Gastric carcinoma cells with endocrine differentiation show no evidence of proliferation

Clinicopathologic significance of gastric adenocarcinoma with neuroendocrine features

PURPOSE

Composite neuroendocrine-exocrine carcinomas are malignancies that have two distinct components residing within the same tumor: an adenocarcinomatous portion and a neuroendocrine portion. This is rare in gastric cancers; however, poorly differentiated adenocarcinomas can sometimes reveal evidence of neuroendocrine features (NEF) or be 'mixed endocrine and exocrine carcinomas'. This study aimed to review NEF in gastric adenocarcinoma and to evaluate its prognostic significance.

MATERIALS AND METHODS

We selected 29 patients who were diagnosed with gastric adenocarcinoma with NEF and received gastrectomies at the Department of Surgery, Ajou University Hospital between January 2001 and December 2009. We analyzed the clinicopathologic features of gastric cancer with NEF and the prognosis associated with such tumors.

RESULTS

THE PATHOLOGIC RESULT WITH RESPECT TO TNM STAGING OF THE GASTRIC CANCERS WITH NEF WERE AS FOLLOWS: 5 cases of T1, 5 cases of T2, 10 cases of T3, and 9 cases of T4. There were 7 cases of N0, 7 cases of N1, 8 cases of N2 and 7 cases of N3. The staging of patients with NEF was higher than that of patients without NEF. Especially tumor lymphovascular invasion rate was 82.8%. The overall survival of patients with gastric cancer characterized by NEF was 73.8 months.

CONCLUSIONS

Positive NEF status might be correlated with clinicopathologic parameters such as a high stage and high frequency of regional lymph node metastasis.

Increased neuroendocrine cells in resected metastases compared to primary colorectal adenocarcinomas

Neuroendocrine differentiation has been described in rectal adenocarcinomas receiving neoadjuvant therapy prior to radical surgery, but its clinical relevance is controversial and no data are currently available in colorectal carcinoma metastases as compared to primary tumors. The presence of chromogranin A positive tumor cells was investigated by means of immunohistochemistry on surgical specimens from 54 primary colorectal carcinomas and their corresponding metastases, resected at diagnosis or during tumor progression. In 47 patients, tumor metastases were resected 1 month to 12 years after chemotherapy and/or radiotherapy, while in the remaining seven patients no additional therapy after primary surgery was performed. In primary tumors, neuroendocrine differentiation was found in 12/54 cases (22.2%) as compared to 25/54 metastatic lesions (46.3%; p = 0.01). The presence of neuroendocrine phenotype was not correlated with any clinical pathological parameter nor with a different proliferation index. However, patients having neuroendocrine cells in the primary tumor had a significantly shorter survival from the time of metastatic spread than those having not (33.3 vs. 55.5 months; p = 0.04). In summary, our data show that colorectal carcinoma metastases contain a higher percentage of neuroendocrine differentiated cells as compared to their corresponding primaries, a finding possibly related to the influence of chemotherapy in neuroendocrine differentiation during colorectal carcinoma progression.

Chromogranin A-positive tumor cells in human esophageal squamous cell carcinomas

Gastrointestinal cancers have frequently shown neuroendocrine (NE) differentiation, but whether NE differentiation occurs in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, tissue sections obtained from 43 patients with ESCC from a high-incidence area of Northern China were used for the assessing of NE differentiation by immunohistochemistry using antibody against chromogranin A (CGA). In addition, the malignant characteristics and proliferation capacity of CGA-positive cells were also examined by immunohistochemistry. The clinicopathological significance of these CGA-positive tumor cells in ESCC was assessed. Of 43 ESCC samples, CGAimmunoreactive tumor cells were detected in 10 cases (23.26%). However, the CGA-positive tumor cells were scattered at a very low number among non-immunoreactive tumor cells and were rarely constituted a major part of cancer cell nests. Only 4.65% (2/43) cases showed a high density (>10 cells but <1% of total tumor cell mass) of CGA-positive tumor cells. P53 immunoreactivity was frequently shown, while Ki67 was hard to detect in these CGApositive cells. In addition, no relationship between CGA positivity rate and clinicopathological parameters was found. Thus, we concluded that lowdensity CGA-positive tumor cells can be detected in ESCC, supporting the notion that heterogeneous NE differentiation also exists in tumors that lack neuroendocrine cells in their normal epithelial counterparts.

Goblet cell carcinoids and other mixed neuroendocrine/nonneuroendocrine neoplasms

Within the spectrum of neuroendocrine tumors arising in different organs, intermediate and controversial entities exist displaying a coexistence of neuroendocrine and nonneuroendocrine cell populations, and that are grouped under terms such as "goblet cell carcinoid", "mixed endocrine-exocrine carcinoma", "combined carcinomas", or "adenocarcinoma with neuroendocrine differentiation". These tumors may display variable amounts of the two components, potentially ranging from 1 to 99%, and variable structural patterns, ranging from single scattered neuroendocrine cells to a well-defined neuroendocrine tumor cell component organized in typical organoid, trabecular, or solid growth patterns. Although variably included in the site-specific World Health Organization classification schemes, clear definitions and diagnostic features are still missing, as well as a definite knowledge of their biological properties and histogenesis. In the present report, the main characteristics of tumors showing mixed neuroendocrine and nonneuroendocrine features will be described, using morphological patterns and site of origin as schematic guidelines. Moreover, molecular and clinical aspects, which might help to understand their possible histogenesis and biological behavior, will be reviewed.

Effect of vasoactive intestinal peptide on gastric adenocarcinoma

BACKGROUND AND AIM

Vasoactive intestinal peptide (VIP) is a gastrointestinal hormone in the secretin-VIP family. It has been reported that VIP affects some tumor growth, and there is a VIP autocrine regulation in some cancers. However, the effect of VIP on gastric adenocarcinoma is not clear yet. The aim of the present study was to investigate the effect of VIP on gastric adenocarcinoma, especially autocrine regulation of VIP on gastric adenocarcinoma.

METHODS

VIP mRNA and protein, and its receptor mRNA (VIPR(1) and VIPR(2)) were measured in 15 normal antrum mucosa, 20 gastric adenocarcinoma tissues, and the SGC7901 gastric adenocarcinoma cell line by using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, or radioimmunoassay methods. The effect of the VIP protein and its antagonist (D-p-Cl-Phe6, Leu17)-VIP on SGC7901 cell growth was detected by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method. The expressions of c-myc mRNA and ornithine decarboxylase (ODC) mRNA in SGC7901 cells before and after the incubated VIP protein and/or its antagonist were also measured by RT-PCR method.

RESULTS

The VIP mRNA expression in gastric adenocarcinoma tissues was significantly higher than that in normal antrum mucosa (P < 0.01). The VIP-positive immunoreactivity cells existed in 40% of gastric adenocarcinoma tissues, but not in normal tissues (P < 0.01). The VIP-positive immunoreactivity nerve fibers were observed in normal tissues, but not in adenocarcinoma tissues (P < 0.01). The expression rate of VIPR(1) mRNA in adenocarcinoma tissues was significantly lower than that in normal tissues, but that of VIPR(2) mRNA in the two kinds of tissues were similar (P > 0.05). In addition, the expression quantity of VIPR(1) mRNA and VIPR(2) mRNA in adenocarcinoma tissues was significantly lower than that in normal tissues (P < 0.05). SGC7901 cells expressed not only VIP mRNA and the VIP protein, but also VIPR(1) and VIPR(2) mRNA. 10(6) SGC7901 cells secreted 13.15 +/- 8.54 pg VIP on average. VIP did not affect the proliferation of SGC7901 cells, but the antagonist stimulated the proliferation of SGC7901 cells from 10(-5) to 10(-8) mol/L concentration incubated for 24-96 h. VIP downregulated the expressions of c-myc and ODC mRNA, but its antagonist upregulated their expressions.

CONCLUSIONS

The expression of VIP mRNA upregulates, but the expressions of VIPR mRNA downregulates in gastric adenocarcinoma tissues. The gastric adenocarcinoma tissues contain endocrine cells to secrete VIP, which show malignant specialities. The VIP autocrine regulation exists in SGC7901 cells, and potentially inhibits the proliferation of the cells by downregulating the expressions of c-myc and ODC mRNA. It suggests that VIP may play an important role in the regulation of the growth of gastric cancer cells.

The grey zone between pure (neuro)endocrine and non-(neuro)endocrine tumours: a comment on concepts and classification of mixed exocrine-endocrine neoplasms

Terms such as "mixed endocrine-exocrine carcinoma" (MEEC) and "adenocarcinoma with neuroendocrine (NE) differentiation" (ADC-NE) identify tumours belonging to the spectrum of neoplasms with divergent exocrine and (neuro)endocrine differentiation. These tumours display variable quantitative extent of the two components, potentially ranging from 1 to 99%, and variable structural patterns, ranging from single scattered NE cells to a well-defined NE tumour cell population organized in organoid, trabecular or solid growth patterns. In the present report, the grey zone of tumours/carcinomas with mixed NE and non-NE features is explored for various organs. From a practical point of view, MEECs differ from carcinomas with focal NE differentiation by (1) the extension of each component (more than 30%) and (2) the structural pattern of the NE component, either organoid for well-differentiated or solid/diffuse for poorly differentiated cases. In MEECs, the most aggressive cell population drives the clinical behaviour. Conversely, ADC-NE generally do not show a different clinical outcome, compared to the corresponding conventional forms, except for prostatic adenocarcinoma, in which NE cells are a negative prognostic factor. The recognition of MEECs may be of relevance for a targeted therapeutic strategy, foreseeing the use of biotherapies similar to those proposed for pure NE tumours.

Neuroendocrine differentiation in gastric adenocarcinomas; correlation with tumor stage and expression of VEGF and p53

Studies on neuroendocrine differentiation (NED) in conventional gastric adenocarcinomas and its significance on tumor behavior are limited. Our aim was to search for the expression of neuroendocrine differentiation in conventional gastric adenocarcinomas and correlate it with tumor type, stage and expression of VEGF and p53. Forty-two gastrectomy specimens with gastric adenocarcinoma were stained with chromogranin A to detect neuroendocrine differentiation and 45% of the cases were found to be NED (+). No significant correlation was found between NED and tumor type. However, NED was more frequent in advanced stage cases independently of tumor type. VEGF expression was also considerably more frequent in NED (+) tumors compared to NED (-) ones (84% vs. 56%). Moreover, we found a significant correlation between NED and the presence of lymph node metastases. P53 expression in NED (+) tumors was 68%. There was no significant correlation between VEGF and p53 in NED (+) cases. In conclusion, neuroendocrine differentiation is a frequent finding in conventional gastric adenocarcinomas, and although it does not seem to play a specific role in tumor progression, it seems that neuroendocrine cells are one of the factors contributing to angiogenesis by expressing VEGF, especially in advanced stage cases, affecting the incidence of lymph node metastases. Further studies with larger series should be performed to confirm this observation.

Characterization of scattered neuroendocrine cells in ductal carcinoma of the pancreas

INTRODUCTION

Scattered neuroendocrine cells, identified by chromogranin A (CGA) immunoreactivity, have been observed in pancreatic ductal carcinomas, accounting for <1% of the entire tumor cell population.

AIMS AND METHODOLOGY

To determine the characteristics of scattered CGA-positive cells, the differentiation markers for the cells of epithelial origin (cytokeratin [CK] 19) and of endocrine origin (CGA) were evaluated by immunohistochemistry and double immunofluorescent staining.

RESULTS

Some of these CGA-positive cells scattered amid malignant cells also express CK19, suggesting that they are neuroendocrine-differentiated carcinoma cells. However, scattered CGA-positive cells, mostly located at the basal and/or outer portions of malignant ducts, did not express CK19, indicating that these cells are probably entrapped endocrine cells. Examination of the lymph node metastases for CGA in 19 patients showed no staining with CGA, suggesting that neuroendocrine-differentiated tumor cells have a different behavior.

CONCLUSION

The current study did not show any clinical significance of these scattered neuroendocrine cells.

Endocrine cells in gastric carcinoma and adjacent mucosa. An immunohistochemical and ultrastructural study

Endocrine cells are often found in human gastric carcinoma and may be recognized by the immunoreactivity of their chromogranin A, peptides and biogenic amines content. Anti-chromogranin A was used to investigate the morphology of endocrine cells using light and electron microscope immunohistochemical techniques. The hormone content of endocrine cells was examined in both tumour tissue and tumour-adjacent mucosa. It was found that the endocrine cells in tumour tissue were malignant, often had amphocrine differentiation and did not resemble a normal cell type. The hormone content of endocrine cells in tumour tissue seldom corresponded to the hormonal content of endocrine cells in tumour-adjacent mucosa. In intestinal-type carcinoma and in some parts of diffuse-type gastric carcinomas, endocrine cell hyperplasia and an alteration of the differentiation in the tumour-adjacent mucosa were discovered. The distribution of endocrine cells in the tumour tissue was different in both types of gastric carcinoma. The results reported here suggest that endocrine cell differentiation of malignant endocrine cells in human gastric carcinoma develops in a different way from that of endocrine cells in tumour-adjacent mucosa, and as a result, diverse hormonal products may appear in tumour tissue.

Detection of chromogranin A in human gastric adenocarcinomas using a sensitive immunohistochemical technique

Neuroendocrine cells are often disclosed in human gastric adenocarcinomas and may be recognised by their immunoreactivity towards chromogranin A. However, in dedifferentiated neuroendocrine tumour cells, the chromogranin A content may be reduced making it difficult to detect with conventional immunohistochemical methods. We therefore used a sensitive signal amplification technique in order to evaluate chromogranin A immunoreactivity and thus neuroendocrine differentiation in 40 gastric adenocarcinomas. Neuroendocrine cells were visualised by means of a monoclonal chromogranin A antibody and the avidin-biotin peroxidase complex technique, without and with addition of tyramide signal amplification. Double immunohistochemistry towards chromogranin A and Ki-67 were used to disclose proliferation in the neoplastic cells. A marked increase in the number of carcinomas containing chromogranin A-immunoreactive neoplastic cells was noted when applying the tyramide signal amplification technique. In addition, the number of immunoreactive cells within each tumour increased, and in some cases almost all the neoplastic cells became immunoreactive. Chromogranin A-immunoreactive tumour cells showing signs of proliferation were found in the majority of these carcinomas. In conclusion, we have disclosed widespread immunoreactivity towards chromogranin A in a proportion of gastric adenocarcinomas when enhancing the signal with tyramide signal amplification. Neuroendocrine differentiation is thus a common finding in gastric carcinomas when using sensitive methods.

Personal review: is profound acid inhibition safe?

Inhibitors of gastric acid secretion, particular proton pump inhibitors, are effective drugs in the treatment and prophylaxis of acid-related diseases. Proton pump inhibitors are therefore prescribed widely, often for minor complaints. Gastric acidity kills swallowed microorganisms, and acid secretion must be of biological importance because it is maintained in phylogenesis. Acid secretion is controlled by feedback mechanisms, mainly via gastrin. A decrease in acidity always causes an increase in plasma gastrin. The trophic effect of gastrin leads to hyperplasia and neoplasia of the enterochromaffin-like (ECL) cell. ECL cell derived tumours in man were previously regarded as rare, and also as rather benign. It is now clear that the ECL cell gives rise to a significant proportion of gastric carcinomas. Moreover, ECL cell carcinoids secondary to hypergastrinaemia may develop into highly malignant tumours. Treatment with a proton pump inhibitor is followed by rebound acid hypersecretion and decreased efficiency of H2-blockers, thus such treatment may induce a type of physical dependence. It is therefore reasonable to be cautious and not to treat younger (< 50 years) patients for long periods of time with profound inhibitors of gastric acid secretion. Chromogranin A in the blood is a sensitive marker of the ECL cell mass, and it could be used to survey patients on long-term proton pump inhibitors.

Chromogranin A gene expression in non-small cell lung carcinomas

Evidence for the existence of neuroendocrine (NE) differentiation in non-small cell lung carcinomas (NSCLCs) is at present based on histochemical, ultrastructural, and immunohistochemical data. The aim of this study was to investigate the extent of NE differentiation in NSCLCs as revealed by mRNA analysis. Different techniques including immunohistochemistry (IHC), northern blot analysis (NBA), and reverse transcriptase-polymerase chain reaction (RT-PCR) were employed in parallel to reveal the panendocrine marker chromogranin A (CgA). The data were related to pathological, immunocytochemical (PGP 9.5, synaptophysin, Leu-7 and neuron-specific enolase), and prognostic indicators. Forty surgically resected cases of NSCLC (24 squamous cell carcinomas, 12 ordinary type adenocarcinomas, 3 bronchiolo-alveolar carcinomas, and 1 anaplastic large cell carcinoma), in which fresh frozen material was available for mRNA analysis, were collected. CgA immunoreactivity was present in five cases (12.5 per cent), generally confined to a minority of the neoplastic cell population. By RT-PCR, CgA mRNA was found in 20 cases (50 per cent), including the five tumours positive by IHC. A statistically significant correlation was found between the two techniques. By NBA, no CgA mRNA expression was detected. Leu-7 immunoreactivity was present in 15 per cent of cases, NSE in 52.5 per cent, synaptophysin in 10 per cent, and PGP 9.5 in 82.5 per cent. In NSCLC, no correlations were found between CgA production, as detected by IHC or RT-PCR methods, and the histological type, stage, grade and proliferative activity of tumours, or the disease-free interval. It is concluded that CgA gene expression can be revealed in NSCLC at both mRNA and protein levels and that RT-PCR is a valuable tool for identifying NE differentiated NSCLCs. Our data suggest that NE differentiation does not represent an independent prognostic factor in surgically resected NSCLCs.

Polyamine levels and ODC activity in intestinal-type and diffuse-type gastric carcinoma

Gastric carcinomas are divided into two types according to Lauren's classification: intestinal and diffuse types. Polyamines (putrescine, spermidine, and spermine) are polycations involved in neoplastic growth of gastrointestinal mucosa. A key role is also played by ornithine decarboxylase, the rate limiting enzyme in polyamine metabolism. Our aim was to investigate whether there were differences between the two types of tumor in polyamine metabolism. Twenty-seven patients with gastric carcinoma entered the study. Seventeen carcinomas were classified as diffuse type and 10 as intestinal type. Polyamine levels were evaluated by high-performance liquid chromatography. Ornithine decarboxylase activity was measured by a radiometric technique. Polyamine levels and ornithine decarboxylase activity were significantly higher in intestinal type samples than diffuse type samples. A similarity of polyamine levels in intestinal type samples with levels previously observed in patients with colorectal adenocarcinoma was also found. These findings show a different proliferative behavior of these two types of tumor, and therefore different therapeutic strategies can be hypothesized.

The incidence of chromogranin A defined endocrine cells decreases with tumour progression in gastric adenocarcinoma

The immunohistochemical expression of chromogranin A (CGA) was investigated in 60 normal mucosas, 95 primary tumours and 38 metastatic lymph nodes. CGA was expressed in 100% of the normal mucosas, 61% of the primary tumours that were restricted within the submucosal layer, 21% of the primary tumours that invaded beyond the submucosal layer, and 11% of the metastatic lymph nodes. The 5-year survival rates in patients with negative and positive expression of CGA in primary tumours were 60.4% and 74.6%, respectively. These results indicate that endocrine cells occupy an integral part of gastric adenocarcinoma with regard to tumour progression.

An Unusual Case of Multiple Gastric Carcinoids Associated with Diffuse Endocrine Cell Hyperplasia and Parietal Cell Hypertrophy

We describe a case of multiple gastric carcinoid tumors in a 47 year-old Japanese man. The patient had markedly elevated serum gastrin levels (>800 pg/mL), which were suppressed by secretin-pancreozymin administration. In the partial gastrectomy specimen, a total of 19 carcinoids arose from diffuse linear and micronodular hyperplasia of the oxyntic mucosal endocrine cells. The carcinoid cells were chromogranin A-positive. Except for a very small number of serotonin-positive cells in several carcinoids, none of the 19 reacted with a battery of antibodies to other bioactive neuroendocrine substances. The most prominent findings in this case were peculiar fundic glands that were distended with a proteinaceous substance and lined with large hypertrophic parietal cells. At the ultra-structural level, these cells showed poorly developed intracytoplasmic canaliculi and vesicotubular profiles, yet their large cytoplasm had numerous mitochondria. On the basis of our histological and ultrastructural findings we suggest that an intrinsic HCI secretion abnormality of the parietal cells may be responsible for the patient's hypergastranemia. Since there have been no reports on similar parietal cells changes, it is possible that our case may represent a pathological entity not previously described.