Comparison of [68 Ga]Ga-FAPI-04 and [18F]-FDG for the detection of primary and metastatic lesions in patients with gastric cancer: a bicentric retrospective study

INTRODUCTION

The low sensitivity of [¹⁸F]-fluorodeoxyglucose ([¹⁸F]-FDG) for the diagnosis of gastric cancer limits its application. In this study, we aimed to investigate the potential advantage of [⁶⁸ Ga]Ga-FAPI-04 over [¹⁸F]-FDG in the evaluation of gastric cancer.

METHODS

This was a bicentric retrospective analysis of a prospective parent study (clinical trial: HS-KY-2020-826 (Huashan Hospital) and DF-2020-102 (Shanghai East Hospital)). Thirty-eight patients with gastric cancer (31 with adenocarcinoma and 7 with signet ring cell carcinoma) were included in this study. All of the participants underwent [⁶⁸ Ga]Ga-FAPI-04 and [¹⁸F]-FDG imaging by positron emission tomography (PET)/computed tomography (CT) or PET/magnetic resonance (MR). The scans were interpreted by two experienced nuclear medicine physicians, and the maximum standardized uptake value (SUV_max) was calculated. Histopathological findings obtained from biopsy or resected surgical specimens were used as a reference for the final diagnosis.

RESULTS

For the detection of primary gastric cancer, the sensitivities of [⁶⁸ Ga]Ga-FAPI-04 PET and [¹⁸F]-FDG PET were 100% (38/38) and 82% (31/38), respectively (P = 0.016). Four cases of adenocarcinoma and three cases of signet ring cell carcinoma were missed by [¹⁸F]-FDG PET. The mean SUV_max of [⁶⁸ Ga]Ga-FAPI-04 in tumours greater than 4 cm (11.0 ± 4.5) was higher than that in tumours less than 4 cm (4.5 ± 3.2) (P = 0.0015). The mean SUV_max of [⁶⁸ Ga]Ga-FAPI-04 was higher in T2-4 tumours (9.7 ± 4.4) than in T1 tumours (3.1 ± 1.5) (P = 0.0002). For the detection of metastatic lesions, the sensitivities of [⁶⁸ Ga]Ga-FAPI-04 PET and [¹⁸F]-FDG PET in 10 patients with regional lymph node metastasis and distant metastasis were 6/10 and 5/10, respectively.

CONCLUSION

In this selected cohort, [⁶⁸ Ga]Ga-FAPI-04 PET had a superior detection rate than [¹⁸F]-FDG PET for primary gastric cancer. [⁶⁸ Ga]Ga-FAPI-04 PET could provide better performance with regard to gastric cancer diagnosis and staging. Prospective clinical trials are warranted.

[Clinical pathological characteristics of 4 cases of gastric gland-derived tumors]

Objective: To investigate the pathological features of gastric tumor originated from the fundic gland, including oxyntic gland adenoma (OGA) and gastric adenocarcinoma of the fundic gland (GA-FG). Methods: A retrospective analysis of 2 cases of OGA and 2 cases of GA-FG admitted to our hospital from February 2019 to September 2019 was performed. The histological features were analyzed by immunohistochemical staining combined with endoscopic observation. Results: The four cases arose from the deep layer of the lamina propria mucosae and well differentiated. Two cases of OGA confined to the mucosa, including 1 case of irregular tubules showing low-degree dysplasia and another case of irregular branching and anastomosing tubules showing high-degree dysplasia. Two cases of GA-FG combined with submucosal invasion, showed irregular branching and anastomosing tubules and formed a so-called "endless glands" pattern. Atypia, helicobacter pylori (HP) infection, chronic gastritis, intestinal metaplasia, or gastric atrophy were not observed in the superficial epithelium covering the tumor extent. Two cases of OGA and 2 cases of GA-FG showed the same result of immunohistochemical staining: pepsinogen-1 was diffusely positive in the tumor tissues and indicated chief cell differentiation, while positive ATPase and PDGFRA-α indicated parietal cells differentiation. The expression of Syn were positive in all cases, while CD10, MUC2 and CD-X2 were negative. The upregulation of p53 protein or nuclear positivity of β-catenin was not observed. The Ki-67 labeling index in the hot area was approximately 1-5%. Conclusions: GA-FG is a well-differentiated, low-grade malignant novel subtype of gastric cancer. The immunohistochemical markers and narrowband imaging combined with magnifying endoscopy (NBI-ME) enhance the diagnostic sensitivity. Whether Syn positive expression can be one of the diagnostic item needs to be further investigate. The process of tumorigenesis of GA-FG might be the transition from low-grade dysplasia to high-grade dysplasia of OGA and further to submucosal infiltration. However, the mechanism of GAFG was still unclear. Disregulation of the Shh and Wnt/β-catenin signaling pathway might be associated with tumorigenesis of GA-FG. Endoscopic submucosal dissection (ESD) is often the preferred and curative treatment.

Molecular Pathology of Gastroesophageal Cancer

Upper gastroesophageal carcinomas consist of cancers arising from the esophagus and stomach. Squamous cell carcinomas and adenocarcinomas are seen in the esophagus and despite arising from the same organ have different biology. Gastric adenocarcinomas are categorized into 4 molecular subtypes: high Epstein-Barr virus load, microsatellite unstable cancers, chromosomal unstable (CIN) cancers, and genomically stable cancers. Genomically stable gastric cancers correlate highly with histologically defined diffuse-type cancers. Esophageal carcinomas and CIN gastric cancers often are driven by high-level amplifications of oncogenes and contain a high degree of intratumoral heterogeneity. Targeted therapeutics is an active area of research for gastroesophageal cancers.

Helicobacter pylori and Gastric Cancer

Helicobacter pylori is present in approximately one-half of the world's population. There are significant differences in prevalence based on region, age, race/ethnicity, and socioeconomic status. H pylori is the most common cause of infection-related cancers. Studies have demonstrated the relationship between H pylori infection and gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. H pylori has features and enzymatic properties allowing it to survive in the acidic stomach environment, and has specific virulence factors that promote an increased risk of gastric pathology. Eradication of H pylori is first-line therapy for mucosa-associated lymphoid tissue lymphoma and decreases the risk of gastric adenocarcinoma.

Tumor-to-tumor metastasis of diffuse large B cell lymphoma to gastric adenocarcinoma via CXCL12 (SDF-1)/CXCR4 axis: a case report

BACKGROUND

Tumor-to-tumor metastasis is the rare phenomenon in which one tumor exhibits metastatic deposits from another. To the best of our knowledge, there has been no prior reported case of tumor-to-tumor metastasis of a diffuse large B cell lymphoma (DLBCL) to a primary gastric adenocarcinoma.

CASE PRESENTATION

A 70-year-old man presented with chest discomfort. An echocardiogram showed the presence of a right ventricular tumor. A positron emission tomogram showed multiple foci of abnormal activity in right cervical lymph nodes, cardiac wall, and stomach. A right cervical lymph node biopsy specimen revealed histological features of DLBCL. An esophagogastroduodenoscopy showed a large circumferential ulceration on the gastric body. Subsequent biopsy revealed adenocarcinoma cells surrounded by infiltrating lymphoma cells. On immunohistochemical staining, lymphoma cells were positive for CXCR4 and adenocarcinoma cells were positive for CXCL12/SDF-1. The patient was treated with six cycles of R-CHOP chemotherapy regimen, resulting in a complete remission.

CONCLUSIONS

This patient's case implies that the interaction between a chemokine and its receptor may be the underlying mechanism for the observed tumor-to-tumor metastasis. Specifically, our case would suggest an involvement of the CXCL12 (SDF-1)/CXCR4 axis in the observed metastasis of DLBCL to primary gastric adenocarcinoma.

Patient-derived cell lines and orthotopic mouse model of peritoneal carcinomatosis recapitulate molecular and phenotypic features of human gastric adenocarcinoma

BACKGROUND

Gastric adenocarcinoma with peritoneal carcinomatosis (PC) is therapy resistant and leads to poor survival. To study PC in depth, there is an urgent need to develop representative PC-derived cell lines and metastatic models to study molecular mechanisms of PC and for preclinical screening of new therapies.

METHODS

PC cell lines were developed from patient-derived PC cells. The tumorigenicity and metastatic potential were investigated by subcutaneously (PDXs) and orthotopically. Karyotyping, whole-exome sequencing, RNA-sequencing, and functional studies were performed to molecularly define the cell lines and compare genomic and phenotypic features of PDX and donor PC cells.

RESULTS

We established three PC cell lines (GA0518, GA0804, and GA0825) and characterized them in vitro. The doubling times were 22, 39, and 37 h for GA0518, GA0804, and GA0825, respectively. Expression of cancer stem cell markers (CD44, ALDH1, CD133 and YAP1) and activation of oncogenes varied among the cell lines. All three PC cell lines formed PDXs. Interestingly, all three PC cell lines formed tumors in the patient derived orthotopic (PDO) model and GA0518 cell line consistently produced PC in mice. Moreover, PDXs recapitulated transcriptomic and phenotypic features of the donor PC cells. Finally, these cell lines were suitable for preclinical testing of chemotherapy and target agents in vitro and in vivo.

CONCLUSION

We successfully established three patient-derived PC cell lines and an improved PDO model with high incidence of PC associated with malignant ascites. Thus, these cell lines and metastatic PDO model represent excellent resources for exploring metastatic mechanisms of PC in depth and for target drug screening and validation by interrogating GAC for translational studies.

The Discordance of Clinical and Pathologic Staging in Locally Advanced Gastric Adenocarcinoma

BACKGROUND

Clinical staging guides decisions about optimal treatment sequence in patients with gastric cancer, although the preoperative accuracy is not strongly established. This study investigates concordance of clinical and pathologic stage as well as its impact on the survival of patients with gastric adenocarcinoma.

METHODS

Patients with clinical stage T2-4, N0, M0 gastric adenocarcinoma who underwent surgery without neoadjuvant therapy were identified from the National Cancer Database (2010-2015). The primary outcome was up-staging, defined as cT < pT, pN1-3, and/or pM1 (AJCC 7^th edition). Multivariable logistic regression analysis was performed to predict up-staging. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

In total, 2254 patients were identified. cTNM staging was discordant with pTNM staging in 65.6% of cases, with 50.4% up-staged and 15.2% down-staged. On multivariable logistic regression, younger age (OR 0.991, 95% CI 0.984-0.999, p=0.0188), male sex (versus female; OR 1.392, 95% CI 1.158-1.673, p=0.0004), poor or undifferentiated tumor grade (versus well differentiated or moderately differentiated; OR 2.399, 95% CI 1.987-2.896; p<0.0001), positive margin status (versus negative; OR 4.575, 95% CI 3.360-6.230; p<0.0001), and days from diagnosis to surgery (15-32 days versus ≤ 14 days; OR 1.411, 95% CI 1.098-1.814, p=0.0072) were predictive of up-staging. Patients who were up-staged had a decreased survival compared to patients who were accurately staged (median survival 27.9 months versus 67.6 months; log-rank p<0.0001).

CONCLUSION

This study found a substantial discordance between clinical and pathologic staging of resectable locally advanced gastric adenocarcinoma. These data support that patients may have more advanced disease at presentation than reflected in clinical staging and may benefit from improved diagnostic modalities and neoadjuvant chemotherapy.

Bioinformatic and integrated analysis identifies an lncRNA-miRNA-mRNA interaction mechanism in gastric adenocarcinoma

BACKGROUND

lncRNAs-miRNAs-mRNAs networks play an important role in Gastric adenocarcinoma (GA). Identification of these networks provide new insight into the role of these RNAs in gastric cancer.

OBJECTIVES

Biological information databases were screened to characterize and examine the regulatory networks and to further investigate the potential prognostic relationship this regulation has in GA.

METHODS

By mining The Cancer Genome Atlas (TCGA) database, we gathered information on GA-related lncRNAs, miRNAs, and mRNAs. We identified differentially expressed (DE) lncRNAs, miRNAs, and mRNAs using R software. The lncRNA-miRNA-mRNA interaction network was constructed and subsequent survival examination was performed. Representative genes were selected out using The Biological Networks Gene Ontology plug-in tool on Cytoscape. Additional analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms were used to screen representative genes for functional enrichment. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to identify the expression of five candidate differential expressed RNAs.

RESULTS

Information of samples from 375 cases of gastric cancer and 32 healthy cases (normal tissues) were downloaded from the TCGA database. A total of 1632 DE-mRNAs, 1008 DE-lncRNAs and 104 DE-miRNAs were identified and screened. Among them, 65 DE-lncRNAs, 10 DE-miRNAs, and 10 DE-mRNAs form lncRNAs-miRNAs-mRNAs regulatory network. Additionally, 10 lncRNAs and 2 mRNAs were associated with the prognosis of GA. Multivariable COX analysis revealed that AC018781.1 and VCAN-AS1 were independent risk factors for GA. GO functional enrichment analysis found DE-mRNA was significantly enriched TERM (P < 0.05). The KEGG signal regulatory network analysis found 11 significantly enrichment networks, the most prevailing was for the AGE-RAGE signaling pathway associated with Diabetic complications. Results of RT-qPCR was consistent with the in silico results.

CONCLUSIONS

The results of the present study represent a view of GA from a analysis of lncRNA, miRNA and mRNA. The network of lncRNA-miRNA-mRNA interactions revealed here may potentially further experimental studies and may help biomarker development for GA.

Partial Gastrectomy is Associated with Improved Overall Survival in Signet-Ring Cell Gastric Cancer

BACKGROUND

Signet-ring cell gastric cancer (SRGC) is a histological variant of gastric adenocarcinoma (GAC) with a worse prognosis compared to non-signet-ring cell gastric cancer (NSRGC). To our knowledge, the overall survival (OS) among patients with SRGC undergoing total/near-total (TG) versus partial gastrectomy (PG) has never been reported from a large-scale Western database.

METHODS

We performed a retrospective analysis of patients with both SRGC and NSRGC using The National Cancer Database.

RESULTS

In total, 17,086 patients were included. Patients who underwent TG versus PG were 25.5% (n = 770) versus 74.5% (n = 2246) for SRGC, and 20.9% (n = 2943) versus 79.1% (n = 11,127) for NSRGC, respectively. Patients who had SRGC were more likely to undergo TG (25.5% versus 20.9% P< 0.0001). Patients with distal gastric tumors were less likely to undergo TG (16.5% versus 25.4% P < 0.0001). Patients undergoing PG for the SRGC histological variant had better OS (HR = 0.68, CI=0.61-0.76; P < 0.0001) versus those who underwent TG. Similarly, NSRGC patients undergoing PG also had improved OS, but to a lesser extent (HR = 0.91, CI = 0.85-0.96; P= 0.002). Overall, PG for GAC was associated with improved OS compared to TG, although the OS benefit is more profound in the SRGC histological variant (P < 0.0001).

CONCLUSIONS

Our results show that TG is not associated with improved OS in patients who undergo gastrectomy for GAC, even when adjusted for tumor location. The survival differences are more pronounced in the SRGC histology variant. The worst survival is observed in patients with SRGC who undergo TG after adjusting for different covariates.

Determination of Pentraxin-3, Interleukin-8 and Vascular Endothelial Growth Factor Levels in Patients with Gastric Adenocarcinoma

INTRODUCTION AND AIM

The purpose of this study was to determine the value, in terms of diagnosis, resectability and prognosis of pentraxin-3 (PTX3), interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) in cases of gastric adenocarcinoma, an important condition both worldwide and in Turkey, and to determine their levels in order to contribute to elucidating the pathogenesis of the disease.

MATERIALS AND METHODS

Serum was separated from blood specimens collected from 45 patients diagnosed with gastric adenocarcinoma and from a 30-member healthy control group. Serum PTX3, IL-8 and VEGF levels were studied by ELISA method.

RESULTS

Serum PTX3 values differed significantly between the patient group and the control group (p <0.05). Serum IL-8 values also differed significantly between the patient group and the control group (p <0.05). A significant difference was also observed between serum VEGF values in the patient group and the control group (p <0.05). Significant correlation was determined between serum PTX3 and VEGF (p <0.01; r=0.833), between serum PTX3 and IL-8 (p <0.01; r=0.818), and between serum VEGF and IL-8 (p <0.01; r=0.803), measurements when the entire study population was evaluated irrespectively of groups.

CONCLUSION

Serum PTX3, IL-8 and VEGF levels decreased in cases of gastric adenocarcinoma compared to the control group, and their levels affected one another.<br />.

Gastric adenocarcinoma at stage IV with complete remission after neoadjuvant therapy concurrent with adenosquamous carcinoma of the ampulla of Vater: a case report and literature review

Background

Adenosquamous carcinoma (ASC) of the ampulla of Vater (AmV) is exceedingly rare with more aggressive behavior and worse prognosis than adenocarcinoma. The finding of ASC at the AmV in combination to the gastric adenocarcinoma has never been reported in the literature before.

Case presentation

An old lady was diagnosed as gastric adenocarcinoma at stage IV with enlargement of supraclavicular lymph nodes by gastroscopy and histopathological evaluation 3 years ago. Afterwards, the patient achieved complete remission after regular chemotherapy. However, the patient manifested yellow sclera and skin, choluria and clay colored stool 3 months ago. Preoperative contrast-enhanced CT, ERCP, MRCP, and PET/CT revealed the presence of an ampullary tumor. The patient then underwent laparoscopic radical gastrectomy and pancreaticoduodenectomy with regional lymph node dissection. Postoperative cytological analyses confirmed the diagnosis of gastric ulcer with complete response to neoadjuvant therapy and ASC at the AmV. The patient’s postoperative outcome was uneventful.

Conclusion

Drawing firm conclusions about the diagnosis of ampullary ASC is difficult because of the difficulty in acquiring both adenocarcinoma and SCC components by fine needle biopsy. The rarity of ASC of the AmV coexistent with gastric carcinoma makes it difficult to elucidate their clinicopathological characteristics, therapeutic strategies and overall prognosis. Surgical resection still remains the main treatment method.

Gastric Histopathologic Findings in South Italian Morbidly Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: Is Histopathologic Examination of All Resected Gastric Specimens Necessary?

BACKGROUND

The value of the routine histopathologic examination of resected gastric remnants following laparoscopic sleeve gastrectomy (LSG) remains to be controversial. This study aimed to determine whether the routine histopathologic examination of gastric specimens is necessary for all patients undergoing LSG if upper gastrointestinal endoscopy (UGIE) plus multiple biopsies are performed routinely during the preoperative work-up.

MATERIALS AND METHODS

Clinicopathologic data of 474 patients who underwent LSG were analysed. Types of histopathologic findings in LSG specimens and the prevalence of these and Helicobacter pylori (HP) infection were estimated. Comparisons were conducted to assess the association of risk factors with the most frequent abnormal and premalignant histopathologic findings.

RESULTS

Chronic gastritis was the most common gastric pathology (63.5%) and premalignant lesions were present in 7.8% of the specimens. The prevalence of HP infection was 36.9%. A statistically significant association was observed between HP infection and chronic gastritis (P = .000), and premalignant lesions (P = .000). Similarly, a statistically significant association was noted between age and premalignant gastric lesions (P = .000).

CONCLUSION

Histopathologic examination of LSG specimens may not be routinely needed and can be performed on selected patients. While we recommend routine preoperative UGIE in all LSG-treated patients, we suggest that histopathologic assessment of the LSG specimens should be mandatory when UGIE biopsies demonstrate HP infection and/or premalignant lesions, in all patients older than 42 years, and in cases of intraoperative detection of incidental tumours or suspicious lesions.

Prognostic implications of visceral obesity on gastric adenocarcinoma: does it really matter?

PURPOSE

To evaluate the association of visceral adiposity measured on computed tomography (CT) in preoperative period with lymph node (LN) metastasis and overall survival in gastric adenocarcinoma patients.

METHODS

Preoperative CT scans of 246 gastric adenocarcinoma patients who did not receive neoadjuvant chemoradiotherapy were evaluated. Visceral fat area (VFA), subcutaneous fat area (SFA) and Total fat area (TFA), VFA/TFA ratio were quantified by CT. VFA/TFA > 29% was defined as visceral obesity. The differentiation, t-stage, n-stage and the number of harvested-metastatic LNs were noted. The maximum thickness of tumor and localization were recorded from CT. Chi-square, Student's t-test, multiple Cox regression, Spearman's correlation coefficient, and Kaplan-Meier algorithm were performed.

RESULTS

The overall survival (OS) rates and N-stage were not different significantly between viscerally obese and non-obese group (p = 0.994, p = 0.325). The number of metastatic LNs were weakly inversely correlated with VFA (r = -0.144, p = 0.024). Univariate analysis revealed no significant association between visceral obesity and OS or LN metastasis (p = 0.377, p = 0.736). In multivariate analyses, OS was significantly associated with poorly differentiation (HR = 1.72, 95% CI =1.04-2.84, p = 0.035), higher pathologic T and N stage (T4 vs T1 + T2 HR = 2.67, 95% CI =1.18-6.04, p = 0.019; T3 vs T1 + T2 HR = 1.98, 95% CI = 0.90-4.33, p = 0.089; N3b vs N0 HR = 2.97, 95% CI1.45-6.0, p = 0.003; N3 (3a+ 3b) vs N0 HR = 2.24 95% CI =1.15-4.36, p = 0.018).

CONCLUSION

Visceral obesity may not be a prognostic factor in resectable gastric adenocarcinoma patients.

Differential prognostic implications of gastric adenocarcinoma based on Lauren's classification: a Surveillance, Epidemiology, and End Results (SEER)-based cohort study

Background

Our study aims to analyze the association between Lauren's classification and gastric adenocarcinoma prognosis using comprehensive statistical analyses.

Methods

According to the selection criteria, patients were included from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression, propensity score matching, and a multivariate competing risk model were used to investigate the association between Lauren's classification and prognosis. Subgroup analysis was used to investigate the role of confounding factors on the association between Lauren types and prognosis.

Results

After exclusion, a total of 20,218 patients from the SEER database were included, with 14,374 intestinal types and 5,844 diffuse types. The univariate Cox regression analysis revealed that the diffuse type had a poorer cancer-specific survival (CSS) rate [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.38-1.50]. After adjusting for confounding variables, the diffuse type also showed a higher risk of cancer-specific death (HR, 1.20; 95% CI, 1.15-1.20). Sensitivity analysis showed that after propensity score matching, the diffuse type had a poorer CSS rate (HR, 1.23; 95% CI, 1.10-1.36), and the competing risk model further validated these results [subdistribution HR (SHR), 1.32; 95% CI, 1.23-1.41]. Moreover, subgroup analysis demonstrated stable results in the subgroups, except for patients with T1 stage (HR, 1.06; 95% CI, 0.87-1.28) and a tumor size <2 cm (HR, 1.00; 95% CI, 0.83-1.21).

Conclusions

Diffuse-type gastric adenocarcinoma had an overall poorer prognosis compared to the intestinal type. However, in patients with T1 stage and tumor size <2 cm, the diffuse type had a comparable survival rate with the intestinal type.

Perioperative outcomes and survival in elderly patients aged ≥ 75 years undergoing gastrectomy for gastric cancer: an 18-year retrospective analysis in a single Western centre

PURPOSE

Surgical resection for elderly patients with gastric cancer is controversial. This study aims to evaluate the preoperative features and postoperative short- and long-term outcomes of elderly patients following surgical resection for gastric adenocarcinoma.

METHODS

Between January 2000 and May 2018, a total of 177 consecutive patients underwent curative gastrectomy for gastric adenocarcinoma was retrospectively reviewed. Propensity score matching (PSM) analysis was used to balance confounding covariates between the elderly and non-elderly groups. Clinicopathological characteristics, intraoperative characteristics, postoperative complications and long-term survival outcomes including overall survival (OS) and Disease Specific Survival (DSS) were compared and analysed using the Kaplan-Meier log-rank test. Multivariate cox proportional hazards regression analysis of clinicopathological factors influencing survival were evaluated.

RESULTS

There were 50 patients in the elderly group (age ≥ 75 years) and 127 patients in the non-elderly group (age < 75 years). Elderly patients had more comorbid conditions (p < 0.001), lower albumin concentration (p = 0.034), lower haemoglobin levels (p = 0.001), and poorer renal function (p = 0.043). TNM stage was similar between both groups (p = 0.174); however, lymphatic invasion (p = 0.006) and lymph node metastasis (p = 0.029) were higher in the elderly group. Elderly patients were much less likely to receive any chemo- (p < 0.001) or radiotherapy treatment (p = 0.007) with surgical treatment. After PSM, there were 50 patients in each group. Elderly patients were more likely to develop complications (Clavien Dindo ≥ 2: 50% vs. 26%, p = 0.003). The most common postoperative complications were pneumonia (12% vs. 6%, p = 0.498) and delirium (10% vs. 0%, p = 0.066). Elderly patients had a longer median length of hospital stay (median (IQR): 15.6(9.5) vs. 11.3 (9.9), p = 0.030). There were no differences in 30-day mortality (elderly vs. non-elderly: 1% vs. 1%, p = 0.988). Before and after PSM, age remains an independent predictor of postoperative complications. Before PSM, the estimated mean OS for the elderly and non-elderly patients were 108 months (95%CI, 72.5-143.5) and 143 months (95%CI, 123.0-163.8), respectively (p = 0.264). After PSM, the estimated mean OS for the elderly and non-elderly patients were 108 months (95%CI, 72.5-143.5) and 140 months (95%CI, 112.1-168.2), respectively, (p = 0.360). Before PSM, the estimated mean DSS for the elderly and non-elderly patients were 94 months (95%CI, 61.9-127.5) and 121 months (95%CI, 100.9-141.0), respectively (p = 0.405). After PSM, the estimated mean DSS for the elderly and non-elderly patients were 94 months (95%CI, 61.9-127.5) and 115 months (95%CI, 87.3-143.3), respectively (p = 0.721). Age was not an independent predictor of mortality following gastrectomy for gastric cancer in both PSM matched and unmatched cohort.

CONCLUSION

Chronological age alone is not a contraindication to curative resection of gastric adenocarcinoma in elderly patients with acceptable risk. Whilst age affects perioperative complications, the incidence of postoperative mortality and overall survival were not significantly different between elderly and non-elderly gastric cancer patients treated with curative surgery. Gastrectomy with D2 lymphadenectomy can also be performed in carefully selected elderly patients by surgeons with expertise in gastric resection along with appropriate perioperative management.

Downregulation of fatty acid oxidation by involvement of HIF-1α and PPARγ in human gastric adenocarcinoma and related clinical significance

Lipid metabolism rewiring in gastric adenocarcinoma (GA) pathogenesis is still not clearly elucidated. This study aimed to describe the role of lipid catabolism in GA patient outcomes and possible therapeutic targets by analyzing the effect of hypoxia-inducible factor-1α (HIF-1α) on fatty acid oxidation (FAO). AGS cell line was cultured in normoxic and hypoxic conditions, and FAO-related genes were analyzed by real-time-PCR and Western-blot. The study group comprised 108 newly diagnosed GA patients and 152 control cases. Serum concentrations of medium and long-chain acyl-CoA dehydrogenases (MCAD and LCAD) proteins were measured using ELISA, and local expression of HIF-1α, carnitine palmitoyl transferase 1 (CPT1A) and peroxisome proliferator-activated receptor γ (PPARγ) was evaluated by immunohistochemistry. In addition, gene expression of PPARγ, CPT1A, LCAD, and MCAD was assessed by real-time-PCR. In vitro findings indicate HIF-1α upregulation and FAO-related genes and proteins reduction in the hypoxic culture of AGS cells. GA patients had significantly lower circulating levels of LCAD compared to controls. Higher protein expression of HIF-1α and downregulated CPT1A and PPARγ were observed in GA tissues versus controls. Gene expression of CPT1A, PPARγ, LCAD, and MCAD were repressed in GA tissues compared to controls. Moreover, reduced expression of CPT1A, PPARγ, and MCAD were correlated with HIF-1α upregulation in GA. Poor patient outcome was associated with lower PPARγ and LCAD expression in GA. HIF-1α upregulation in human GA patients and AGS cells was paralleled by downregulation of lipid catabolism genes potentially via reduced PPARγ-mediated FAO. This metabolic adaptation to hypoxic condition may play a role in GA pathogenesis and might have clinical and therapeutic value in GA patients.

Characterization of Chronic Gastritis in Lynch Syndrome Patients With Gastric Adenocarcinoma

Background

Gastric cancer is one of the Lynch syndrome (LS)-associated malignancies. Previous studies have suggested that LS patients with gastric cancer also had chronic atrophic gastritis in the background mucosa, but further histologic characterization was not attempted. This study aims to understand the histologic features of background chronic gastritis in LS patients with gastric adenocarcinoma.

Methods

Eleven LS-associated gastric cancer cases were collected from five institutions. Demographics and clinical features were retrieved by review of medical charts. Pathological material was reviewed for tumor location and histologic type. In addition, non-neoplastic gastric mucosa was assessed for inflammation (chronic and active), atrophy, intestinal metaplasia (IM) in the antrum and body, as well as pyloric gland metaplasia and enterochromaffin-like (ECL) cell hyperplasia in the body.

Results

Eleven LS patients with gastric cancer (four male and seven female) with a mean age of 63 years (range: 23 - 83) were included. Ten (90.9%) had personal cancer histories; however none of the patients had family history of gastric cancer. Eight (72.7%) patients underwent gastrectomy and three had endoscopic resection. Nine (81.8%) patients had tumor in the fundus and/or body and two had tumor present in the antrum. Seven (63.6%) cases were intestinal type or mixed type carcinoma, and the remaining four were signet ring cell carcinoma. Eight (of 11, 72.7%) patients had chronic gastritis, five (45.4%) had atrophy, and four (36.3%) had intestinal metaplasia. Four of five patients with both antrum and body mucosa available for evaluation (80%), demonstrated body-predominant chronic gastritis. Four patients had germline MLH1 alterations and all of these patients had chronic gastritis, including one Helicobacter pylori (H. pylori) gastritis and three H. pylori-negative gastritis.

Conclusions

None of LS patients with gastric cancer in our cohort had a family history of gastric cancer. Gastric adenocarcinomas in LS patients were primarily located in the fundus and/or body. Two-thirds of these tumors were of intestinal type and had a background chronic, H. pylori-negative gastritis. These results support a chronic atrophic gastritis with intestinal metaplasia-dysplasia-carcinoma sequence in LS-related gastric tumorigenesis, particularly in MLH1-mutated LS patients.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) - A Helicobacter-opposite point

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare familial gastric cancer syndrome with an autosomal dominant pattern of inheritance. It is characterised by fundic gland polyposis of the gastric body and is associated with a significant risk of gastric adenocarcinoma. Unlike sporadic gastric cancer, Helicobacter pylori is usually absent in patients with GAPPS. This opposite-point finding has so far not been fully clarified. Prophylactic total gastrectomy is indicated in all cases of GAPPS with fundic gland polyposis and the presence of any dysplasia. If no dysplasia is found at histology, prophylactic gastrectomy is suggested at between 30 and 35 years of age, or at five years earlier than the age at which the youngest family member developed gastric cancer. Different phenotypes of GAPPS demand an individual approach to particular family members.

Deep Targeted Sequencing and Its Potential Implication for Cancer Therapy in Chinese Patients with Gastric Adenocarcinoma

INTRODUCTION

Gastric cancer (GC) has a high incidence and mortality rate, especially in East Asians, and about 90% of GCs are adenocarcinomas. Histological and etiological heterogeneity and ethnic diversity make molecular subtyping of GC complicated, thus making it difficult to determine molecular division systems and standard treatment modalities. Limited cohorts from South Korea, Singapore, Australia, and Japan have been studied; however, the mutational landscape of gastric adenocarcinomas in Chinese patients is still unknown.

METHODS

We performed a targeted sequencing panel focusing on cancer-related genes and tumor-associated microorganisms of 529 gastric adenocarcinoma samples with matched blood controls. We identified 449 clinically relevant gene mutations.

RESULTS

Approximately 47.1% of Chinese patients with GC harbored at least one actionable mutation. The top somatic mutations were TP53, ARID1A, LRP1B, PIK3CA, ERBB2, CDH1, KRAS, FAT4, CCNE1, and KMT2D. Truncation mutations of ARID1A, KMT2D, RNF43, TGFBR2, and CIC occurred in patients with high tumor mutational burden. Gene amplifications of ERBB2, CCNE1, CDK12, and CCND1 were detected in patients with low tumor mutational burden. Pathway analysis revealed common gene alterations in the Wnt and PI3K/Akt signaling pathways. The ratio of patients with high microsatellite instability was significantly lower than other cohorts, and high microsatellite instability and Epstein-Barr virus (EBV)-positive features seemed mutually inclusive in Chinese patients with GC. In 44 (8.3%) patients, 45 germline mutations were identified, among which SPINK1 mutations, all SPINK1 c.194 + 2T > C, were present in 15.9% (7/44) of patients. Microorganisms found in Chinese patients with GC included Helicobacter pylori, EBV, hepatitis B virus, and human papillomavirus types 16 and 18.

CONCLUSION

Identification of varied molecular features by targeted next-generation sequencing provides more insight into patient stratification and offers more possibilities for both targeted therapies and immunotherapies of Chinese patients with GC.

IMPLICATIONS FOR PRACTICE

This study investigated the genomic alteration profile of 529 Chinese patients with gastric adenocarcinoma by deep targeting sequencing, which might be the largest Chinese cohort on the genomic research of gastric adenocarcinoma up to now.

CpG Islands Methylation Analysis of CDH11, EphA5, and HS3ST2 Genes in Gastric Adenocarcinoma Patients

PURPOSE

Gastric cancer is an aggressive disease which is the fourth prevalent malignancy in the world. Beside the genetic factors, epigenetic alterations such as promoter CpG island hyper methylation are involved in the emergence of gastric cancer. Herein, we investigated the methylation status of CDH11, EphA5, and HS3ST2 genes in patients with and without gastric adenocarcinoma for the first time.

METHODS

In the study 40 paraffin-embedded tissue sections from gastric adenocarcinoma patients and 40 specimens from patients with functional dyspepsia were taken. DNA extraction was performed using a modified salting out method. Epizen DNA methylation kit was used to the bisulfite DNA conversion. The methylation status of CDH11, EphA5, and HS3ST2 genes were analyzed by methylation-specific PCR (MSP) technique.

RESULTS

Among the 80 specimens, 71 DNA samples were achieved (34 gastric adenocarcinoma patients and 37 control patients). The results showed that CDH11, EphA5, and HS3ST2 genes are methylated in 28 (82.45%), 19 (55.88%), and 26 (76.47%) of 34 DNA samples from gastric adenocarcinoma patients, respectively, whereas, these genes are methylated in 7 (18.91%), 9 (24.32%) and 7 (18.91%) of 37 samples from noncancerous patients, respectively. Statistical analyses using a chi-squared test showed that there is a statistically significant difference in methylation level of CDH11, EphA5, and HS3ST2 genes between gastric cancer and uncancerous patients (p < 0.05).

CONCLUSION

To the best of our knowledge, this is the first report on methylation of CDH11, EphA5, and HS3ST2 promoters' in gastric adenocarcinoma patients using MSP. Identification of novel cancer-related molecular mechanisms can be useful in detection of new treatment strategies.

Circulating tumor cells: A surrogate to predict the effect of treatment and overall survival in gastric adenocarcinoma

BACKGROUND

Circulating tumor cells and serum tumor markers have been found significant in predicting outcome for several malignancies. However, their role in gastric cancer is not fully clarified. We conducted a retrospective study to explore the prognostic value of circulating tumor cells and their applicability in assessing the treatment efficacy in gastric cancers.

METHODS

From September 2015 to December 2018, 116 patients with newly pathologically diagnosed gastric adenocarcinoma were enrolled. At both baseline and two courses after chemotherapy, the data of circulating tumor cells and serum tumor markers, such as CEA, CA72-4, CA19-9, CA50, and CA242, were collected. The relationships between the change trend of circulating tumor cells and the treatment efficacy were analyzed after chemotherapy, with a paired t-test. Univariate and multivariable analysis were used to find prognostic factors for overall survival (OS).

RESULTS

We found there is a significant difference between the circulating tumor cells-positive and circulating tumor cells-negative before and after therapy (mOS 12.6 vs. 31.6 months, P<0.001; mOS 12.4 vs. 24.2 months, P=0.002), respectively. Also, differentiation, pre-therapeutic circulating tumor cells and therapeutic response were independent predictors of overall survival. Following two courses of chemotherapy, the number of circulating tumor cells increased obviously in the progressive disease group (P=0.002), while they decreased in the non-progressive disease group (P=0.02). Thus, the change in the circulating tumor cells count had a close association with the therapeutic response (P=0.004).

CONCLUSION

Generally, circulating tumor cells provide a novel tool to evaluate the outcomes of gastric cancer patients. Since the change of circulating tumor cells was highly related to treatment response, it may be an auxiliary to assess the effect of chemotherapy, leading an earlier adjustment of following regimens.

[Regional distribution and clinicopathological characteristics of Epstein-Barr virus associated gastric cancer]

Objective: To investigate regional distribution and clinicopathological features of Epstein-Barr virus associated gastric cancer (EBVaGC). Methods: Epstein-Barr virus encoded RNA (EBER)was detected in 4 081 cases of gastric adenocarcinoma in Cancer Hospital, Chinese Academy of Medical Sciences by using in situ hybridization. EBVaGCs were identified and their proportions in different provinces, autonomous regions and municipalities were compared. The correlation between EBVaGC and clinicopathological features was also analyzed. Results: A total of 3.0% (123/4 081) patients with gastric adenocarcinoma are EBVaGCs. Among the areas with cases more than 90, the highest proportion of EBVaGC was found in Jilin province, accounting for 7.6%, and then followed by 5.4% in Liaoning province, 4.1% in Anhui province, 3.9% in Beijing, 3.7% in Inner Mongolia Autonomous Region, 3.4% in Shanxi province, 3.0% in Heilongjiang province, 2.1% in Shandong province, 1.6% in Hebei province, and no EBVaGC was found in Henan province. EBVaGC proportions are significantly different in these provinces, autonomous regions and municipalities (P<0.05). Multivariate analysis of logistic regression revealed that gender (OR=2.231, 95%CI: 1.290~3.858), WHO classification (OR=2.338, 95%CI: 2.051~2.664) and N stage (OR=0.420, 95%CI: 0.284~0.621) were independent impact factors for EBVaGC. The proportion of EBVaGC was higher in males, gastric carcinomas accompanied with lymphoid stroma and patients without lymph node metastasis. Conclusions: The proportion of EBVaGC in gastric adenocarcinoma displays area distribution disparity in China. The gender, WHO classification and N stage are closely associated with EBVaGC.

Bioinformatic analysis of potential hub genes in gastric adenocarcinoma

Gastric adenocarcinoma is the most common histologic type of gastric cancer; however, the pathogenic mechanisms remain unclear. To improve mechanistic understanding and identify new treatment targets or diagnostic biomarkers, we used bioinformatic tools to predict the hub genes related to the process of gastric adenocarcinoma development from public datasets, and explored their prognostic significance. We screened differentially expressed genes between gastric adenocarcinoma and normal gastric tissues in Gene Expression Omnibus datasets (GSE79973, GSE118916, and GSE29998) using the GEO2R tool, and their functions were annotated with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes signaling pathway enrichment analyses in the DAVID database. Hub genes were identified based on the protein-protein network constructed in the STRING database with Cytoscape software. A total of 10 hub genes were selected for further analysis, and their expression patterns in gastric adenocarcinoma patients were investigated using the Oncomine GEPIA database. The expression levels of ATP4A, CA9, FGA, ALDH1A1, and GHRL were reduced, whereas those of TIMP1, SPP1, CXCL8, THY1, and COL1A1 were increased in gastric adenocarcinoma. The Kaplan-Meier online plotter tool showed associations of all hub genes except for CA9 with prognosis in gastric adenocarcinoma patients; CXCL8 and ALDH1A1 were positively correlated with survival, and the other genes were negatively correlated with survival. These 10 hub genes may be involved in important processes in gastric adenocarcinoma development, providing new directions for research to clarify the role of these genes and offer insight for improved treatment.

Lack of National Adoption of Evidence-Based Treatment for Resectable Gastric Adenocarcinoma

BACKGROUND

Level 1 evidence for multimodal treatment of resectable gastric adenocarcinoma from the Intergroup 0116 (2001) and MAGIC (2006) trials demonstrated survival benefit of adjuvant chemoradiation (CRT) and perioperative chemotherapy, respectively. We evaluated the adoption of evidence-based treatment in the post-MAGIC era and its impact on survival.

METHODS

A total of 7058 patients with resectable gastric adenocarcinoma undergoing definitive surgical resection between 2004 and 2015 were analyzed using the National Cancer Database.

RESULTS

Over the study period, the proportion of patients receiving adjuvant CRT decreased from 19.1% to 9.1%, while perioperative chemotherapy increased from 1.9% to 28.6%. Utilization of perioperative chemotherapy surpassed adjuvant CRT in 2011. Evidence-based treatment (either perioperative chemotherapy or adjuvant CRT) had better overall survival (OS) than other treatments for clinical stage II-III patients (p < 0.05). On multivariate analysis of the whole study period, evidence-based treatments were associated with better OS (HR 0.67 [0.60-0.74], p < 0.05). Only 360/1262 (28.5%) patients in the perioperative chemotherapy group completed postoperative therapy, which was associated with improved OS (p < 0.05). For clinical stage III patients (n = 2402), only 806 (33.6%) received evidence-based treatment, while 487 (22.2%) underwent surgery alone. On multivariate analysis of these patients between 2010 and 2015, both perioperative chemotherapy (HR 0.49 [0.35-0.68]) and adjuvant CRT (HR 0.31 [0.21-0.44]) were associated with better OS than surgery alone (p < 0.05).

CONCLUSIONS

Since the INT-0116 and MAGIC trials, utilization of evidence-based treatments for resectable gastric adenocarcinoma has increased, with perioperative chemotherapy surpassing adjuvant CRT as the preferred practice. However, overall utilization of these regimens remains quite low nationally despite association with improved OS.

A systematic review and meta-analysis of PD-1/PD-L1 inhibitors in specific patient subgroups with advanced gastro-oesophageal junction and gastric adenocarcinoma

BACKGROUND

immune checkpoint inhibitors(ICIs) have shown contradictory results in patients with advanced gastro-oesophageal junction/gastric cancer(GOJ/GC).

AIM

to identify specific patient subgroups that would derive survival benefit from ICIs.

METHODS

a subgroup meta-analysis of randomised clinical trials(RCTs) was carried out.

RESULTS

four phase-III-RCTs were identified with data on the following variables: primary location(Gastric vs GOJ); age(≤ 65 vs >65); gender(male vs female); ECOG PS(0 vs 1); ethnicity (Asian vs non-Asian), histology(intestinal vs diffuse), PD-L1 expression(≥ 1% vs < 1%). PD-L1 positivity was significantly associated with survival benefit from ICIs (HR: 0.82, p 0.047), with a significant interaction between PD-L1 expression and ICI efficacy (interaction HR: 1.41, p 0.02). Numerically, the second most relevant interaction was ICI efficacy and gender, with ICI being more effective in males.

CONCLUSION

The PD-L1 positive patient subgroup derives significant survival benefit from ICI in GOJ/GC, however other predictors are eagerly needed to further refine patient selection.