Clinicopathological and molecular characteristics of Epstein-Barr virus associated gastric cancer: a single center large sample case investigation / 北京大学学报(医学版)

OBJECTIVE@#Epstein-Barr virus associated gastric cancer (EBVaGC) is different from the traditional gastric cancer (Epstein-Barr virus non-associated gastric cancer, EBVnGC), and has unique clinicopathological features. This study investigated the largest single center cancer series so as to establish the clinicopathological and molecular characteristics of EBVaGC in China.@*METHODS@#A retrospective analysis was conducted on EBVaGC and EBVnGC patients diagnosed at Peking University Cancer Hospital from 2003 to 2018 by comparing their clinicopathological features and prognosis. The gastric cancer (GC) dataset of public database was analyzed to obtain differentially expressed genes. The expression of important genes and their association with prognosis of GC were verified in GC tissues from our hospital.@*RESULTS@#In this study, 3 241 GC patients were included, and a total of 163 EBVaGC (5.0%) patients were identified. Compared with EBVnGC, EBVaGC was higher in male and younger patients, and positively associated with remnant GC, poorly differentiated adenocarcinoma, and mixed type GC. EBVaGC was inversely related to lymph node metastasis. The 5-year survival rate of EBVnGC and EBVaGC was 59.6% and 63.2% respectively (P<0.05). In order to explore molecular features of EBVaGC, the Cancer Genome Atlas (TCGA) dataset was analyzed (n=240), and 7 404 significant differentially expressed genes were obtained, involving cell proliferation, apoptosis, invasion and metastasis. The down-regulated invasion/metastasis gene SALL4 and the up-regulated immune checkpoint gene PD-L1 were important molecular features of EBVaGC. Validation of these two genes in large GC series showed that the majority of the EBVaGC was SALL4 negative (1/92, 1.1%, lower than EBVnGC, 303/1 727, 17.5%), and that PD-L1 was mostly positive in EBVaGC (81/110, 73.6%, higher than EBVnGC, 649/2 350, 27.6%). GC patients with SALL4 negative and PD-L1 positive were often associated with better prognosis.@*CONCLUSION@#EBVaGC is a unique subtype of GC with less metastasis and a good prognosis. It also has a distinct molecular background. The down-regulation of invasion/metastasis gene SALL4 and up-regulation of immune checkpoint gene PD-L1 are important molecular features.

Effect of MicroRNA-199 on Proliferation and Migration of Gastric Carcinoma Cells / 中国医学科学院学报

Objective To detect the expression of microRNA(miR)-199 in gastric carcinoma tissues and cell lines, and further explore the effect and molecular mechanism of miR-199 on the proliferation and migration of gastric carcinoma cell lines. Methods Reverse transcriptase-polymerse chain reaction was used to detect the expression of miR-199 in gastric carcinoma and adjacent normal tissue obtained from 51 patients and in gastric carcinoma cell lines and human gastric epithelial cell line GES-1. The gastric carcinoma cell lines over-expressing and low-expressing miR-199 were established to detect their proliferation and migration abilities. Dual-luciferase reporter assay was performed to detect the regulatory effect of miR-199 on the 3'untranslated region of TBL1XR1. Western blot was used to explore the miR-199-related mechanism. Results The relative expression of miR-199 in gastric carcinoma tissues was significantly lower than that in the adjacent normal tissue (0.2635±0.0303 vs. 1.6700±0.9613, t=13.95, P<0.001). The relative expressions of miR-199 in gastric carcinoma cell lines AGS (0.81, t=9.13, P<0.001), SGC-7901 (0.83, t=8.88, P<0.001), MKN28 (0.58, t=10.80, P<0.001), KATO-3 (0.60, t=10.31, P<0.001), MKN-45 (0.27, t=13.10, P<0.001) were significantly lower than that in the normal gastric cell line GES-1 (2.1). In miR-199 over-expressed cell lines, the cell proliferation and migration significantly decreased as compared with the control group of gastric carcinoma cells (731±13 vs. 345±18, t=24.90, P<0.001), and in miR-199 low-expressed group, the cell proliferation and migration increased compared with the control group of gastric carcinoma cells (257±16 vs. 657±8, t=32.59, P<0.001). Dual-luciferase reporter assay proved that miR-199 directly targeted on the 3' untranslated region of TBL1XR1. Western blot analysis showed that miR-199 inhibited the expression of TBL1XR1. Conclusion The over-expression of miR-199 in gastric carcinoma is associated with the decreased ability of proliferation and migration of gastric carcinoma cells by targeting TBL1XR1.

Regulation mechanism study of S100A6 on invasion and metastasis in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To detect the expression of S100A6 in gastric cancer, and to investigate the regulation mechanism of S100A6 in invasion and metastasis of gastric cancer.</p><p><b>METHODS</b>Expression of S100A6 protein in gastric cancer specimens, tissue adjacent to cancer, liver and lymph node metastasis tissue specimens was detected by immunohistochemical staining in 166 patients with gastric cancer from January 1995 to December 2001. Their association with clinicopathological factors was analyzed. Chromatin Immunoprecipitation-chip was used to detect the downstream factors potentially regulated by S100A6 in gastric cancer cell lines KATO3. S100A6 gene was transfected into gastric cancer cell line AGS, and cell invasion experiment and real time Q-polymerase chain reaction(RT Q-PCR) were used to detect the cell invasive ability and the mRNA expression of invasion-related factors (CDK5 and FLJ12438) in transfection group, negative control group and blank control group, respectively.</p><p><b>RESULTS</b>Low expression of S100A6 protein was found in cytoplasm of peritumoral tissues. In gastric cancer, liver and lymph node metastasis tissues, S100A6 protein expression was up-regulated in cytoplasm and (or) nuclei, especially in the tumor cells of invasive edge. The expression rates of gastric cancer, liver and lymph node metastasis tissues were 67.5%(112/166), 92.9%(26/28) and 100% (30/30) respectively. The high expression of S100A6 was associated with tumor local invasion, lymph node metastasis, cancer embolus, distant metastasis and TNM stages(all P<0.05). The transmembrane cell number was 31.3±5.5 in the S100A6 transfection group, significantly higher than that in negative control group (7.7±1.5) and blank control group (9.3±2.1)(both P<0.05), indicating an increase of cell invasion after S100A6 transfection. In transfection group, CDK5 mRNA expression was significantly higher than that in negative control group and blank control group(P<0.05). While FLJ1243 mRNA expression was similar among the three groups(P<0.05).</p><p><b>CONCLUSION</b>S100A6 may affect the malignant biological behavior of gastric cancer cells by regulating the expressions of down-stream invasion-associated factors, such as CDK5.</p>

Application of matrix assisted laser desorption ionization-time of flight-mass spectrometry in detecting K-ras gene mutation of colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical value of matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in detecting K-ras gene mutation.</p><p><b>METHODS</b>Sixty-one paraffin-embeded specimens of colorectal cancer were selected. MALDI-TOF-MS and regular sequencing were used to test the mutation of codon 12 and 13 in K-ras exon 2.</p><p><b>RESULTS</b>Only 47 specimens could be detected successfully in regular sequencing, while all the specimens were tested successfully in MALDI-TOF-MS. Fourteen specimens had K-ras mutation in regular sequencing (30.0%), while 22 specimens had mutation in MALDI-TOF-MS (36.1%). Six specimens with mutation were found in MALDI-TOF-MS but were wild-type in regular sequencing. Same mutation types from 14 specimens were confirmed by both regular sequencing and MALDI-TOF-MS. MALDI-TOF-MS was able to detect the mutation in 2 specimens that was not identified in regular sequencing.</p><p><b>CONCLUSIONS</b>MALDI-TOF-MS is a feasible approach of K-ras gene mutation testing in colorectal cancer, which is less demanding in terms of specimen quality and is more sensitive as compared to regular sequencing.</p>

Expression of CCAAT/enhancer binding protein beta in human gastric carcinoma and its clinical significance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the expression of CCAAT/enhancer binding protein beta (CEBPB) in gastric carcinoma tissues and its association with clinicopathological features and prognosis.</p><p><b>METHODS</b>CEBPB protein expression level was detected by immunohistochemistry method in resected gastric carcinomas and adjacent gastric mucosa tissues (n=81), and its association with clinicopathological features and prognosis was analyzed.</p><p><b>RESULTS</b>The immunohistochemical staining of CEBPB was predominantly in the nucleus with some cytoplasmic staining. As a result, 16% (13/81) of the gastric carcinomas were stained positively, whereas there was hardly positive expression in adjacent gastric mucosa tissues. There was a significant association between the expression of CEBPB and distant metastasis on univariate analysis (P<0.05). The median survival time in patients with positive CEBPB expression was significantly lower than those with negative CEBPB expression (19.4 months vs. 45.2 months, P=0.024). Multivariable analysis showed that CEBPB was independently associated with prognosis (HR=2.544, 95%CI:1.154-5.610, P=0.021).</p><p><b>CONCLUSION</b>Up-regulation of CEBPB suggests poor prognosis in patients with gastric cancer.</p>

Prognostic biomarkers and targeted therapies for gastric cancer / 中华胃肠外科杂志

Gastric cancer patients with the same clinical stage may vary greatly in prognosis, which makes the improvement of current staging-based treatment imperative. The systematic biology approaches are the solution for systematic identification of biomarkers for prognostic evaluation and targeted therapy. These markers will be applied to classify the patients by molecular traits and then to guide the individualized medication. Although HER-2 antibody is currently the only targeted drug in guideline, more drugs are now addressed in early phases of clinical trials and parts of them will be eventually approved.

Application of perioperative imatinib mesylate therapy in initial resectable primary local advanced gastrointestinal stromal tumor at intermediate or high risk / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of perioperative imatinib mesylate (IM) therapy for patients with initial resectable primary local advanced gastrointestinal stromal tumor (GIST) at intermediate or high risk on R0 resection rate and the prognosis.</p><p><b>METHODS</b>Forty-eight above GIST patients between December 2001 and February 2012 were divided into 2 groups: neoadjuvant group (15 cases, pre- and post-operation IM therapy) and adjuvant group (33 cases, post-operative IM therapy). R0 resection rate, complication rate, disease-free survival (DFS) and overall survival (OS) were analyzed and compared between the two groups.</p><p><b>RESULTS</b>The maximal tumor diameter and average tumor diameter were larger in neoadjuvant group as compared to adjuvant group (11.2 cm vs. 7.7 cm, P=0.005; 9.1 cm vs. 6.2 cm, P=0.014). The response rate of preoperative IM therapy was 93.3% (14/15). The R0 resection rate was 86.7% and 84.8% (P=1.000), and the complication rate was 13.3% and 9.1% (P=0.642) in neoadjuvant and adjuvant group respectively. The 3-year DFS was 55% and 41% (P=0.935), and 5-year OS was 83% and 75% (P=0.766) in neoadjuvant and adjuvant group respectively.</p><p><b>CONCLUSIONS</b>Resectable primary local advanced GIST at intermediate or high risk with larger tumor diameter receiving perioperative IM therapy can achieve the same R0 resection rate, complication rate, DFS and OS as the GIST with smaller diameter receiving operation first. Perioperative IM therapy has potential advantage.</p>

Clinical value of serum CEA, CA19-9, CA72-4 and CA242 in the diagnosis and prognosis of gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical value of tumor markers CEA, CA19-9, CA72-4 and CA242 in the diagnosis and prognosis of patients with gastric cancer.</p><p><b>METHODS</b>One hundred and sixty gastric cancer patients who had received treatment from 2002 to 2007 at the Beijing Cancer Hospital were retrospectively analyzed. Blood samples were taken from patients upon admission to the hospital, and CEA, CA19-9, CA72-4, CA242 levels were detected. Statistical analysis was performed to identify the clinical value of these tumor markers in diagnosis and prognosis.</p><p><b>RESULTS</b>On initial diagnosis, the positive rates of CEA, CA19-9, CA72-4 and CA242 were 37.7%, 26.7%, 37.6% and 21.3%, respectively, and the positive rate of combined detection was 62.9%. CEA was more frequently positive in patients with lymph node metastasis (P=0.029); CA72-4 was more frequently positive in patients with vascular involvement and advanced stage (P=0.039, P=0.011). Multivaraite analysis showed that CA72-4 was an independent prognostic factor (P=0.012). Patients with positive CA72-4 carried a 2.147-fold increased risk of death than those with negative CA72-4. Kaplan-Meier analysis showed that patients with positive CA19-9 or positive CA72-4 had worse survival than those with negative CA19-9 or CA72-4 (P=0.006, P=0.002).</p><p><b>CONCLUSIONS</b>Tumor markers including CEA, CA19-9, CA72-4 and CA242 have clinical significance and prognostic value in patients with gastric cancer. Combined detection of four tumor markers can increase the positive rate. CA72-4 is an independent prognostic factor. CA19-9 and CA72-4 are associated with the prognosis of patients with gastric cancer.</p>

Expression of human epidermal growth factor receptor 2 in gastroesophageal cancer with different scoring systems and its relationship with clinicopathological features / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the expression of human epidermal growth factor receptor 2 (HER2) under different scoring systems in gastroesophageal cancer and its relationship with clinicopathological features.</p><p><b>METHODS</b>Clinicopathological data were retrospectively reviewed of 127 patients with gastroesophageal cancer between January and December 2009 in the Department of Surgery at the Cancer Hospital of Peking University. Tumor specimens were collected. The expression of HER2 protein was detected by immunohistochemistry.</p><p><b>RESULTS</b>HER2 positive rate(++/+++) in gastroesophageal cancer was 15.0%(19/127) with both new and traditional immunohistochemical scoring systems, while HER2 strong positive rate(+++) was 10.2%(13/127) and 6.3%(8/127), respectively(P=0.26). Univariate analysis showed that the expression rate of HER2 protein was associated with differentiation and Lauren classification of the tumor. Multivariable analysis showed that TNM staging and tumor differentiation were independently associated with the expression of HER2 protein(both P<0.05).</p><p><b>CONCLUSIONS</b>There is no change in HER2 positive rate in gastroesophageal cancer between the new and traditional immunohistochemical scoring systems. Expression of HER2 is associated with clinicopathological features in the gastroesophageal cancer.</p>

Analysis of splenic hilar lymph node metastasis in advanced gastric cancer and dissection techniques / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the status of splenic hilar lymph nodes(No.4sa, No.10 or No.11d lymph nodes) metastasis and to investigate the proper dissection technique in patients with advanced gastric cancer.</p><p><b>METHODS</b>A retrospective study was performed to investigate 590 patients who underwent D2 curative proximal or total gastrectomy for gastric carcinoma from January 2006 to December 2009. Clinicopathological factors such as sex, age, location of the primary tumor, tumor sizes, gross type, depth of invasion, microscopic classification, neoadjuvant chemotherapy and the metastasis of adjacent lymph node were analyzed with univariate and multivariate analysis. Influence of combined splenectomy or pancreatectomy on lymph node dissection was also investigated.</p><p><b>RESULTS</b>The overall ratio of metastatic lymph node(positive lymph nodes/lymph nodes harvested) in the splenic hilum was 17.5%(99/565). The positive rates of No.4sa, No.10, No.11d lymph nodes were 17.8% (41/230), 13.9%(29/209), and 22.8%(29/127), respectively. A total of 7.1%(42/590) of the patients had lymph node metastasis in the splenic hilum. Multivariable logistic regression analysis showed that age, tumor size, depth of tumor invasion, positive metastasis of No.4sb lymph node were independent risk factors for lymph node metastasis in the splenic hilum region. When comparing patients undergoing combined splenectomy or pancreatectomy(n=23) and those who did not undergo combined organ resection (n=553), the ratios of metastatic lymph node in the splenic hilum were 14.8%(4/27) and 17.2%(91/527), respectively, and the difference was not statistically significant(P>0.05). The postoperative complication rates were 26.1%(6/23) and 5.4%(30/553), respectively, and the difference was statistically significant(P<0.05). The operative mortality rates were 4.3% and 0.9%, respectively, and the difference was not statistically significant(P>0.05).</p><p><b>CONCLUSIONS</b>Metastasis to lymph nodes in the splenic hilum region in patients with gastric cancer possesses a certain pattern, and it is associated with tumor location, size, depth of invasion, and metastasis in No.4sb. Combined resection of the spleen or pancreas does not result in increased number of harvested lymph nodes or positive lymph nodes, yet is associated with higher complication rate. Therefore, combined organ resection should be meticulous.</p>

Clinicopathological observation of gastric cancer with pathological complete response following neoadjuvant chemotherapy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To observe the clinicopathological characteristics of gastric cancer with pathological complete response(pCR) following neoadjuvant chemotherapy.</p><p><b>METHODS</b>Data of gastric cancer patients who received neoadjuvant chemotherapy from 2002 to 2008 in the Beijing Cancer Hospital were reviewed. Five cases were found to have pCR. The slides were reviewed by two experienced pathologists independently. Histological structure, morphology of tumor cells, morphology and quantity of stromal cells were evaluated.</p><p><b>RESULTS</b>Structure of the gastric wall was distinguishable in all the 5 cases, while distortion and rupture of muscular layer were found in 2 cases. Exudative inflammatory reaction was present in the whole gastric wall including the serosa layer. Three patients had ulcerative lesions with epithelial layer shedding, and atypical hyperplasia was found around the border of the ulcer, and vascular endothelial cells were swollen. Residual distorted necrotic tumor cells resided in 1 case only and no residual tumor cells was present in the other 4 patients. Significant hyperplasia of fibroblasts was present in 4 cases, large amount of lymphocytes infiltration in 3 cases including concurrent plasma cell infiltration in 1 case, multinucleated giant cell reaction in the muscular layer of 1 case, and foam cells aggregation in 1 case with mucinous adenocarcinoma. In addition, there were 2 cases with pCR had lymph node metastasis.</p><p><b>CONCLUSIONS</b>For cases with pCR following neoadjuvant chemotherapy, heterogeneity of stromal cells reaction is found in previous tumor site. Furthermore, the response of primary tumor does not necessarily parallel to that of lymph nodes.</p>

Surgical treatment results and prognostic analysis of 514 cases with gastroesophageal junction carcinoma / 中华外科杂志

<p><b>OBJECTIVE</b>To clarify the important clinicopathological and therapeutical factors affecting the prognosis of patients with gastroesophageal junction carcinoma.</p><p><b>METHODS</b>Data of 514 cases with gastroesophageal junction carcinoma who underwent surgical treatment from September 1995 to January 2007 was retrospectively analyzed. Relevant prognostic factors were studied with univariate and multivariate analysis.</p><p><b>RESULTS</b>For all 514 cases (424 men and 90 women), the median age was 63 years. The 1-, 3- and 5-year survival rates of this group were 74.8%, 42.1% and 29.1%, respectively. Gross type, TNM classification, histological type, vascular invasion and extent of surgical resection affected patients' survival remarkably. There was no significant difference in survival between operative approaches (via laparotomy or left thoracotomy) (P > 0.05). Long-term survival was similar between proximal subtotal gastrectomy and total gastrectomy in advanced cases (P > 0.05). For stage II and III tumors, patients with neoadjuvant chemotherapy had better prognosis than those without (P < 0.05). Cox multivariate regression analysis revealed TNM classification and vascular invasion were independent prognostic factors.</p><p><b>CONCLUSIONS</b>TNM classification and vascular invasion are independent prognostic factors for gastroesophageal junction carcinoma. Neoadjuvant chemotherapy may improve prognosis of the patients with stage II and III tumors. Radical resection should be achieved with rational surgical procedures tailored by tumor position, size, staging and so on.</p>

Characteristics of lymph node metastasis and prognostic analysis in 157 early gastric cancer patients / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the pattern of lymph node metastasis and its influence on the prognosis of early gastric cancer(EGC).</p><p><b>METHODS</b>The pattern of lymph node metastasis and the 3-,5-year survival rates in 157 EGC patients undergone surgery from October 1995 to October 2005 were analyzed retrospectively. The SPSS 11.5 statistics software was used to perform univariate and multivariate analysis.</p><p><b>RESULTS</b>Twenty-two cases had lymph node metastasis among 157 EGC patients(14%). Two mucous cancers(2.4%) and 20 submucosal tumors(27.0%) had lymph node metastases (P<0.01). Lymph node metastasis was not seen in minute gastric cancer(diameter < or =0.5 cm). Lymph node metastasis rates were 6.4% in the cancers with diameter 1.1-2.0 cm and 21.5% in the cancers with the diameter >2.0 cm(P<0.01). Besides, lymph node metastasis rate of well-differentiated EGC was 0, of moderate differentiated EGC 11.1%, and poor-differentiated EGC 0.9%(P<0.01). Of 9 cases with vascular cancer embolus, 4 had lymph node metastases. Logistic regression analysis showed that tumor size, vascular cancer embolus, histopathological type and depth of invasion were independent factors of lymph node metastasis in EGC. The 3- and 5-year survival rates of EGC patients with lymph node metastasis were 81.6 % and 79.5% respectively, which were much lower than those without lymph node metastasis(95.7% and 93.2%, P<0.01).</p><p><b>CONCLUSIONS</b>Lymph node metastasis in EGC is mainly correlated with depth of infiltration, tumor size, vascular cancer embolus and differentiation. For EGC treatment, choice should be made reasonably based on the risk of lymph node metastasis.</p>

Clinical study of Ligasure versus conventional surgery for D2 lymphadenectomy of gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To examine the utility of the Ligasure vessel-sealing system in D(2) lymphadenectomy of gastric cancer, and compare with conventional hand tie method.</p><p><b>METHODS</b>One hundred and twenty-four consecutive patients undergone D(2) lymphadenectomy of gastric cancer from Jan. to Oct. 2005 were enrolled in this study. Operations of 62 patients were performed with Ligasure, whereas the other 62 patients with hand tie method. Operative duration, volume of intraoperative hemorrhage and postoperative course were analyzed.</p><p><b>RESULTS</b>There was significant difference in operative duration (187.3 min vs 210.5 min, P< 0.05) and no significant differences in volume of intraoperative hemorrhage, postoperative course, or duration of postoperative drainage between Ligasure group and conventional method group. No significant difference was observed in the frequency of postoperative complications between the two groups.</p><p><b>CONCLUSION</b>D(2) lymphadenectomy of gastric cancer using Ligasure instead of conventional hand tie method appears to be technically feasible and easy.</p>

Nuclear expression of S100A4 is associated with lymph node metastasis in gastric carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the intracellular localization of S100A4 in gastric carcinoma cells and the relationship between S100A4 expression status and lymph node metastasis of gastric carcinoma.</p><p><b>METHODS</b>Western blotting analysis was performed to locate the expression of S100A4 protein in sub-fraction components of frozen tissues. S100A4 protein expression was also determined by immunohistochemical method in 131 samples of gastric cancer and 20 samples of matched metastatic lymph nodes.</p><p><b>RESULTS</b>Thirty-two of 131 (24.4%) gastric carcinoma showed positive S100A4 nuclear expression and 50/131 (38.2%) carcinoma showed positive cytoplasmic expression. In 32 samples with positive S100A4 nuclear expression, 30 (93.8%) carcinomas had positive lymph node metastases. S100A4 nuclear expression level was higher in gastric carcinoma with lymph node metastasis (29.1%) than that without lymph node metastasis (7.1%) (P=0.016).</p><p><b>CONCLUSION</b>Nuclear expression of S100A4 is associated with lymph node metastasis of gastric carcinoma.</p>