High Expression of PRL-3 can Promote Growth of Gastric Cancer and Exhibits a Poor Prognostic Impact on Patients

High expression of PRL-3 had been implicated in lymph node metastasis of gastric cancer. In the present study, we detected the expression of PRL-3 in primary gastric cancer tissue, and evaluated its role in gastric cancer growth and the prognostic impact on patients. PRL-3 phosphatase expression was measured in 137 gastric tumor samples by using the immunohistochemistry method, and the overall survival rate was compared between the patients with high PRL-3 expression (n = 85) and those with moderate or low PRL-3 expression (n = 52). RNA interference, mediated by recombinant lentivirus expressing artificial PRL-3 miRNA, was used to knockdown PRL-3 expression in SGC7901 cell line. MTT assay and animal experiment were conducted to determine the role of PRL-3 in the proliferation of SGC7901 cells and tumor growth. PRL-3 expression was more frequently detected in tumors with a diameter >40 mm and in advanced stages. Furthermore, the overall survival rate of high PRL-3 expression was significantly lower than that of moderate or low PRL-3 expression (P < 0.001), and multivariate analysis showed that PRL-3 expression level independently influences the survival of patients (P = 0.024). Importantly, knockdown of PRL-3 significantly suppressed the proliferation of SGC7901 cells and slowed the tumor growth compared with controls (P < 0.05). PRL-3 is associated with gastric cancer progression. High PRL-3 expression in the primary lesion had a negative impact on prognosis. PRL-3 plays a key role in the control of gastric cancer growth. PRL-3 should be considered as a potential therapeutic target and a prognostic factor. Zhao Wang and Shi-Rong Cai contributed equally to this work.     

Borrmann Type IV: An Independent Prognostic Factor for Survival in Gastric Cancer

Background  Borrmann type IV gastric cancer has a poorer prognosis than other gastric carcinomas. This study compared the clinicopathological features of Borrmann type IV gastric cancer with those of other types of cancer and examined the significance of a Borrmann type IV carcinoma as a prognostic factor after gastrectomy. Methods  The clinicopathological features, tumor–node–metastasis (TNM) stage, and survival rates of 4,191 advanced gastric cancer patients, who had undergone a gastrectomy at the Samsung Medical Center between 1995 and 2005, were reviewed. Results  Borrmann type IV gastric cancer was found to be associated with more advanced and unfavorable clinicopathological features at diagnosis than the other cancers. The 5-year survival rate of the patients with Borrmann type IV cancer was 27.6%. In contrast, the 5-year survival rate of patients with the other types of cancer was 61.2%. The 5-year survival rate for each stage of Borrmann type IV gastric cancer and the other type gastric cancer was 61.0% and 88.8% for stage Ib (P < 0.001), 49.8% and 76.1% for stage II (P < 0.001), 36.4% and 55.1% for stage IIIa (P < 0.001), 15.2% and 38.5% for stage IIIb (P = 0.001), and 10.2% and 20.1% for stage IV (P = 0.008), respectively. Multivariate analyses revealed a Borrmann type IV carcinoma, the surgical extent, curability, tumor stage, including T, N, and M status, and adjuvant therapy to be independent prognostic factors for survival. Conclusion  A Borrmann type IV carcinoma has unique clinicopathological features compared with other types of gastric carcinomas and is an important independent prognostic factor.     

Occult disseminated tumor cells in lymph nodes of patients with gastric carcinoma. A critical appraisal of assessment and relevance

Background and aims  In gastric cancer, regional lymph node metastasis verified by histopathological examination is the most important prognostic factor after complete surgical tumor resection (R0). However, the prognostic value of immunohistochemically identifiable disseminated tumor cells in lymph nodes without histopathological tumor burden in patients with gastric cancer is still controversially discussed. The aim of the study was to assess the frequency and prognostic impact of minimal tumor cell spread to lymph nodes in these patients. Patients–methods  One hundred sixty lymph nodes judged as “tumor free” on routine histopathology obtained from 58 patients with gastric adenocarcinoma were analyzed immunohistochemically using the monoclonal anti-EpCAM antibody Ber-EP4 for occult disseminated tumor cells. Results  Tumor cells in lymph nodes were detected in 62 (38.8%) of the 160 “tumor-free” lymph nodes obtained from 39 (67.2%) patients. Multivariate Cox regression analysis confirmed the presence of disseminated tumor cells in “tumor-free” lymph nodes as an independent prognostic factor for both a significantly reduced relapse-free survival (p = 0.008) and overall survival (p = 0.009). Conclusions  The frequent occurrence and prognostic impact of minimal disseminated tumor cells in lymph nodes of patients with gastric carcinoma support the need for a refined staging system of excised lymph nodes, which should include immunohistochemical examination.     

Lack of death receptor 4 (<Emphasis Type="Italic">DR4</Emphasis>) expression through gene promoter methylation in gastric carcinoma

Background and aims  To determine the underlying mechanism for the differential expression, the extent of promoter methylation in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-related genes acting downstream of TRAIL was examined in early and advanced gastric carcinomas. Methods  The extent of promoter methylation in the DR4, DR5, DcR1, DcR2, and CASP8 genes was quantified using bisulfite modification and methylation-specific polymerase chain reaction. Results  The promoters for DcR1, DcR2, and CASP8 were largely unmethylated in early gastric carcinoma, advanced gastric carcinoma, and controls, with no significant difference among them. Protein levels of DR4, DcR1, and DcR2 as revealed by immunohistochemistry correlated with the extent of the respective promoter methylation (P < 0.05 in all cases). Hypomethylation, rather than hypermethylation, of the DR4 promoter was noted in invasive gastric malignancies, with statistical significance (P = 0.003). Conclusion  The promoter methylation status of TRAIL receptors in gastric carcinoma may have clinical implications for improving therapeutic strategies in patients with gastric carcinoma.     

Prognostic Factors in 2230 Korean Colorectal Cancer Patients: Analysis of Consecutively Operated Cases

To define the prognostic factors in Korean colorectal cancer patients, univariate and multivariate analysis were performed on data from 2230 consecutive patients who underwent resection for colorectal cancer at the Seoul National University Hospital. The prognostic variables used for the analysis included patient's age, gender, bowel obstruction, bleeding, symptom duration, preoperative leukocyte count, preoperative serum carcinoembryonic antigen (CEA) level, Dukes' stage, tumor location, tumor size, depth of bowel wall invasion, number of lymph node metastases, histologic differentiation, and gross morphology of tumor. The overall 5-year survival rate was 62%. In the univariate analysis, all the factors except sex, symptom duration, and tumor size were associated with prognosis. Among the factors significant in the univariate analysis, Dukes' stage (p < 0.001), number of lymph node metastasis (p < 0.001), CEA level (p < 0.001), tumor location (p= 0.003), gross morphology of tumor (p= 0.017), and depth of bowel wall invasion (p= 0.031) were significant in the multivariate analysis. Several differences in prognostic factors between colon cancer and rectal cancer were observed. In the multivariate analysis, gross tumor morphology was significant only for colon cancer, and histologic differentiation was significant only for rectal cancer. Lymph node metastasis was an independent prognostic variable for both colon and rectal cancer, but its significance was more prominent for rectal cancer. Although Dukes' stage is the most reliable prognostic predictor, this study shows that other factors (preoperative CEA level, gross morphology of tumor, location of tumor, nodal status) also provide important information for the outcome of the patient.     

CD24 Expression Is a Novel Prognostic Factor in Esophageal Squamous Cell Carcinoma

Esophageal cancer is one of the most difficult malignancies to cure, and identification of novel prognostic markers for patients with this disease is important. CD24 is a small highly glycosylated mucin-like protein. Several studies have shown that higher CD24 expression is significantly associated with shorter patient survival in various malignant tumors. However, the expression of CD24 and its clinicopathological significance in esophageal cancer remain largely unknown. Immunohistochemical analyses of CD24 and Ki-67 overexpression in 151 cases of esophageal squamous cell carcinoma were performed to examine the relationships of CD24 expression with clinicopathological parameters and patient survival. Five cell lines derived from esophageal cancer were subjected to Western blot analyses to evaluate CD24 expression. Immunohistochemically, CD24 expression was judged to be positive in 61 (40.4%) cases. CD24 expression was associated with lymph node metastasis (p = 0.005), pathologic stage (p = 0.018), number of nodal metastases (p = 0.003), lymphatic invasion (p = 0.002), venous invasion (p < 0.001), and Ki-67 labeling index (p < 0.001). The Pearson’s correlation coefficient between the CD24 expression score and the Ki-67 labeling index was 0.404 (p < 0.001). CD24 expression was associated with disease-free survival (p < 0.001). A Cox multivariate regression analysis revealed that CD24 expression was an independent prognostic factor (p = 0.033). On Western blot analysis, CD24 was detected in all five cell lines. We conclude that overexpression of CD24, which was correlated with Ki-67 expression, is a novel independent prognostic marker for identifying patients with poor prognosis after curative resection of esophageal squamous cell carcinoma.     

Survivin转录变异体在胃癌组织中的表达及其与预后的关系

目的研究survivin各转录变异体在胃癌组织中的表达情况及与其预后的关系。方法采用实时荧光定量RT-PCR技术,对77例胃恶性肿瘤患者的肿瘤组织、正常胃黏膜的成对标本进行mRNA定量检测。结果在检测患者肿瘤组织中野生型survivin、survivin-2B与survivin-△Ex3的表达量均显著高于其对应正常胃黏膜组织中的表达量(P<0.01)。在胃癌组织中,survivin的表达率为100%(77/77),survivin-2B的表达率为79.8%(61/77),survivin-△Ex3的表达率为64.9%(50/77)。survivin高表达组患者的生存率明显低于低表达组(P<0.01)。结论Survivin的3个转录变异体中,野生型survivin对胃癌患者预后具有重要的评估价值。     

Epidermal Growth Factor Receptor (EGFR) Expression is Associated With a Worse Prognosis in Gastric Cancer Patients Undergoing Curative Surgery

Background In gastric cancer, the recurrence rate is high even after curative surgery. A relevant issue is the identification of independent prognostic factors to select high-risk patients; such features can be used as predictive factors for tailored therapies. In this study we have investigated the role of epidermal growth factor receptor (EGFR) expression as a prognostic marker for predicting cancer behavior and clinical outcome in gastric cancer patients undergoing potentially curative surgery. Methods Epidermal growth factor receptor determination using a commercially available immunohistochemistry (IHC) kit was performed in tissues from 82 gastric cancer patients receiving primary surgical treatment and in 25 normal gastric mucosa specimens from noncancer patients. The EGFR positivity was correlated with disease recurrence and survival in univariate and multivariate analyses. Results Forty-four percent (36 cases) of gastric cancers were EGFR positive. In 66 curatively treated patients, EGFR expression correlated with disease recurrence and poorer survival in both univariate and multivariate analyses. In a multivariate model for predicting recurrence and survival, advanced tumor extension (T₃ or T₄), nodal metastases, and EGFR expression were the only independent covariates. In particular, EGFR expression was shown to be a significant predictor of poor prognosis among gastric cancer patients having the same stage according to the current TNM staging system. Conclusions These findings suggest that EGFR expression may be useful in identifying high-risk gastric cancer patients undergoing potentially curative surgery. Multimodal treatments should be considered in the adjuvant treatment of these patients.     

The expression of long non-coding RNA LINC01279 in gastric adenocarcinoma and its clinical significance

ObjectiveTo investigate the expression of long non-coding RNA LINC01279 in gastric cancer and its relationship with the clinicopathological features and prognosis of gastric cancer patients.MethodsSerum, gastric cancer and adjacent tissue samples from 90-patients with gastric-cancer treated by surgery and serum samples from 90-healthy adults were collected. The expression level of LINC01279 was analyzed by RT-PCR. The clinical baseline data of gastric cancer patients were obtained. Correlation between the expression level of LINC01279 and the clinicopathological characteristics of gastric cancer patients was assessed.ResultsLINC01279 was highly expressed in gastric cancer tissues and serum of gastric cancer patients (P < 0.05). The expression level of lncRNA 01279 was closely related to vascular invasion, nerve invasion, T-stage, lymph node metastasis, and advanced clinical-stage of gastric cancer (P < 0.05). The expression level was not correlated with gender, age, tumor size, location, and differentiation. There was a significant negative correlation between the expression of LINC01279 and the overall survival of gastric-cancer patients (P < 0.05).ConclusionLINC01279 is highly expressed in gastric-cancer tissues and serum, which is closely related to tumor-invasion. Serum LINC01279 is a better prognostic indicator of invasive cancer than current tumor markers.     

The Global Histone Modification Pattern Correlates with Cancer Recurrence and Overall Survival in Gastric Adenocarcinoma

Background  Epigenetic alterations such as DNA methylation and histone modification play important roles in carcinogenesis. It has been recently suggested that global histone modification patterns are independent predictors of cancer recurrence. In this study, we used immunohistochemistry to evaluate the patterns of histone H3 and H4 acetylation and trimethylation in gastric adenocarcinomas. Methods  Double 2-mm core tissue microarrays were made from 261 paraffin-embedded gastric adenocarcinoma samples and examined by immunohistochemistry for histone H3 lysine 9 (H3K9) acetylation and trimethylation, histone H4 lysine 16 acetylation, and histone H4 lysine 20 trimethylation. Sections were graded according to the proportion of tumor cells showing nuclear staining. Results  Trimethylation of H3K9 positively correlated with tumor stage (P = 0.043); lymphovascular invasion (P = 0.029), cancer recurrence (P = 0.043), and higher level of H3K9 trimethylation correlated with a poor survival rate (P = 0.008). Multivariate survival analysis showed that H3K9 trimethylation status is an independent prognostic factor (P = 0.014). After categorizing cases according to the dominant modification pattern, we found that methylation dominance was associated with lymphovascular invasion (P = 0.001), cancer recurrence (P = 0.001), and poor survival rate (P = 0.028). Methylation dominance was also an independent prognostic factor (P = 0.026) in multivariate survival analysis. Conclusion  The pattern of histone modification as detected by immunohistochemistry may be useful as a predictor for the recurrence of cancer and may be an independent prognostic factor in gastric adenocarcinomas.     

The Lymph Node Ratio is the Strongest Prognostic Factor after Resection of Pancreatic Cancer

Introduction  Survival after surgery of pancreatic cancer is still poor, even after curative resection. Some prognostic factors like the status of the resection margin, lymph node (LN) status, or tumor grading have been identified. However, only few data have been published regarding the prognostic influence of the LN ratio (number of LN involved to number of examined LN). We, therefore, evaluated potential prognostic factors in 182 patients after resection of pancreatic cancer including assessment of LN ratio. Methods  Since 1994, 204 patients underwent pancreatic resection for ductal pancreatic adenocarcinoma. Survival was evaluated in 182 patients with complete follow-up evaluations. Of those 182 patients, 88% had cancer of the pancreatic head, 5% of the body, and 7% of the pancreatic tail. Patients underwent pancreatoduodenectomy (85%), distal resection (12%), or total pancreatectomy (3%). Survival was analyzed by the Kaplan–Meier and Cox methods. Results  In all 204 resected patients, operative mortality was 3.9% (n = 8). In the 182 patients with follow-up, 70% had free resection margins, 62% had G1- or G2-classified tumors, and 70% positive LN. Median tumor size was 30 (7–80) mm. The median number of examined LN was 16 and median number of involved LN 1 (range 0–22). Median LN ratio was 0.1 (0–0.79). Cumulative 5-year survival (5-year SV) in all patients was 15%. In univariate analysis, a LN ratio ≥ 0.2 (5-year SV 6% vs. 19% with LN ratio < 0.2; p = 0.003), LN ratio ≥ 0.3 (5-year SV 0% vs. 18% with LN ratio < 0.3; p < 0.001), a positive resection margin (p < 0.01) and poor differentiation (G3/G4; p < 0.03) were associated with poorer survival. In multivariate analysis, a LN ratio ≥ 0.2 (p < 0.02; relative risk RR 1.6), LN ratio ≥ 0.3 (p < 0.001; RR 2.2), positive margins (p < 0.02; RR 1.7), and poor differentiation (p < 0.03; RR 1.5) were independent factors predicting a poorer outcome. The conventional nodal status or the number of examined nodes (in all patients and in the subgroups of node positive or negative patients) had no significant influence on survival. Patients with one metastatic LN had the same outcome as patients with negative nodes, but prognosis decreased significantly in patients with two or more LN involved. Conclusions  Not the lymph node involvement per se but especially the LN ratio is an independent prognostic factor after resection of pancreatic cancers. In our series, the LN ratio was even the strongest predictor of survival. The routine estimation of the LN ratio may be helpful not only for the individual prediction of prognosis but also for the indication of adjuvant therapy and herein related outcome and therapy studies. Presented in part at the 49th Annual Meeting of the Society for Surgery of the Alimentary Tract, May 2008 in San Diego and at the Annual Meeting of the German Cancer Society, February 2008 in Berlin, Germany     

Identification of Calreticulin as a Prognosis Marker and Angiogenic Regulator in Human Gastric Cancer

The purpose of this study was to identify genes of interest for a subsequent functional and clinical cohort study using complementary (c)DNA microarrays. cDNA microarray hybridization was performed to identify differentially expressed genes between tumor and nontumor specimens in 30 gastric cancer patients. Subsequent functional studies of the selected gene were carried out, including cell cycle analysis, cell migration analysis, analyses of vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF), and oligo-microarray studies using two pairs of stable cell lines of the selected gene. Another independent cohort study of 79 gastric cancer patients was conducted to evaluate the clinical significance of the selected gene in human gastric cancer. Calreticulin (CRT) was selected for further investigation. Two pairs of stable cell lines of CRT overexpression and CRT knockdown were constructed to perform functional studies. CRT enhanced gastric cancer cell proliferation and migration. Overexpressed CRT upregulated the expression and secretion of PlGF and VEGF. CRT had a reciprocal effect on connective tissue growth factor (CTGF) expression. Positive immunohistochemical staining of calreticulin was significantly correlated with high microvessel density (MVD) (p = 0.014), positive serosal invasion (p = 0.013), lymph node metastasis (p = 0.002), perineural invasion (p = 0.008), and poor patient survival (p = 0.0014). Multivariate survival analysis showed that CRT, MVD, and serosal invasion were independent prognosticators. We conclude that CRT overexpression enhances angiogenesis, and facilitates proliferation and migration of gastric cancer cells, which is in line with the association of CRT with MVD, tumor invasion, lymph node metastasis, and survival in gastric cancer patients. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Clinicopathologic Study of Gastric Cancer Based on Dukes' Classification

Dukes' classification is a useful staging system in patients with colorectal cancer. The aim of this study was to present clinicopathologic characteristics and survival of patients with gastric cancer based on Dukes' classification. A total of 273 patients with gastric cancer curatively treated by radical gastrectomy and lymph node dissection (D2, D3) were studied. With the modified Dukes' classification, A includes tumors limited to the mucosa, submucosa, or muscularis propria; B includes tumors extending into the subserosa or serosa; Ca includes tumors with one to six positive lymph nodes; and Cb includes tumors with seven or more positive lymph nodes. Dukes' classification modified by the number of positive lymph nodes well correlated with the tumor size (p < 0.01), depth of wall invasion (p < 0.01), level of lymph node metastasis (p < 0.01), and degree of lymphatic permeation (p < 0.01) and venous permeation (p< 0.01). The 5-year survival rate was significantly different among Dukes' A (98%), Dukes' B (90%), Dukes' Ca (75%), and Dukes' Cb (44%) cases. The results indicate that Dukes' classification modified by the number of positive lymph nodes (Dukes' A, B, Ca, an Cb) significantly correlates with tumor progression and patient survival; and it may be a simple and useful staging system for gastric cancer.     

Validation of a rodent model of Barrett’s esophagus using quantitative gene expression profiling

Background  A rodent model of gastroduodenal–esophageal reflux can result in replacement of squamous esophageal mucosa with intestinal-type columnar mucosa and carcinoma. The validity of this model is debated, as it is unproven whether this mucosa is intestinal metaplasia due to reflux or represents migration of adjacent jejunal mucosa above the anastomosis. The aim of this study was to evaluate the esophageal intestinal-type mucosa in these animals by measuring expression of trefoil factor genes (TFF-1, -2, -3) and comparing it with adjacent jejunum in order to determine its etiology. Methods  Twenty-five rats underwent esophagojejunostomy at the ligament of Treitz to induce reflux of gastric and duodenal contents. The animals were sacrificed at 16 weeks (n = 14) and 30 weeks (n = 11). After sacrifice, the distal esophagus, jejunum, and colon were obtained. RNA was isolated, reverse transcribed, and messenger RNA (mRNA) expression of TFF-1, -2, and -3 was measured with real-time polymerase chain reaction (PCR). Linear discriminant analysis classified samples based on gene expression. Results  Esophageal intestinal-type mucosa was present at sacrifice in 18 animals. Compared to jejunum, the expression of TFF-1 and TFF-2 mRNA in the intestinal mucosa of the distal esophagus was increased (p = 0.0007 and p < 0.0001, respectively). Expression of TFF-3 was also increased in esophageal intestinal mucosa compared with jejunum (p = 0.0002), but there was significant overlap in expression between these tissues for this gene. Linear discriminant analysis misclassified esophageal intestinal-type mucosa as jejunum in only one case. In no cases was jejunum misclassified as esophageal intestinal-type mucosa. Conclusion  The gene expression profile of esophageal intestinal-type mucosa following surgically induced reflux in a rodent model indicates that this represents intestinal metaplasia, not proximal migration of jejunum. This validates this model for studying the pathogenesis of Barrett’s esophagus. Use of this model has potential for assessment of the impact of various therapies on the natural history of reflux disease. Presented at the 2007 Annual SAGES Meeting, Las Vegas, NV April 21, 2007 (Oral Presentation).     

Leptin Expression Correlates with Favorable Clinicopathologic Phenotype and Better Prognosis in Colorectal Adenocarcinoma

Leptin, the product of the ob gene, is an adipocyte-derived neurohormone that regulates body fat storage and feeding behavior. Some studies have suggested that leptin has growth-factor-like functions in epithelial cells and its abnormal expression may be involved in cancer development and progression. We investigated leptin expression in normal and neoplastic colorectal tissues and its association with clinicopathological features and clinical outcome in colorectal adenocarcinoma patients. Leptin expression was evaluated on the tissue microarray of 44 normal colon mucosal tissues, 44 adenomatous polyps, and 437 colorectal adenocarcinomas by immunohistochemistry. Data were analyzed by chi-square test, one-way analysis of variance (ANOVA), Cox regression hazards model, and log-rank test with Kaplan–Meier curves. Frequency of leptin expression was dramatically increased from normal colonic mucosa (2/44, 4.5%) to adenomas (13/44, 29.5%) and adenocarcinomas (321/437, 73.5%) as neoplastic progression. Interestingly, leptin expression was correlated with favorable tumor features in depth of invasion (p = 0.033), lymph node metastasis (p = 0.019), American Joint Committee on Cancer (AJCC) and Dukes’ stage (p = 0.021 and p = 0.005, respectively), differentiation (p = 0.010), and lymphatic invasion (p = 0.003). In univariate survival analysis, patients with leptin-positive adenocarcinoma revealed better overall and disease-free survivals (p = 0.032 and p = 0.004, respectively, log-rank test). In multivariate survival analysis with Cox proportional hazards model, leptin expression was an independent prognostic marker of disease-free survival (p = 0.009). We conclude that leptin was gradually expressed during the normal–adenoma–adenocarcinoma sequence, suggesting an association in colorectal carcinogenesis. In addition, high leptin expression was an indicator of favorable tumor features and better survival of colorectal cancer patients.