Differentiation pathways in duodenal and ampullary carcinomas: a comparative study on mucin and trefoil peptide expression, including gastric and colon carcinomas

Mucin 5AC expression is common but unrelated to tumor progression in pancreatic adenocarcinoma

Introduction: Mucin 5AC (MUC5AC) belongs to the family of secreted gel-forming mucins. It is physiologically expressed in some normal mucin producing epithelial cells but also in pancreatic, ovarian, and colon cancer cells. The role of MUC5AC expression in cancer is not fully understood. This study was designed to explore the role of MUC5AC for pancreatic cancer progression, its association to microsatellite instability, and its diagnostic utility. Methods: Mucin 5AC expression was studied immunohistochemically in a tissue microarray (TMA) from 532 pancreatic cancers, 61 cancers of the ampulla Vateri, six acinar cell carcinomas and 12 large sections of pancreatitis. Results: Mucin 5AC staining was interpretable in 476 of 599 (79%) arrayed cancers. Staining was completely absent in normal pancreas and pancreatitis, but frequent in pancreatic cancer. Membranous and cytoplasmic MUC5AC expression was most common in pancreatic adenocarcinomas (71% of 423), followed by carcinomas of the ampulla Vateri (43% of 47), and absent in six acinar cell carcinomas. Mucin 5AC expression was unrelated to tumor phenotype (tumor stage, tumor grade, lymph node, and distant metastasis), and microsatellite instability in ductal adenocarcinomas and carcinomas of the ampulla Vateri. Conclusion: Our study indicates that MUC5AC is an excellent biomarker for pancreatic cancer diagnosis, especially to support the sometimes-difficult diagnosis on small biopsies. Mucin 5AC expression is unrelated to pancreatic cancer aggressiveness.

Genomic Sequencing Identifies ELF3 as a Driver of Ampullary Carcinoma

Ampullary carcinomas are highly malignant neoplasms that can have either intestinal or pancreatobiliary differentiation. To characterize somatic alterations in ampullary carcinomas, we performed whole-exome sequencing and DNA copy-number analysis on 60 ampullary carcinomas resected from clinically well-characterized Japanese and American patients. We next selected 92 genes and performed targeted sequencing to validate significantly mutated genes in an additional 112 cancers. The prevalence of driver gene mutations in carcinomas with the intestinal phenotype is different from those with the pancreatobiliary phenotype. We identified a characteristic significantly mutated driver gene (ELF3) as well as previously known driver genes (TP53, KRAS, APC, and others). Functional studies demonstrated that ELF3 silencing in normal human epithelial cells enhances their motility and invasion.

Signet ring cell carcinoma of the non-ampullary duodenum: A case report

We describe a case of signet ring cell carcinoma of the non-ampullary duodenum in an 86-year-old woman. Endoscopic examination revealed a fungating lesion (Borrmann classification; type 2) on the anterior wall of the descending duodenum (second part). Pylorus-preserving pancreaticoduodenectomy and lymphadenectomy were performed. The tumor (pT3 and pN0) was predominantly composed of signet ring cells, characterized by a central, optically clear, globoid droplet of cytoplasmic mucin with an eccentrically placed nucleus. The cells were positive for periodic acid Schiff with diastase and Alcian blue pH 2.5. On immunohistochemical examination, MUC-5AC, MUC-2 and CDX2 were diffusely positive, and MUC-6 was negative in the tumor cells, which consisted of mixed gastric foveolar and intestinal phenotypes. Cytokeratin 7 was focally positive, but cytokeratin 20 was negative. Nuclear staining of p53 was diffusely and weakly positive. Signet ring cell carcinoma occurring in the non-ampullary duodenum might derive from duodenal goblet cells with MUC-5AC expression.

Signet ring cell carcinoma of the ampulla of Vater: Immunophenotype and differentiation

Signet ring cell carcinoma (SRC) of the ampulla of Vater is extremely rare and the histogenesis remains unknown. In the present study, to investigate the immunohistochemical phenotypes, discuss the histological origin and evaluate the correlation between the immunohistochemical phenotypes and survival of ampullary SRC patients, a retrospective review was conducted. This included all ampullary carcinoma patients treated at The First Affiliated Hospital, College of Medicine, Zhejiang University, and was performed over a five-year period between 2008 and 2012. Eight resected ampullary SRC specimens were examined histopathologically and immunohistochemically, using cytokeratin (CK) and mucin (MUC) immunohistochemical phenotypes. Of all 162 patients with ampullary lesions, eight cases (4.9%) of ampullary SRC were identified. Immunohistochemical analyses of the eight cases revealed the positive expression of CK7 in five, CK19 in seven, CK20 in one, MUC1 in five, MUC2 in three, caudal-related homeobox transcription factor 2 in one, MUC5AC in seven and MUC6 in four of the eight cases, while loss of E-cadherin and β-catenin was observed in four of the eight cases. According to immunohistochemical classification, ampullary SRC can be classified into four subtypes: Intestinal (I), pancreatobiliary (PB), gastric and mixed types (composed of I mucosa lining and PB epithelium). Patients with the I-type ampullary SRC demonstrated a more favorable prognosis than that of patients with the PB-type ampullary SRC. Additionally, patients with ampullary SRC of I or PB type with gastric differentiation may have a worse prognosis than others. The coexpression of the E-cadherin/β-catenin complex may also indicate poor prognosis in PB-type ampullary SRC. In conclusion, the clinical five-year follow-up of the patients with pure SRC was more positive than that of those with I-, PB-, gastric- or mixed-type ampullary SRC. The coexpression of the E-cadherin/β-catenin complex may present a poor prognosis in the PB type of ampullary SRC.

Crohn enteritis-associated small bowel adenocarcinomas exhibit gastric differentiation

Primary small bowel adenocarcinoma is rare. Although generally similar to colonic adenocarcinoma, some small bowel adenocarcinomas exhibit unique morphologic features, particularly those arising in association with Crohn disease. In this study, 15 sporadic small bowel adenocarcinomas and 11 Crohn enteritis-associated small bowel adenocarcinomas were examined for histology and immunohistochemical profile including cytokeratins (CK) 7 and 20, intestinal markers CDX2 and MUC2, and gastric epithelial markers MUC5AC and MUC6. We found that Crohn enteritis-associated small bowel adenocarcinomas frequently resemble gastric tubular adenocarcinoma histologically. In addition, when compared to sporadic small bowel adenocarcinoma, the former expressed MUC5AC and MUC6 with much higher frequency (82% vs. 7% and 73% vs. 0%, respectively). Ten of 11 Crohn enteritis-associated small bowel adenocarcinomas (91%) were positive for at least one gastric-type marker (MUC5AC or MUC6). Expression of CK7 was also more frequent in Crohn enteritis-associated small bowel adenocarcinoma (73% versus 27%) while expression of CK20 was less frequent (64% vs. 100%). There was no difference between sporadic and Crohn enteritis-associated small bowel adenocarcinoma in expression of CDX2 (100% vs. 91%) and MUC2 (93% vs. 73%). These observations suggest that there is a difference in the morphologic and immunohistochemical characteristics of sporadic versus Crohn enteritis-associated small bowel adenocarcinoma, particularly in their expression of gastric-type mucin. The findings also suggest that gastric differentiation in Crohn enteritis-associated small bowel adenocarcinoma is related to gastric metaplasia, a common phenomenon in Crohn disease.

The co-expression of functional gastric proteins in dynamic gastric diseases and its clinical significance

Background

Pepsinogen C (PGC) and mucin1 (MUC1) are important physiologically functional gastric proteins; Mucin2 (MUC2) is an “ectopic” functional protein in intestinal metaplasia of gastric mucosa. We analyzed the co-expression of the above-mentioned three proteins in dynamic gastric diseases {superficial gastritis (SG)-atrophic gastritis (AG)--gastric cancer (GC)} as well as different histological types of gastric cancer in order to find molecular phenotypes of gastric cancer and precancerous disease and further explore the potential co-function of PGC, MUC1 and MUC2 in the occurrence and development of gastric cancer.

Methods

The SG-AG-GC sequence was 57-57-70 cases in this case–control study, respectively. Different histological types of GC were 28 cases of highly and moderately differentiated aden ocarcinoma (HMDA)、30 of poorly differentiated adenocarcinoma (PDA) and 12 of mucinous adenocarcinoma (MA) or signet ring cell carcinoma (SRCC). PGC, MUC1 and MUC2 expression in situ were detected in all 184 cases using immunohistochemistry.

Results

Both PGC and MUC1 had a significantly decreased expression in GC than in SG and AG (P < 0.0001 and P < 0.01, respectively); While MUC2 had a significant increased expression in AG than in SG and GC (P < 0.0001). Seven phenotypes of PGC, MUC1 and MUC2 co-expression were found in which PGC+/MUC1+/MUC2- phenotype took 94.7%(54/57) in SG group; PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+ phenotype took 43.9% (25/57) and 52.6% (30/57) in AG; the phenotypes in GC group appeared variable; extraordinarily, PGC-/MUC1-/MUC2+ phenotype took 100% (6/6) in MA or SRCC group and had a statistical significance compared with others (P < 0.05).

Conclusions

Phenotypes of PGC, MUC1 and MUC2 co-expression in dynamic gastric diseases are variable. In SG group it always showed PGC+/MUC1+/MUC2- phenotype and AG group showed two phenotypes (PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+); the phenotypes in GC group appeared variable but the phenotype of PGC-/MUC1-/MUC2+ may be a predictive biomarker for diagnosing MA or SRCC, or distinguishing histological MA or SRCC from tubular adenocarcinoma accompanied by mucinous secretion or signet ring cell scattered distribution.

Mucins differently expressed in various ampullary adenocarcinomas

Background

We investigated the occurrence and clinical significance of mucin expression in ampullary adenocarcinoma.

Methods

We retrospectively analyzed clinical, pathological, and survival data from 74 ampullary adenocarcinoma patients who received radical operation from January 2004 to November 2006.

Results

The tumors were located in the lower end of the common bile duct (46%), papillary duodenum (42%), and ampullary duodenum (12%), and expressed MUC1 (72%), MUC2 (20%), MUC5AC (43%), and MUC6 (27%). Expression of MUC1 was associated with tumor differentiation (OR: 4.71, 95% CI: 1.26, 17.66, P = 0.021). Expression of MUC5AC was associated with age (OR: 1.07, 95% CI: 1.11, 1.14, P = 0.026) and less vessel invasion(OR: 0.14, 95% CI: 0.03, 0.72, P = 0.019). The survival rates were not significantly different when patients had or had no expression of MUC1, MUC2, MUC5AC, or MUC6 in tumor. Patients with tumors positive for MUC5AC in the papillary duodenum had worse survival than those with tumors negative for MUC5AC (P = 0.044).

Conclusions

Expression of MUC1 was high (72%) in ampullary adenocarcinoma, while expressions of MUC2, MUC5AC, and MUC6 were lower. Mucins are useful markers to diagnose and identify ampullary adenocarcinoma, particularly in determining the degree of malignancy of ampullary adenocarcinoma.

Expression of MUC1 and MUC2 in ampullary cancer

BACKGROUND

Mucins are high-molecular-weight glycoproteins that play important roles in carcinogenesis or tumor invasion. The authors investigated the expression of mucins in ampullary cancer.

METHODS

MUC1 and MUC2 expressions were examined using immunohistochemistry. Tissue samples were obtained from 32 patients with ampullary cancer who underwent resection at Yamagata University Hospital, Japan. The authors classified the cases with ampullary cancer into 2 subtypes--pancreatobiliary type (PB type) and intestinal type (I type)--using H&E, MUC1, and MUC2 staining. Then, the authors made a comparison of the clinicopathologic data of the 2 subtypes.

RESULTS

Fourteen patients (44%) were classified as PB type and 18 patients (56%) as I type. The PB-type group had significantly worse histopathologic characteristics than the I-type group in nodal involvement (PB type 57% vs I type 22%; P = .04), perineural invasion (PB type 50% vs I type 17%; P = .04), duodenal invasion (PB type 100% vs I type 33%; P = .01), and pancreatic invasion (PB type 71% vs I type 33%; P = .03). The PB-type group had significantly worse outcome than the I-type group (5-year survival: PB type 40% vs I type 72%; P = .03).

CONCLUSION

PB-type ampullary cancers were more aggressive than I-type carcinomas. MUC1 and MUC2 expression was useful for classification as PB or I type.

Cytokeratin 20 (CK20) and apomucin 1 (MUC1) expression in ampullary carcinoma: Correlation with tumor progression and prognosis

Background

We assessed the expression of cytokeratin (CK) and apomucin (MUC) in ampullary carcinoma (AC) to develop a system for the classification of ACs on the basis of their clinical significance.

Method

We studied the expressions of CK7, CK20, MUC1, MUC2, MUC5AC, and MUC6 in 43 patients with ACs. Clinical data were obtained retrospectively by examining surgically resected ACs of the patients.

Results

We classified the cases into 3 groups: tumors expressing CK20 and lacking MUC1 (intestinal type [I-type], 26%), tumors expressing MUC1 and lacking CK20 (pancreatobiliary type [PB-type], 35%), and those expressing or lacking both CK20 and MUC1 (other type [O-type], 39%). Eight (73%) of 11 I-type carcinomas, 3 (20%) of 15 PB-type carcinomas, and 4 (24%) of 17 O-type carcinomas were classified as pT1. The number of I-type carcinomas in the early tumor stages was significantly higher than the number of PB- and O-type carcinomas (p = 0.014 and p = 0.018, respectively). The 5-year survival rates for pT1, pT2, and pT3 tumors were 76%, 33%, and 22%, respectively (p < 0.001). Rates of MUC5AC and MUC6 coexpression for I-type, PB-type, and O-type tumors were 18%, 13%, and 53%, respectively. There was a significant correlation between MUC5AC and MUC6 coexpression and O-type characteristics (p = 0.031). The five-year survival rates for O-type ACs with and without MUC5AC and MUC6 coexpression were 71% and 17%, respectively (p = 0.048).

Conclusions

The immunohistochemical subtypes based on CK and MUC expression correlated with tumor progression. Gastric MUC5AC and MUC6 coexpression correlated with better prognosis for O-type ACs.

Expression of gastric pyloric mucin, MUC6, in colorectal serrated polyps

Serrated polyps of the colorectal mucosa represent a heterogeneous and controversial taxonomic category with variation in histopathological, molecular, and immunohistochemical characteristics and with an incomplete understanding of pathogenesis. A previous study reported that the expression of gastric pyloric-type mucin, MUC6, characterized sessile serrated adenomas. We therefore evaluated the expression of MUC6 in serrated polyps identified among 2502 participants in a Phase III chemoprevention trial within the Arizona Cancer Center Colorectal Cancer Prevention Trials Program and characterized the associated histopathological features and location. We carried out immunohistochemistry for MUC6 on 146 serrated lesions and 87 conventional tubular adenomas, and assessed the percentage of cells with expression and the grade of staining intensity. In all 92 hyperplastic polyps, 43 sessile serrated adenomas, and 11 traditional serrated adenomas were included. Polyps ranged in size from 1-150 mm. The association of MUC6 staining with serrated polyp category was evaluated using classification and regression tree (CART) analysis and two-sided Fisher's exact test. A total of 53% of sessile serrated adenomas (n=23), 17% of hyperplastic polyps (n=16), and 18% of traditional serrated adenomas (n=2), but none of 87 tubular adenomas, expressed MUC6. Expression was limited to the lower crypts in all serrated polyps. The extent of positive staining ranged from 2-100% of crypt cells and was independent of the histopathological type. MUC6 expression had relatively high specificity for sessile serrated adenoma (82%) but low sensitivity (54%). In CART analysis, proximal location was found to be the best partitioning factor for MUC6, followed by classification as sessile serrated adenoma. We conclude that MUC6 expression is strongly associated with proximal location of serrated polyps, but only has modest utility as a tissue biomarker for sessile serrated adenoma.

Histopathologic features and microsatellite instability of cancers of the papilla of vater and their precursor lesions

The prevalence and development of microsatellite instability (MSI) and underlying mismatch repair (MMR) deficiency in the carcinogenesis of adenocarcinomas of the papilla of Vater and their precursor lesions are not well established. We analyzed 120 ampullary adenomas (31 pure adenomas and 89 carcinoma-associated adenomas) and 170 pure adenocarcinomas for MSI, immunohistochemical expression of MMR proteins and specific histopathologic features. The most common histologic subtype was intestinal (46.5%), followed by pancreatobiliary (23.5%), poorly differentiated adenocarcinomas (12.9%), intestinal-mucinous (8.2%), and invasive papillary carcinomas (5.3%). Eight of 89 adenomas (9%) and 15/144 carcinomas (10%) showed high microsatellite instability (MSI-H), 10/89 adenomas (11%) and 5/144 carcinomas (4%) showed low microsatellite instability (MSI-L), and 71/89 adenomas (80%) and 124/144 carcinomas (86%) were microsatellite stable (MSS). MSI analysis from carcinomas contiguous with an adenomatous component (n=54) exhibited concordant results in 6/8 (75%) MSI-H and 42/46 (91.3%) MSS tumors. Of 14 carcinomas with MSI-H, 7 showed loss of MLH1 and 5/6 (83%) MLH1 promoter methylation, and 2 carcinomas showed simultaneous loss of MSH2 and MSH6. Two carcinomas and 3 adenomas with MSI-H revealed exclusive loss of MSH6. MSI-H cancers were significantly associated with intestinal mucinous subtype (P<0.001), high tumor grade (P=0.003), expansive growth pattern (P=0.044), and marked lymphoid host response (P=0.004). Patients with MSI-H carcinoma had a significantly longer overall survival (P=0.0082) than those with MSI-L or MSS tumors. Our findings indicate that the MSI-phenotype is an early event, which develops at the stage of adenoma and is reliably detectable in the precursor lesion. The MMR deficient molecular pathway of carcinogenesis is associated with a histopathologic phenotype in ampullary cancer, similar to the one that has been well described in colon cancer.

Enhanced expression of mucin 6 glycoprotein in cholangiocarcinoma tissue from patients in Thailand as a prognostic marker for survival

BACKGROUND AND AIM

Cholangiocarcinoma (CCA) is a mucin-producing cancer that has poor prognosis. Mucin 6 (MUC6) is a mucin that is normally co-expressed with the trefoil factor family-2 (TFF2) trefoil peptide. Both MUC6 and TFF2 have been reported to be involved in the progression of many types of cancers. The aim of this study was to determine the expression of MUC6 and TFF2 in CCA tissues and associate these results with clinical data.

METHODS

MUC6 and TFF2 were detected in CCA tissues by immunohistochemistry. The correlations of MUC6 and TFF2 expressions with clinical data were analyzed.

RESULTS

We determined the significant co-expression of both proteins in serial CCA tissues. The high expressions of MUC6 and TFF2 were demonstrated in 37% and 31% of patients, respectively. The expression levels decreased in the advanced stage of CCA when clinical metastasis was exhibited. The high expression of either protein showed a correlation with prolonged postoperative survival time, but only a high expression of MUC6 is significantly correlated with a 5-year survival rate. A multivariate Cox regression analysis revealed that a low expression of MUC6, high expression of TFF2, age of patients >56 years, tumor size >5 cm, and poorly-differentiated histological type were independent, poor prognostic indicators for CCA.

CONCLUSION

MUC6 showed a good correlation with the survival of CCA patients. It may be of value to propose that MUC6 is a good prognostic marker for CCA management.

Immunohistochemical biomarkers of value in distinguishing primary ovarian carcinoma from gastric carcinoma: a systematic review with statistical meta-analysis

AIMS

To compare the relative risk of antigen expression being detected immunohistochemically in ovarian and gastric carcinoma aggregated from studies performed for diagnostic purposes, with the relative risks of their expression in all patients in the English literature.

METHODS AND RESULTS

Both types of series indicated that cytokeratin (CK) 7 expression was greater and that of CK20 and carcinoembryonic antigen less in ovarian than in gastric carcinoma (P < 0.05). Synthesis of all data available for MUC-2 suggested it was more commonly expressed in ovarian carcinoma, whereas the relative risk in papers that directly compared its expression suggested that it was more common in the gastric carcinoma (P = 0.2, NS). Aggregating all possible data suggested villin was more likely to be expressed in ovarian cancers, whereas studies in which its expression was compared directly in both tumours suggested the opposite. Although statistically significant, patient numbers were small.

CONCLUSION

Provided sufficient numbers of cases are studied, analysis of studies comparing antigen expression for diagnostic purposes in tumours from two body sites is likely to be supported in the wider literature. The design of such comparative studies is informed by aggregating data from single tumour studies.

Prognostic factors for ampullary adenocarcinomas: tumor stage, tumor histology, tumor location, immunohistochemistry and microsatellite instability

Prognostic factors for ampullary carcinomas (ACs) are poorly defined. Fifty three resected ACs were analyzed for CDX2, MUC1, MUC5AC, MUC6, MUC2, and for mismatch repair proteins (hMLH1, hMSH2, PMS2, hMSH6) using immunohistochemistry. Microsatellite instability (MSI) status was evaluated by fluorescently labeled PCR using an automated sequencer. Univariate and multivariate analysis was performed for clinicopathological, immunohistochemical and molecular parameters. CDX2 was found in 32 out of 53 (60%) ACs with a significantly higher frequency among intestinal ACs compared with biliopancreatic (BP) ACs. The MUC1, MUC5AC, MUC6, MUC2 apomucins were expressed in 75, 43, 39, and 28% of ACs, respectively, with a significantly higher coexpression of MUC1/MUC5AC in BP ACs. MSI and loss of expression of hMLH1/PMS2 or hMSH2/hMSH6 proteins were observed only in intestinal ACs. Factors significantly correlated with improved survival in the univariate analysis were: low stage, absence of lymph nodes metastases, negative surgical margins (R0 status), and presence of MSI. In the multivariate analysis, stage was the only independent prognostic factor of survival. We conclude that stage is the only independent prognostic factor of survival in the multivariate analysis, whereas histological criteria and the immunohistochemical expression of apomucins and CDX2 are helpful in the classification and understanding of the histogenesis of ACs.

Expression profiles of MUC mucins and trefoil factor family (TFF) peptides in the intrahepatic biliary system: physiological distribution and pathological significance

Mucin secreted by mucosal epithelial cells plays a role in the protection of the mucosal surface and also is involved in pathological processes. So far, MUC1-4, 5AC, 5B, 6-8, 11-13 and 15-17 genes coding the backbone mucin core protein have been identified in humans. Their diverse physiological distribution and pathological alterations have been reported. Trefoil factor family (TFF) peptides are mucin-associated molecules co-expressed with MUC mucins and involved in the maintenance of mucosal barrier and the biological behavior of epithelial and carcinoma cells. Intrahepatic biliary system is a route linking the bile canaliculi and the extrahepatic bile duct for the excretion of bile synthesized by hepatocytes. Biliary epithelial cells line in the intrahepatic biliary system, secreting mucin and other molecules involved in the maintenance and regulation of the system. In this review, the latest information regarding properties, expression profiles and regulation of MUC mucins and TFF peptides in the intrahepatic biliary system is summarized. In particular, we focus on the expression profiles and their significance of MUC mucins in developmental and normal livers, various hepatobiliary diseases and intrahepatic cholangiocarcinoma.

Prognostic value of mucins in the classification of ampullary carcinomas

The ampulla of Vater is of high clinical relevance with regard to influx of chyme, ascending inflammation, intubation during diagnostic and therapeutic endoscopic investigation, therapeutic papillotomy, and especially to malignant transformation. Little is known about the distribution of mucins in the ampulla. In this study, we have investigated the mucin distribution in the normal ampulla of Vater and compared it to duodenal mucosa and Brunner glands. Expression of mucins in the ampulla of Vater and duodenum was monitored by reverse transcription-polymerase chain reaction and localization of the products by immunohistochemistry. The samples investigated originated from 30 autopsy cases. Mucins MUC1, MUC3, MUC4, MUC5AC, MUC5B, MUC6, MUC7, and MUC8 were expressed in the ampulla of Vater. Immunohistochemistry revealed production of MUC4, MUC5AC, MUC5B, and MUC6. The mucin composition varied in comparison with the duodenum referring to MUC2, MUC7, and MUC8. Detected mucins contribute to innate immunity, epithelial restitution, and protection against the aggressive secretions of the liver, gall bladder, and pancreas. By cross-linking, they influence the rheological properties of the secretions in the ampulla and facilitate unidirectional flow into the duodenum. Knowledge of their pattern of expression has prognostic value with regard to the detection of malignancy. The observed differences in the mucin distribution between the duodenum and the ampulla of Vater support the use of MUC2, MUC7, and MUC8 as useful tool in the classification of ampullary carcinomas.

KL-6 mucin expression in carcinoma of the ampulla of Vater: Association with cancer progression

AIM: To assess histochemical expression of KL-6 and its clinicopathological significance in carcinoma of the ampulla of Vater.

METHODS: Ampullary carcinoma tissues were collected from 38 patients who underwent pancreatoduodenectomy or local resection. Tissues were subjected to immunohi-stochemical analysis using KL-6 antibody.

RESULTS: Positive staining of ampullary carcinoma cells was observed in 26 (68.4%) cases. Staining was not found in the surrounding non-cancer regions of the ampullary tissues. Remarkable KL-6 expression was observed in invasive carcinoma cells in pancreatic and duodenal tissues and in metastatic carcinoma cells in lymph nodes. Positive KL-6 expression was related to lymph node metastasis (P = 0.020), pancreatic invasion (P = 0.016), duodenal invasion (P = 0.034), and advanced stage of TNM clinical classification (P = 0.010). Survival analysis showed that positive expression of KL-6 was related to a poorer prognosis (P = 0.029).

CONCLUSION: The aberrant expression of KL-6 mucin is significantly related to unfavorable behaviors of carcinoma of the ampulla of Vater.

Trefoil factor family (TFF) peptides of normal human Vater's ampulla

Vater's ampulla is of great clinical relevance with regard to the influx of chyme, ascending inflammation, intubation during diagnostic and therapeutic endoscopic maneuvers, therapeutic papillotomy and, especially, the formation of malignancies. Little is known about the distribution of trefoil factor family (TFF) peptides in the ampulla. We have therefore examined TFF peptide distribution in the normal ampulla of Vater and compared it with that in duodenal mucosa and Brunner's glands. Expression and synthesis of TFF peptides in Vater's ampulla and duodenum was investigated by reverse transcription-polymerase chain reaction, Western blot and immunohistochemistry. The samples studied originated from 30 autopsy cases with short postmortem intervals. TFF3 was expressed in the ampulla of Vater. mRNA expression of TFF1 was detected in only approximately 25% of the investigated samples. Western blot revealed the production of TFF3 and immunohistochemistry showed that TFF3 was the product of goblet cells. TFF peptide composition of Vater's ampulla varied in comparison with that in the duodenum regarding TFF2 expression. The ampulla of Vater thus has a unique profile of TFF peptide production, supporting the hypothesis that the ampulla is an autonomous organ. The observed differences in the TFF peptide distribution between the duodenum and Vater's ampulla favour the investigation of TFF peptides as prognostic markers in the classification of ampullary carcinomas.