Prognostic factors in gastric cancer

Multivisceral Resection for Locally Advanced Gastric and Gastroesophageal Junction Cancers-11-Year Experience at a High-Volume North American Center

INTRODUCTION

The oncologic benefit of multivisceral en bloc resections for T4 gastroesophageal tumors has been questioned, given the increased morbidity associated. We thus sought to investigate the surgical and oncologic outcomes of curative-intent en bloc multivisceral resections for T4 gastroesophageal carcinomas.

METHODS

Between 2005 and 2016, 35 of the 525 patients who had gastric or EGJ carcinomas underwent curative-intent multivisceral resections for direct invasion or adhesion to adjacent organs.

RESULTS

Postoperative complications occurred in 16(46%), 10 of which were Clavien-Dindo ≥ 3 (29%). Ninety-day mortality was 3%. The R0 resection rate was 94% (33). Direct organ invasion (pT4b) was confirmed on pathological analysis in 14 (40%) and did not affect survival. The majority (28, 80%) had lymph node involvement with a high nodal disease burden and was associated with decreased survival. Overall 5-year survival rate was 34%, and the vast majority of recurrences were distant/peritoneal (81%). On multivariate analysis, positive lymph nodes (H.R. 21.2; 95%CI 2.34-192) and R1 resection (H.R. 5.6; 95%CI 1.02-30.9) were predictors of survival.

CONCLUSION

Multivisceral resections for T4 gastric and GEJ adenocarcinomas, in combination with effective systemic therapy, result in prolonged long-term survival with acceptable morbidity. Complete resection to negative margins should remain a mainstay of curative-intent treatment in carefully selected patients.

Cathepsins in digestive cancers

Cathepsins are lysosomal peptidases belonging to the papain family, and based on their catalytic sites, these enzymes can be divided into serine, cysteine and aspartic proteases. The studies conducted to date have identified, 15 types of cathepsins that are widely distributed in intracellular and extracellular spaces. These proteases participate in various pathological activities, including the occurrence and development of human cancers. Several recent studies suggest that cathepsins, particularly cathepsins B, D, E and L, contribute to digestive tumorigenesis. Cathepsins were found to promote the development of most digestive cancers except liver cancer, in which they might have the opposite effects. Due to their important roles in digestive tumors, cathepsins might be therapeutic targets for the treatment of digestive cancers.

Clinical Assessment and Prognostic Evaluation of Tumor Markers in Patients with Gastric Cancer

Aim

To investigate the relationship between the serum levels of CEA, CA19-9, CA24-2, CA72-4, and AFP in patients with gastric cancer (GC) and their clinicopathological characteristics; to analyze the efficacy of these tumor markers in evaluating the prognosis of GC.

Methods

Overall, 389 patients with GC either located in the gastric cardia (132), the pyloric antrum (112) or the body of the stomach (145) were included in the study. Serum levels of CEA, CA19-9, CA72-4, and AFP were detected with the ECLIA method, while CA24-2 was measured with ELISA.

Results

First, the serum level of CEA in GC patients with a cardia-located cancer was significantly higher than in patients with pyloric antrum-located cancer (p=0.050). CA72-4 level in patients with GC located in the gastric body was significantly higher than in patients with cardia and pyloric antrum-located cancers (p=0.042 and p=0.039, respectively). Secondly, serum CA19-9 and CA24-2 levels in females with cardia-located GC were significantly higher than those in males with the same type of tumor (p=0.037 and p=0.033, respectively). Additionally, for females with gastric body-located GC the levels of CEA and CA72-4 were significantly higher than those in male patients with the same type of tumor (p=0.047 and p=0.048, respectively). Conversely, in female GC patients with pyloric antrum-located cancer the serum levels of CA19-9 and CA24-2 were significantly lower than those in male patients with the same type of cancer (p=0.013 and p=0.007, respectively). Moreover, CEA, CA19-9, CA24-2, and CA72-4 levels were strongly related to TNM grade and histological anatomy stage, whereas CEA and CA72-4 levels were strongly related to lymph node stage (p=0.000 and p=0.042, respectively). Patients with vascular embolism had higher serum levels of CEA, CA19-9, CA24-2, and CA72-4 compared with patients without vascular embolism (p=0.005, p=0.031, p=0.007, and p=0.014, respectively). In patients with distant metastases and ascites the levels of CEA, CA19-9, and CA24-2 were higher than in patients without these conditions (p=0.003, p=0.001, p=0.001, p=0.016, p= 0.011, and p=0.030, respectively). Serum CEA, CA19-9, and CA24-2 levels showed correlations with tumor invasive depth and growth types (p=0.001, p=0.040, and p=0.035, respectively). Patients with lump and catheter tumor growth types had significantly higher AFP levels than patients with invasion and anabrosis growth types (p=0.034 and p=0.005, respectively). Tumor size was correlated with the preoperative serum levels of CEA, AFP, and CA72-4 (p=0.007, p=0.020, and p=0.008, respectively). Additionally multiple linear regression analysis showed that preoperative levels of CEA and CA72-4 were correlated to TNM stages, CA19-9 and CA24-2 levels were correlated to both gender and distant metastasis, and AFP was correlated only to ascites. During follow-up there were 115 deaths. Median survival time for GC patients with negative preoperative CEA was 18.07 months, and was 10.97 months for patients with preoperative CEA positive levels (p=0.0005). Similarly, the median survival time for GC patients with negative preoperative CA72-4 was 33.60, and was 16.03 months for patients with preoperative CA72-4 positive levels (p=0.0041).

Conclusions

The preoperative levels of CEA, CA19-9, CA24-2, CA72-4, and AFP were closely related to TNM grade, gender, distant metastasis and ascites. These makers seem to play important roles in predicting recurrence and metastasis, and in evaluating prognosis.

How does epidemiological and clinicopathological features affect survival after gastrectomy for gastric cancer patients-single Egyptian center experience

AIM: To investigate the clinicopathological features and the significance of different prognostic factors which predict surgical overall survival in patients with gastric carcinoma.

METHODS: This retrospective study includes 80 patients diagnosed and treated at gastroenterology surgical center, Mansoura University, Egypt between February 2009 to February 2013. Prognostic factors were assessed by cox proportional hazard model.

RESULTS: There were 57 male and 23 female. The median age was 57 years (24-83). One, 3 and 5 years survival rates were 71%, 69% and 46% respectively. The median survival was 69.96 mo. During the follow-up period, 13 patients died (16%). Hospital morbidity was reported in 10 patients (12.5%). The median number of lymph nodes removed was 22 (4-41). Lymph node (LN) involvement was found in 91% of cases. After R0 resection, depth of wall invasion, LN involvement and the number (> 15) of retrieved LN, LN ratio and tumor differentiation predict survival. In multivariable analysis, tumor differentiation, curability of resection and a number of resected LN superior to 15 were found to be independent prognostic factors.

CONCLUSION: Surgery remains the cornerstone of treatment. Tumor differentiation, curability of resection and a number of resected LN superior to 15 were found to be independent prognostic factors. Extended LN dissection does not increase the morbidity or mortality rate but markedly improves long term survival.

Is there a role for urokinase-type plasminogen activator inhibitors as maintenance therapy in patients with ovarian cancer?

There is abundant evidence that the urokinase-type plasminogen activator (uPA), its inhibitors PAI-1 and PAI-2 (plasminogen activator inhibitor type-1 and type-2) and its cells surface receptor (uPA-R, CD87) play a fundamental role in tumor invasion and metastasis and are of significant prognostic significance for many tumor types. We performed a systematic Med-line search on uPA, PAI, uPA-R and (epithelial) ovarian cancer (EOC). The majority of malignant EOC specimens show moderate to strong immunostating of tumor and stromal cells. Overexpression of u-PA and PAI-1 can be found in more the 75% of primary ovarian carcinomas, in most metastatic EOC samples and all examined epithelial ovarian cancer cell lines. uPA overexpression in primary specimens was significantly associated with tumor stage, grade, residual disease status after cytoreductive surgery, and poor clinical outcome. This may be explained by increased chemoresistance, a lower resectability and more aggressive tumor biology and tumor dissemination in patients with high uPA and PAI-1. Several therapeutical approaches aimed at inhibiting the uPA/uPAR functions have shown to possess anti-tumor effects in vitro and in animal models. When treating a patient with advanced ovarian cancer it may to be assumed that inhibiting the progression of established (micro) metastases may be more therapeutically relevant than trying to destroy all tumor cells which is not possible in most cases with current systemic treatment modalities. Taking into account the role of uPA and PAI in cell detachment, formation of new stroma, tumor cell reimplantation and metastasis uPA inhibition should be further investigated as maintenance treatment in patients with advanced EOC.

Prognostic value of Muc5AC in gastric cancer: A meta-analysis

AIM: To assess the correlation between decreased Muc5AC expression and patients’ survival and clinicopathological characteristics by conducting a meta-analysis.

METHODS: Literature searches were performed in PubMed and EMBASE, and 11 studies met our criteria. Summary hazard ratios or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the effect. For the pooled analysis of the correlation between decreased Muc5AC expression and clinicopathological characteristics (tumour invasion depth, lymph node metastasis, tumour-node-metastasis stage, tumour size, venous invasion and lymphatic invasion), ORs and their variance were combined to estimate the effect.

RESULTS: Eleven retrospective cohort studies comprising 2135 patients were included to assess the association between Muc5AC expression and overall survival and/or clinicopathological characteristics. Decreased Muc5AC expression was significantly correlated with poor overall survival of gastric cancer patients (pooled HR = 1.35, 95%CI: 1.08-1.7). Moreover, decreased Muc5AC expression was also significantly associated with tumour invasion depth (pooled OR = 2.12, 95%CI: 1.56-2.87) and lymph node metastasis (pooled OR = 1.56, 95%CI: 1.00-2.44) in gastric cancer.

CONCLUSION: Decreased Muc5AC expression might be a poor prognostic predictor for gastric cancer.

Inhibition of plasminogen activator inhibitor-1 is a potential therapeutic strategy in ovarian cancer

Plasminogen activator inhibitor (PAI)-1 is predictive of poor outcome in several types of cancer. The present study investigated the biological role for PAI-1 in ovarian cancer and potential of targeted pharmacotherapeutics. In patients with ovarian cancer, PAI-1 mRNA expression in tumor tissues was positively correlated with poor prognosis. To determine the role of PAI-1 in cell proliferation in ovarian cancer, the effects of PAI-1 inhibition were examined in PAI-1-expressing ovarian cancer cells. PAI-1 knockdown by small interfering RNA resulted in significant suppression of cell growth accompanied with G2/M cell cycle arrest and intrinsic apoptosis. Similarly, treatment with the small molecule PAI-1 inhibitor TM5275 effectively blocked cell proliferation of ovarian cancer cells that highly express PAI-1. Together these results suggest that PAI-1 promotes cell growth in ovarian cancer. Interestingly, expression of PAI-1 was increased in ovarian clear cell carcinoma compared with that in serous tumors. Our results suggest that PAI-1 inhibition promotes cell cycle arrest and apoptosis in ovarian cancer and that PAI-1 inhibitors potentially represent a novel class of anti-tumor agents.

Bcl-2 expression and patient survival in gastric cancer: a systematic review of the literature with meta-analysis

The prognostic role of Bcl-2 in gastric cancer remains controversial. We systematically reviewed the evidence for the effect of Bcl-2 expression in gastric cancer to elucidate this issue. PubMed, EMBASE, and Web of Science were searched to identify eligible studies to evaluate the association between Bcl-2 expression and overall survival (OS) and clinicopathological features of gastric cancer. Hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence interval (95 % CI) were pooled to estimate the effect. Bcl-2 expression was not significantly correlated with OS of gastric cancer patients (combined HR 0.88, 95 % CI 0.62-1.25). Subgroup analysis indicated that Bcl-2 expression had a favorable impact on OS in Asian countries (HR 0.60, 95 % CI 0.47-0.77) and cutoff value <15 % (HR 0.69, 95 % CI 0.48-0.97). Furthermore, Bcl-2 expression was significantly associated with TNM stage (OR 0.58, 95 % CI 0.41-0.80), the depth of invasion (OR 0.53, 95 % CI 0.37-0.76), and lymph node metastasis (OR 0.55, 95 % CI 0.42-0.71). Bcl-2 expression predicts less invasion and malignancy in clinicopathological features. Moreover, Bcl-2 could be a favorable prognostic marker for patients of Asian countries.

Potential prognostic, diagnostic and therapeutic markers for human gastric cancer

The high incidence of gastric cancer (GC) and its consequent mortality rate severely threaten human health. GC is frequently not diagnosed until a relatively advanced stage. Surgery is the only potentially curative treatment. Thus, early screening and diagnosis are critical for improving prognoses in patients with GC. Gastroscopy with biopsy is an appropriate method capable of aiding the diagnosis of specific early GC tumor types; however, the stress caused by this method together with it being excessively expensive makes it difficult to use it as a routine method for screening for GC on a population basis. The currently used tumor marker assays for detecting GC are simple and rapid, but their use is limited by their low sensitivity and specificity. In recent years, several markers have been identified and tested for their clinical relevance in the management of GC. Here, we review the serum-based tumor markers for GC and their clinical significance, focusing on discoveries from microarray/proteomics research. We also review tissue-based GC tumor markers and their clinical application, focusing on discoveries from immunohistochemical research. This review provides a brief description of various tumor markers for the purposes of diagnosis, prognosis and therapeutics, and we include markers already in clinical practice and various forthcoming biomarkers.

MicroRNA-196a/-196b promote cell metastasis via negative regulation of radixin in human gastric cancer

MicroRNAs (miRNAs) play an important role to contribute carcinogenesis. The aim of the current study was to identify useful biomarkers from miRNAs. Differential miRNA profiles were analyzed using the miRNA qRT-PCR-based assay. Two of the most upregulated miRNAs were selected and validated. The miR-196a/-196b levels were significantly increased in gastric cancer (GC) tissues (n=109). Overexpression of miR-196a/-196b was significantly associated with tumor progression and poorer 5-year survival outcomes. Overexpression of miR-196a/-196b enhances GC cell migration and invasion. Further, radixin was identified as a target gene of miR-196a/-196b. Elevated miR-196a/-196b expression in GC cells led to reduced radixin protein levels and vice versa. Notably, an inverse correlation between miR-196a/-196b and radixin mRNA and protein expression was observed in GC tissues with in situ hybridization and immunohistochemistry analyses. Together, miR-196a/-196b inhibitory oligonucleotides or overexpression of the radixin may thus have therapeutic potential in suppressing GC metastasis.

Clinicopathological characteristics and prognosis of signet ring cell carcinoma of the stomach

BACKGROUND

Signet ring cell carcinoma (SRC) of the stomach is a histological type based on microscopic characteristics. Although the distinctive clinicopathological features of SRC have been reported, results are inconsistent and survival outcomes are uncertain.

METHODS

We retrospectively studied 769 patients with gastric carcinoma who underwent gastrectomy in our institute from 1999 to 2009. Among them, 326 patients (42.4 %) had early gastric cancer (EGC) and 443 patients (57.6 %) had advanced gastric cancer (AGC). Sex, age, tumor location, macroscopic type, tumor size, microscopic invasion, and survival rate were compared between patients with SRC, differentiated-, and undifferentiated-type gastric carcinomas.

RESULTS

Fifty-one patients (15.6 %) had SRC in EGC; there were significant differences in sex, age, location, macroscopic type, and size between SRC and the differentiated histological type. However, there was no difference between SRC and undifferentiated-type gastric carcinoma, except for the macroscopic type. Fifty-seven patients (12.9 %) had SRC in AGC. Sex, age, location, size, macroscopic type, perineural invasion, N stage, and hepatic metastasis were significantly different between SRC and the differentiated histological type. Undifferentiated-type gastric carcinoma differed in sex, macroscopic type, and hepatic metastasis. The overall survival rate differed between SRC and other cell types (P < 0.001). Among all the study patients, age [hazard ratio (HR) 1.013, P = 0.041] and tumor, node, and metastasis (TNM) stage (HR 2.350, P < 0.001) were important factors for predicting survival. Omitting patients with palliative resection or metastases, TNM stage was still an important factor for survival (HR 2.077, P < 0.001).

CONCLUSIONS

Patients with SRC showed similar clinicopathological features with undifferentiated histology. The survival of patients with SRC reflected a better prognosis in patients with undifferentiated gastric carcinoma. However, when narrowing the patients to those with EGC only, survival in EGC patients exhibited no difference between histological types. Among AGC patients, SRC patients had a worse prognosis than other cell types.

Variable copy number of mitochondrial DNA (mtDNA) predicts worse prognosis in advanced gastric cancer patients

BACKGROUND

Change of mitochondrial DNA (mtDNA) copy number is widely reported in various human cancers, including gastric cancer, and is considered to be an important hallmark of cancers. However, there is remarkably little consensus on the value of variable mtDNA content in the prognostic evaluation of this cancer.

METHODS

Using real-time quantitative PCR approach, we examined mtDNA copy number in a cohort of gastric cancers and normal gastric tissues, and explored the association of variable mtDNA content with clinical outcomes of gastric cancer patients.

RESULTS

Our data showed that the majority of gastric cancer patients had low mtDNA content as compared to control subjects although the relative mean mtDNA content was higher in the former than the latter. Moreover, we found that variable mtDNA content was strongly associated with lymph node metastasis and cancer-related death of the patients with late-stage tumors. Notably, variable mtDNA content did not affect overall survival of gastric cancer patients, however, we found that increased mtDNA content was associated with poor survival in the patients with late-stage tumors.

CONCLUSION

In this study, we demonstrated that variable mtDNA content markedly increased the risk of lymph node metastasis and high mortality of the patients with late-stage tumors. Additionally, we found a strong link between increased mtDNA content and worse survival of the patients with late-stage tumors. Taken together, variable mtDNA content may be a valuable poor prognostic factor for advanced gastric cancer patients.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1344721463103353.

Comparison between artificial neural network and Cox regression model in predicting the survival rate of gastric cancer patients

The aim of this study was to determine the prognostic factors and their significance in gastric cancer (GC) patients, using the artificial neural network (ANN) and Cox regression hazard (CPH) models. A retrospective analysis was undertaken, including 289 patients with GC who had undergone gastrectomy between 2006 and 2007. According to the CPH analysis, disease stage, peritoneal dissemination, radical surgery and body mass index (BMI) were selected as the significant variables. According to the ANN model, disease stage, radical surgery, serum CA19-9 levels, peritoneal dissemination and BMI were selected as the significant variables. The true prediction of the ANN was 85.3% and of the CPH model 81.9%. In conclusion, the present study demonstrated that the ANN model is a more powerful tool in determining the significant prognostic variables for GC patients, compared to the CPH model. Therefore, this model is recommended for determining the risk factors of such patients.

Matrix metalloproteinase-9 as a prognostic factor in gastric cancer: a meta-analysis

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) is associated with disruption of basement membranes of blood vessels and promotion of metastasis through the lymphatics. However, its prognostic value for survival in patients with gastric cancer remains controversial.

METHOD

We therefore conducted a meta-analysis of the published literature in order to clarify the impact of MMP-9. Clinical studies were selected for further analysis if they provided an independent assessment of MMP-9 in gastric cancer and reported analysis of survival data according to MMP-9 expression.

RESULTS

A total of 11 studies, covering 1700 patients, were included for meta- analysis. A summary hazard ratio (HR) of all studies and sub-group hazard ratios were calculated. The combined HR suggested that a positive MMP-9 expression had an impact on overall survival: 1.25 (95% confidence interval 1.11-1.40) in all eligible studies; 1.13 (1.06-1.20) in 8 studies detecting MMP-9 by immunohistochemistry; 1.36 (1.12-1.65) in 7 studies from Asia. Only one study for DFS showed a significant impact on disease free survival (HR 1.73, 95%CI 1.27-2.34).

CONCLUSIONS

Our findings suggested that MMP-9 protein expression might be a factor for a poor prognosis in patients with gastric cancer. However, the association was rather weak, so that more prospective studies should further explore the prognostic impact of MMP-9 mRNA and correlations between MMP-9 and clinicopathological characteristics.

Protumorigenic activity of plasminogen activator inhibitor-1 through an antiapoptotic function

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is a protease inhibitor but is paradoxically associated with poor outcomes in cancer patients. However, the mechanisms of its effects on tumor cells have not been explored.

METHODS

Endogenous PAI-1 in human tumor cell lines (HT-1080, A549, HCT-116, and MDA-MB-231) was suppressed by small interfering RNAs (siRNAs) and PAI-039, a small molecule inhibitor of PAI-1, and the effects on apoptosis were examined. Tumorigenicity of PAI-1 knockdown (KD) tumor cells was examined in immunodeficient PAI-1 wild-type and knockout (KO) mice (9-15 per group), and event-free survival was analyzed by the Kaplan-Meier method. The effect of PAI-1 suppression on HT-1080 xenotransplanted tumors was evaluated for cell proliferation, apoptosis, and angiogenesis. All statistical tests were two-sided.

RESULTS

Genetic and pharmacological inhibition of PAI-1 in the four tumor cell lines increased spontaneous apoptosis (mean fold increase relative to control: HT-1080, siRNA#1, mean = 4.0, 95% CI = 2.6 to 5.3, P < .001; siRNA#2, mean = 2.6, 95% CI = 2.4 to 2.9, P < .001, Student t test), which was blocked in the presence of recombinant PAI-1, a caspase-8 inhibitor, or Fas/FasL neutralizing antibodies and was partially attenuated by a plasmin inhibitor-aprotinin. PAI-1 KO mice implanted with PAI-1 KD HT-1080 cells had decreased tumorigenesis and prolonged survival compared with control mice (P = .002, log-rank test), and their tumors exhibited decreased cell proliferation and angiogenesis and increased apoptosis. Furthermore, five of 15 PAI-1 KO mice implanted with PAI-1 KD HT-1080 cells never developed tumors.

CONCLUSIONS

These data suggest that PAI-1 exerts a protective effect against tumor cell apoptosis by a mechanism that, in part, involves plasmin activation and inhibition of Fas/Fas-L-mediated apoptosis and may be a promising therapeutic target.

Expression profile as predictor of relapse after adjuvant treatment in gastric cancer

INTRODUCTION

TNM and histological subtype are the most important prognostic criteria in gastric cancer. In this study, we have tried to identify an immunohistochemical protein profile involved in gastric recurrence after a radical surgery.

MATERIALS AND METHODS

In this paper, protein panels involved in gastric carcinogenesis and progression was analyzed by immunohistochemistry expression: p53, Ki-67, Bcl-2, COX-2, c-erb-B2, EPO-R, E-cadherin, and β-catenin in 44 gastrectomy samples coming from gastrectomy pieces of patients diagnosed and operated on adenocarcinoma of the stomach followed by adjuvant treatment based on MacDonald chemoradiation regimen. An immunostaining profile that could predict the relapse after the end of adjuvant treatment was tried to find. These results have shown that the expression of the adverse prognostic protein profile based on positive p53 immunohistochemical expression and non-conserved E-cadherin/B-catenin staining is associated with tumor recurrence and a poor disease-free survival in operated gastric cancer patients with curative intent followed by adjuvant chemoradiation according to MacDonald's regimen. A protein profile based on immunohistochemical expression of p53 and E-cadherin-B-catenin that has a significant correlation to disease-free survival was identified in gastric cancer samples.

Overexpression of ADP-ribosylation factor 1 in human gastric carcinoma and its clinicopathological significance

Gastric cancer is the sixth leading cause of cancer-related death in Taiwan, and the identification of related factors is essential to increase patient survival. ADP-ribosylation factor 1 (ARF1) was initially identified using 2-D electrophoresis combined with MALDI-time-of-flight mass spectrometry. ADP-ribosylation factor 1 belongs to the Ras superfamily or GTP-binding protein family and has been shown to enhance cell proliferation. In the current study, we evaluated the potential of ARF1 as a biomarker for gastric cancer detection. ADP-ribosylation factor 1 mRNA was upregulated in tumor tissues (compared with adjacent non-tumor tissues, n = 55) in approximately 67.2% of gastric cancer patients. Expression of ARF1 protein was additionally observed using Western blot and immunohistochemistry (IHC) analyses. The clinicopathological correlations of ARF1 were further evaluated. Elevated ARF1 expression was strongly correlated with lymph node metastasis (P = 0.008), serosal invasion (P = 0.046), lymphatic invasion (P = 0.035), and pathological staging (P = 0.010). Moreover, the 5-year survival rate for the lower ARF1 expression group (n = 50; IHC score < 90) was higher than that of the higher expression group (n = 60; IHC score ≥ 90) (P = 0.0228, log-rank test). To establish the specific function of ARF1 in human gastric cancer, isogenic ARF1-overexpressing cell lines were prepared. Our results showed that ARF1-overexpressing clones display enhanced cell proliferation, migration, and invasion. Furthermore, ARF1-overexpression might contribute to poor prognosis of patients. These findings collectively support the utility of ARF1 as a novel prognostic marker for gastric cancer and its role in cell invasion.

Quantitative assessment of gene methylation and their impact on clinical outcome in gastric cancer

BACKGROUND

Promoter methylation is an alternative mechanism of gene silencing in human tumorigenesis. Although a number of methylated genes have been found in gastric cancer, useful methylation markers for early diagnosis and prognostic evaluation of this cancer remain largely unknown.

METHODS

Using quantitative methylation-specific PCR (Q-MSP), we examined promoter methylation of 6 genes, including CALCA, DAPK1, RARbeta, RASSF1A, TIMP3, and PAX6, and explored their association with clinical outcome in gastric cancer.

RESULTS

We found that most of the genes investigated in the present study had significantly higher methylation level in tumor tissues than normal gastric tissues, including CALCA, RARbeta, RASSF1A, TIMP3, and PAX6. With more focus on specificity compared to sensitivity, all genes were hypermethylated in gastric cancer, ranging from 12.8% to 36.9%. Methylation of TIMP3 and PAX6 was strongly associated with differentiation and lymph node metastasis, respectively. Importantly, most of gene methylation, except for DAPK1, was closely associated with poor survival in gastric cancer.

CONCLUSION

We found that a panel of genes was specifically methylated in gastric cancer, and demonstrated the effect of promoter methylation of some genes on clinical outcome in gastric cancer, indicating these methylated genes may be useful biomarkers for prognostic evaluation in this cancer.

Clinical utility of level-of-evidence-1 disease forecast cancer biomarkers uPA and its inhibitor PAI-1

The prognostic and/or predictive value of the cancer biomarkers, urokinase-type plasminogen activator (uPA) and its inhibitor (plasminogen activator inhibitor [PAI]-1), determined by ELISA in tumor-tissue extracts, was demonstrated for several cancer types in numerous clinically relevant retrospective or prospective studies, including a multicenter breast cancer therapy trial (Chemo-N0). Consequently, for the first time ever for any cancer biomarker for breast cancer, uPA and PAI-1 have reached the highest level of evidence, level-of-evidence-1. At present, two other breast cancer therapy trials, NNBC-3 and Plan B, also incorporating uPA and PAI-1 as treatment-assignment tools are in effect. Furthermore, small synthetic molecules targeting uPA are currently in Phase II clinical trials in patients afflicted with advanced cancer of the ovary, breast or pancreas.

Is hypoalbuminemia an independent prognostic factor in patients with gastric cancer?

BACKGROUND

Studies have indicated that hypoalbuminemia is associated with decreased survival of patients with gastric cancer. However, the prognostic value of albumin may be secondary to an ongoing systemic inflammatory response. The aim of the study was to assess the relation between hypoalbuminemia, the systemic inflammatory response, and survival in patients with gastric cancer.

METHODS

Patients diagnosed with gastric carcinoma attending the upper gastrointestinal surgical unit in the Royal Infirmary, Glasgow between April 1997 and December 2005 and who had a pretreatment measurement of albumin and C-reactive protein (CRP) were studied.

RESULTS

Most of the patients had stage III/IV disease and received palliative treatment. The minimum follow-up was 15 months. During follow-up, 157 (72%) patients died of their cancer. On univariate analysis, stage (p < 0.001), treatment (p < 0.001), albumin level (p < 0.001), and CRP level (p < 0.001) were significant predictors of survival. On multivariate analysis, stage (p < 0.001), treatment (p < 0.001), and CRP level (p < 0.001) remained significant predictors of survival. Albumin was no longer an independent predictor of survival.

CONCLUSIONS

Low albumin concentrations are associated with poorer survival in patients with gastric cancer. However, the strength of this relation with survival is dependent on the presence of a systemic inflammatory response, as evidenced by an elevated CRP level. Therefore, it appears that the relation between hypoalbuminemia and poor survival is secondary to that of the systemic inflammatory response.

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.

Identification of prognosis-related proteins in advanced gastric cancer by mass spectrometry-based comparative proteomics

PURPOSE

The objective of this study was to identify differentially expressed proteins of advanced gastric cancer from patients with different prognosis using NanoLC-MS/MS (LTQ) (nanoflow liquid chromatography system interfaced with a linear ion trap LTQ mass spectrometer).

METHODS

Eight gastric cancer patients with relatively early TNM stage and survival time >34 months were identified as good survival (group G), while the other eight with late stage and survival time <15 months as poor survival (group P). The total protein of the tissue samples from each group was extracted and pooled together respectively. The resulting two protein mixtures were trypsin-digested and analyzed using NanoLC-MS/MS (LTQ). Database searches were done against NCBI non-redundant database and SWISS-PROT database and the identified proteins were classified through an online Web Gene Ontology Annotation Plot tool. Immunohistochemistry was used to verify candidate prognosis-related proteins.

RESULTS

There were 284 and 213 proteins identified for group G and group P respectively. And 117 proteins were detected exclusively in group G and 46 proteins exclusively in group P. These protein markers function in calcium ion signaling pathway, cellular metabolism, cytoskeleton formation, stress reaction, etc. Among those, the down-regulated expression of S100P was verified to claim a poor clinical outcome of gastric cancer patients (P = 0.0375).

CONCLUSION

The MS-based proteomics approach is efficient in identifying differentially expressed proteins in relation to prognosis of advanced gastric cancer patients. These differentially expressed proteins could be potential prognosis-related cancer markers and deserve further validation and functional study.

Advanced gastric cancer with or without peritoneal carcinomatosis treated with hyperthermic intraperitoneal chemotherapy: a single western center experience

INTRODUCTION

The aim of this article was to evaluate the role of hyperthermic intraperitoneal chemotherapy (HIPEC), associated or not to cytoreductive surgery (CS) in the treatment of different stages of advanced gastric cancer (AGC).

PATIENTS AND METHODS

Thirty seven patients with AGC who underwent 43 HIPEC from June 1992 to February 2007 were included. HIPEC used Mitomycin-C and Cisplatin for 60-90 min at 41-43 degrees C intra-abdominal temperature. The main endpoints were long-term survivals, morbidity and mortality rates.

RESULTS

Eleven patients had no demonstrable sign of PC and constituted the Prophylactic-group, while 26 patients had macroscopic PC (PC-group). Five patients were Gilly 1 or 2 (nodules <0.5 cm) and 21 Gilly 3 or 4 (nodules >or=0.5 cm). In the PC-group a complete curative CS was achieved before HIPEC in 8 (PC-curative subgroup) and a palliative HIPEC in 18 patients (PC-palliative subgroup). The overall 30-days mortality was 5% (2 patients). Two patients in the Prophylactic group died within 6 months after hospital discharge (overall mortality 11%). The estimated risk of death per procedure was 9%. Ten patients (27%) presented one or more complications. The median survival was 23.4 months in the Prophylactic group, and 6.6 months in the PC-group (p<0.05). The median survival in the PC-curative subgroup was 15 vs 3.9 months in the PC-palliative subgroup (p=0.007). The median survival according to Gilly classification was significantly different (Gilly 1&2 vs Gilly 3&4, 15 vs 4 months respectively, p=0.014). The global recurrence rates between the Prophylactic group and the PC-curative subgroup at 2years were 36% vs 50% respectively. The median delay to recurrence was 18.5 vs 9.7 months respectively.

CONCLUSION

HIPEC might be useful to improve the survival in selected patients with ACG only when a complete cytoreduction can be achieved. Despite encouraging data, prospective studies, based on larger cohorts of patients are required to assess the role of this procedure as a prophylactic treatment in patients with AGC.

CA72-4 antigen levels in serum and peritoneal washing in gastric cancer: correlation with morphological aspects of neoplasia

BACKGROUND: Determining levels of tumor markers in peritoneal washing enables likelihood of peritoneal recurrence to be ascertained in patients with high marker levels, thereby allowing provision of more accurate adjuvant treatment and postoperative follow up. AIM: To analyze the relationship between levels of tumor marker CA72-4 in serum and peritoneal washing, and morphological aspects of gastric carcinoma. METHOD: This study analyzed 32 consecutively-operated patients with gastric carcinoma, who underwent subtotal, total or palliative gastrectomy. The variables studied were CA72-4 levels in serum and peritoneal washing, lesion site, stage, degree of cell differentiation, operation performed, and number of extirpated and involvement lymph nodes. Of the 32 patient sample, 21 (65.6%) were male and 11 (34.4%) female. Mean age was 62.6 ± 14.2 years (29 to 91 years). Following anesthetic induction, peripherical venous blood was collected through percutaneous punction of an upper limb vein. After the procedure, 50 mL of physiologic solution at 37ºC was introduced into the cul-de-sac. A 10 mL volume of this liquid was aspirated from the cavity and the peritoneal washing tested for CA72-4 levels. Normal values for CA72-4 levels in serum were considered <7 U/mL and high levels as >7U/mL, whilst for the peritoneal washing normal levels were <0.61 U/mL, and abnormal >0.61 U/mL. RESULTS: Mean pre-operative serum levels for CA72-4 were 6.55 U/mL ± 15.30 (0.3 to 75.30 U/mL) whilst the mean level of CA72-4 in peritoneal washing was 8.50 U/mL ± 26.72 (0.3 to 142.00 U/mL); correlation between these levels was significant. Lymph nodes involvement by the gastric carcinoma correlated significantly with higher CA72-4 levels in both serum and peritoneal wash. There was no statistically significant correlation between serum level of CA72-4 and invasion into serosa by the gastric carcinoma. There was however, significant correlation between peritoneal washing levels of CA72-4 and involvement of serosa by gastric carcinoma. There was also a significant correlation between more advanced stages of gastric carcinoma and higher levels of CA72-4 in the peritoneal washing, although serum levels of CA72-4 and more advanced stage of gastric neoplasia showed no significant correlation. Degrees of cellular differentiation in the gastric carcinoma did not differ significantly with CA72-4 levels in serum or peritoneal washing. CONCLUSION: High levels of CA72-4 in peritoneal washing correlated significantly with lymph node metastasis and serosa involvement by the neoplasia, and also with more advanced stage of gastric carcinoma. The levels of CA72-4 in the blood correlated significantly with lymph node involvement by the gastric carcinoma, but not with serosa invasion or more advanced stage of neoplasia.

Overexpression of CLIC1 in human gastric carcinoma and its clinicopathological significance

Gastric cancer is the second most common cancer worldwide and the fifth leading cause of cancer-related death in Taiwan. Identification of biomarkers is essential to improve patient survival. Fifty aberrantly expressed proteins were identified using 2-DE combined with MALDI TOF MS and were grouped based on their function. The overexpression of proteins was confirmed using real-time quantitative RT-PCR, Western blot, and immunohistochemical analysis. The clinicopathological correlations and prognostic significance of these aberrantly expressed proteins were evaluated to determine the novel gastric cancer biomarkers. In this study, expression of chloride intracellular channel 1 (CLIC1) is significantly up-regulated in 67.9% of gastric patients and was selected for further study. The CLIC1 expression in tumor tissues was increased by 1.95-fold (range, 0.01-6.19-fold) compared with that expressed by adjacent noncancerous mucosa. Elevated CLIC1 expression was strongly correlated with lymph node metastasis, lymphatic invasion, perineural invasion, and pathological staging. Additionally, the 5-year survival rate for the low CLIC1 expression group (n = 28; <1.72-fold) was higher than that for the high CLIC1 expression group (n = 28; >or=1.72-fold) (log rank, p = 0.0300). Experimental results indicate that overexpression of CLIC1 is a potential prognostic marker for gastric cancer.

Overexpression of Cripto and its prognostic significance in breast cancer: a study with long-term survival

INTRODUCTION

Cripto is a founding member of the EGF-CFC family, and plays an important role in tumourigenesis, tumour cell proliferation and migration. We aimed to determine the significance of Cripto expression on the survival of patients with breast cancer.

METHODS

Immunohistochemical detection of Cripto was performed by using mAb C13 on 120 formalin-fixed paraffin-embedded breast tumour specimens in tissue microarrays. This cohort comprises a series of 120 patients with primary operable breast cancer diagnosed between 1989 and 1995, retrieved from the Concord Repatriation General Hospital breast carcinoma database.

RESULTS

Using a cutoff value of 80%, Cripto overexpressed in 57 of the 120 (47.5%) patients. We found significant associations between overexpression of Cripto and the Nottingham Prognostic Index (NPI, p<0.01), histological grade (p<0.01), pathological tumour type (p=0.04), PR (p=0.02) as well as Ki-67 (p=0.02). Univariate analysis reveals that there is a significant correlation between overexpression of Cripto and survival (p=0.0003). Cox regression analysis indicates that the overexpression of Cripto is an independent prognostic factor in breast cancer (HR 2.79, 95%CI 1.20-6.50).

CONCLUSION

The unique epitope recognized by mAb C13 is overexpressed on breast tumour tissues. In this series of invasive breast cancers, overexpression of Cripto was more often found in high grade and poor prognosis tumours compared to low grade and good prognosis breast cancers. Moreover, overexpression of Cripto was significantly associated with decreased patient survival.

Molecular regulation of an invasion-related molecule – options for tumour staging and clinical strategies

This review provides a summary of the European Association for Cancer Research Award Lecture, presented at the ECCO13 meeting in Paris in November 2005. It is a brief overview on the biological and clinical relevance of the urokinase receptor (u-PAR), an essential molecule to promote invasive and metastatic tumour phenotype and shown to be associated with early relapse and poor prognosis in many different types of cancers. The review summarizes the most important transcriptional mechanisms regulating u-PAR gene, and will focus on the differential binding of transcription factors to u-PAR promoter elements from studies in resected tumour and normal tissues of colorectal and gastric cancer patients. These studies conducted by our group may help to understand transcriptional mechanisms, which are employed to promote invasion and metastasis, in subpopulations of cancer patients. Such studies could lead to a more target-oriented patient selection and therapy against transcriptional and oncogeneic regulators in cancer.

Evaluation of an inflammation-based prognostic score in patients with inoperable gastro-oesophageal cancer

There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients with advanced cancer. The aim of the present study was to examine whether an inflammation-based prognostic score (Glasgow Prognostic score, GPS) was associated with survival, in patients with inoperable gastro-oesophageal cancer. Patients diagnosed with inoperable gastro-oesophageal carcinoma and who had measurement of albumin and C-reactive protein concentrations, at the time of diagnosis, were studied (n=258). Clinical information was obtained from a gastro-oesophageal cancer database and analysis of the case notes. Patients with both an elevated C-reactive protein (>10 mg l(-1)) and hypoalbuminaemia (<35 g l(-1)) were allocated a GPS score of 2. Patients in whom only one of these biochemical abnormalities was present were allocated a GPS score of 1, and patients with a normal C-reactive protein and albumin were allocated a score of 0. On multivariate survival analysis, age (hazard ratio (HR) 1.22, 95% CI 1.02-1.46, P<0.05), stage (HR 1.55, 95% CI 1.30-1.83, P<0.001), the GPS (HR 1.51, 95% CI 1.22-1.86, P<0.001) and treatment (HR 2.53, 95% CI 1.80-3.56, P<0.001) were significant independent predictors of cancer survival. A 12-month cancer-specific survival in patients with stage I/II disease receiving active treatment was 67 and 60% for a GPS of 0 and 1, respectively. For stage III/IV disease, 12 months cancer-specific survival was 57, 25 and 12% for a GPS of 0, 1 and 2, respectively. In the present study, the GPS predicted cancer-specific survival, independent of stage and treatment received, in patients with inoperable gastro-oesophageal cancer. Moreover, the GPS may be used in combination with conventional staging techniques to improve the prediction of survival in patients with inoperable gastro-oesophageal cancer.

Predicting individual survival after gastric cancer resection: validation of a U.S.-derived nomogram at a single high-volume center in Europe

OBJECTIVE

Validation of a U.S.-derived nomogram for individual prediction of disease-specific gastric cancer survival at a European institution.

SUMMARY BACKGROUND DATA

One major issue of modern cancer treatment is the individualization of therapy. For gastric cancer, Kattan et al, at Memorial Sloan-Kettering Cancer Center, New York, NY, developed a nomogram, allowing to predict individual patient risk of tumor-related death after R0 resection from basic patient-related variables. The validity of the nomogram has not yet been shown in patients from other institutions. The accuracy of the nomogram when applied to patients after having undergone R0 gastric cancer resection at a European high-volume center was investigated.

METHODS

Clinical data from patients who underwent R0 gastric cancer resection at Klinikum rechts der Isar, Technical University of Munich, Germany and fitted the respective derivation criteria were used for external validation (n = 862). Nomogram predictions for 60- and 108-month disease-specific survival were calculated for each patient and compared with actual survival. The concordance index was used as an accuracy measure.

RESULTS

The bootstrap-corrected concordance index was 0.77 and was superior when compared with the predictive ability of International Union Against Cancer tumor stage (P < 0.008). Nomogram calibration was excellent for 60-month disease-specific survival. Nomogram predictions showed the trend to underestimate survival in stage II/III disease of the MRI patients.

CONCLUSIONS

The use of the nomogram created by Kattan et al is not only confined to the institution where it was created, but it can be adopted by other institutions with similar surgical strategies.

Gene expression profile predicts patient survival of gastric cancer after surgical resection

PURPOSE

This study was conducted to characterize gene expression profile of survival in patients with surgically curable gastric cancer by using an in-house membrane microarray and developing a survival prediction model.

MATERIALS AND METHODS

Data of cDNA microarrays were obtained from 18 pairs of cancerous and noncancerous gastric tissues. Nine patients who survived > 30 months were identified as good survival, and the other nine, who survived < 12 months, were identified as poor survival. Supervised analysis was performed to identify a gene expression profile by good and poor survival. Semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to confirm the microarray data in 10 patients with sufficient RNA. Using these 10 patients and another 10 patients selected randomly from 40 newly enrolled patients as the training group, the RT-PCR status of the confirmed genes was used for predicting good versus poor survival. Finally, the prediction model was tested in the remaining 30 newly enrolled gastric cancer patients.

RESULTS

A survival prediction model consisting of three genes (CD36, SLAM, PIM-1) was developed. This model could correctly predict poor or good survival in 23 (76.7%) of 30 newly enrolled patients, and yielded a specificity of 80% and a sensitivity of 73.3%. The survival rate of the patients predicted to have good survival was significantly higher than that of those predicted to have poor survival in the test group as a whole (N = 30; P = .00531) and in stage III patients (n = 16; P = .04467).

CONCLUSION

The semiquantitative RT-PCR gene expression profiling of three genes extracted from microarray study can accurately predict surgery-related outcome in gastric cancer patients.

Relationship between matrix metalloproteinase-2 mRNA expression and clinicopathological and urokinase-type plasminogen activator system parameters and prognosis in human gastric cancer

AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer.

METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively. Survival analyses were done using the Kaplan-Meier method.

RESULTS: The expression rates of MMP-2 mRNA, uPA and uPA-R mRNA in tumor tissues (31%, 41%, and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; χ² = 4.59, 43.58, and 53.24 respectively, P<0.05, 0.0001, and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, χ² = 7.61, P<0.05), Lauren’s classification of diffuse/mixed types: 54.2%, intestinal type: 26.3%, χ² = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, χ² = 5.72 and 6.40 respectively, P<0.05). Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P = 0.0083, 0.0160, and 0.0094, respectively).

CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.

Prediction of recurrence in advanced gastric cancer patients after curative resection by gene expression profiling

The prognosis of patients with advanced gastric cancer remains unfavorable. Even after curative resection, 40% of patients with advanced gastric cancer die of recurrence. Conventional clinicopathlogic findings are sometimes inadequate for predicting recurrence in individuals. Hence, we tried to construct a new diagnostic system, which predicts recurrence in patients with advanced gastric cancer after curative resection based on molecular analysis. Gastric cancer progression is a function of multiple genetic events that may affect the expression of large number of genes. We performed gene expression profiling with 2,304 genes in 60 advanced gastric cancer patients who underwent curative resection using a PCR array technique, a high-throughput quantitative RT-PCR technique. The diagnostic system, which was constructed from the learning set comprised of 40 patients with the most informative 29 genes, classified each case into a good-signature or poor-signature group. Then, we confirmed the predictive performance in an additional test set comprised of 20 patients, and the prediction accuracy for recurrence was 75%. Kaplan-Meier analysis revealed significant difference between the good-signature and the poor-signature group (p = 0.0125). Especially in patients with smaller tumor (< or = 5 cm), less developed LN metastasis (N(0,1)), or earlier stage (stages I and II), the prediction accuracy was high (88.9%, 84.6%, or 81.8%, respectively). Our diagnostic system based on systematic analysis of gene expression profiling can predict the recurrence at clinically meaningful level. By combining our system with conventional clinicopathologic factors, we can improve the prediction of recurrence in patients with advanced gastric cancer who underwent curative surgery.

Lysophospholipids transactivate HER2/neu (erbB-2) in human gastric cancer cells

The ligand-less receptor HER2/neu (erbB-2) has been proposed as a prognostic marker of gastric cancer that correlates with poor clinical outcome, indicating that HER2 signals play an important role in gastric cancer progression. This study demonstrated that two major natural lysophospholipids, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), induce rapid and transient phosphorylation of HER2 in two human gastric cancer cell lines, MKN28 and MKN74 cells. We also revealed that tyrosine phosphorylation of HER2 induced by both lysophospholipids was significantly attenuated by two inhibitors, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, AG1478, and a broad-spectrum matrix metalloproteinase inhibitor, GM6001. This suggests that the pathway of HER2 transactivation induced by these lysophospholipids is dependent on the proteolytically released EGFR ligands. Our results indicate that LPA and S1P act upstream of HER2 in gastric cancer cells, and thus may act as potent stimulators of gastric cancer.

Overexpression of SPARC gene in human gastric carcinoma and its clinic-pathologic significance

Gastric cancer is the second most common cancer in the world and the fifth leading cause of cancer-related death in Taiwan. To improve the survival of gastric cancer patients, biomarkers for early detection and effective anticancer therapy are required. An essential first step is to profile gene expression in gastric cancer and identify genes that are aberrantly expressed, and to do this cDNA microarrays were performed. The clinic–pathologic correlation and prognostic significance of the aberrantly expressed genes were evaluated to identify novel biomarkers of gastric cancer. Fresh surgical samples of tumour tissue and matching noncancerous mucosa were obtained immediately after gastric resection in 43 patients. Secreted Protein, Acidic and Rich in Cysteine (SPARC) (Osteonectins), one of the most highly expressed genes in both intestinal and diffuse gastric cancers in our microarray results, was selected for further study. The overexpression of SPARC was verified using real-time quantitative-reverse transcription–polymerase chain reaction (Q-RT–PCR), Northern blot and immunohistochemical staining. The expression of SPARC in tumour tissues was, on average, 4.27-fold increased (95% CI 2.68–5.85) compared to adjacent noncancerous mucosa (P<0.001). The expression of SPARC was higher in advanced (T2, T3 and T4) cancer compared to the early (T1) cancer (P=0.048) with regard to depth of wall invasion. Higher expression of SPARC was significantly associated with lymph node metastasis (P<0.001), lymphatic invasion (P=0.004) and perineural invasion (P=0.047). Expression of SPARC in patients in stage II and above was significantly higher than those in stage I (P=0.017). The 3-year survival of patients with lower expression of SPARC was significantly better than those with a higher expression (log rank P=0.047). These data indicate the potential of SPARC as a prognostic marker for gastric cancer.

Clinical significance of preoperative regional intra-arterial infusion chemotherapy for advanced gastric cancer

AIM: Preoperative intra-arterial infusion chemotherapy could increase the radical resection rate of advanced gastric cancer, but its effect on the long-term survival has not been assessed. This study was designed to evaluate the clinical significance of preoperative intra-arterial infusion chemotherapy for advanced gastric cancer.

METHODS: Clinicopathological data of 91 patients who underwent curative resection for advanced gastric cancer were collected. Among them, 37 patients undertaken preoperative intra-arterial infusion chemotherapy were used as the interventional chemotherapy group, and the remaining 54 patients as the control group. Eleven factors including clinicopathological variables, treatment procedures and molecular biological makers that might contribute to the long-term survival rate were analyzed using Cox multivariate regression analysis.

RESULTS: The 5-year survival rate was 52.5% and 39.8%, respectively, for the interventional group and the control group (P < 0.05). Cox multivariate regression analysis revealed that the TNM stage (P < 0.001), preoperative intra-arterial infusion chemotherapy (P = 0.029) and growth pattern (P = 0.042) were the independent factors for the long-term survival of patients with advanced gastric cancer.

CONCLUSION: Preoperative intra-arterial infusion chemotherapy plays an important role in improving the prognosis of advanced gastric cancer.

Molecular regulation of urokinase-receptor gene expression as one potential concept for molecular staging and therapy

The urokinase-receptor (u-PAR) is a central molecule of invasion and metastasis promoting plasminogen-dependent extracellular matrix degradation in diverse carcinoma types such as gastric or colon cancer. Overexpression of u-PAR has been reported to occur mainly at the transcriptional level in malignant cells, and has been shown to indicate a poor clinical prognosis of cancer patients. This review will give an overview on experimental findings on u-PAR and its function, molecular mechanisms of its regulation, and its impact for future clinical decision planning and potential therapeutic concepts.

Transcriptional regulation of the urokinase receptor (u-PAR)--a central molecule of invasion and metastasis

The phenomenon of tumor-associated proteolysis has been acknowledged as a decisive step in the progression of cancer. This short review focuses on the urokinase receptor (u-PAR), a central molecule involved in tumor-associated invasion and metastasis, and summarizes the transcriptional regulation of u-PAR. The urokinase receptor (u-PAR) is a heavily glycosylated cell surface protein and binds the serine protease urokinase specifically and with high affinity. It consists of three similar cysteine-rich repeats and is anchored to the cell membrane via a GPI-anchor. The u-PAR gene comprises 7 exons and is located on chromosome 19q13. Transcriptional activation of the u-PAR promoter region can be induced by binding of transcription factors (Sp1, AP-1, AP-2, NF-kappa B). One current study gives an example for transcriptional downregulation of u-PAR through a PEA3/ets transcriptional silencing element. Knowledge of the molecular regulation of this molecule in tumor cells could be very important for diagnosis and therapy in the near future.

Combined p53/Bax mutation results in extremely poor prognosis in gastric carcinoma with low microsatellite instability

Gastric cancer is highly refractory to DNA-damaging therapies. We therefore studied both gene mutation and protein expression of p53 and Bax in a cohort of 116 patients with gastric cancer who underwent R0-resection with a curative intent. Bax mutation was independent from severe microsatellite instability (MSI), that is, global mismatch repair deficiency as determined by analysis of BAT-25/BAT-26 microsatellite markers. Thus, Bax-frameshift mutation is a feature of tumors with low MSI. In contrast and as expected, no p53 mutations were observed in the microsatellite instable tumors. p53 Mutation or p53 overexpression did not have an impact on disease prognosis. p53-Inactivation was, however, associated with an extremely poor prognosis in the subgroup of patients with Bax-mutated tumors. Thus, we show for the first time that the combined mutation of p53 and Bax, two key regulators of the mitochondrial apoptosis pathway, results in an extremely aggressive tumor biology and poor clinical prognosis.

The active fraction of plasmatic plasminogen activator inhibitor type 1 as a possible indicator of increased risk for metastatic melanoma

Plasminogen activator inhibitor type 1 (PAI1) is considered to be the main regulator of fibrinolytic activity in blood and has been identified as a key-enzyme in the metastasis and vascularization of solid tumors. The aim of this study was to determine whether high or low plasma levels and/or activity of PAI1 correlate with the presence of metastatic disease for patients with melanoma. We hypothesized that the presence of metastases could result in a disturbance of the fibrinolytic balance of the blood. To test our hypothesis, we have developed a unique enzyme-linked immunosorbent assay (ELISA) that can measure both the total amount as well as the active fraction of PAI1 in the plasma. We then used this novel assay to analyze the plasmatic PAI1 levels and activity of patients with advanced melanoma (AM, n = 18) and primary melanoma (PM, n = 21) and compare it to a control population (n = 38). We found no statistically significant difference in the total plasmatic PAI1 levels between the controls and patients with PM or AM (P = 0.6199). In contrast, there was a significant difference in the active fraction of PAI1 between the controls and patients with PM or AM (P = 0.0076). The difference between the control and AM groups was highly significant (P = 0.0042). A value of less than 44% active PAI1 was shown to be clinically meaningful by linear discriminant analysis. Surprisingly, the difference between the control and PM groups was also significant--although borderline (P = 0.0488). Of the patients with PM, 19% had PAI1 activity values less than 44%, which strongly supports further investigations to determine whether plasmatic PAI1 activity might be a biological marker of increased metastatic risk.

c-erb B-2 expression is associated with tumor location and venous invasion and influences survival of patients with gastric carcinoma

The HER-2/neu gene or c-erb B-2, localized on chromosome 17q, belongs to a family of tyrosine kinase receptors and shares extensive homology with the epidermal growth factor receptor. c-erb B-2 gene amplification and protein overexpression have been reported in several human cancers. The prognostic value of this genetic alteration in gastric carcinoma is far from being established. In the present study, formalin-fixed, paraffin-embedded gastric carcinoma tissues from 157 patients were evaluated for c-erb B-2 overexpression, by immunohistochemistry using a polyclonal antibody. c-erb B-2 expression was evaluated according to clinical and pathological parameters, and to the survival of the patients. Our results show that: (1). c-erb B-2 was overexpressed in 15.3% of gastric carcinoma cases; (2). c-erb B-2 overexpression was significantly more frequent in cardia (23.8%) and fundus/body (25.0%) carcinomas than in antrum (7.2%) carcinomas; (3). c-erb B-2 overexpression was significantly associated with venous invasion; (4). c-erb B-2 is a prognostic factor for gastric carcinoma.

Biomarker identification by feature wrappers

Gene expression studies bridge the gap between DNA information and trait information by dissecting biochemical pathways into intermediate components between genotype and phenotype. These studies open new avenues for identifying complex disease genes and biomarkers for disease diagnosis and for assessing drug efficacy and toxicity. However, the majority of analytical methods applied to gene expression data are not efficient for biomarker identification and disease diagnosis. In this paper, we propose a general framework to incorporate feature (gene) selection into pattern recognition in the process to identify biomarkers. Using this framework, we develop three feature wrappers that search through the space of feature subsets using the classification error as measure of goodness for a particular feature subset being "wrapped around": linear discriminant analysis, logistic regression, and support vector machines. To effectively carry out this computationally intensive search process, we employ sequential forward search and sequential forward floating search algorithms. To evaluate the performance of feature selection for biomarker identification we have applied the proposed methods to three data sets. The preliminary results demonstrate that very high classification accuracy can be attained by identified composite classifiers with several biomarkers.

p27(Kip1) loss does not predict survival in patients with advanced gastric carcinoma

BACKGROUND

p27(Kip1) is a cyclin-dependent kinase inhibitor whose loss is associated with disease progression and an unfavorable outcome in several malignancies. The authors studied its expression in a consecutive series of resected gastric carcinomas.

METHODS

Expression of p27(Kip1) in 71 advanced gastric carcinomas and 10 lymph nodes containing metastases was determined using an avidin-biotin-peroxidase immunohistochemical method. The relations between p27(Kip1) expression and pathologic features, patient characteristics, and survival were analyzed.

RESULTS

p27(Kip1) levels in gastric carcinomas ranged from 0.63-82.97% (median, 23. 10%; mean, 27.99%). There was no association found between p27(Kip1) expression and patient gender (P = 0.21), patient age (P = 0.13), tumor stage (P = 0.17), tumor grade (P = 0.22), or histologic type (P = 0.72). Univariate analysis showed that long term survival was related to stage (P < 0.0001) and grade (P = 0.03). However, tumors with p27(Kip1) levels above and below the median value were associated with a similar outcome, regardless of whether all cases (P = 0.19) or those without metastatic disease (P = 0.50) or those with residual or metastatic disease (P = 0.92) were included. When entered into a multivariate analysis, stage (P < 0.0001) and grade (P = 0.05), but not p27(Kip1) levels (P = 0.16), were found to be related to patient outcome. In lymph node metastases, p27(Kip1) expression (median, 16.5%) was similar to that found in the corresponding primary lesion (median, 30.9%).

CONCLUSIONS

p27(Kip1) may play a role in the pathogenesis and progression of gastric carcinoma, but its expression is unlikely to be useful as a prognostic indicator, at least in European patients with advanced disease.

Multidisciplinary approach to esophageal and gastric cancer

Despite marked advances in surgical therapy for patients with esophageal, esophagogastric, and gastric cancers, the overall prognosis of these patients has not markedly improved during the past decades. Multidisciplinary approaches using adjuvant postoperative and neoadjuvant preoperative therapeutic principles have received increasing attention with regard to the management of these patients. A series of randomized, prospective trials has demonstrated that adjuvant postoperative radiation or chemotherapy does not result in a convincing survival advantage after complete tumor resection in esophageal, esophagogastric junction, or gastric cancer. The available data on the role of neoadjuvant preoperative therapy are not yet conclusive. Although neoadjuvant therapy may reduce the tumor mass in many patients, several randomized, controlled trials have shown that, compared with primary resection, a multimodal approach does not result in a survival benefit in patients with locoregional, that is, potentially resectable, tumors. In contrast, in patients with locally advanced tumors, that is, patients in whom complete tumor removal with primary surgery seems unlikely, neoadjuvant therapy increases the likelihood of complete tumor resection on subsequent surgery, but only patients with objective histopathologic response to preoperative therapy seem to benefit from this approach. Consequently, in the future, improvements in the overall survival of patients with esophageal, esophagogastric junction, or gastric cancer most likely will be achieved only by tailored therapeutic strategies that are based on the individual tumor location, tumor stage, and consideration of established prognostic factors. A clear classification of the underlying tumor entity, a profound knowledge of the prognostic factors applicable, a thorough preoperative staging, and identification of parameters that allow for the prediction of response to preoperative therapy will become essential for the selection of the optimal therapeutic modality for individual patients.