Gastric and intestinal phenotypic marker expression in gastric carcinomas and recurrence pattern after surgery-immunohistochemical analysis of 213 lesions

The Role of Mucin Expression in the Diagnosis of Oesophago-Gastric Cancer: A Systematic Literature Review

Survival in oesophago-gastric cancer (OGC) is poor due to early diagnostic challenges. Non-invasive risk stratification may identify susceptible patients with pre-malignant or benign disease. Following diagnostic confirmation with endoscopic biopsy, early OGC may be treated sooner. Mucins are transmembrane glycoproteins implicated in OGC with potential use as biomarkers of malignant transformation. This systematic review defines the role of mucins in OGC diagnosis. A literature search of MEDLINE, Web of Science, Embase and Cochrane databases was performed following PRISMA protocols for studies published January 1960-December 2022. Demographic data and data on mucin sampling and analysis methods were extracted. The review included 124 studies (n = 11,386 patients). Gastric adenocarcinoma (GAc) was the commonest OG malignancy (n = 101) followed by oesophageal adenocarcinoma (OAc, n = 24) and squamous cell carcinoma (OSqCc, n = 10). Mucins MUC1, MUC2, MUC5AC and MUC6 were the most frequently implicated. High MUC1 expression correlated with poorer prognosis and metastases in OSqCc. MUC2 expression decreases during progression from healthy mucosa to OAc, causing reduced protection from gastric acid. MUC5AC was upregulated, and MUC6 downregulated in GAc. Mucin expression varies in OGC; changes may be epigenetic or mutational. Profiling upper GI mucin expression in OGC, with pre-malignant, benign and healthy controls may identify potential early diagnostic biomarkers.

Association between mucin phenotype and lesion border detection using acetic acid-indigo carmine chromoendoscopy in early gastric cancers

BACKGROUND

For successful treatment of early gastric cancers (EGCs), it is crucial to define the horizontal border of the lesion with high accuracy. Acetic acid-indigo carmine (AI) chromoendoscopy has been used to determine the horizontal border in EGCs, but this technique is less potent in certain situations. Mucin phenotype in gastric cancers refers to biological differences in precursor lesions and differences in histopathologic findings, and it might affect AI chromoendoscopy findings. We aimed to investigate the association between mucin phenotype and AI chromoendoscopy findings in EGCs.

METHODS

We prospectively evaluated 126 lesions in 126 patients with endoscopically diagnosed EGCs. Conventional endoscopy and AI chromoendoscopy findings of these lesions before treatment were prospectively analyzed. The border distinction between the lesion and surrounding mucosa was classified as distinct or indistinct on conventional endoscopy and AI chromoendoscopy, respectively. Mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null type by immunohistochemistry.

RESULTS

The lesion borders were distinct in 46.8% (59/126) of the lesions assessed using conventional endoscopy and in 73.0% (92/126) of those assessed with AI chromoendoscopy (p < 0.001). The border distinction rate of differentiated-type cancers on AI chromoendoscopy was significantly higher than that on conventional endoscopy (66/71 [93.0%] vs. 34/71 [47.9%], p < 0.001), but the border distinction rate of undifferentiated-type cancers on AI chromoendoscopy was not different from that on conventional endoscopy (26/55 [47.3%] vs. 25/55 [45.5%], p = 0.848). Compared with conventional endoscopy, AI chromoendoscopy identified borders in a significantly higher percentage of gastric, intestinal, and gastrointestinal mucin types; however, there was no difference in AI chromoendoscopy findings according to the mucin phenotype (p = 0.271).

CONCLUSION

AI chromoendoscopy was effective in horizontal border delineation in differentiated-type EGCs, but not in undifferentiated-type EGCs. Mucin phenotype had no effect on border distinction using AI chromoendoscopy.

Gastric mucin phenotype indicates aggressive biological behaviour in early differentiated gastric adenocarcinomas following endoscopic treatment

Background

The distribution of mucin phenotypes and their relationship with clinicopathological features in early differentiated gastric adenocarcinomas in a Chinese cohort are unknown. We aimed to investigate mucin phenotypes and analyse the relationship between mucin phenotypes and clinicopathological features, especially biological behaviours, in early differentiated gastric adenocarcinomas from endoscopic specimens in a Chinese cohort.

Methods

Immunohistochemical staining of CD10, MUC2, MUC5AC, and MUC6 was performed in 257 tissue samples from patients with early differentiated gastric adenocarcinomas. The tumour location, gross type, tumour size, histological type, depth of invasion, lymphovascular invasion, mucosal background and other clinicopathological parameters were evaluated. The relationship between mucin phenotypes and clinicopathological features was analysed with the chi-square test.

Results

The incidences of gastric, gastrointestinal, intestinal and null phenotypes were 21 %, 56 %, 20 and 3 %, respectively. The mucin phenotypes were related to histology classification (P < 0.05). The proportion of the gastric phenotype became greater during the transition from differentiated to undifferentiated (P < 0.05). Complete intestinal metaplasia was higher in the gastric and intestinal phenotypes than in the gastrointestinal phenotype (P < 0.05). Tumours with poorly differentiated adenocarcinoma were mainly of the gastric phenotype, which was significantly higher than that of purely differentiated tubular adenocarcinoma (P < 0.05), and the depth of invasion in the mixed type was deeper (P < 0.05). Neither recurrence nor metastasis was detected.

Conclusions

The mucin phenotype of early-differentiated gastric adenocarcinoma has clinical implications, and the gastric phenotype has aggressive biological behaviour in early differentiated gastric cancers, especially in those with poorly differentiated adenocarcinoma or papillary adenocarcinoma components.

Evaluation of the recurrence pattern of gastric cancer after laparoscopic gastrectomy with D2 lymphadenectomy

Background

The aim of this study was to analyze the oncological aspects of gastric cancer following laparoscopic gastrectomy with D2 lymphadenectomy (LG-D2).

Methods

We retrospectively evaluated the long-term outcomes of 354 patients who underwent LG-D2 for primary gastric cancer. Recurrence patterns and predictors of peritoneal metastasis were analyzed.

Results

Median follow-up time was 43.8 months. Five-year overall survival rates for yp/pStages I, II, and III gastric cancer were 93.7, 78.5, and 42.2 %, respectively. Recurrence was observed in 86 patients. Peritoneal metastasis was the most frequent recurrence pattern (n = 51), followed by hepatic metastasis (n = 17). Lymphatic recurrence at distant sites was observed in 10 patients. No locoregional lymph node metastasis or local recurrence was seen. Nine of 51 cases of peritoneal recurrence were detected by probe laparoscopy. Peritoneal recurrence rates were significantly higher in yp/pT4 and yp/pN3 diseases compared with yp/pT ≤ 3 and yp/pN ≤ 2 diseases. Multivariate analyses demonstrated that yp/pT4, yp/pN3, tumor size ≥70 mm, vascular invasion, and undifferentiated tumors were predictors of peritoneal recurrence following LG-D2.

Conclusion

Long-term outcomes of gastric cancer following LG-D2, including recurrence patterns and predictors of peritoneal metastasis, were comparable to those following open D2 gastrectomy. LG-D2 showed good local control. Probe laparoscopy after LG may be effective in detecting peritoneal recurrence, which is not determined with less invasive examinations, including a CT scan. Future large-scale prospective studies are desirable to evaluate not only surgical but also oncological benefits and safety of LG-D2 for advanced gastric cancer.

Fukutin, identified by the Escherichia coli ampicillin secretion trap (CAST) method, participates in tumor progression in gastric cancer

BACKGROUND

Gastric cancer (GC) is the fifth commonest malignancy worldwide and still one of the leading causes of cancer-related death. The aim of this study was to identify a novel prognostic marker or therapeutic target for GC.

METHODS

We analyzed candidate genes from our previous Escherichia coli ampicillin secretion trap (CAST) libraries in detail, and focused on the FKTN gene because it was overexpressed in both GC cell line CAST libraries, MKN-1 and MKN-45.

RESULTS

Quantitative reverse transcriptase PCR analysis of FKTN revealed that FKTN messenger RNA was overexpressed in nine of 28 (32.1 %) GC tissue samples compared with nonneoplastic gastric mucosa. Immunostaining of fukutin showed that 297 of 695 cases (42.7 %) were positive for fukutin. Fukutin-positive GC cases were significantly associated with differentiated histological features, and advanced T grade and N grade. In addition, fukutin expression was observed more frequently in the intestinal phenotype (51 %) of GC than in other phenotypes (37 %) when defined by the expression patterns of mucin 5AC, mucin 6, mucin 2, and CD10. FKTN small interfering RNA treatment decreased GC cell proliferation.

CONCLUSIONS

These results indicate that the expression of fukutin may be a key regulator for progression of GC with the intestinal mucin phenotype.

Bile acid induces MUC2 expression and inhibits tumor invasion in gastric carcinomas

PURPOSE

Bile acids might induce mucin expression and regulate tumor behavior in esophageal and colon cancers. However, little is known about the effect of bile acids on tumor invasiveness of gastric carcinoma (GC). The aim of the current study was to elucidate the mechanisms by which bile acids regulate tumor invasion in GC.

METHODS

We investigated bile acid-induced MUC2 expression and cell invasion and migration in the cultured GC cell lines, SNU-216, and MKN45. In addition, immunohistochemical analysis of MUC2 and Snail was performed on 389 archival paraffin-embedded tissues of GC to evaluate the correlation of their expression with prognosis.

RESULTS

Deoxycholic acid (DCA), a secondary bile acid, had no effect on the viability of SNU-216 and MKN45 GC cells at low concentrations (0-100 μM), but decreased viability at a higher concentration (200 μM). MKN45 cells showed higher MUC2 expression than SNU-216 cells under basal conditions. DCA treatment upregulated MUC2 mRNA expression in both SNU-216 and MKN45 cells. Expression of Snail and MMP9 was markedly decreased by DCA treatment, and E-cadherin expression was subsequently increased. DCA significantly inhibited invasion and migration of SNU-216 and MKN45 cells. In human GC, MUC2 expression showed a negative correlation with Snail expression (P = 0.021) and a significantly positive correlation with better prognosis (P = 0.023).

CONCLUSIONS

Taken together, our data suggest that DCA induced MUC2 expression in GC cells and inhibited tumor invasion and migration. Additionally, MUC2-expressing GCs showed low rates of Snail expression and were associated with a favorable prognosis.

Loss of gastric gland mucin-specific O-glycan is associated with progression of differentiated-type adenocarcinoma of the stomach

Gastric gland mucin secreted from the lower portion of the gastric mucosa contains unique O-linked oligosaccharides having terminal α1,4-linked N-acetylglucosamine (αGlcNAc) residues largely attached to a MUC6 scaffold. Previously, we generated A4gnt-deficient mice, which totally lack αGlcNAc, and showed that αGlcNAc functions as a tumor suppressor for gastric cancer. Here, to determine the clinicopathological significance of αGlcNAc in gastric carcinomas, we examined immunohistochemical expression of αGlcNAc and mucin phenotypic markers including MUC5AC, MUC6, MUC2, and CD10 in 214 gastric adenocarcinomas and compared those expression patterns with clinicopathological parameters and cancer-specific survival. The αGlcNAc loss was evaluated in MUC6-positive gastric carcinoma. Thirty-three (61.1%) of 54 differentiated-type gastric adenocarcinomas exhibiting MUC6 in cancer cells lacked αGlcNAc expression. Loss of αGlcNAc was significantly correlated with depth of invasion, stage, and venous invasion by differentiated-type adenocarcinoma. Loss of αGlcNAc was also significantly associated with poorer patient prognosis in MUC6-positive differentiated-type adenocarcinoma. By contrast, no significant correlation between αGlcNAc loss and any clinicopathologic variable was observed in undifferentiated-type adenocarcinoma. Expression of MUC6 was also significantly correlated with several clinicopathological variables in differentiated-type adenocarcinoma. However, unlike the case with αGlcNAc, its expression showed no correlation with cancer-specific survival in patients. In undifferentiated-type adenocarcinoma, we observed no significant correlation between mucin phenotypic marker expression, including MUC6, and any clinicopathologic variable. These results together indicate that loss of αGlcNAc in MUC6-positive cancer cells is associated with progression and poor prognosis in differentiated, but not undifferentiated, types of gastric adenocarcinoma.

The contribution of cell phenotype to the behavior of gastric cancer

BACKGROUND

Several histochemical studies suggest a role of tumor cell phenotype and related differentiation markers in the prognostic assessment of gastric cancer. Unfortunately, most studies have dealt with single or a few markers and have paid limited attention to their interplay with tumor histological types, which are potentially informative of prognosis.

METHODS

In this study, 292 invasive (T1b to T4) gastric cancers with prolonged follow-up and carefully analyzed histotype, inclusive of histotype-based grade, were investigated histochemically with a panel of 14 phenotypic markers known to be expressed in normal gut tissues and gastric cancer.

RESULTS

Three of seven intestinal type markers investigated showed a trend for improved prognosis, one of which, CDX2, was stage independent. Three among gastric and pancreatobiliary duct markers (MUC1, MUC6, and pepsinogen II), predicted more severe prognosis stage independently, as did a combination of eight potentially informative (p < 0.1 at univariable Cox analysis) markers. Cancers with predominantly intestinal phenotype had significantly better prognosis than those with predominantly gastric, mixed, or poorly defined phenotypes; among the latter, those with high lymphocyte response, with favorable outcome, were separated from anaplastic cancers, with ominous prognosis. At multivariable analysis, CDX2 and the eight marker combination proved to be stage- and grade-independent predictors.

CONCLUSIONS

When individually considered, and with the exception of CDX2, the biomarkers investigated gave an appreciable, although moderate, contribution to the prognostic evaluation of gastric cancer. Combined analysis of all potentially informative markers gave more important information, highly additive to both stage and histotype-based grade.

CD44 variant 9 expression in primary early gastric cancer as a predictive marker for recurrence

BACKGROUND

Multiple early gastric cancers (EGCs) may develop in 6-14% of patients even after achieving curative endoscopic submucosal dissection (ESD); however, a useful biomarker for predicting recurrence is not available. The present study investigated whether the expression of CD44 variant 9 (CD44v9), a functional cancer stem cell marker, in the primary gastric cancer tissue represents an indicator of recurrence.

METHODS

Eighty-eight patients who underwent ESD for EGC from 2008 to 2010 were enrolled and monitored for recurrence for 3 years. The expression levels of CD44v9 in the tissue of initial EGCs were evaluated by immunohistochemistry, and the recurrence rate was compared between CD44v9-positive and CD44v9-negative groups. The mucin phenotype and expression of microRNA-21 (miR-21) and programmed cell death protein 4 (PDCD4) were also analysed.

RESULTS

The recurrence rate of EGC was significantly higher in the CD44v9-positive group than in the CD44v9-negative group (hazard ratio (HR), 21.8; 95% confidence interval (CI), 5.71-83.1). However, mucin phenotypes and the expression of miR-21 and PDCD4 did not predict recurrence after ESD. Meanwhile, grade of gastric atrophy was also identified as a significant marker of multiple recurrence (HR, 4.95; 95% CI, 1.30-18.8).

CONCLUSION

CD44 variant 9 expression represents a potential predictive marker for recurrence in EGC.

Establishment and characterization of novel gastric signet-ring cell and non signet-ring cell poorly differentiated adenocarcinoma cell lines with low and high malignant potential

BACKGROUND

Poorly differentiated signet-ring cell carcinoma (SRCC) and non signet-ring cell carcinoma (NSRCC) are prevalent histological subtypes of gastric cancers with distinct morphological features. To date, however, the molecular basis of their growth, differentiation, and metastasis still remains unclear, because of the limitation of available cell lines.

METHODS

In the present study, we established novel SRCC and NSRCC cell lines (designated GPM-2 and GPM-1) derived from the ascites of two individual gastric cancer patients with peritoneal metastasis.

RESULTS

Immunohistochemical and quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that GPM-2 cells showed both gastric and intestinal differentiation phenotypes (E-cadherin+/MUC5AC+/MUC6+/Villin+), and formed xenografted tumors with typical SRCC histology in nude mice. In contrast, GPM-1 cells only weakly expressed differentiation markers, showing a phenotype of E-cadherin(low)+/MUC2-/MUC5AC-/Villin(low)+. Characteristically, GPM-2 cells were found to highly express both membrane-bound mucin (MUC1/MUC4) and secreted mucin glycoproteins (MUC5AC/MUC6), whose expression is regulated by an epigenetic mechanism such as histone acetylation. GPM-2 cells also secreted a large amount of sTn antigen into the culture medium. These mucin profiles of GPM-2 cells are distinct from those of conventional SRCC cell lines (KATO III and HSC-39), which preferentially express intestinal MUC2/MUC4 as well as sLe(x) and sLe(A) antigens. In addition, GPM-2 cells showed a slow growth rate, and a lower metastatic potential than GPM-1 cells.

CONCLUSIONS

These results indicate that the cells of the new SRCC line, GPM-2 cells, are more differentiated and less aggressive than NSRCC-type GPM-1 cells, and would thus offer an excellent model for understanding the molecular mechanism underlying the growth, differentiation, and mucin production of an SRCC gastric cancer cell line.

Exocrine and endocrine modulation in common gastric carcinoma

Diagnostic and prognostic implications of endocrine differentiation were evaluated in 103 common gastric adenocarcinomas and undifferentiated carcinomas. Maturely differentiated exocrine and endocrine phenotypes were evaluated by using gastric exocrine and endocrine markers along with intestinal exocrine and endocrine markers. Immunohistochemical analysis revealed that 66 tumors (64%) were positive for generic endocrine markers such as chromogranin A and/or synaptophysin. The 14 patients with more than 20% tumor cells positive for at least 1 endocrine marker experienced a poorer prognosis than patients with no (n = 37) or 1% to 20% (n = 52) positivity. The 16 carcinomas expressing the maturely differentiated exocrine gastric phenotype significantly correlated with poorer outcome compared with carcinomas with mature exocrine intestinal (n = 22) or mixed/gastrointestinal (n = 64) phenotypes. Among tumors expressing chromogranin A and/or synaptophysin, the maturely differentiated endocrine gastric phenotype (n = 26) was a negative prognostic factor compared with mature endocrine intestinal (n = 21) and mixed/gastrointestinal (n = 5) phenotypes. Endocrine differentiation and maturely exocrine/endocrine gastric phenotypes are associated with an unfavorable prognosis and may identify subsets of patients for tailored therapy.

High CD10 expression in lymph node metastases from surgically treated prostate cancer independently predicts early death

Patients with nodal positive prostate cancers are an important cohort with poorly defined risk factors. CD10 is a cell surface metallopeptidase that has been suggested to play a role in prostate cancer progression. CD10 expression was evaluated in 119 nodal positive prostate cancer patients using tissue microarrays constructed from primary tumors and lymph node metastases. All patients underwent radical prostatectomy and standardized extended lymphadenectomy. They had no neoadjuvant therapy and received deferred androgen deprivation. In the primary tumor, high CD10 expression was significantly associated with earlier death from disease when compared with low CD10 expression (5-year survival 73.7% vs. 91.8%; p = 0.043). In the metastases, a high CD10 expression was significantly associated with larger total size of metastases (median 11.4 vs. 6.5 mm; p = 0.015), earlier death of disease (5-year survival 71.5% vs. 87.3%; p = 0.017), and death of any cause (5-year survival 70.0% vs. 87.2%; p = 0.001) when compared with low CD10 expression. CD10 expression in the metastases added independent prognostic information for overall survival (p = 0.029) after adjustment for Gleason score of the primary tumor, nodal tumor burden, and resection margins. In conclusion, a high CD10 expression in prostate cancer predicts early death. This information is inherent in the primary tumors and in the lymph node metastases and might help to personalize patient management.

Differences of immunophenotypic markers and signaling molecules between adenocarcinomas of gastric cardia and distal stomach

During the past decades, the subsites of gastric carcinoma underwent significant changes. The incidence of the adenocarcinoma at distal stomach has been decreased, whereas cardiac adenocarcinoma remained increasing in many countries. The aim of this study was to investigate the differences between gastric cardiac and distal adenocarcinomas. We detected expressions of cytokeratins (cytokeratins 7, 14, 19, and 20) and mucins (mucins 1, 2, and 5AC) by immunohistochemistry and signaling molecules (p38, mitogen-activated protein kinase-interacting kinase 1 (MNK1), extracellular signal-regulated kinase, Jun N-terminal kinase, and phosphoinositide 3 kinase) by reverse transcription-polymerase chain reaction in both groups. The incidence of mucin 2 expression was lower in total (50.0%) and advanced-stage cases (52.0%) with cardiac adenocarcinomas than those in distal cases with total (70.2%) and advanced stage (71.4%), respectively. However, the staining for cytokeratin 14 was also significantly higher in total or advanced-stage tumors from the cardia. Our data showed no significant difference of cytokeratin 7/cytokeratin 20 pattern between 2 groups, but cytokeratin 20 expression was significantly higher in advanced-stage carcinomas of the cardia (58.7%) than in distal ones with advanced stage (38.3%). A multivariate analysis demonstrated different relationships between immunophenotypic markers and pathologic parameters in adenocarcinomas of the cardia and distal stomach. Moreover, significantly lower expressions of MNK1 and p38 in cardiac tumors were also detected. In summary, we found significant differences in patterns of immunophenotypic markers and expressions of signaling molecules between the 2 groups. It is indicated that adenocarcinoma of the cardia was different in histotype and histologic origin from distal adenocarcinoma. The cardiac adenocarcinoma might be a special subtype or an independent entity of gastric carcinoma in China.

Immunohistochemical analysis of colorectal cancer with gastric phenotype: claudin-18 is associated with poor prognosis

Claudin-18 plays a key role in constructing tight junctions, and altered claudin-18 expression has been documented in various human malignancies; however, little is known about the biological significance of claudin-18 in colorectal cancer (CRC). The aim of this study is to investigate the significance of claudin-18 expression in CRC and its association with clinicopathological factors. We performed clinicopathological analysis of claudin-18 expression in a total of 569 CRCs by immunohistochemistry. Moreover, we investigated the association between claudin-18 and various markers including gastric/intestinal phenotype (MUC5AC, MUC6, MUC2 and CD10), CDX2, claudin-3, claudin-4, p53 and Ki-67. Claudin-18 expression was detected in 21 of the 569 CRCs (4%) and was seen exclusively on the cell membrane. Positive expression of claudin-18 showed a significant correlation with positive expression of MUC5AC (P < 0.0001) and negative expression of CDX2 (P= 0.0013). The prognosis of patients with positive claudin-18 expression was significantly poorer than in negative cases (P= 0.0106). Multivariate analysis revealed that T grade, M grade and claudin-18 expression were independent predictors of survival in patients with CRC. We revealed that claudin-18 expression correlates with poor survival in patients with CRC and is associated with the gastric phenotype.

Relationship between clinicopathological features and mucin phenotypes of advanced gastric adenocarcinoma

AIM

To investigate a relationship between the clinicopathological features and mucin phenotypes in advanced gastric adenocarcinoma (AGA).

METHODS

Immunohistochemical staining was performed to determine the mucin phenotypes in 38 patients with differentiated adenocarcinomas (DACs), 9 with signet-ring cell carcinomas (SIGs), and 48 with other diffuse-type adenocarcinomas (non-SIGs) of AGA. The mucin phenotypes were classified into 4 types: gastric (G), gastrointestinal (GI), intestinal, and unclassified.

RESULTS

The G-related mucin phenotypes were highly expressed in all the histological subtypes of AGA. The expression of the GI phenotype in SIG patients was lower than that in DAC patients (P = 0.02), and this phenotype was observed in 56% of the non-SIG patients in the intramucosal layer. Among non-SIG cases, the expression of the GI phenotype was significantly higher in patients with extended adenocarcinomas and those with positive rates of lymph node metastasis. There was no difference between the expressions of the G and other GI phenotypes factors. Among DAC and non-SIG patients, there were no differences between the survival rates of the corresponding patient groups.

CONCLUSION

The GI phenotype might possess more invasive characteristics than the G phenotype in non-SIG. Neither of the phenotypes indicated a poor prognosis of DAC and non-SIG.

Multi-institutional study of risk factors of liver metastasis from colorectal cancer: correlation with CD10 expression

BACKGROUND

The risk factors for liver metastasis from colorectal cancer are still unclear. We therefore evaluated the relationships between various clinicopathological factors, including CD10 expression, liver metastasis, and survival, in patients with colorectal cancer.

METHODS

Clinicopathological data for 1,025 patients with stage II or III colorectal cancer who underwent curative surgery in four participating hospitals were collected and evaluated. Three pathologists examined focal dedifferentiation, venous invasion, and CD10 expression without knowledge of the clinical outcome.

RESULTS

Univariate analysis showed that pathological T (pT), pathological N (pN), venous invasion, focal dedifferentiation, and CD10 expression were significantly associated with liver metastasis. Multivariate analysis selected pT, pN, and CD10 expression as significant risk factors for liver metastasis. pT, pN and CD10 were also shown by univariate and multivariate analyses to be significantly associated with disease-free survival. The incidence of liver metastasis was 3% in pN0 patients with CD10-negative or pT2 or pT3 tumors and 28% in pN2 patients with CD10-positive or pT4 tumors.

CONCLUSIONS

CD10 expression is a significant risk factor for liver metastasis in patients with colorectal cancer and is correlated with prognosis. Patients with a high risk of liver metastasis can be selected on the basis of pT, pN, and CD10 expression.

Confocal endomicroscopy for phenotypic diagnosis of gastric cancer

BACKGROUND AND AIM

Relationships between mucin phenotype and malignant potential in gastric cancers have attracted attention. We attempted to assess the possibility of obtaining phenotypic diagnoses by confocal endomicroscopy.

METHODS

Confocal images of target lesions were obtained in 29 of 40 patients with gastric cancer. Appearances of the brush border, goblet cells, and gastric foveolar epithelium were investigated with immunohistochemical staining using CD10, MUC2, and human gastric mucin to evaluate phenotypic expression in gastric carcinomas. Confocal images were compared with immunohistochemical findings for goblet cells and brush borders.

RESULTS

Both the endoscopists and the pathologist obtained high accuracy rates for differential diagnosis. Sensitivity and specificity for goblet cells were 85.7% and 92.3% (Endoscopist A), and 85.7% and 88.5% (Endoscopist B). The kappa-value for correspondence between two endoscopists for the diagnosis of goblet cells in confocal images was 0.73. Sensitivity and specificity for the brush border were 93.8% and 91.7% (Endoscopist A), and 81.3% and 91.7% (Endoscopist B). The kappa-value for correspondence between two endoscopists for diagnosis of the brush border in confocal images was 0.79. Intestinal phenotypic gastric cancers show a brush border, goblet cells, or both. Sensitivity and specificity for the intestinal phenotype in confocal endomicroscopy were 90.9% and 77.8% (Endoscopist A), and 86.4% and 83.3% (Endoscopist B).

CONCLUSION

The confocal endomicroscopic diagnosis of the mucin phenotype in gastric cancers was limited to intestinal and mixed phenotypes, but may be useful for the diagnosis of mucin phenotype and differential diagnosis.

Unclassified mucin phenotype of gastric adenocarcinoma exhibits the highest invasiveness

BACKGROUND AND AIM

Gastric cancers present with distinctive carcinogenesis pathways that vary with the mucin phenotypes. We attempted to elucidate the relations between the characteristics of the mucin phenotypes of gastric cancer and the tumor invasiveness.

METHODS

Gastric adenocarcinomas that were resected surgically between August 2005 and April 2007 were included in the present study. The gastric cancers were subclassified into gastric and intestinal mucin phenotypes if more than 10% of cancer cells exhibited gastric (MUC5AC and/or MUC6) and intestinal (MUC2 or CD10) markers, respectively.

RESULTS

The mucin phenotypes of 123 gastric cancers were gastric (n = 31), intestinal (n = 43), mixed (n = 28) and unclassified (n = 21). The mucin phenotype was related to histological type (P < 0.001), Lauren's classification (P = 0.001) and size (P = 0.014) of the gastric adenocarcinoma, but not to its location or to the presence of Helicobacter pylori infection. The unclassified mucin phenotype exhibited the largest number of lymph node metastases (P = 0.007), lymphatic invasions (P < 0.001) and neural invasions (P = 0.026), whereas the intestinal mucin phenotype exhibited the lowest invasiveness.

CONCLUSION

The mucin phenotype reflects the biological behavior of gastric cancer, with the intestinal and unclassified mucin phenotypes exhibiting the lowest and highest invasiveness, respectively.

Clinicopathological and prognostic significance of mucin phenotype in gastric cancer

BACKGROUND AND OBJECTIVES

Gastric and intestinal mucin phenotype cell markers are widely expressed in gastric carcinoma cells, irrespective of their tumor histological type. In the present study, we tried to reveal the clinicopathological significance of mucin phenotype in human gastric carcinomas. Moreover, we investigated the clinical significance of RUNX3 in association with mucin phenotype.

METHODS

The mucin expression of MUC5AC, MUC6, MUC2, and CD10 was evaluated in 97 gastric carcinomas by immunohistochemistry. Tumors were classified into gastric (G), gastric and intestinal mixed (GI), intestinal (I), and null (N) phenotype according to combination of mucin expression.

RESULTS

The rate of G, GI, I, and N phenotype was 40.0%, 38.1%, 10.3%, and 19.6%, respectively. Mucin phenotype was also significantly correlated with several clinicopathological findings. Patients with I phenotype had a significantly poorer prognosis than those with any other phenotypes. They also had a higher rate of postoperative liver metastasis. Multivariate analysis revealed that mucin phenotype was a significant independent prognostic factor. We suggested that Loss of RUNX3 expression might correlate with intestinal phenotype and postoperative outcome.

CONCLUSIONS

Mucin phenotype has a significant prognostic value and may be a useful marker for the treatment of human gastric carcinoma.

Markers of tumour angiogenesis and tumour cells in bone marrow in gastric cancer patients

AIMS

Vascular endothelial growth factors VEGF-A, VEGF-C and VEGF-D are considered to be potentially angiogenetic and lymphangiogenetic. "Minimal residual disease" is responsible for cancer progression and recurrence. In this study, we investigated the relation between expressions of VEGF-A, VEGF-C and VEGF-D in gastric cancer tissue and the presence of tumour cells in bone marrow.

METHODS

A total of 50 resected primary gastric adenocarcinomas, 44 non-cancerous gastric mucosa and 36 lymph node metastases were analyzed by immunohistochemistry for VEGF-A, VEGF-C and VEGF-D. The specimens used were drawn from a previous study cohort, where the presence of ITC in bone marrow was confirmed with immunohistochemical assay with cytokeratin (CK)-18.

RESULTS

The levels of expression of VEGF-A, VEGF-C and VEGF-D were highest in tumour (p < 0.001), and the level in lymph node metastases was significantly higher (p < 0.01) than in mucosa. The expression of VEGF-A was correlated significantly with venous tumour invasion (p < 0.05) and the presence of tumour cells in bone marrow (p < 0.05). Tumours expressing high levels of VEGF-D showed significantly advanced stages of tumour infiltration (p < 0.05) and lymph node metastasis (p < 0.01).

CONCLUSIONS

VEGF-A is a significant marker for the presence of tumour cells in the bone marrow of gastric cancer patients. Our results confirm VEGF-D as a predictor for the lymphatic spread of tumour cells. Therefore, the route of metastatic spread of gastric cancer could be determined, at least in part, by the profile of VEGF family members expressed in the primary tumour of gastric cancer patients.

Phenotypic classification of gastric signet ring cell carcinoma and its relationship with clinicopathologic parameters and prognosis

AIM: To distinguish subtypes of gastric signet ring cell (SRC) carcinoma by investigating the expression of gastric and intestinal phenotypic markers, and to study the significance of phenotypic classification in predicting tumor progression and outcome.

METHODS: Immunohistochemistry was performed in 66 cases of SRC carcinoma with MUC2, VILLIN, CDX2, Li-cadherin antibodies as intestinal phenotype markers and MUC5AC, HGM, MUC6 antibodies as gastric phenotype markers, and the relationship was analyzed between the phenotypic expression pattern and clinicopathologic parameters, as well as the 3-year survival rate.

RESULTS: Expression of intestinal phenotypic markers was positively associated with tumor size, wall invasion, vascular invasion, lymph node metastasis and tumor-node-metastasis (TNM) stage. Cases expressing one or more intestinal markers had a significant lower survival rate than cases expressing none of the intestinal markers.

CONCLUSION: The SRC carcinomas expressing intestinal phenotype markers exhibited a high pro-liferative potential, bad biological behaviors and poor prognosis. Examination of phenotype expression may be useful in distinguishing histological type and in predicting the prognosis of gastric SRC carcinoma.

Differences in the histological findings, phenotypic marker expressions and genetic alterations between adenocarcinoma of the gastric cardia and distal stomach

Adenocarcinoma of the gastric cardia (C-Ca) is possibly a specific subtype of gastric carcinoma. The purpose of this study was to clarify the differences in the clinicopathological characteristics between C-Ca and adenocarcinoma of the distal stomach (D-Ca), and also the differences in the expressions of gastric and intestinal phenotypic markers and genetic alterations between the two. The clinicopathological findings in 72 cases with C-Ca were examined and compared with those in 170 cases with D-Ca. The phenotypic marker expressions examined were those of human gastric mucin (HGM), MUC6, MUC2 and CD10. Furthermore, the presence of mutations in the APC, K-ras and p53 genes and the microsatellite instability status of the tumour were also determined. C-Ca was associated with a significantly higher incidence of differentiated-type tumours and lymphatic vessel invasion (LVI) as compared with D-Ca (72.2 vs 48.2%, P=0.0006 and 72.2 vs 55.3%, P=0.0232, respectively). Oesophageal invasion by the tumour beyond the oesophago-gastric junction (OGJ) was found in 56.9% of cases with C-Ca; LVI in the area of oesophageal invasion was demonstrated in 61% of these cases. Also, LVI was found more frequently in cases of C-Ca with oesophageal invasion than in those without oesophageal invasion (82.9 vs 58.1%, P=0.0197). The incidence of undifferentiated-type tumours was significantly higher in cases with advanced-stage C-Ca than in those with early-stage C-Ca (5 vs 36.5%, P=0.0076). A significantly greater frequency of HGM expression in early-stage C-Ca and significantly lower frequency of MUC2 expression in advanced-stage C-Ca was observed as compared with the corresponding values in cases of D-Ca (78.9 vs 52.2%, P=0.0402 and 51.5 vs 84.6%, P=0.0247, respectively). Mutation of the APC gene was found in only one of all cases of C-Ca, and the frequency of mutation of the APC gene was significantly lower in cases of C-Ca than in those of D-Ca (2.4 vs 20.0%, P=0.0108). The observations in this study suggest that C-Ca is a more aggressive tumour than D-Ca. The differences in biological behavior between C-Ca and D-Ca may result from the different histological findings in the wall of the OGJ and the different genetic pathways involved in the carcinogenesis.

Gastric and intestinal phenotypic marker expression in early differentiated-type tumors of the stomach: clinicopathologic significance and genetic background

PURPOSE

Gastric and intestinal phenotypic cell markers are expressed in gastric carcinomas, irrespective of their histologic type. In the present study, we determined the clinicopathologic significance of phenotypic marker expression in early-stage gastric differentiated-type tumors and the association between marker expression and genetic alterations.

EXPERIMENTAL DESIGN

Phenotypic marker expression was determined by examining the expressions of human gastric mucin (HGM), MUC6, MUC2, and CD10 in 63 gastric adenomas, 133 early differentiated-type carcinomas, and 24 follow-up cases with gastric adenoma. Tumors were classified into gastric, gastric and intestinal mixed, or intestinal phenotypes according to the immunopositivity of the above markers. The presence of mutations in APC, K-ras, and p53 and the microsatellite instability status were also determined in all tumors.

RESULTS

The expressions of HGM and MUC6, representing gastric or gastric and intestinal mixed phenotypes, were significantly associated with high-grade atypia in the 63 gastric adenomas. Among the 133 early differentiated-type carcinomas, HGM expression was significantly associated with mixed-type (with an undifferentiated-type component) tumors and lymph node metastasis. MUC2 expression was inversely associated with submucosal invasion. A multivariate analysis revealed that gastric adenomas were significantly associated with the intestinal phenotype and were inversely associated with p53 mutation compared with early differentiated-type carcinomas. Among all 196 tumors, APC mutation was significantly associated with CD10 expression and the intestinal phenotype and was inversely associated with the expressions of HGM and MUC6. The microsatellite instability status was significantly associated with MUC6 expression. Malignant transformation from gastric adenoma to carcinoma was shown in 5 of the 24 follow-up cases of gastric adenoma. The malignant transformation was significantly associated with the gastric and intestinal mixed phenotype and was inversely associated with APC mutation. No malignant transformation was found in intestinal phenotype gastric adenomas with APC mutation.

CONCLUSIONS

Our present findings show that phenotypic marker expression is associated with tumor aggressiveness during the early stage of gastric differentiated-type tumors. Differences in the biological behavior of tumors with different phenotypes may result from differences in the genetic backgrounds during the incipient phase of gastric tumorigenesis.

Gastric tube cancer: immunohistochemical study of 10 lesions in six patients

BACKGROUND AND AIM

Gastric tube cancer (GTC), defined as carcinoma arising in the reconstructed gastric tube after esophagectomy, has been increasingly reported, but its pathogenesis remains unclear. Therefore, the aim of this study was to examine clinically and pathologically 10 GTCs in six patients.

METHODS

In addition to examination of the clinicopathological features of GTCs, the adjacent gastric tube mucosa was also evaluated immunohistochemically using gastric foveolar markers (MUC5AC and human gastric mucin), pyloric gland markers (MUC6 and M-GGMC-1), and intestinal markers (MUC2 and CD10).

RESULTS

All patients were men and three patients had multiple GTCs. All GTCs were located on the middle to lower portion of the gastric tube. Nine GTCs had tubular and/or papillary adenocarcinoma components, and another was signet-ring cell carcinoma. Intestinal metaplasia was found in non-neoplastic mucosa adjacent to nine GTCs. Metaplastic goblet cells adjacent to five GTCs expressed both gastric and intestinal markers, which were similar to the corresponding GTC cells, indicating a close association between the GTCs and metaplastic goblet cells. The other three GTCs expressed only intestinal markers, which may support the suggestion that the intestinal phenotype is expressed later in cancerous development.

CONCLUSION

Pathogenesis of GTCs could be identical to that of ordinary gastric cancer. Cancerous multiplicity associated with esophageal cancer may also play a role in the development of GTCs.

Assessment of microsatellite instability status for the prediction of metachronous recurrence after initial endoscopic submucosal dissection for early gastric cancer

The technique of endoscopic submucosal dissection (ESD) has been developed for en bloc resection of early gastric cancer (EGC); however, little is known about the risk of metachronous cancer in the remnant stomach after initial ESD. In this study, we investigated the correlation between microsatellite instability (MSI) status and the incidence of metachronous recurrence of gastric cancer. According to the genetic/molecular background determined with MSI status and expression levels of hMLH1 and p53 tumour suppressor, 110 EGCs removed with ESD were subclassified into three groups: the mutator/MSI-type (8%), suppressor/p53-type (45%) and unclassified type (47%). Interestingly, patients with the mutator/MSI-type tumour had a high incidence (67%) of metachronous recurrence of gastric cancer within a 3-year observation after initial ESD, which was significantly higher than those with the suppressor/p53-type and unclassified type tumours (P<0.01). Although we investigated mucin phenotypes, there was no correlation between mucin phenotype and the recurrence of EGC. These findings suggest that subclassification of molecular pathological pathways in EGCs is required for the assessment of patients with a high risk of recurrent gastric cancer. The information delivered from our investigation is expected to be of value for decisions about therapy and surveillance after ESD.

Prognostic Value of Cytokeratin-Positive Bone Marrow Cells of Gastric Cancer Patients

BACKGROUND

Epithelial cells in the bone marrow of patients with gastric cancer suggest tumor dissemination; however, their prognostic implications are controversial. We prospectively evaluated the correlation of bone marrow findings, recurrence rate, and disease-free survival after long-term follow-up.

METHODS

Bone marrow were aspirated from both iliac crests and stained with monoclonal cytokeratin (CK)-18 antibody in 209 patients before their initial operation. Patients were followed up for a median of 56 months.

RESULTS

Overall, 39 (19%) of 209 patients and 15 (14%) of 109 R0-resected patients had CK-positive cells. CK-positive patients had more local, regional, and distant recurrence than CK-negative patients (P < .05). We found a significantly shorter disease-free survival (P < .05) in the patients with >2 CK-positive cells per 2 x 10(6) bone marrow cells (mean, 35 months) than in patients with <or=2 CK-positive cells per 2 x 10(6 )bone marrow cells (mean, 70 months) or in patients with no CK-positive cells (mean, 86 months). Multivariate analysis confirmed that >2 CK-positive cells per 2 x 10(6) bone marrow cells was an independent prognostic factor for tumor-related death (P < .05).

CONCLUSIONS

Not only the mere presence of CK-positive epithelial cells in bone marrow, but also the cell number, correlates with prognosis. Our findings suggest that classifying CK-positive bone marrow cells in these patients will facilitate future studies.

Hedgehog signal activation in gastric pit cell and in diffuse-type gastric cancer

BACKGROUND & AIMS

Sonic hedgehog (SHH) and Indian hedgehog (IHH) have cell-specific actions in some organs. Only SHH has been shown to regulate parietal cell differentiation. This study examined whether SHH, 2 other ligands IHH and Desert hedgehog, and receptors or downstream targets are expressed in normal gastric epithelium or in intestinal and diffuse-type gastric cancers. The effects of a Hedgehog (Hh) inhibitor, cyclopamine, were assessed in primary gastric epithelium cultures and gastric cancer cell lines.

METHODS

Reverse-transcription polymerase chain reaction and immunostaining compared expression and localization of Hh signaling molecules and phenotypic markers of pit, neck, and gland cells in situ and in cultured cells treated with cyclopamine. Bromodeoxyuridine staining assessed the effects of cyclopamine on proliferation.

RESULTS

Hh signaling molecules were expressed differentially in pit, neck, and gland cells. IHH co-expressed with most downstream targets in the pit. IHH, SHH, Patched (PTCH), Smoothened (SMO), and downstream targets were expressed more frequently and highly in the diffuse as compared with intestinal type cancers. In diffuse cancers, IHH was expressed in cells with an epithelial phenotype and SHH in cells with a mesenchymal phenotype. Cyclopamine reduced the number of cells with a pit phenotype but not a gland phenotype in primary cultures. Cyclopamine had particularly potent effects of inhibiting the growth of cell lines that expressed high levels of SMO.

CONCLUSIONS

Expression of IHH and downstream targets correlates with pit cells. IHH and SMO may be useful biomarkers of diffuse cancers that may show growth inhibition with Hh antagonists such as cyclopamine.

Tumor differentiation phenotype in gastric differentiated-type tumors and its relation to tumor invasion and genetic alterations

AIM: To clarify the relations between tumor differentiation phenotype and tumor invasion or genetic alterations in gastric differentiated-type tumors.

METHODS: We examined the tumor differentiation phenotype, the presence of mutations in APC and p53, and the microsatellite instability (MSI) status in 48 gastric adenomas and 171 differentiated-type carcinomas. The tumor differentiation phenotype was determined by examining the expression of human gastric mucin (HGM), MUC6, MUC2 and CD10. The tumors were then classified into gastric- (G-), gastric and intestinal mixed- (GI-), or intestinal- (I-) phenotypes, according to the immunopositivity of the above markers. The presence of mutations in APC and p53 and the MSI status were also investigated in all the tumors.

RESULTS: Gastric adenomas were significantly associated with CD10 expression, I-phenotype tumors and the presence of APC mutations, compared with carcinomas (66.7% vs 25.1%, P < 0.0001; 56.3% vs 14.6%, P < 0.0001; 39.6% vs 14.0%, P < 0.0001, respectively) and inversely associated with expressions of HGM and MUC6 and the presence of p53 mutations (10.4% vs 62.6%, P < 0.0001; 39.6% vs 64.3%, P = 0.003; 2.0% vs 26.3%, P = 0.001, respectively). The frequency of APC mutations was significantly higher in HGM-negative tumors, MUC6-negative tumors, CD10-positive tumors and I-phenotype tumors than in HGM-positive tumors, MUC6-positive tumors, CD10-negative tumors and G-phenotype tumors (32.7% vs 7.1%, P < 0.0001; 27.8% vs 14.0%, P = 0.0182; 37.3% vs 10.4%, P < 0.0001; and 38.5% vs 9.5%, P = 0.0017, respectively). The frequency of MSI was significantly higher in MUC6-positive tumors, CD10-negative tumors and G-phenotype tumors than in MUC6-negative tumors, CD10-positive tumors and I-phenotype tumors (24.8% vs 6.7%, P = 0.0009; 22.2% vs 8.0%, P = 0.0143; and 28.6% vs 9.6%, P = 0.0353, respectively).

CONCLUSION: The tumor differentiation phenotype is closely related to tumor invasion and genetic alterations in gastric differentiated-type tumors.

Gastric and intestinal phenotypic cell marker expressions in gastric differentiated-type carcinomas: association with E-cadherin expression and chromosomal changes

Gastric and intestinal phenotypic cell markers are widely expressed in gastric carcinomas, irrespective of their histological type. In the present study, the relations between the phenotypic marker expression of the tumour, histological findings, expression of cell adhesion molecules, and the chromosomal changes in gastric differentiated-type carcinomas were examined. The phenotypic marker expression of the tumour was determined by the combination of the expression of the human gastric mucin (HGM), MUC6, MUC2 and CD10, and was evaluated in comparison with the expression of cell adhesion molecules, such as E-cadherin and beta-catenin, and chromosomal changes by comparative genomic hybridization (CGH) in 34 gastric differentiated-type carcinomas. Tumours were classified into the gastric- (G-), gastric and intestinal mixed- (GI-), intestinal- (I-), or unclassified- (UC-) phenotype according to the immunopositivity of staining for HGM, MUC6, MUC2, and CD10. G-phenotype tumours were significantly associated with a higher incidence of differentiated-type tumours mixed with undifferentiated-type component, compared with GI- and I-phenotype tumours (88.9 vs 33.3%, P=0.0498 and 88.9 vs 42.9%, P=0.0397; respectively). HGM-positive tumours were significantly associated with a higher incidence of tumours with abnormal expression of E-cadherin, compared with HGM-negative tumours (66.7 vs 21.1%, P=0.0135). GI-phenotype tumours were significantly associated with a higher incidence of tumours with abnormal expression of E-cadherin, compared with I-phenotype tumours (77.8 vs 21.4%, P=0.0131). HGM-negative tumours were significantly associated with higher frequencies of the gains of 19q13.2 and 19q13.3, compared with HGM-positive tumours (57.9 vs 20.0%, P=0.0382 and 63.2 vs 13.3%, P=0.0051; respectively). MUC6-positive tumours were significantly associated with higher frequencies of the gains of 20q13.2, compared with MUC6-negative tumours (71.4 vs 30.0%, P=0.0349). MUC2-positive tumours were significantly associated with the gain of 19p13.3, compared with MUC2-negative tumours (41.2 vs 5.9%, P=0.0391). I-phenotype tumours were significantly associated with higher frequencies of gains of 5p15.2 and 13q33-34, compared with G-phenotype tumours (66.7 vs 0%, P=0.0481, each) and also associated with higher frequencies of gain of 7p21, compared with GI-phenotype tumours (66.7 vs 0%, P=0.0481). Our present results show that gastric differentiated-type carcinomas have different characteristics according to the phenotypic marker expression of the tumour in terms of histological findings, E-cadherin expression and pattern of chromosomal changes.