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Objective: To detect the expression of S100A6 in gastric cancer, and to investigate the regulation mechanism of S100A6 in invasion and metastasis of gastric cancer., Methods: 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., Results: 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)., Conclusion: S100A6 may affect the malignant biological behavior of gastric cancer cells by regulating the expressions of down-stream invasion-associated factors, such as CDK5.

Objective: 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., Methods: 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., Results: 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., Conclusions: 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.

Objective: To observe the clinicopathological characteristics of gastric cancer with pathological complete response(pCR) following neoadjuvant chemotherapy., Methods: 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., Results: 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., Conclusions: 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.

Objective: 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., Methods: 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., Results: 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)., Conclusions: 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.

Objective: To clarify the important clinicopathological and therapeutical factors affecting the prognosis of patients with gastroesophageal junction carcinoma., Methods: 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., Results: 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., Conclusions: 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.

Objective: To determine if human papillomavirus (HPV) infection could be associated with the development of adenocarcinoma of esophagogastric junction (AEG)., Methods: A total of 106 consecutive AEG patients and 59 consecutive gastric carcinoma patients who accepted surgery at our department between January 2004 and December 2006 were selected. Specimens from tumors and uninvolved mucosa were obtained intra-operatively. Genomic DNA was extracted by the phenol-chloroform-isoamyl alcohol extraction protocol. The HPV infection was determined by PCR using primer set SPF1 and GP6+. Specificity of the amplified products was confirmed by sequencing., Results: The HPV infection rates in AEG and gastric cancer were 10.4% (11/106) and 10.2% (6/59) separately (P = 0.966)., Conclusion: HPV is not a major factor in the carcinogenesis of AEG type II, AEG type III or stomach.

Objective: To explore the pattern of lymph node metastasis and its influence on the prognosis of early gastric cancer(EGC)., Methods: 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., Results: 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)., Conclusions: 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.

Objective: To examine the utility of the Ligasure vessel-sealing system in D(2) lymphadenectomy of gastric cancer, and compare with conventional hand tie method., Methods: 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., Results: 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., Conclusion: D(2) lymphadenectomy of gastric cancer using Ligasure instead of conventional hand tie method appears to be technically feasible and easy.