscopy with narrow-band imaging is the standard diagnostic test for gastric cancer, diagnosing gastric cancer using this technology requires considerable skill. Artificial intelligence has superior image recognition, and its usefulness in endoscopic image diagnosis has been reported in many cases. The diagnostic performance (accuracy, sensitivity, and specificity) of artificial intelligence using magnifying endoscopy with narrow band still images and videos for gastric cancer was higher than that of expert endoscopists, suggesting the usefulness of artificial intelligence in diagnosing gastric cancer. Histological diagnosis of gastric cancer using artificial intelligence is also promising. However, previous studies on the use of artificial intelligence to diagnose gastric cancer were small-scale; thus, large-scale studies are necessary to examine whether a high diagnostic performance can be achieved. In addition, the diagnosis of gastric cancer using artificial intelligence has not yet become widespread in clinical practice, and further research is necessary. Therefore, in the future, artificial intelligence must be further developed as an instrument, and its diagnostic performance is expected to improve with the accumulation of numerous cases nationwide.

Risk Factors of Gastric Cancer and Lifestyle Modification for Prevention

Gastric cancer has been consistently decreasing worldwide, whereas cardia gastric cancer is on the rise. This indicates that the exposure rates to epidemiological causes are changing. In this study, we aim to review the risk factors for gastric cancer with respect to cardia and non-cardia types. One of the most significant risk factors for gastric cancer is Helicobacter pylori infection. H. pylori infection is known as a risk factor for non-cardia gastric cancer, and there have been results indicating that H. pylori infection is not associated with cardia gastric cancer. However, in the East Asian region, there is epidemiological evidence suggesting that H. pylori infection might be a risk factor for cardia gastric cancer. Smoking and alcohol consumption are known risk factors for gastric cancer, regardless of anatomical location. Obesity is considered a factor in the development of cardia gastric cancer. However, further research is needed to understand the specific relationship with non-cardia gastric cancer. The consumption of high-salt and processed meat is more distinctly associated with non-cardia gastric cancer than in cardia gastric cancer. In addition to these factors, exposure to chemicals and radiation are considered risk factors for gastric cancer. Primary prevention of gastric cancer involves eliminating or avoiding risk factors such as H. pylori eradication and adopting a healthy lifestyle, including quitting smoking, reducing alcohol consumption, maintaining a healthy weight, and having a low-salt diet.

GASTric Cancer HER2 Re-Assessment Study 2 (GASTHER2): HER2 Re-assessment for Initially HER2-Negative Advanced Gastric Cancer Patients after Progression on First-Line Treatment

PURPOSE

Heterogeneous human epidermal growth factor receptor 2 (HER2) overexpression in gastric cancer may lead to a misdiagnosis of HER2 status. Accurate assessment of HER2 status is essential for optimal treatment as novel HER2-directed agents are being investigated in various clinical settings. We evaluated the usefulness of HER2 re-assessment following progression on first-line treatment in initially HER2-negative advanced gastric cancer (AGC) patients.

MATERIALS AND METHODS

We enrolled 177 patients with baseline HER2-negative AGC and performed HER2 re-assessment after progression on first-line treatment from February 2012 to June 2016 at Asan Medical Center, Seoul, Korea. The re-assessed HER2 status was analyzed with baseline HER2 status and clinical characteristics.

RESULTS

The median age was 54 years (range, 24 to 80 years), and 123 patients (69.5%) were men. Seven patients (4.0%) were HER2-positive on the re-assessment. Patients with baseline HER2 negativity confirmed by a single test (n=100) had a higher HER2-positive re-assessment rate compared to those who had repeated baseline testing (n=77) (5.0% vs. 2.6%). Among the patients with single baseline HER2 testing, the rate was higher in patients with baseline HER2 immunohistochemistry (IHC) 1+ compared to those with IHC 0 (13.4% vs. 3.6%).

CONCLUSION

Overall, 4.0% of patients with baseline HER2-negative AGC were HER2-positive on re-assessment, and the HER2-positive re-assessment rate was higher among patients who had a single test at baseline. HER2 re assessment may be considered for initially HER2-negative patients to determine their eligibility for HER2-directed therapy, particularly if their HER2 negativity was determined by a single test, especially if they had a single baseline HER2 IHC 1+ test.

First-in-Human Phase 1 Study of a B Cell- and Monocyte-Based Immunotherapeutic Vaccine against HER2-Positive Advanced Gastric Cancer

PURPOSE

BVAC-B is an autologous B cell- and monocyte-based immunotherapeutic vaccine that contains cells transfected with a recombinant human epidermal growth factor receptor 2 (HER2) gene and loaded with the natural killer T cell ligand alpha-galactosylceramide. Here, we report the first BVAC-B study in patients with HER2-positive advanced gastric cancer.

MATERIALS AND METHODS

Patients with advanced gastric cancer refractory to standard treatment with HER2+ immunohistochemistry ≥ 1 were eligible for treatment. Patients were administered low (2.5×107 cells/dose), medium (5.0×107 cells/dose), or high dose (1.0×108 cells/dose) of BVAC-B intravenously four times every 4 weeks. Primary endpoints included safety and maximum tolerated BVAC-B dose. Secondary endpoints included preliminary clinical efficacy and BVAC-B-induced immune responses.

RESULTS

Eight patients were treated with BVAC-B at low (n=1), medium (n=1), and high doses (n=6). No dose-limiting toxicity was observed, while treatment-related adverse events (TRAEs) were observed in patients treated with medium and high doses. The most common TRAEs were grade 1 (n=2) and grade 2 (n=2) fever. Out of the six patients treated with high-dose BVAC-B, three had stable disease with no response. Interferon gamma, tumor necrosis factor-α, and interleukin-6 increased after BVAC-B treatment in all patients with medium and high dose, and HER2-specific antibody was detected in some patients.

CONCLUSION

BVAC-B monotherapy had a safe toxicity profile with limited clinical activity; however, it activated immune cells in heavily pretreated patients with HER2-positive gastric cancer. Earlier treatment with BVAC-B and combination therapy is warranted for evaluation of clinical efficacy.

Construction and Validation of a Gastric Cancer Diagnostic Model based on Blood Groups and Tumor Markers

Objective: The aim of this study is to explore the value of combined detection of ABO blood group and tumor markers in the diagnosis of gastric cancer. Methods: A total of 3650 gastric cancer patients treated in our center from January 2015 to December 2019, and 5822 controls were recruited, and divided into training set and validation set according to 7:3. The diagnostic and predictive model of gastric cancer was constructed by binary logistic regression method in the training set. The diagnostic value of the prediction model for gastric cancer was evaluated by calculating the prediction probability P value and drawing the Receiver operating characteristic (ROC) curve, and was verified in the validation set. Results: The Area under the curve (AUC) of the diagnosis and prediction model in the training set was 0.936 (95%CI: 0.926-0.941), the sensitivity was 81.66%, and the specificity was 98.61%. In the validation set, the AUC was 0.941 (95%CI: 0.932-0.950), the sensitivity was 82.33%, and the specificity was 99.02%. Furthermore, the diagnostic model obtained in this study had a high diagnostic value for early gastric cancer patients in the healthy population (AUC of training set, validation set and total population were 0.906, 0.920 and 0.908, respectively). Conclusions: We constructed a diagnostic model for gastric cancer including blood group and tumor markers, which has high reference value for the diagnosis of gastric cancer patients, and the model can better distinguish early gastric cancer from healthy people.

Genomic and Transcriptomic Characterization of Gastric Cancer with Bone Metastasis

PURPOSE

Bone metastasis (BM) adversely affects the prognosis of gastric cancer (GC). We investigated molecular features and immune microenvironment that characterize GC with BM compared to GC without BM.

MATERIALS AND METHODS

Targeted DNA and whole transcriptome sequencing were performed using formalin-fixed paraffin-embedded primary tumor tissues (gastrectomy specimens) of 50 GC cases with distant metastases (14 with BM and 36 without BM). In addition, immunohistochemistry (IHC) for mucin-12 and multiplex IHC for immune cell markers were performed.

RESULTS

Most GC cases with BM had a histologic type of poorly cohesive carcinoma and showed worse overall survival (OS) than GC without BM (p < 0.05). GC with BM tended to have higher mutation rates in TP53, KDR, APC, KDM5A, and RHOA than GC without BM. Chief cell-enriched genes (PGA3, PGC, and LIPF), MUC12, MFSD4A, TSPAN7, and TRIM50 were upregulated in GC with BM compared to GC without BM, which was correlated with poor OS (p < 0.05). However, the expression of SERPINA6, SLC30A2, PMAIP1, and ITIH2 were downregulated in GC with BM. GC with BM was associated with PIK3/AKT/mTOR pathway activation, whereas GC without BM showed the opposite effect. The densities of helper, cytotoxic, and regulatory T cells did not differ between the two groups, whereas the densities of macrophages were lower in GC with BM (p < 0.05).

CONCLUSION

GC with BM had different gene mutation and expression profiles than GC without BM, and had more genetic alterations associated with a poor prognosis.

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.

New developments and standard of care in the management of advanced gastric cancer

Advanced gastric adenocarcinoma is a common disease with a poor prognosis whose treatment has for decades been based on cytotoxic chemotherapy, including platinum salts in first-line, and taxane or irinotecan in second or later line. Recent years have seen the emergence of new drugs that have improved patient survival, such as trastuzumab in first-line for HER2-positive tumors, ramucirumab alone or in combination with paclitaxel in second-line, and trifluridine-tipiracil beyond the second-line treatment. More recently, two monoclonal antibodies have demonstrated their efficacy in combination with oxaliplatin-based first-line chemotherapy, nivolumab (anti-PD1) for PD-L1 CPS ≥5 tumors, and zolbetuximab for tumors overexpressing Claudin 18.2. In addition, regorafenib has been also showed effective in phase 3 trial for heavily pretreated patients. Based on phase 2 studies, trastuzumab-deruxtecan was approved in 2022 by the EMA for HER2-positive pretreated patients. This agent is currently evaluated in phase 3 study (DESTINY-Gastric04 trial), as are several other anti-HER2 (zanidatamab, margetuximab, tucatinib), immune checkpoint inhibitors, or targeted therapies (anti-FGFR2b).

Clinical outcomes of Epstein-Barr virus (EBV)-associated metastatic and locally advanced unresectable gastric cancers (GCs) in patients receiving first-line fluoropyrimidine and platinum (FP) doublet chemotherapy

BACKGROUND

Epstein-Barr virus-associated gastric cancer (EBVaGC) is a distinct molecular subgroup showing excellent outcomes after surgery for localized disease. Prominent immune cell infiltration in EBVaGC reflects the immunogenicity of Epstein-Barr virus (EBV) and, as suggested by some investigators, responsiveness to immune checkpoint inhibitors in the palliative setting. However, few data are available on the prevalence, clinical characteristics, and prognosis of EBVaGC patients receiving palliative cytotoxic chemotherapy.

METHODS

In this retrospective study, we identified 1061 patients with metastatic, recurrent, or locally advanced unresectable gastric cancer (GC) who started first-line fluoropyrimidine/platinum (FP) doublet chemotherapy with or without trastuzumab from January 2015 to August 2018. For 766 patients with available tumor tissue, the presence of EBV in cancer cells was evaluated by EBV-encoded RNA in situ hybridization and correlated with clinical characteristics and treatment outcomes.

RESULTS

Among the patients evaluated (n = 766), 40 (5.0%) were EBV-positive. EBVaGC was associated with male sex (p = 0.009) and lower neutrophil-lymphocyte ratio (NLR < 2.46, p = 0.03). Efficacy of first-line FP chemotherapy, in terms of response rate ad progression-free survival (PFS), did not differ between EBVaGC and EBV-negative GC (overall response rate: 53.8% vs. 51.8%, p = 0.99; median PFS: 6.4 vs. 6.7 months, p = 0.90). However, overall survival tended to be better with EBVaGC than EBV-negative GC (16.4 vs. 14.0 months, p = 0.07).

CONCLUSIONS

EBVaGC accounted for 5% of metastatic/unresectable GCs. While EBVaGC was not associated with better response to or PFS following first-line cytotoxic chemotherapy, it showed a trend toward better overall survival.

Current Issues in Reduced-Port Gastrectomy: A Comprehensive Review

Reduced-port gastrectomy (RPG) includes all procedures derived from various efforts to minimize surgical invasiveness, with single-incision laparoscopic gastrectomy (SILG) being the ultimate reduced-port technique. However, there are challenges related to its feasibility, oncological validity, training, and education. This review describes the current issues and challenges, as well as the future prospects of RPG for gastric cancer. Gastrectomy, which started as an open surgery, has evolved into a laparoscopic surgery. With the advancements in laparoscopic technology, SILG has been used to minimize surgical scarring. However, owing to the technical difficulties of SILG, cases involving the addition of 1 trocar or needle grasper alongside the multichannel port have also been reported. Additionally, 3-port laparoscopic gastrectomy (3PLG) using only 3 trocars is also being performed. RPG, as a concept, includes a range of approaches such as SILG, 2-port laparoscopic gastrectomy, and 3PLG. These techniques aimed to reduce the number of ports or incisions required for laparoscopic gastrectomy. Despite technical difficulties, RPGs offer numerous advantages, including minimal invasiveness, excellent cosmetic outcomes, and the potential for improved post-operative recovery, such as reduced length of hospital stay and post-operative pain. It could be considered similar to conventional laparoscopic gastrectomy, and may not be oncologically inferior. Ongoing studies, such as the KLASS 12, are required to gain further insights.

Does total omentectomy prevent peritoneal seeding for advanced gastric cancer with serosal invasion?

BACKGROUND

Radical gastrectomy is composed of gastrectomy, lymph node dissection, and omentectomy. Total omentectomy (TO) is expected to reduce the incidence of peritoneal recurrence. We aimed to investigate the necessity of TO for advanced gastric cancer (AGC) with serosal invasion.

METHODS

We retrospectively reviewed 310 patients who underwent radical gastrectomy with TO and 93 patients who underwent partial omentectomy (PO) for gastric cancer with serosal invasion between August, 2005 and December, 2017. Finally, 91 patients in the PO group and 91 in the TO group were enrolled based on a 1:1 propensity-score matching analysis. We evaluated surgical and oncological outcomes, including 5-year overall and recurrence-free survival rates.

RESULTS

There was no statistically significant difference between the two groups in postoperative complications. Recurrence sites showed similar patterns in both groups, including peritoneal recurrence (PO vs. TO, 18.7% vs. 28.6%; p = 0.188). Five-year overall survival was better in the PO group (p = 0.018), while 5-year recurrence-free survival was similar in both groups (p = 0.066).

CONCLUSION

TO might not be an essential part of preventing peritoneal recurrence for AGC with serosal invasion. PO could be considered a radical gastrectomy for T4a gastric cancer.

Ethnic-specific associations between body mass index and gastric cancer: a Mendelian randomization study in European and Korean populations

BACKGROUND

Given the uncertainties surrounding the associations in previous epidemiological studies, we conducted linear and nonlinear Mendelian randomization (MR) studies to evaluate whether body mass index (BMI) associated with gastric cancer (GC) risk in European and Korean.

METHODS

Genome-wide association study-summary statistics were used from the Pan-UK Biobank, the Genetic Investigation of Anthropometric Traits consortium, the K-CHIP consortium, and BioBank Japan. BMI-associated single nucleotide polymorphisms (SNPs) were used as instrumental variables (IVs) in MR to identify the association between BMI and GC. Both linear and nonlinear MR analyses were performed. Sensitivity analyses were also conducted for individuals below or above a BMI of 24 kg/m2.

RESULTS

The study used 22 and 55 SNPs as IVs for BMI in European and Korean populations, respectively. Genetically predicted BMI was positively associated with GC risk in the European population (Odds ratio per 1 kg/m2 increase; 95% CI = 1.17; 1.01-1.36 using simple median method), but no significant association was observed in the Korean population. However, the nonlinear MR identified a U-shaped association between BMI and GC in the Korean population, with both low and high BMIs associated with increased GC risk. A BMI of 24 kg/m2 presented the lowest risk. Sensitivity analyses did not yield any genome-wide significant SNPs.

CONCLUSION

While MR analysis suggests a linear association between BMI and GC in those of European ancestry, nonlinear MR hints at a U-shaped association in Koreans. This suggests the association between BMI and GC risk may vary according to ethnic ancestry.

Concordance of circulating tumor DNA and matched formalin-fixed paraffin-embedded tumor tissue in gastric cancer as a predictor of recurrence

PURPOSE

Combined analysis of the variant composition of circulating tumor DNA (ctDNA) from cell-free plasma and DNA from tumor tissue could provide insight into the implications of the genetic alterations responsible for the intratumoral and intertumoral heterogeneity of gastric cancer. We aimed to evaluate the usefulness of this approach in these patients.

METHODS

Cell-free plasma and formalin-fixed paraffin-embedded tumor tissue samples from 46 patients with gastric cancer were examined. Targeted deep sequencing was performed using a commercially available kit.

RESULTS

The cell-free DNA (cfDNA) concentration was higher in stage II-IV versus stage I patients and in larger versus smaller tumors. Only 12 of the 36 (33.3%) alterations in the tumor tissue samples were in concordance with those in the ctDNA samples. Two variants were in concordance in stage I samples and 10 in stage II-IV samples. Actionable variants that were detected in concordance were in the stage II-IV samples. Preoperative ctDNA positivity of actionable variants was significantly associated with cfDNA concentration, lymphatic invasion, N stage, and TNM stage. Cancer recurrence was significantly associated with tumor size, lymphatic/vascular invasion, TNM stage, and ctDNA-tumor tissue variant concordance.

CONCLUSION

Preoperative ctDNA genetic analysis using a multigene panel offers substantial clinical benefits when performed in conjunction with targeted deep sequencing of tumor tissue. Concordance between preoperative ctDNA and tumor tissue mutations may serve as a prognostic indicator in patients with gastric cancer.

Gastric schwannoma: Two case reports and review of the literature

Gastric schwannomas are rare, slow-growing tumors whose clinical presentation is nonspecific. These are mostly benign, with a low probability of malignant transformation and an excellent prognosis. We present 2 cases of gastric schwannomas with distinct clinical features and imaging patterns, whose therapeutic approach differed. Case 1 is a 73-year-old woman with a voluminous subepithelial lesion in the greater gastric curvature, with predominantly endoluminal growth. Clinically the patient presented with nonspecific abdominal complaints and underwent complete surgical excision. Case 2 is a 69-year-old woman with an exophytic lesion adjacent to the gastric antrum, diagnosed incidentally and managed conservatively, with imaging follow-up, for the last 5 years and stable ever since. This article aims to focus on this rare disease, illustrating its main imaging findings, particularly in magnetic resonance imaging, along with pathological correlation, as well as reviewing the literature, discussing the differential diagnosis, and exploring clinical management and prognosis.