CDX2 expression in the stomach with intestinal metaplasia and intestinal-type cancer: Prognostic implications

Ampullary Cancer: Histological Subtypes, Markers, and Clinical Behaviour-State of the Art and Perspectives

There are different cancers in the peri-ampullary region, including pancreatic ductal adenocarcinoma (PDAC), duodenum cancers (DCs), and ampullary adenocarcinoma (AAC). Here, significant morphological-molecular characterizations should be necessary for the distinction of primary tumours and classifications of their subtypes of cancers. The sub classification of AACs might include up to five different variants, according to different points of view, concerning the prevalence of the two more-cellular components found in the ampulla. In particular, regarding the AACs, the most important subtypes are represented by the intestinal (INT) and the pancreato-biliary (PB) ones. The subtyping of AACs is essential for diagnosis, and their identifications have been impacting clinical management responses to treatments and overall survival (os) after surgery. Pb is associated with a worse clinical outcome. Otherwise, the criteria, through which are possible to attribute its subtype classification, are not well established. A triage of immune markers represented by CK7, CK20, and CDX-2 seem to represent the best compromise in order to split the cohort of AAC patients in the INT and PB groups. The test of choice for the sub-classification of AACs is represented by the immuno-histochemical approach, in which its molecular classification acquires its diagnostic, predictive, and prognostic value for both the INT and PB patients.

A Core Response to the CDX2 Homeoprotein During Development and in Pathologies

Whether a gene involved in distinct tissue or cell functions exerts a core of common molecular activities is a relevant topic in evolutionary, developmental, and pathological perspectives. Here, we addressed this question by focusing on the transcription factor and regulator of chromatin accessibility encoded by the Cdx2 homeobox gene that plays important functions during embryonic development and in adult diseases. By integrating RNAseq data in mouse embryogenesis, we unveiled a core set of common genes whose expression is responsive to the CDX2 homeoprotein during trophectoderm formation, posterior body elongation and intestinal specification. ChIPseq data analysis also identified a set of common chromosomal regions targeted by CDX2 at these three developmental steps. The transcriptional core set of genes was then validated with transgenic mouse models of loss or gain of function of Cdx2. Finally, based on human cancer data, we highlight the relevance of these results by displaying a significant number of human orthologous genes to the core set of mouse CDX2-responsive genes exhibiting an altered expression along with CDX2 in human malignancies.

Tissue microarray-chip featuring computerized immunophenotypical characterization more accurately subtypes ampullary adenocarcinoma than routine histology

BACKGROUND

Ampullary adenocarcinomas (AACs) are heterogeneous tumors currently classified into three important sub-classes (SC): Intestinal (INT), Pancreato-Biliary (PB) and Mixed-Type (MT). The different subgroups have similar clinical presentation and are treated by pancreatoduodenectomy with curative intent. However, they respond differently to chemotherapy and have different prognostic outcomes. The SC are often difficult to identify with conventional histology alone. The clinical outcome of all three remains unclear, particularly for MT.

AIM

To identify two main subtypes of AACs, using an immunohistochemical (IHC) score based on CDX2, CK7 and CK20.

METHODS

Tissue samples from 21 patients who had undergone resection of AAC were classified by HE histology and IHC expression of CDX2, CK7 and CK 20. An IHC score was obtained for each marker by counting the number of positive cells (0 = no stained cells; 1 < 25%; 2 < 50% and 3 > 50%) and their intensity (1 = weak; 2 = moderate and 3 = strong). A global score (GS) was then obtained by summation of the IHC scores of each marker. The MT tumors were grouped either with the INT or PB group based on the predominant immuno-molecular phenotype, obtaining only two AACs subtypes. The overall survival in INT and PB patients was obtained by Kaplan-Meier methods.

RESULTS

Histological parameters defined the AACs subtypes as follows: 15% INT, 45% PB and 40% MT. Using IHC expression and the GS, 75% and 25% of MT samples were assigned to either the INT or the PB group. The mean value of the GS was 9.5 (range 4-16). All INT samples had a GS above the average, distinct from the PB samples which had a GS score significantly below the average (P = 0.0011). The INT samples were identified by high expression of CDX2 and CK20, whereas PB samples exhibited high expression of CK7 and no expression of CK20 (P = 0.0008). The INT group had a statistically significant higher overall survival than in the PB group (85.7 mo vs 20.3 mo, HR: 8.39; 95%CI: 1.38 to 18.90; P = 0.0152).

CONCLUSION

The combination of histopathological and molecular criteria enables the classification of AACs into two clinically relevant histo-molecular phenotypes, which appear to represent distinct disorders with potentially significant changes to the current therapeutic strategies.

Homeobox protein CDX2 as a prognostic biomarker in solid malignancies: a meta-analysis

Background

CDX2 is a caudal-homeobox gene and its expression is abnormal in numerous tumour cell types. Nevertheless, its prognostic value for solid tumours requires further investigation. Hence, we conducted a meta-analysis to determine the significance of CDX2 as a prognostic biomarker in solid malignancies systematically.

Materials and Methods

We performed a systematic literature search in PUBMED and EMBASE up to May 2017. Retrospective studies comparing the prognostic value of different CDX2 levels in human malignancies were included. Data extractions and methodological assessments were performed separately by two investigators using a standard procedure. The statistical procedures were performed using Review Manager 5.3 and STATA/MP 14.0.

Results

A total of 26 retrospective studies met the inclusion criteria and comprised 5008 participants. Patients with CDX2 overexpression had significantly better 3-year, 5-year, 10-year and disease-free survival outcomes in solid malignancies, regardless of the cancer type, mean age, and source region. Nevertheless, there was no significant difference in the patients from Europe. The expression level of CDX2 was not statistically associated with cancer relapse. Moreover, our analysis showed that CDX2 overexpression is correlated to better responses to chemotherapy in patients with TNM IV stage cancers. The stability of the pooled outcomes was verified by sensitivity analysis. The funnel plots, Egger's test and Begg's test jointly confirmed that there was no publication bias.

Conclusions

Overexpression of CDX2 is a reliable biomarker of a better prognosis in solid malignancies.

Targeted CDX2 expression inhibits aggressive phenotypes of colon cancer cells in vitro and in vivo

Loss of caudal type homeobox 2 (CDX2) is associated with the development of human colorectal cancer, while human telomerase reverse transcriptase (hTERT) frequently occurs in variety of human cancers. We investigated the effects of restoration of CDX2 expression using a hypoxia-inducible hTERT promoter-driven vector (pLVX-5HRE-hTERTp-CDX2-3FLAG) on colon cancer cell viability, cell cycle distribution, apoptosis, colony formation, invasion ability and xenograft tumor growth in nude mice. CDX2 overexpression significantly inhibited viability, colony formation, and the invasion and migration ability of LoVo cells, and induced cell cycle arrest and apoptosis in vitro, especially under hypoxic culture conditions. Overexpression of CDX2 under normoxic conditions significantly suppressed the expression of TGF-β, cyclin D1, uPA, MMP-9, MMP-2, and Bcl-2, and stimulated the expression of collagen IV, laminin-1, and Bax. Overexpression of CDX2 reduced colon cancer xenograft tumor formation in nude mice which was associated with downregulation of Ki-67. In conclusion, overexpression of CDX2 using a hypoxia-inducible hTERT promoter-driven vector suppressed malignant progression of colon cancer cells in vitro and in vivo. These results suggest that pLVX-5HRE-hTERTp-CDX2-3FLAG gene therapy may be a promising novel approach to treat colon cancer.

Intestine-specific homeobox (ISX) induces intestinal metaplasia and cell proliferation to contribute to gastric carcinogenesis

BACKGROUND

Helicobacter pylori induces chronic inflammation and intestinal metaplasia (IM) through genetic and epigenetic changes and activation of intracellular signaling pathways that contribute to gastric carcinogenesis. However, the precise mechanism of IM in gastric carcinogenesis has not been fully elucidated. We previously found that intestine-specific homeobox (ISX) mRNA expression increased in organoids cultured from Helicobacter-infected mouse mucosa. In this study, we elucidate the role of ISX in the development of IM and gastric carcinogenesis.

METHODS

ISX expression was assessed in Helicobacter-infected mouse and human gastric mucosa. MKN45 gastric cancer cells were co-cultured with H. pylori to determine whether Helicobacter infection induced ISX expression. We established stable MKN45 transfected cells expressing ISX (Stable-ISX MKN45) and performed a spheroid colony formation assay and a xenograft model. We performed ISX immunohistochemistry in cancer and adjacent gastric tissues.

RESULTS

ISX expression was increased in mouse and human gastric mucosa infected with Helicobacter. The presence of IM and H. pylori infection in human stomach was correlated with ISX expression. H. pylori induced ISX mRNA and protein expression. CDX1/2, cyclinD1, and MUC2 were upregulated in Stable-ISX MKN45, whereas MUC5AC was downregulated. Stable-ISX MKN45 cells formed more spheroid colonies, and had high tumorigenic ability. ISX expression in gastric cancer and adjacent mucosa were correlated.

CONCLUSIONS

ISX expression induced by H. pylori infection may lead to IM and hyperproliferation of gastric mucosa through CDX1/2 and cyclinD1 expression, contributing to gastric carcinogenesis.

Lauren classification and individualized chemotherapy in gastric cancer

Gastric cancer is one of the most common malignancies worldwide. During the last 50 years, the histological classification of gastric carcinoma has been largely based on Lauren's criteria, in which gastric cancer is classified into two major histological subtypes, namely intestinal type and diffuse type adenocarcinoma. This classification was introduced in 1965, and remains currently widely accepted and employed, since it constitutes a simple and robust classification approach. The two histological subtypes of gastric cancer proposed by the Lauren classification exhibit a number of distinct clinical and molecular characteristics, including histogenesis, cell differentiation, epidemiology, etiology, carcinogenesis, biological behaviors and prognosis. Gastric cancer exhibits varied sensitivity to chemotherapy drugs and significant heterogeneity; therefore, the disease may be a target for individualized therapy. The Lauren classification may provide the basis for individualized treatment for advanced gastric cancer, which is increasingly gaining attention in the scientific field. However, few studies have investigated individualized treatment that is guided by pathological classification. The aim of the current review is to analyze the two major histological subtypes of gastric cancer, as proposed by the Lauren classification, and to discuss the implications of this for personalized chemotherapy.

Oesophageal adenocarcinoma and gastric cancer: should we mind the gap?

Over recent decades we have witnessed a shift in the anatomical distribution of gastric cancer (GC), which increasingly originates from the proximal stomach near the junction with the oesophagus. In parallel, there has been a dramatic rise in the incidence of oesophageal adenocarcinoma (OAC) in the lower oesophagus, which is associated with antecedent Barrett oesophagus (BO). In this context, there has been uncertainty regarding the characterization of adenocarcinomas spanning the area from the lower oesophagus to the distal stomach. Most relevant to this discussion is the distinction, if any, between OAC and intestinal-type GC of the proximal stomach. It is therefore timely to review our current understanding of OAC and intestinal-type GC, integrating advances from cell-of-origin studies and comprehensive genomic alteration analyses, ultimately enabling better insight into the relationship between these two cancers.

Reactivation of CDX2 in Gastric Cancer as Mark for Gene Silencing Memory

To explore the epigenetic mechanism that reactivates CDX2 (a homeobox transcription factor that serves as a tumor-suppressor gene) in intestinal-type gastric cancer during cancer progression, we examined the methylation status of the CDX2 gene promoter and the expression pattern of methyl-CpG binding protein-2 (MeCP2). From archives of the pathology records of surgically excised advanced stomach cancer cases in the Department of Molecular Pathology, Ehime University in a past decate (n=265), 10 cases of intestinal-type tubular adenocarcinoma, well-differentiated type (wel) with minor poorly-differentiated adenocarcinoma (por) components were selected. The expression pattern of CDX2, MUC2 and MeCP2 in these 10 cases was analyzed by immunohistochemistry. The cancerous and non-cancerous areas were selectively obtained by microdissection, and the methylation status of the CDX2 promoter of each area was assessed by methylation-specific polymerase chain reaction (MSP). In all 10 cases, CDX2 expression was clearly observed in the nucleus of the non-cancerous background of the intestinal metaplasic area, where the unmethylation pattern of the CDX2 gene promoter prevailed with reduced MeCP2 expression. In this metaplastic area, CDX2 expression was co-localized with its target gene, MUC2. CDX2 expression then disappeared from the deep invasive wel area. Reflecting the reduced CDX2 expression, microdissected samples from all the wel areas showed hypermethylation of the CDX2 gene promoter by MSP, with prominent MeCP2 expression. Interestingly, while hypermethylation of the CDX2 gene promoter was maintained in the por area in 8 of the 10 cases, CDX2 expression was restored in por areas where MeCP2 expression was markedly and selectively reduced. The other two cases, however, showed a constant MeCP2 expression level comparable to the surrounding deep invasive wel area with negative CDX2 expression. Therefore, gene silencing by hypermethylation may be overcome by the reduction of methyl-CpG binding proteins, resulting in apparent but non-functional reactivation of CDX2 as a mere molecular mark for gene silencing memory.

Validation of histomolecular classification utilizing histological subtype, MUC1, and CDX2 for prognostication of resected ampullary adenocarcinoma

Background:

Outcomes for ampullary adenocarcinomas are heterogeneous, and numerous methods of categorisation exist. A histomolecular phenotype based on histology, caudal-type homeodomain transcription factor 2 (CDX2) staining and Mucin 1 (MUC1) staining has recently been tested and validated in two cohorts. We attempt to validate this classification in a large patient population.

Methods:

Tissue samples from 163 patients with resected ampullary adenocarcinoma were classified based on histology and immunohistochemical expression of CDX2 and MUC1. A pancreaticobiliary histomolecular classification (PB) was defined as a sample with pancreaticobiliary histology, positive MUC1 and negative CDX2 expression.

Results:

There were 82 deaths; median follow-up of 32.4 months; and median overall survival of 87.7 (95% CI 42.9–109.5) months. PB comprised 28.2% of the cases. Factors associated with overall survival were histological subtype (P=0.0340); T1/2 vs T3/4 (P=0.001); perineural (P<0.0001) and lymphovascular (P=0.0203) invasion; and histomolecular intestinal histomolecular phenotype (INT) vs PB phenotype (106.4 vs 21.2 months, P<0.0001). Neither MUC1 nor CDX2 was statistically significant, although MUC1 positivity defined as ⩾10% staining was significant (P=0.0023). In multivariate analysis, age (HR 1.03), PB phenotype (HR 2.26) and perineural invasion (PNI; HR 2.26) were associated with poor survival.

Conclusions:

The prognostic ability of histomolecular phenotype has been validated in an independent cohort of ampullary adenocarcinoma patients.

Extending the functions of the homeotic transcription factor Cdx2 in the digestive system through nontranscriptional activities

The homeoprotein encoded by the intestinal-specific Cdx2 gene is a major regulator of gut development and homeostasis, also involved in colon cancer as well as in intestinal-type metaplasias when it is abnormally expressed outside the gut. At the molecular level, structure/function studies have demonstrated that the Cdx2 protein is a transcription factor containing a conserved homeotic DNA-binding domain made of three alpha helixes arranged in a helix-turn-helix motif, preceded by a transcriptional domain and followed by a regulatory domain. The protein interacts with several thousand sites on the chromatin and widely regulates intestinal functions in stem/progenitor cells as well as in mature differentiated cells. Yet, this transcription factor also acts trough original nontranscriptional mechanisms. Indeed, the identification of novel protein partners of Cdx2 and also of a splicing variant revealed unexpected functions in the control of signaling pathways like the Wnt and NF-κB pathways, in double-strand break DNA repair and in premessenger RNA splicing. These novel functions of Cdx2 must be considered to fully understand the complexity of the role of Cdx2 in the healthy intestine and in diseases.

OCT-1 overexpression is associated with poor prognosis in patients with well-differentiated gastric cancer

Octamer transcription factor-1 (OCT-1) is a well-known transcription factor that is reportedly overexpressed in intestinal metaplasia and gastric carcinoma in the intestine. In this study, we investigated OCT-1 overexpression as a prognostic factor for gastric cancer. The association between OCT-1 overexpression (detected using immunohistochemistry) and clinicopathological features including survival was evaluated. In vitro gain-of-function approaches were utilized to assess the function of OCT-1 in malignancy. Analysis of OCT-1 expression in patients with gastric cancer with well-differentiated carcinoma as per the World Health Organization classification showed that OCT-1 overexpression was correlated with advanced tumor invasion (58.8 % of patients with advanced tumor invasion vs. 21.2 % of patients with early tumor invasion; p<0.01), lymph node metastasis (63.9 % of patients with metastasis vs. 24.1 % of those without; p=0.015), and cancer recurrence (83.3 % of patients with recurrence vs. 25.4 % of those without; p<0.01), as well as a lower survival rate (62.8 vs. 87.9 Mo; p<0.01). However, there were no significant differences in the levels of OCT-1 expression in gastric cancer patients with other carcinoma types (p>0.05). Furthermore, we found that the proliferation rate of OCT-1-overexpressing MKN-45 cells was higher than that of the control cells. OCT-1 overexpression may be a marker for poor prognosis in patients with well-differentiated gastric adenocarcinoma.

Utilization of CDX2 expression in diagnosing pancreatic ductal adenocarcinoma and predicting prognosis

CDX2, a master transcriptional regulator of intestinal cell differentiation and survival, has been used as a marker to indicate colorectal lineage in adenocarcinomas of unknown origin. Pancreatic ductal adenocarcinoma (PDAC) is one of the most common causes for adenocarcinomas of unknown origin, but CDX2 expression in pancreatic disease remains unclear. In this study, we systemically and extensively investigated the expression and role of CDX2 in PDAC. We reported that CDX2 expression is weak and heterogeneous is all normal pancreas and chronic pancreatitis. It is largely expressed in epithelial-lining cells of pancreatic ducts including main ducts, inter-lobular ducts, intra-lobular ducts, intercalated ducts and centroacinar cells, but not in acinar cells or islet cells. CDX2 expression is down regulated during the transformation process from PanIN to PDAC. Only one third of PDACs retain some degree of CDX2 expression, and this group of PDACs have reduced median survival time compared to that of CDX2 negative group (308 days vs. 586 days, p = 0.0065). Metastatic PDACs remain similar expression pattern to that of the primary sites. Our study clearly demonstrates CDX2 expression in pancreatic diseases including PDAC, which is practically important when CDX2 is used to establish the primary sites of adenocarcinomas of unknown origin. In addition, our study also provides CDX2 as a prognostic marker for PDAC and implicates an important role of CDX2 in the development of normal pancreas and PDAC.

Significance of glutathione peroxidase 1 and caudal-related homeodomain transcription factor in human gastric adenocarcinoma

Aim. To investigate the expressions of glutathione peroxidase 1 (GPX1) and caudal-related homeodomain transcription factor (CDX2) in GAC and their correlation with clinicopathological features and tumor cell proliferation. Methods. The expressions of GPX1, CDX2, and Ki67 were immunohistochemically evaluated in 172 GAC specimens. The association of GPX1 and CDX2 with patient's clinicopathological features and Ki67 positive rate was analyzed statistically. Results. In 172 cases of GAC, the expression of GPX1 was weaker than that in adjacent normal mucosa, and the expression of CDX2 was higher than that in adjacent normal mucosa. High expression GPX1 strong-expression was associated with differentiation, Lauren type, WHO type and extensive lymph node metastasis of GAC. High expression of CDX2 was associated with differentiation, Lauren type, WHO type, extensive lymph node metastasis, and TNM of GAC. Survival curves showed that expressions of GPX1 and CDX2 were factors of good outcome (P = .03 and .02, resp.). According to multivariate analysis, only lymph node metastasis, TNM stage, and CDX2 expression were independently associated with survival. In addition, a strong association of GPX1 expression was noted with Ki67 and CDX2. Conclusions. The expression of GPX1 and CDX2 may play a role in the carcinogenesis, differentiation, and progression of GAC, and CDX2 may be an independent prognostic factor.

Reactivation of the homeotic tumor suppressor gene CDX2 by 5-aza-2'-deoxycytidine-induced demethylation inhibits cell proliferation and induces caspase-independent apoptosis in gastric cancer cells

The DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is widely used as an anticancer drug for the treatment of leukemia and solid tumors. Gastric cancer (GC) patients who were positive for caudal type homeobox transcription factor 2 (CDX2) expression showed a higher survival rate compared with those who were CDX2 negative, which suggests that CDX2 performs a tumor suppressor role. However, the molecular mechanisms leading to the inactivation of CDX2 remain unclear. In the present study we demonstrated that the expression levels of CDX2 and DNA methyltransferase enzyme 1 (DNMT1) mRNA were significantly higher in GC compared with distal non-cancerous tissue. The expression of CDX2 mRNA was significantly correlated with Lauren classification, TNM stage and lymph node metastasis. DNMT1 mRNA expression was significantly correlated with TNM stage, pathological differentiation and lymph node metastasis. The expression of CDX2 mRNA was inversely correlated with that of DNMT1 mRNA in GC. Hypermethylation of the CDX2 gene promoter region, extremely low expression levels of CDX2 mRNA and no expression of CDX2 protein were the characteristics observed in MKN-45 and SGC-7901 GC cell lines. Following the treatment of MKN-45 cells with 5-aza-CdR, the hypermethylated CDX2 gene promoter region was demethylated and expression of CDX2 was upregulated, while DNMT1 expression was downregulated. Furthermore, a concentration- and time-dependent growth inhibition as well as increased apoptosis were observed. Caspase-3, −8 and −9 activities increased in a concentration-dependent manner following exposure to different concentrations of 5-aza-CdR. Therefore, our data show that the overexpression of DNMT1 and methylation of the CDX2 gene promoter region is likely to be responsible for CDX2 silencing in GC. 5-Aza-CdR may effectively induce re-expression of the CDX2 gene, inhibit cell proliferation and enhance the caspase-independent apoptosis of MKN-45 cells in vitro.

Prognostic significance of Cdx2 immunohistochemical expression in gastric cancer: a meta-analysis of published literatures

Cdx2 is a homeobox domain-containing transcription factor that is important in the development and differentiation of the intestinal cells, and served as a potential biomarker of tumor progression in early intestinal-type gastric cancer. However, its prognostic value and significance in gastric cancer remain controversial. A meta-analysis based on published studies was performed to obtain an accurate evaluation of the association between the presence of Cdx2-positive in clinical samples and clinical outcome. A total of 13 eligible retrospective cohort studies with 1513 patients were included. Cdx2-positive cases were significantly associated with higher male-to-female ratio (RR=1.27, 95% CI: 1.17-1.38, P<0.00001 fixed-effect), lower (I+II) clinical stage (RR=1.63, 95% CI: 1.42-1.87, P<0.00001 fixed-effect), better histologic differentiation (RR=1.54, 95% CI: 1.34-1.76, P<0.00001 fixed-effect), and lower rate of vascular invasion (RR=1.23, 95% CI: 1.08-1.41, P=0.002 fixed-effect) and lymph node metastasis (RR=1.52, 95% CI: 1.33-1.73, P<0.00001 fixed-effect), as well as higher 5-year survival rate (HR=2.22, 95% CI: 1.78-2.75, P<0.00001 fixed-effect). However, the presence of Cdx2 was not associated with tumor size. In summary, Cdx2 is a prognostic factor in gastric cancer, which acts as a marker of good outcome in patients with gastric cancer. Further clinical studies are needed to confirm the role of Cdx2 in clinical practice.

Expression and significance of homeodomain protein Cdx2 in gastric carcinoma and precancerous lesions

AIM: To investigate the expression and significance of caudal-related homeobox transcription factor (Cdx2) in gastric carcinoma (GC) and precancerous lesions.

METHODS: The expression of Cdx2 in GC, precancerous lesions and normal gastric mucosa were detected using immunohistochemical method. Hematoxylin and eosin staining, alcian blue/periodic acid-schiff and high iron diamine/alcian blue staining were used to classify intestinal metaplasia (IM) and GC.

RESULTS: Cdx2 was not detected in normal gastric mucosa. Cdx2 expression was detected in 87.1% (101/116) of IM, 50% (36/72) of dysplasia and 48.2% (41/85) of GC. The Cdx2-expressing cells in IM were more prevalent than in dysplasia and carcinoma (P < 0.05). There was no relationship between Cdx2 expression and the classification of IM or the degree of dysplasia. Expression of Cdx2 was significantly higher in intestinal-type carcinoma than in diffuse and mixed-type carcinoma (P < 0.05). Positive expression of Cdx2 was mainly found in moderately to well differentiated GC. There was a negative association between nuclear Cdx2 expression and lymph node metastasis and tumor, nodes, metastasis stage of GC (P < 0.05). The patients with Cdx2-positive expression showed a higher survival rate than those with Cdx2-negative expression (P = 0.038). Multivariate analysis revealed that the expression of Cdx2 and lymph node metastasis were independent prognostic indicators of GC (P < 0.05).

CONCLUSION: Cdx2 may be closely related to IM and the intestinal-type GC and implicate better biological behavior and outcome. Cdx2 is useful for predicting the prognosis of GC.

Gastric composite tumor of alpha fetoprotein-producing carcinoma/hepatoid adenocarcinoma and endocrine carcinoma with reference to cellular phenotypes

Alpha-fetoprotein-producing carcinoma (AFPC)/hepatoid adenocarcinoma (HAC) and neuroendocrine carcinoma (NEC) are uncommon in the stomach. Composite tumors consisting of these carcinomas and their histologic phenotypes are not well known. Between 2002 and 2007, to estimate the prevalence of composite tumors consisting of tubular adenocarcinoma, AFPC/HAC and NEC, we reviewed specimens obtained from 294 consecutive patients treated surgically for gastric cancer. We examined histological phenotype of tumors of AFPC or NEC containing the composite tumor by evaluating immunohistochemical expressions of MUC2, MUC5AC, MUC6, CDX2, and SOX2. Immunohistochemically, AFPC/HAC dominantly showed the intestinal or mixed phenotype, and NEC frequently showed the gastric phenotype. In the composite tumor, the tubular and hepatoid components showed the gastric phenotype, and the neuroendocrine component showed the mixed type. The unique composite tumor predominantly showed the gastric phenotype, and the hepatoid and neuroendocrine components were considered to be differentiated from the tubular component.

CDX2 as a marker for intestinal differentiation: Its utility and limitations

CDX2 is a nuclear homeobox transcription factor that belongs to the caudal-related family of CDX homeobox genes. The gene encoding CDX2 is a nonclustered hexapeptide located on chromosome 13q12-13. Homeobox genes play an essential role in the control of normal embryonic development. CDX2 is crucial for axial patterning of the alimentary tract during embryonic development and is involved in the processes of intestinal cell proliferation, differentiation, adhesion, and apoptosis. It is considered specific for enterocytes and has been used for the diagnosis of primary and metastatic colorectal adenocarcinoma. CDX2 expression has been reported to be organ specific and is normally expressed throughout embryonic and postnatal life within the nuclei of epithelial cells of the alimentary tract from the proximal duodenum to the distal rectum. In this review, the authors elaborate on the diagnostic utility of CDX2 in gastrointestinal tumors and other neoplasms with intestinal differentiation. Limitations with its use as the sole predictor of a gastrointestinal origin of metastatic carcinomas are also discussed.

The relationship among PDX1, CDX2, and mucin profiles in gastric carcinomas; correlations with clinicopathologic parameters

PURPOSE

Several studies performed on pancreatic-duodenal homeobox 1 (PDX1) have demonstrated a loss of expression and negative tumor modulator effect in gastric carcinoma. Relations between PDX1 and gastric metaplasia, differentiated type of gastric carcinoma, and the early stage of the disease have been exhibited in previous reports. The aim of this study was to examine expressions of PDX1, caudal type homeobox 2 (CDX2) and mucin (MUC) profiles to address the role of PDX1 in gastric carcinogenesis and its relationship with CDX2.

METHODS

Seventy gastrectomy specimens were analyzed immunohistochemically for PDX1, CDX2, MUC2, MUC5AC, and MUC6 expressions. The sum of cytoplasmic and nuclear PDX1 immunostaining and PDX1 positivity were assessed. All of the antibodies were examined for a correlation with tumor type, clinicopathologic parameters, and metaplasias. The relation of Ki-67 proliferation index with the expression profiles was also investigated.

RESULTS

Neither PDX1 (66/70) nor CDX2 (37/70) and the mucin profiles (MUC2:11/70, MUC5AC:48/70, MUC6:41/70) showed a significant difference between differentiated and undifferentiated types of gastric carcinoma and clinicopathologic parameters. The PDX1 expression frequency was 94.3%, with an average PDX1 score of 8.8 ± 4.2. PDX1 and CDX2 expression showed a significant difference (P = 0.026 and P = 0.002, respectively) among the phenotypic classification of gastric carcinomas. All of the gastric and intestinal mixed-phenotype gastric carcinomas (GI-type) showed both PDX1 and CDX2 immunopositivity. Except for the relation of PDX1 score with MUC6 expression, no significant difference was detected between PDX1 and CDX2, MUC2, and MUC5AC expressions. A relationship between CDX2 and MUC2 and also between MUC5AC and MUC6 was found statistically. The Ki-67 proliferation index revealed a significant positive correlation with PDX1, CDX2, and MUC2 positivity.

CONCLUSIONS

PDX1 expression revealed a higher positivity in gastric carcinomas than the previous studies and showed no relation with tumor type, clinicopathologic parameters, CDX2 expression, or mucin profiles. However, a significant relation of PDX1 and CDX2 expressions among phenotypic classification of gastric carcinomas reveals an idea about similar functions for PDX1 and CDX2 in the evolution of gastric carcinoma.

CDX1 and CDX2 expression in intestinal metaplasia, dysplasia and gastric cancer

Intestinal metaplasia (IM) has been regarded as a premalignant condition. However, the pathogenesis of IM is not fully understood. The aim of this study was to evaluate the role of CDX1 and CDX2 in the formation of IM and the progression to dysplasia and gastric cancer (GC). A total of 270 subjects included 90 with GC, dysplasia and age- and sex-matched controls. Real-time PCR (RT-PCR) was performed with body specimens for CDX1 and CDX2. The expression of CDX2 was significantly higher in H. pylori positive group than H. pylori negative group (P = 0.045). CDX1 and CDX2 expression increased proportional to the IM grade of the body (P < 0.001). CDX2 expression was significantly higher in incomplete type of IM than in complete type (P = 0.045). The expression of CDX1 in dysplasia group was significantly higher than in the control group (P = 0.001); in addition, CDX1 and CDX2 in cancer group was significantly higher than control group (P < 0.001, and P < 0.001, respectively). Aberrant expression of CDX1 and CDX2 correlated with H. pylori infection and grade of IM in the body. Furthermore, the results suggest that CDX1 and CDX2 play a role in the progression to GC and dysplasia.

Expression of CDX2 and hepatocyte antigen in benign and malignant lesions of gallbladder and its correlation with histopathologic type and clinical outcome

Recent studies have shown that both CDX2 and Hepatocyte antigen (Hep) are detected in different types of cancer and associated with clinical prognosis. However, fever studies have examined gallbladder cancer specimens, and little is known about the clinicopathological significance of both CDX2 and Hep expression in gallbladder adenocarcinomas. In present study, we examined the expression frequencies of CDX2 and Hepatocyte antigen (Hep), and explored their clinicopathologic significances in gallbladder adenocarcinoma. Immunohistochemistry was used to detect and compare the frequencies of CDX2 and Hep expression in 108 samples of gallbladder adenocarcinoma, 46 peri-tumor tissues and 35 chronic cholecystitis. The expression frequencies for CDX2 and Hep were 49/108 (45.4%) and 45/108 (41.7%) in gallbladder carcinoma; 13/46 (28.3%) and 11/46 (23.9) in peri-tumor tissues; 5/35 (14.3%) and 2/35 (5.7%) in chronic cholecystitis. The positive staining of CDX2 or Hep in gallbladder adenocarcinoma was significantly higher than that in peritumoral tissues (both, P < 0.05), and chronic cholecystits (both, P < 0.01). The expression of CDX2 or Hep was negatively correlated to grade of differentiation, tumor size and lymph node metastasis (P < 0.01 or P < 0.05). Elevated expression frequency of CDX2 or Hep was associated with increased overall survival (P = 0.003 or P = 0.002). Multivariate Cox regression analysis showed that CDX2 (P = 0.014) or Hep (P = 0.026) expression was an independent prognostic predictor in gallbladder adenocarcinoma. CDX2 and Hep might function as important biological markers in the development and prognosis of gallbladder adenocarcinoma.

Bile acids induce cdx2 expression through the farnesoid x receptor in gastric epithelial cells

Clinical and experimental studies showed that the reflux of bile into the stomach contributes to the induction of intestinal metaplasia of the stomach and gastric carcinogenesis. Caudal-type homeobox 2 (Cdx2) plays a key role in the exhibition of intestinal phenotypes by regulating the expression of intestine-specific genes such as goblet-specific gene mucin 2 (MUC2). We investigated the involvement of the farnesoid X receptor (FXR), a nuclear receptor for bile acids, in the chenodeoxycholic acid (CDCA)-induced expression of Cdx2 and MUC2 in normal rat gastric epithelial cells (RGM-1 cells). RGM-1 cells were treated with CDCA or GW4064, an FXR agonist, in the presence or absence of guggulsterone, an FXR antagonist. CDCA induced dose-dependent expression of Cdx2 and MUC2 at both the mRNA and protein levels. The maximum stimulation of Cdx2 and MUC2 mRNA induced by CDCA was observed at 3 h and by 6 h, respectively. GW4064 also induced expression of these molecules. The effects of CDCA and GW4064 on expression of Cdx2 and MUC2 were abolished by guggulsterone. These findings suggest that bile acids may induce gastric intestinal metaplasia and carcinogenesis through the FXR.

Indefinite for non-invasive neoplasia lesions in gastric intestinal metaplasia: the immunophenotype

BACKGROUND

In the Padova International Classification, gastric precancerous lesions are labelled as "indefinite for non-invasive neoplasia" (Indef-NiN) cytohistological alterations mimicking non-invasive neoplasia (NiN), but lacking all the attributes required for a definite NiN categorisation.

AIM

To apply a panel of immunohistochemical (IHC) markers of cell proliferation (Mib1), intestinal differentiation (Cdx2), apoptosis (pro-caspase 3) and cell immortalisation (hTERT) to compare the IHC profiles of a series of precancerous lesions arising in gastric intestinalised (ie, IM-positive) glands.

MATERIALS AND METHODS

By applying the histological criteria consistently provided by both the Padova Classification and the World Health Organization International Agency, 112 consecutive cases were considered: intestinal metaplasia (IM; n = 54), Indef-NiN in IM-positive gastric glands (n = 28) and low-grade (LG) NiN (n = 30). In each histological category, the expression of the marker was separately scored in superficial, proliferative and coil compartments.

RESULTS

In all glandular compartments, Mib1, Cdx2, hTERT and pro-caspase 3 were consistently more expressed in LG-NiN than in either IM or Indef-NiN lesions (analysis of variance: p<0.001). Significant ORs (calculated by ordinal logistic regression analysis for each glandular compartment) associated IM, Indef-NiN and LG-NiN with the expression of the considered markers.

CONCLUSIONS

A consistent overexpression (unrestricted to the proliferative zone) of IHC markers of cell proliferation, intestinal differentiation, decreased apoptosis and cell immortalisation differentiates LG-NiN from both (simple) IM and Indef-NiN (arising in IM). An increased proliferative activity in the proliferative zone discriminates Indef-NiN lesions (ie, hyperproliferative IM) from IM. Such divergent IHC profiles may provide a rationale for scheduling follow-up protocols more properly tailored on the patient's risk for cancer.

The pathogenesis of Barrett's esophagus: secondary bile acids upregulate intestinal differentiation factor CDX2 expression in esophageal cells

INTRODUCTION

Clinical evidence strongly suggests that bile acids are important in the development of Barrett's esophagus, although the mechanism remains unknown. Caudal-related homeobox 2 (CDX2) is a transcription factor recently implicated in early differentiation and maintenance of normal intestinal epithelium and is suggested to play a key role in the pathogenesis of intestinal metaplasia in Barrett's esophagus.

OBJECTIVE

The aim of this study was to investigate the effect of primary and secondary bile acids on CDX2 mRNA expression in human esophageal cells.

METHODS

Human esophageal cells: (1) squamous, immortalized by SV40 (Het-1A); (2) adenocarcinoma (SEG-1); and (3) squamous cell carcinoma (HKESC-1 & HKESC-2), were exposed in cell culture for 1-24 h to 100-1,000 microM deoxycholic, chenodeoxycholic, and glycocholic acids. Total RNA was extracted before and after bile acid treatment and reverse transcribed to cDNA. CDX2 mRNA expression was determined by both quantitative real-time and reverse transcription PCR (RT-PCR).

RESULTS

CDX2 mRNA expression was absent before bile acid exposure in all cell lines. CDX2 expression increased in a dose- and time-dependent fashion with deoxycholic and chenodeoxycholic, but not glycocholic, acid in all four cell lines. The maximal induction of CDX2 expression was seen in SEG-1 adenocarcinoma cells. Expression in Het-1A cells also increased significantly as did expression in HKESC-1,2 cells, although to a lesser extent than in adenocarcinoma.

CONCLUSIONS

These findings show that secondary bile acid stimulation upregulates CDX2 gene expression in both normal and cancer cell lines. They further support the role of bile acids in the pathogenesis of Barrett's esophagus and link the clinical evidence of a high prevalence of luminal bile acids in Barrett's to expression of the gene thought to be responsible for the phenotypic expression of intestinal metaplasia.

Expression of Cdx2 and hepatocyte antigen in gastric carcinoma: correlation with histologic type and implications for prognosis

PURPOSE

This study was designed to (a) analyze the correlation between the expression of Cdx2 and Hep and the clinicopathologic features of patients with gastric carcinoma, and (b) determine the value of combined analysis of Cdx2 and Hep expression in distinguishing histologic types and prognoses of gastric carcinomas.

EXPERIMENTAL DESIGN

The expression of Cdx2 and Hep were studied using immunohistochemistry of paraffin-embedded tumor specimens from 109 patients who underwent D2 resection for gastric adenocarcinoma from 1995 to 1998.

RESULTS

Nuclear Cdx2 and Hep expression was detected in 36.7% (40 of 109) and 54.1% (59 of 109) of gastric carcinoma cases, respectively. Expression of Cdx2 and Hep was significantly higher in intestinal-type carcinomas than in diffuse-type carcinomas (P = 0.027 and P = 0.037, respectively). There was a clear negative correlation between Cdx2 expression and lymph node metastasis (P = 0.029), as well as between Hep expression and depth of wall invasion (P = 0.011). The patients with Cdx2-positive or Hep-positive expression shows higher survival rate than those with Cdx2-negative or Hep-negative expression (P = 0.0008 and P = 0.003, respectively). Multivariate analysis revealed that the expression of Cdx2 and Hep were independent prognostic indicators of gastric carcinoma. The combination of Cdx2 and Hep expression was significantly lower in diffuse-type carcinoma than in intestinal or mixed-type carcinoma. Multivariate analysis revealed that Cdx2 and Hep expression was an independent prognostic indicator of gastric carcinoma (P < 0.001).

CONCLUSIONS

These data suggest that combined analysis of Cdx2 and Hep has significant value in distinguishing histologic types and in predicting the prognosis of gastric carcinoma.

Differential expression of the eukaryotic release factor 3 (eRF3/GSPT1) according to gastric cancer histological types

BACKGROUND

There are now several lines of evidence to suggest that protein synthesis and translation factors are involved in the regulation of cell proliferation and cancer development.

AIMS

To investigate gene expression patterns of eukaryotic releasing factor 3 (eRF3) in gastric cancer.

METHODS

RNA was prepared from 25 gastric tumour biopsies and adjacent non-neoplastic mucosa. Real time TaqMan reverse transcription polymerase chain reaction (RT-PCR) was performed to measure the relative gene expression levels. DNA was isolated from tumour and normal tissues and gene dosage was determined by a quantitative real time PCR using SYBR Green dye.

RESULTS

Different histological types of gastric tumours were analysed and nine of the 25 tumours revealed eRF3/GSPT1 overexpression; moreover, eight of the 12 intestinal type carcinomas analysed overexpressed the gene, whereas eRF3/GSPT1 was overexpressed in only one of the 10 diffuse type carcinomas (Kruskal-Wallis Test; p < 0.05). No correlation was found between ploidy and transcript expression levels of eRF3/GSPT1. Overexpression of eRF3/GSPT1 was not associated with increased translation rates because the upregulation of eRF3/GSPT1 did not correlate with increased eRF1 levels.

CONCLUSIONS

Overexpression of eRF3/GSPT1 in intestinal type gastric tumours may lead to an increase in the translation efficiency of specific oncogenic transcripts. Alternatively, eRF3/GSPT1 may be involved in tumorigenesis as a result of its non-translational roles, namely (dis)regulating the cell cycle, apoptosis, or transcription.

The usefulness of CDX-2 for differentiating primary and metastatic ovarian carcinoma: an immunohistochemical study using a tissue microarray

Distinguishing primary ovarian carcinoma from metastatic carcinoma to the ovary is often difficult by histologic examination alone. Recently an immunohistochemical marker CDX-2 was found to be of considerable diagnostic value in establishing the gastrointestinal origin of metastatic tumors. The aim of this study was to determine whether CDX-2 can distinguish between these malignancies. Paraffin-embedded tissue sections from 57 primary ovarian tumors and 40 metastatic tumors to the ovary were immunostained for CDX-2, and results were compared to the ancillary immunohistochemical results for CK7/CK20, CEA, CA125, and her-2/neu. CDX-2 immunoreactivity was observed in most of metastatic carcinomas with colorectal (91%) and appendiceal (100%) origin, however CDX-2 was negative in all primary ovarian carcinomas, except for the mucinous subtype. Almost all primary ovarian carcinomas including the mucinous subtype showed diffuse and strong immunoexpression for CK7. CEA and CA125 were mainly found in metastatic and primary ovarian carcinoma, respectively. Her-2/neu overexpression was only noted in a small proportion of primary and metastatic ovarian carcinomas. These results suggest that CDX-2 is very useful immunohistochemical marker for distinguishing metastatic colorectal carcinoma to the ovary from primary ovarian carcinoma, including the mucinous subtype. Furthermore, combination with CDX-2 and CK7 strengthen the differential diagnosis between these tumors.

Expression of caudal-related homeobox transcription factor 2 in normal human epithelia and epithelial neoplasms

AIM: To evaluate the expression of caudal-related homeobox transcription factor 2 (CDX2) in various normal epithelia and epithelial neoplasm and its clinical significance.

METHODS: Three hundred and ten specimens were collected, including normal epithelia (n = 73), epithelial neoplasms (n = 199) and lymph node-metastatic adenocarcinomas (n = 38). The expression of CDX2 was detected in all the tissues by microarray technique and immunohischemistry.

RESULTS: For the digestive tract, the positive rates of CDX2 expression in normal epithelia, epithelial neoplasms and lymph node-metastatic adenocarcinomas were higher than those in the corresponding tissues of other organs (94.7%, 76.5%, 76.9% vs 14.8%, 8.4%, 4.0%; P<0.01). The level of CDX2 expression in tissues from duodenum colon and rectum are higher than those from stomach and esophagus (H = 59.585, P<0.01). Most tissues from non-gastrointestinal tract exhibited negative CDX2 expression, except bile duct, ovary, pancreas and cervix showed relatively weaker CDX2 expression.

CONCLUSION: CDX2 is specifically expressed in the epithelia of duodenum, colon and rectum and it can be used as an important marker in the pathological diagnosis.

Co-expression of CDX2 and MUC2 in gastric carcinomas: Correlations with clinico-pathological parameters and prognosis

AIM: To evaluate the role of CDX2 homeobox protein as a predictor for cancer progression and prognosis as well as its correlation with MUC2 expression. CDX2 represents a transcription factor for various intestinal genes (including MUC2) and thus an important regulator of intestinal differentiation, which could previously be identified in gastric carcinomas and intestinal metaplasia.

METHODS: Formalin-fixed and paraffin-embedded tissues from 190 gastric carcinoma patients were stained with monoclonal antibodies recognizing CDX2 and MUC2, respectively. Immunoreactivity was evaluated semiquantitatively and statistical analyses including χ² tests, uni- and multi-variate survival analyses were performed.

RESULTS: CDX2 was mostly expressed in a nuclear or supranuclear pattern, whereas MUC2 showed an almost exclusive supranuclear reactivity. Both antigens were present in >80% of areas exhibiting intestinal metaplasia. An immunoreactivity in >5% of the tumor area was observed in 57% (CDX2) or in 21% (MUC2) of the carcinomas. The presence of both molecules did not correlate with WHO, Laurén and Goseki classification (with the exception of a significantly stronger MUC2 expression in mucinous tumors). CDX2 correlated with a lower pT and pN stage in the subgroups of intestinal and stage I cancers and was associated with MUC2 positivity. A prognostic impact of CDX2 or MUC2 was not observed.

CONCLUSION: CDX2 and MUC2 play an important role in the differentiation of normal, inflamed, and neoplastic gastric tissues. According to our results, loss of CDX2 may represent a marker of tumor progression in early gastric cancer and carcinomas with an intestinal phenotype.

MUC1 and MUC2 in pancreatic neoplasia

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.

N/A

N/A

Expression of the intestine-specific transcription factors, Cdx1 and Cdx2, correlates shift to an intestinal phenotype in gastric cancer cells

PURPOSE

It is well known that gastric cancers (GCs) at early stages, independent of the histological type, mainly consist of gastric phenotype malignant cells, while those at advanced stage tend to have a more intestinal phenotype with progression. However, the connection between this shift and expression of homeobox genes, which are important factors to maintain tissue character, has remained unclear. We therefore evaluated the expression of Cdx1/2 in relation to the phenotype of GCs.

METHODS

We analyzed the expression of Cdx1/2 mRNAs by Northern blotting and Cdx2 protein by immunohistochemistry in seventy advanced GCs, and evaluated phenotypically using mucin- and immunohistochemistry.

RESULTS

Seventy GCs were divided phenotypically into 16 gastric (G type), 18 gastric and intestinal mixed (GI type), 18 intestinal (I type), and 18 null (N type) phenotypes, independent of the histological classification. Cdx1 and Cdx2 mRNAs statistically demonstrated an increase with shift from G to I ( P=0.042 and P=0.0082, respectively). Cdx2 nuclear staining was observed immunohistochemically in the intestinal phenotypic cancer cells, but could not be detected in those with only the gastric phenotype.

CONCLUSIONS

These results show that Cdx1 and Cdx2 might be indispensable for intestinal phenotypic expression even in gastric cancer cells.

CDX2 immunoreactivity in primary and metastatic ovarian mucinous tumours

The caudal-related homeobox transcription factor CDX2 regulates the differentiation of intestinal epithelial cells. Recent studies have suggested that CDX-2 immunoreactivity is strictly confined to benign and malignant intestinal epithelium. In the present study, we evaluated the prevalence of CDX2 immunoreactivity in a series of benign, borderline and malignant primary ovarian mucinous neoplasms. We tested 62 mucinous tumours of the ovary, including 28 benign cystadenomas, 18 borderline tumours, 16 adenocarcinomas, 35 serous and endometrioid ovarian lesions and 10 ovarian metastases of colonic adenocarcinoma. Overall, the CDX2 prevalence in primary mucinous tumours was 79%, including 20 of 28 (71.5%) cystadenomas, 14 of 18 (77.7%) borderline tumours and 15 of 16 (93.5%) adenocarcinomas. Immunoreactivity usually correlated with intestinal differentiation of tumour cells, although wide heterogeneity in the distribution of immunolabelled cells was noted. No immunoreactivity was observed in serous lesions; whereas, 1 of 13 (7.7%) endometrioid adenocarcinomas and all of the 10 metastatic colonic adenocarcinomas were immunostained. These results indicate that CDX2 is detectable in the majority of benign, borderline and malignant ovarian mucinous tumours and, therefore, makes this marker unsuitable when distinguishing primary from metastatic ovarian mucinous adenocarcinomas. However, CDX2 immunoreactivity could be useful in the distinction between endocervical and intestinal-type mucinous tumours of the ovary, which may have clinical relevance.

Expression of Cdx2 and the phenotype of advanced gastric cancers: relationship with prognosis

PURPOSE

The clinicopathologic significance of the phenotype and Cdx2 expression has hitherto remained unclear in gastric cancers. In the present study, we therefore examined the correlation between prognosis, phenotype, and Cdx2 expression in advanced cases.

METHODS

We evaluated 177 advanced gastric carcinomas histologically and phenotypically. The expression of Cdx2 was also assessed by immunohistochemistry.

RESULTS

The lesions were phenotypically divided into 32 gastric (G type), 36 gastric and intestinal mixed (GI type), 53 intestinal (I type), and 56 null (N type) types, independent of the histological classification. Cdx2 nuclear staining demonstrated a close relation to intestinal phenotypic expression, not with the histological classification. Kaplan-Meier analysis of Cdx2 expression and the phenotype showed that the Cdx2 positive groups had a significantly better outcome than the negative ones (P=0.0013), and the patients with GI type cancers had significant better survival than those with N type (P=0.0052).

CONCLUSIONS

Our results suggest that Cdx2 is a useful prognostic marker. In addition, advanced gastric cancers with both intestinal and gastric phenotypic expression have a relatively good prognosis. Combined evaluation of gastric and intestinal epithelial cell markers, including Cdx2, is clinically useful to predict outcome in patients with advanced neoplasm of the stomach.