Cytokeratin 7/20 and mucin core protein expression in ulcerative colitis-associated colorectal neoplasms

Ki-67 distribution, α-methylacyl-CoA racemase (AMACR) expression and mucin phenotypes are associated with non-polypoid growth in ulcerative colitis-associated neoplasia

AIMS

Ulcerative colitis-associated neoplasia (UCAN) is characterised by multifocal tumourigenesis. A wide range of metachronous lesions have been reported to occur after endoscopic treatment of UCAN, which suggests the development of sporadic tumours in lesions treated as UCAN. Therefore, we aimed to evaluate differences of immunohistochemistry (IHC) in features and clinicopathological characteristics of intramucosal lesions in patients with ulcerative colitis (UC).

METHODS AND RESULTS

We examined 35 intramucosal lesions resected for carcinoma or dysplasia by total colectomy from patients with UC and 71 sporadic adenomas (SAs) endoscopically resected from patients without UC. UC lesions were divided into the conventional UCAN group, defined as p53 mutant pattern and normal expression of β-catenin, and the non-conventional UCAN group, defined as the rest. Ki-67 distribution, α-methylacyl-CoA racemase (AMACR) expression and mucin phenotypes were compared using IHC, and clinicopathological characteristics were investigated. Conventional and non-conventional UCAN lesions were located in the left colon and rectum. Relative to the SA lesions, UCAN lesions occurred in much younger patients and exhibited more frequent basal distribution of Ki-67 in tumour crypts. Conventional UCAN lesions tended to be non-polyploid and exhibited a higher frequency of normal AMACR expression than SA lesions. UC lesions were heterogeneous-only two of the eight patients with multiple lesions had lesions (both non-conventional UCAN lesions) exhibiting concordant IHC staining features.

CONCLUSIONS

The basal pattern of Ki-67 distribution, normal expression of AMACR and a non-intestinal mucin phenotype were determined as characteristic features suggestive of UCAN. Non-polypoid growth was another a key feature of UCAN.

Active nanoparticle targeting of MUC5AC ameliorates therapeutic outcome in experimental colitis

Inflammatory bowel diseases (IBDs), which include Crohn's disease (CD) and ulcerative colitis (UC), are chronic inflammatory diseases of the gastrointestinal tract and are characterized by chronic recurrent ulceration of the bowels. Colon-targeted drug delivery systems (DDS) have received significant attention for their potential to treat IBD by improving the inflamed tissue selectivity. Herein, antiMUC5AC-decorated drug loaded nanoparticles (NP) are suggested for active epithelial targeting and selective adhesion to the inflamed tissue in experimental colitis. NPs conjugated with antiMUC5AC (anti-MUC5) were tested for their degree of bioadhesion with HT29-MTX cells by comparison with non-targeted BSA-NP conjugates. In vivo, the selectivity of bioadhesion and the influence of ligand density in bioadhesion efficiency as well as the therapeutic benefit for glucocorticoid loaded anti-MUC5-NP were studied in a murine colitis model. Quantitative adhesion analyses showed that anti-MUC5-conjugated NP exhibited a much higher binding and selectivity to inflamed tissue compared to PNA-, IgG1- and BSA-NP conjugates used as controls. This bioadhesion efficiency was found to be dependent on the ligand density, present at the NP surface. The binding specificity between anti-MUC5 ligand and inflamed tissues was confirmed by fluorescence imaging. Both anti-MUC5-NP and all other glucocorticoid containing formulations led to a significant mitigation of the experimental colitis, as became evident from the substantial reduction of myeloperoxidase activity and pro-inflammatory cytokine concentrations (TNF-α, IL-1β). Targeted NP by using anti-MUC5 appears to be a very promising tool in future treatment of various types of local disorders affecting the gastro-intestinal tract but not limited to colitis.

Pathology and Clinical Significance of Inflammatory Bowel Disease-Associated Colorectal Dysplastic Lesions

Timely diagnosis and effective management of colorectal dysplasia play a vital role in preventing mortality from colorectal cancer in patients with chronic inflammatory bowel disease. This review provides a contemporary overview of the pathologic and endoscopic classification of dysplasia in inflammatory bowel disease, their roles in determining surveillance and management algorithms, and emerging diagnostic and therapeutic approaches that might further enhance patient management.

Keratin 7 expression in different anatomical parts of colonic epithelium in inflammatory bowel diseases and its prognostic value: a 3-year follow-up study

The diagnosis of inflammatory bowel diseases (IBD) may be challenging and their clinical course, characterized by relapses and spontaneous or drug-induced remissions, is difficult to predict. Novel prognostic biomarkers are needed. Keratin 7 (K7) is a cytoskeletal intermediate filament protein which is not normally expressed in the colonic epithelium. It was recently shown that K7 expression in the colonic epithelium is associated with ulcerative colitis and Crohn's disease, the two main subtypes of IBD. Here we investigated IBD associated K7 neo-expression in different regions of colon and terminal ileum. The correlation of the K7 expression with the inflammatory activity of the epithelium was analyzed in each region. The prognostic value of K7 was estimated by comparing the clinical disease activity after 3 years with the K7 expression at the time of enrollment. Our data shows that the level of K7 expression in inflamed epithelium varies depending on the anatomical region and it is the most pronounced in ascending and descending colon, but it did not predict the severity of IBD for the following 3 years. These results warrant future studies focusing on the biological role of K7 in colon and its utilization as potential IBD biomarker.

Aberrant MUC Immunohistochemical Expressions in Inflammatory Bowel Diseases

Ulcerative colitis (UC) and Crohn disease (CD) are cryptogenic inflammatory bowel diseases that are suggestive of aberrant mucin (MUC) expression; however, their relationship remains unclear. Here, we examined aberrant MUC expression in intestinal samples from UC and CD patients in comparison to samples from patients with ischemic colitis and control groups. To study the expression of MUC1 , MUC5AC , and MUC6 in different patient groups, we reviewed the slides stained with hematoxylin and eosin and performed immunohistochemistry. The results revealed that MUC1 was expressed more in the UC group and MUC6 in the CD group. No significant changes were observed in MUC expression in the ischemic colitis group. Overall, we demonstrated changes in MUC expression in UC and CD, which can help in the diagnosis and early clinical management of UC and CD.

Colonocyte keratin 7 is expressed de novo in inflammatory bowel diseases and associated with pathological changes and drug-resistance

The clinical course of IBD, characterized by relapses and remissions, is difficult to predict. Initial diagnosis can be challenging, and novel disease markers are needed. Keratin 7 (K7) is a cytoskeletal intermediate filament protein not expressed in the colonic epithelium but has been reported in IBD-associated colorectal tumors. Our aim was to analyze whether K7 is expressed in chronic colonic inflammatory diseases and evaluate its potential as a novel biomarker. K7 was analyzed in two patient cohorts using immunohistochemistry-stained colon samples and single-cell quantitative digital pathology methods. K7 was correlated to pathological changes and clinical patient characteristics. Our data shows that K7 is expressed de novo in the colonic epithelium of ulcerative colitis and Crohn's disease IBD patients, but not in collagenous or lymphocytic colitis. K7 mRNA expression was significantly increased in colons of IBD patients compared to controls when assessed in publicly available datasets. While K7 increased in areas with inflammatory activity, it was not expressed in specific crypt compartments and did not correlate with neutrophils or stool calprotectin. K7 was increased in areas proximal to pathological alterations and was most pronounced in drug-resistant ulcerative colitis. In conclusion, colonic epithelial K7 is neo-expressed selectively in IBD patients and could be investigated for its potential as a disease biomarker.

Adenocarcinoma arising in the multiple heterotopic submucosal glands of the intestine in a Satoyoshi syndrome patient: A case report

Satoyoshi syndrome is a rare multisystemic disorder of unknown etiology characterized by progressive muscle spasms, alopecia and diarrhea. Multiple protruding lesions with cystic glands, namely gastroenterocolitis cystica polyposa, manifest in the gastrointestinal tract. Since the first report of these lesions in 1977, which was unique to Satoyoshi syndrome, few studies have focused on their role, and the associated clinicopathological features are not well understood. Here, we report a 64-year-old Japanese woman with Satoyoshi syndrome who presented with multiple polypoid lesions in the stomach, duodenum, jejunum, ileum and colon. Histologically, the polypoid lesions in the intestine comprised multiple heterotopic submucosal glands containing cystically dilated glands and smooth muscle fibers in the lamina propria mucosa and/or submucosa. Additionally, we observed stromal changes, such as fibrosis, discontinuous and thinning muscularis mucosae, and diffuse neural fiber proliferation in the entire intestinal tract. Furthermore, multiple foci of adenocarcinomas were identified within several heterotopic submucosal glands. We hypothesized that multiple heterotopic submucosal glands in the present case corresponded to previously reported gastroenterocolitis cystica polyposa, suggesting that these lesions are essential in the histopathology and are a unique manifestation of Satoyoshi syndrome.

Keratin intermediate filaments in the colon: guardians of epithelial homeostasis

Keratin intermediate filament proteins are major cytoskeletal components of the mammalian simple layered columnar epithelium in the gastrointestinal tract. Human colon crypt epithelial cells express keratins 18, 19 and 20 as the major type I keratins, and keratin 8 as the type II keratin. Keratin expression patterns vary between species, and mouse colonocytes express keratin 7 as a second type II keratin. Colonic keratin patterns change during cell differentiation, such that K20 increases in the more differentiated crypt cells closer to the central lumen. Keratins provide a structural and mechanical scaffold to support cellular stability, integrity and stress protection in this rapidly regenerating tissue. They participate in central colonocyte processes including barrier function, ion transport, differentiation, proliferation and inflammatory signaling. The cell-specific keratin compositions in different epithelial tissues has allowed for the utilization of keratin-based diagnostic methods. Since the keratin expression pattern in tumors often resembles that in the primary tissue, it can be used to recognize metastases of colonic origin. This review focuses on recent findings on the biological functions of mammalian colon epithelial keratins obtained from pivotal in vivo models. We also discuss the diagnostic value of keratins in chronic colonic disease and known keratin alterations in colon pathologies. This review describes the biochemical properties of keratins and their molecular actions in colonic epithelial cells and highlights diagnostic data in colorectal cancer and inflammatory bowel disease patients, which may facilitate the recognition of disease subtypes and the establishment of personal therapies in the future.

Mechanistic and Functional Shades of Mucins and Associated Glycans in Colon Cancer

Mucus serves as the chief protective barrier against pathogenic and mechanical insults in respiratory, gastrointestinal, and urogenital tracts. Altered mucin expression, the major component of mucus, in conjunction with differential glycosylation has been strongly associated with both benign and malignant pathologies of colon. Mucins and their associated glycans arbitrate their impact sterically as well as mechanically by altering molecular and microbial spectrum during pathogenesis. Mucin expression in normal and pathological conditions is regulated by nonspecific (dietary factors and gut microbiota) and specific (epigenetic and transcriptional) modulators. Further, recent studies highlight the impact of altering mucin glycome (cancer-associated carbohydrate antigens including Tn, Sialyl-Tn, Sialyl-Lew A, and Sialyl-Lewis X) on host immunomodulation, antitumor immunity, as well as gut microbiota. In light of emerging literature, the present review article digs into the impact of structural organization and of expressional and glycosylation alteration of mucin family members on benign and malignant pathologies of colorectal cancer.

Intramucosal poorly differentiated and signet-ring cell components in patients with ulcerative colitis-associated high-grade dysplasia

Despite the rarity of colorectal poorly differentiated adenocarcinoma (Por) and signet-ring cell carcinoma (Sig), they are more frequent in patients with ulcerative colitis (UC). However, little is known about these components of early colitis-associated cancer due to the difficulty of detection at an early stage. Here, we reviewed colitis-associated high-grade dysplasia/cancer with Por/Sig components within the submucosa among 103 lesions of 79 UC patients who presented between 1997 and 2017. In total, one Sig in situ, three intramucosal and two submucosal carcinomas (8.7%) were identified among 69 lesions within the submucosa. Depressed appearance, loss of crypt architecture and amorphous surface pattern suggested the presence of Por/Sig, rather than submucosal infiltration. All lesions were located in the rectosigmoid colon and included high-grade dysplasia. While the surrounding noncancerous mucosa expressed E-cadherin and MUC5AC, the expression of E-cadherin was reduced and the expression of MUC5AC was negative in all of the carcinomas except for the Sig in situ. The gastric type metaplasia associated with altered MUC5AC profiles may be a sign of the stepwise accumulation of molecular alterations, including TP53 defects and a reduced expression level of E-cadherin.

Clinicopathological features and phenotypic classification of de novo-type colorectal carcinomas differ from those of colorectal carcinomas derived from flat adenomas

Since adenoma components disappear with tumor progression, it is not known whether colorectal carcinomas (CRCs) are derived from an adenoma-carcinoma sequence or are de novo. We compared 38 cases of ≤10-mm flat CRCs without an adenoma component (de novo type) with 39 cases of ≤10-mm flat CRCs with an adenoma component (carcinoma in adenoma (CIA) type). Compared to the CIA type, the de novo-type CRCs were more frequently located in the proximal colon; more frequently invaded submucosa, and more frequently had venous permeation. Regarding the phenotypic classification based on the immunohistochemical expressions of CD10, MUC2 and MUC5AC, the incidence of unclassified type (CD10-, MUC2- and MUC5AC-) was significantly more frequent in the de novo (32%) than CIA (5%) type. In one de novo-type case, mismatch repair (MMR) protein loss was judged, because MLH1 and PMS2 protein expressions were immunohistochemically negative. BRAF mutation (V600E) was seen in one de novo-type case and two CIA-type cases, but none of these cases had MMR protein loss. In conclusion, small-intestinal type (CD10+ and MUC5AC-) is the most common in flat CRC and unclassified type is mainly characteristic of de novo type. In this study, small flat CRCs with BRAF mutation do not have MMR protein loss.

CK7 expression associates with the location, differentiation, lymph node metastasis, and the Dukes' stage of primary colorectal cancers

Purpose: Most colorectal cancers (CRCs) show positive immunohistochemical (IHC) staining for CK20 and negative staining for CK7. However, in clinical settings, some CRCs show positive IHC staining for CK7, and the clinicopathological significance of this needs to be studied. This study investigated the clinicopathological significance of CK7 positivity in CRCs.

Materials and Methods: A total of 178 patients with CRC were used to study the clinicopathological significance of CK7 positivity. Western blotting and immunocytochemical (ICC) staining were used to compare the expression levels of CK7 before and after CoCl₂ treatment.

Results: CK7 expression was associated with the location, differentiation, lymph node metastasis, and the Dukes' stage of CRCs. CK7 positive cells were mainly distributed at the edge of cancer nests, at the invasion front, as single stromal polyploid giant cancer cells (PGCCs), in tumor buds, in intravascular tumor emboli, and in a micropapillary pattern. Results of ICC staining showed that CK7 expression was almost negative in LoVo and HCT116 before CoCl₂ treatment. After CoCl₂ treatment, the PGCCs and their daughter cells of LoVo and HCT116 yielded positive results in CK7 ICC staining. Results of western blotting also confirmed that there was higher CK7 expression in LoVo and HCT116 after CoCl₂ treatment than in the control.

Conclusion: CRC cells expressing CK7 may have strong invasive and metastatic abilities. Some metastasis-related morphological characteristics in CRCs including the invasion front, micropapillary pattern, tumor emboli, and single stromal PGCCs associated with CK7 positive expression.

Colitis-associated colorectal adenocarcinomas are frequently associated with non-intestinal mucin profiles and loss of SATB2 expression

The special AT-rich sequence binding protein 2 (SATB2) is a sensitive and specific diagnostic marker for colorectal adenocarcinoma and reduced expression of SATB2 is associated with a poor prognosis. Colitis-associated colorectal adenocarcinoma often shows distinct morphologic and molecular phenotypes compared to sporadic cases. However, the SATB2 expression profile in colitis-associated carcinoma has not been defined. We performed immunohistochemistry for SATB2 as well as CDX2, MUC5AC, MUC6 and mismatch repair proteins on 60 consecutive colitis-associated carcinomas from 58 inflammatory bowel disease patients and compared the expression profile to a control group of 32 sporadic colorectal carcinomas. Only 26 (43%) colitis-associated carcinomas expressed SATB2, compared to 29 (91%) sporadic colorectal carcinomas (p < 0.0001). MUC5AC expression was more frequently observed in colitis-associated carcinomas than sporadic colorectal caracinomas (52% and 25% respectively; p = 0.013). Eight (13%) cases of colitis-associated carcinoma showed loss of CDX2 expression, which was retained in all of the sporadic controls (p = 0.047). In colitis-associated carcinoma, 50% of SATB2 negative cases had lymph node metastasis compared to only 15% of SATB2 positive cases (p = 0.007). Loss of SATB2 was particularly frequent in mucinous-type tumors, occurring in 83% of these cases. There was no significant association between SATB2 expression and mismatch repair protein status. These data show that the immunoprofile of colitis-associated carcinoma is different than that seen in sporadic cases. In particular, SATB2 is significantly less sensitive in colitis-associated carcinoma and it should be interpreted cautiously as a marker of colorectal origin in colitis patients. The association between loss of SATB2 and lymph node metastasis suggests that it may have similar prognostic value in the setting of inflammatory bowel disease as in sporadic cases.

Ramifications of secreted mucin MUC5AC in malignant journey: a holistic view

Heavily glycosylated secreted mucin MUC5AC, by the virtue of its cysteine-rich repeats, can form inter- and intramolecular disulfide linkages resulting in complex polymers, which in turn craft the framework of the polymeric mucus gel on epithelial cell surfaces. MUC5AC is a molecule with versatile functional implications including barrier functions to epithelial cells, host-pathogen interaction, immune cell attraction to sites of premalignant or malignant lesions and tumor progression in a context-dependent manner. Differential expression, glycosylation and localization of MUC5AC have been associated with a plethora of benign and malignant pathologies. In this era of robust technologies, overexpression strategies and genetically engineered mouse models, MUC5AC is emerging as a potential diagnostic, prognostic and therapeutic target for various malignancies. Considering the clinical relevance of MUC5AC, this review holistically encompasses its genomic organization, domain structure, glycosylation patterns, regulation, functional and molecular connotation from benign to malignant pathologies. Furthermore, we have here explored the incipient and significant experimental tools that are being developed to study this structurally complex and evolutionary conserved gel-forming mucin.

An Overview of Molecular Profiles in Ulcerative Colitis-Related Cancer

Ulcerative colitis (UC) is an independent risk factor of colorectal cancer (CRC). Both genetic and epigentic events induce a unique molecular profile during the development from UC to UC-related CRC (UCRC). These molecular changes play varied roles in DNA repair, immune response, cell metabolism, and interaction with the microbiota during the carcinogenesis process. This review will systmatically discuss the molecular characteristics of UCRC and point out the future perspectives in this research field.

Clinical value of a diagnostic score for colon cancer based on serum CEA, CA19-9, cytokeratin-1 and mucin-1

BACKGROUND

Although established markers such as CEA and CA19-9 are important for diagnosing early stages of colon cancer, they are not ideal. Developing promising markers include cytokeratin 1 (CK1) and mucin-1 (MUC1), but the combined value of each of these markers is unclear. We therefore evaluated the value of a combined laboratory-based score of these four markers in the diagnosis of colon cancer.

METHODS

Two hundred patients who had undergone colonoscopic examination (150 colon cancer, 50 benign growths) were recruited. The study was controlled by 35 healthy subjects. CEA, CA19-9, CK1 and MUC1 were measured by ELISA and evaluated for cancer diagnosis using area under the receiver operating characteristic curve (AUC).

RESULTS

Serum levels of all four markers were increased in the order colon cancer > benign disease > healthy controls (p < 0.001). In multivariate analysis, CA19.9 (p = 0.025), CK1 (p < 0.001) and MUC1 (p = 0.009) were significant independent predictors of colon cancer. A score that gave the greatest power of discrimination for colon cancer was defined as 1.06 + [0.001 × CA19.9 result] + [0.003 × CEA result] + [0.03 × CK1 result] + [0.05 × MUC1 result]. The colon score provided superior discrimination, AUC, and sensitivity and specificity for colon cancer versus benign growth than each of the individual markers. Similarly, the colon score provided superior AUC, and sensitivity and specificity that each individual marker for tumour stage, lymph node invasion and distant organ metastases than each individual marker.

CONCLUSION

A colon score derived from serum CEA, CA19-9, CK1 and MUC1 is a potential valuable non-invasive index that could be used for detection and screening early stage colon cancer patients.

Altered expression of cytokeratin 7 and CD117 in transitional mucosa adjacent to human colorectal cancer

The multi-step progression of colorectal cancer through precancerous lesions (adenoma and dysplasia) is associated with cumulative molecular alterations, a number of which have also been demonstrated to be present in morphologically normal transitional mucosa adjacent to colorectal cancer. The cytoskeletal protein cytokeratin 7 (CK7) and the receptor tyrosine kinase, KIT proto-oncogene receptor tyrosine kinase (CD117), encoded by the proto-oncogene c-Kit, are lacking in normal colorectal crypt epithelium and are aberrantly expressed in a subset of colorectal cancer. The aim of the present study was to evaluate the expression of CK7 and CD117 in morphologically normal transitional mucosa adjacent to colorectal cancer. Immunohistochemical staining for CK7 and CD117 was performed in the mucosa adjacent to five groups of surgically resected colorectal tumors [low-grade adenoma, high-grade adenoma, mucosal adenocarcinoma, small-sized invasive adenocarcinoma (≤2 cm) and large-sized invasive adenocarcinoma (>2 cm)]. CK7 was expressed in the mucosa adjacent to a subset of colorectal tumors, and the positivity ratio increased according to tumor grade from low-grade adenoma up to small-sized invasive adenocarcinoma (61.2%). However, the positivity ratio of CK7 in the mucosa adjacent to the large-sized invasive adenocarcinoma (25.0%) was significantly lower compared with that of the next lower grade. CD117 was also expressed in the mucosa adjacent to a subset of colorectal tumors. In contrast to CK7, the positivity ratio of CD117 increased according to tumor grade from low-grade adenoma all the way through to the large-sized invasive adenocarcinoma (45.0%). Based on these results, the mechanism of CK7 and CD117 expression in the transitional mucosa adjacent to colorectal cancer may be different, and analysis of their individual expression may provide novel insights into the development and progression of colorectal cancer.

Well-differentiated adenocarcinoma associated with ulcerative colitis

Objectives:

Adenocarcinoma is known to be associated with ulcerative colitis, but the diagnosis is sometimes challenging, both clinically and pathologically.

Methods and Results:

We present a case of extremely well-differentiated adenocarcinoma associated with ulcerative colitis, in which preoperative diagnosis was not possible. Glands in biopsy specimens showed a serrated appearance that looked like low-grade dysplasia or regenerative mucosa. After an operation due to severe symptoms of stenosis, carcinoma was diagnosed. Tumor cells, especially in invasive glands, tended to show stronger immunoreactivity against anti-CK7, TNF-α and Aurora B antibodies compared to cells of mucosal lesion. Interestingly, CD44v6, one of the adhesion molecules, was less expressed in invasive glands, while those glands exhibited stronger expression of a disintegrin and metalloproteinase 17 (ADAM 17), one of the sheddases that cleaves an extracellular domain of CD44.

Conclusions:

These observations appear interesting to consider the pathogenesis and to diagnose extremely well-differentiated adenocarcinoma in ulcerative colitis, although further investigation is needed.

Mucins and associated glycan signatures in colon adenoma-carcinoma sequence: Prospective pathological implication(s) for early diagnosis of colon cancer

Development of biomarkers that detect early stage resectable premalignant lesions of colon can provide critical aid in the prevention of colorectal cancer. Recent lines of evidence suggest the utility of mucin expression to predict malignant transformation of colon pre-neoplastic lesions. In this study, we investigated the combined expression of multiple mucins and mucin-associated glycans during the adenoma-carcinoma sequence of colon cancer progression. Further, we evaluated their applicability as markers for differentiating adenomas/adenocarcinomas from hyperplastic polyps. Immunohistochemical analyses performed on colon disease tissue microarrays revealed downregulation of MUC2 and MUC4 expression (p < 0.0001) while MUC1 and MUC5AC expressions were upregulated (p = 0.01) during adenoma-adenocarcinoma progression. Expression of MUC17 was downregulated in inflamed tissues compared to normal tissues, but its increased expression differentiated adenomas (p = 0.0028) and adenocarcinomas (p = 0.025) from inflammation. Glycan epitope-Tn/STn on MUC1 showed higher expression in hyperplastic polyps (p = 0.023), adenomas (p = 0.042) and adenocarcinomas (p = 0.0096) compared to normal tissues. Multivariate regression analyses indicated that a combination of MUC2, MUC5AC, and MUC17 could effectively discriminate adenoma-adenocarcinoma from hyperplastic polyps. Altogether, a combined analysis of altered mucins and mucin-associated glycans is a useful approach to distinguish premalignant/malignant lesions of colon from benign polyps.

Colitis cystica profunda indefinite for dysplasia in Crohn disease: a potential diagnostic pitfall

Colitis cystica profunda (CCP) is a nonneoplastic condition characterized by misplaced glands deep to the muscularis mucosae of the colon and may be difficult to differentiate from well-differentiated mucinous adenocarcinoma. Absence of dysplasia in CCP usually aids in this distinction. We present a challenging case of CCP in the setting of Crohn disease (CD) containing foci of atypical epithelium. A right hemicolectomy from a 46-year-old woman contained a stricture associated with a proximal multilocular cystic lesion containing mucin-filled glands dissecting through the colonic wall. These glands had lobulated architecture with smooth contours surrounded by lamina propria and lacking desmoplastic stroma. The epithelium had focal nuclear crowding, enlargement, and hyperchromasia, with increased nucleus to cytoplasm ratio, but overall preserved polarity. Atypical cells were focally positive for CK7 and p53, with increased MIB-1 staining. These findings were interpreted as indefinite for dysplasia. Chronic transmural inflammation and mucosal regeneration probably facilitated epithelial misplacement, which secondarily developed cytologic atypia. However, the overall architecture and lack of dysplasia in the overlying mucosa argue against a diagnosis of adenocarcinoma. Our case illustrates the difficult diagnosis of this uncommon but problematic phenomenon, awareness of which is paramount for pathologists and clinicians participating in the management of CD patients.

Predictive proteomic biomarkers for inflammatory bowel disease-associated cancer: Where are we now in the era of the next generation proteomics?

Recent advances in genomic medicine have opened up the possibility of tailored medicine that may eventually replace traditional “one-size-fits all” approaches to the treatment of inflammatory bowel disease (IBD). In addition to exploring the interactions between hosts and microbes, referred to as the microbiome, a variety of strategies that can be tailored to an individual in the coming era of personalized medicine in the treatment of IBD are being investigated. These include prompt genomic screening of patients at risk of developing IBD, the utility of molecular discrimination of IBD subtypes among patients diagnosed with IBD, and the discovery of proteome biomarkers to diagnose or predict cancer risks. Host genetic factors influence the etiology of IBD, as do microbial ecosystems in the human bowel, which are not uniform, but instead represent many different microhabitats that can be influenced by diet and might affect processes essential to bowel metabolism. Further advances in basic research regarding intestinal inflammation may reveal new insights into the role of inflammatory mediators, referred to as the inflammasome, and the macromolecular complex of metabolites formed by intestinal bacteria. Collectively, knowledge of the inflammasome and metagenomics will lead to the development of biomarkers for IBD that target specific pathogenic mechanisms involved in the spontaneous progress of IBD. In this review article, our recent results regarding the discovery of potential proteomic biomarkers using a label-free quantification technique are introduced and on-going projects contributing to either the discrimination of IBD subtypes or to the prediction of cancer risks are accompanied by updated information from IBD biomarker research.

Adalimumab Treatment in Biologically Naïve Crohn's Disease: Relationship with Ectopic MUC5AC Expression and Endoscopic Improvement

Background. Adalimumab (ADA) is effective for patients with Crohn's disease (CD). However, there have been few reports on ADA therapy with respect to its relationship with pathologic findings and drug efficacy in biologically naïve CD cases. Methods. Fifteen patients with active biologically naïve CD were treated with ADA. We examined them clinically and pathologically with ectopic MUC5AC expression in the lesions before and after 12 and 52 weeks of ADA therapy, retrospectively. Results. Both mean CD activity index scores and serum C-reactive protein values were significantly lower after ADA therapy (P < 0.001). In the MUC5AC negative group, all cases exhibited clinical remission (CR) and endoscopic improvement at 52 weeks. In MUC5AC positive groups, loss of MUC5AC expression was detected in cases having CR and endoscopic improvement at 52 weeks, while remnant ectopic MUC5AC expression was observed in those exhibiting no endoscopic improvement and flare up after 52 weeks. Conclusions. ADA leads to CR and endoscopic improvement in biologically naïve CD cases. In addition, ectopic MUC5AC expression may be a predictive marker of flare up and endoscopic improvement in the intestines of CD patients.

Diagnostic utility of TP53 and cytokeratin 7 immunohistochemistry in idiopathic inflammatory bowel disease-associated neoplasia

Long-standing inflammatory bowel disease is associated with increased risk of developing colorectal adenocarcinoma. Significant intra- and inter-observers' variability exists in histologic interpretation of dysplasia in surveillance biopsies. In this study, we evaluated the utility of a panel of immunohistochemical markers in diagnosing inflammatory bowel disease-associated neoplasia. We reviewed 39 colectomy specimens with inflammatory bowel disease-associated neoplasia. In these 39 cases, we identified 172 foci of interest (5 normal, 58 negative for dysplasia, 15 indefinite for dysplasia, 59 low-grade dysplasia, 18 high-grade dysplasia, and 17 invasive adenocarcinoma). They were subjected to immunohistochemistry for TP53 and CK7. Logistic regression was used to evaluate their association with the presence of dysplasia. Receiver operating characteristic curves were used to determine the optimal cutoffs and assess the diagnostic performance of TP53 and CK7. Both TP53 nuclear staining and CK7 immunoreactivity gradually increased in the progression of inflammatory bowel disease-associated neoplasia (P<0.0001). CK7 immunoreactivity increased along with the increase of inflammation severity (P=0.0002) as well as reactive changes (P=0.04) in the colonic mucosa. But TP53 nuclear staining was independent of either feature. When both TP53>8% and CK7>30% as identified from logistic regression and receiver operating characteristic curves were used to diagnose dysplasia, the specificity achieved as high as 95%. When either TP53>8% or CK7>30% was used to diagnose dysplasia, the sensitivity achieved was 82%. Our results suggested that a combination of CK7 and TP53 immunohistochemistry may be helpful in diagnosing inflammatory bowel disease-associated dysplasia in difficult cases.

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.

Colon Mucosa Exhibits Loss of Ectopic MUC5AC Expression in Patients with Ulcerative Colitis Treated with Oral Tacrolimus

Background. Tacrolimus (FK506) is effective for patients with ulcerative colitis (UC). However, there are few reports on tacrolimus therapy (TT) with respect to the relationship with endoscopic and clinicopathologic findings. Methods. Thirty patients with moderate/severe active UC refractory to or dependent on corticosteroid were treated with oral tacrolimus. The expression of ectopic MUC5AC in the colon was pathologically analyzed before and at 12 weeks after TT, evaluating the Mayo score and steroid-sparing effects. Results. Both mean disease and endoscopic activity index scores were reduced at levels of statistical significance in 26 UC patients receiving more than one month of TT (P < 0.0001). The dose of prednisolone was reduced by a statistically significant amount (P = 0.00022), and 14 of the 26 patients (53.8%) had steroid-free status 12 weeks after TT. The decrease in ectopic MUC5AC expression in the mucous cells of the colon was significantly associated with endoscopic improvement of inflammation in the UC patients with TT (P = 0.043). Loss of ectopic MUC5AC expression was detected in all patients who had complete response. Conclusions. Tacrolimus appears to be effective for the treatment of moderate/severe UC patients. Loss of ectopic MUC5AC expression may be important for pathologic remission in the colon of UC patients.

Mucin function in inflammatory bowel disease: an update

MUC2 is the primary component of the mucin barrier that separates the intestinal microbiota and the intestinal epithelium. This mucous barrier is affected by both luminal/microbial factors and host/immune factors, both of which have genetic and environmental determinants. The complex interactions between these players in health and disease states are not fully understood. Inflammatory bowel disease (IBD) has both genetic and environmental etiologies that lead to the breakdown of the epithelial barrier. In this review, we explore the up-to-date evidence that implicates mucin in the pathogenesis of IBD. In IBD, quantitative changes in mucin secretion occur, as well as structural changes in mucin's glycoprotein core and the sulfation and sialylation of mucin's oligosaccharide residues. These changes are associated with a diminished functionality of the mucous barrier. We identify the various genetic mutations associated with these changes and outline the animal models that have enhanced the current understanding of the genetic basis for IBD. Further study is needed to better characterize the immune and genetic influences on mucin expression and secretion and role of endoplasmic reticulum stress and a defective unfolded protein response in mediating these changes.

Keratins in colorectal epithelial function and disease

Keratins are the largest subgroup of intermediate filament proteins, which are an important constituent of the cellular cytoskeleton. The principally expressed keratins (K) of the intestinal epithelium are K8, K18 and K19. The specific keratin profile of a particular epithelium provides it with strength and integrity. In the colon, keratins have been shown to regulate electrolyte transport, likely by targeting ion transporters to their correct location in the colonocytes. Keratins are highly dynamic and are subject to post-translational modifications including phosphorylation, acetylation and glycosylation. These affect the filament dynamics and hence solubility of keratins and may contribute to protection against degradation. Keratin null mice (K8(-/-) ) develop colitis, and abnormal keratin mutations have been shown to be associated with inflammatory bowel disease (IBD). Abnormal expression of K7 and K20 has been noted in colitis-associated dysplasia and cancers. In sporadic colorectal cancers (CRCs) may be useful in predicting tumour prognosis; a low K20 expression is noted in CRCs with high microsatellite instability; and keratins have been noted as dysregulated in peri-adenomatous fields. Caspase-cleaved fragment of K18 (M30) in the serum of patients with CRC has been used as a marker of cancer load and to assess response to therapy. These data suggest an emerging importance of keratins in maintaining normal function of the gastrointestinal epithelium as well as being a marker of various colorectal diseases. This review will primarily focus on the biology of these proteins, physiological functions and alterations in IBD and CRCs.

Barrett's esophagus. Practical issues for daily routine diagnosis

Most clinicians and researchers agree that Barrett's esophagus (BE) is a precancerous condition which, however, is not easily defined. Whether goblet cells must be present or not is a matter of debate and definitions vary worldwide. Although the use of the term "columnar metaplasia" tends to circumvent these issues, it can also be subdivided into those with and without goblet cells. There is some evidence that Barrett's esophagus results from a multistep process in which goblet cells are a secondary event. Hence, Barrett's adenocarcinoma has recently been shown to originate from areas lacking goblet cells. The histological diagnosis of neoplasia is often hampered by marked interobserver variation. New endoscopic techniques allow for local resections of neoplasia with curative intent. Pathologists should know which pieces of information gastroenterologists need for management options: surveillance versus therapy such as endoscopic resection with or endoscopic ablation without histological specimen. The most important information for gastroenterologists is whether there is neoplasia or not; if any, they need to know the grade (low grade, high grade, carcinoma) and risk factors (vessel permeation, poor differentiation, resection complete in case of endoscopic resection, depth of infiltration).

Keratin 7 expression in colorectal cancer--freak of nature or significant finding?

AIMS

 To assess the prevalence of keratin 7 (K7) expression in colorectal cancer and to correlate findings with clinicopathological parameters and patients' outcome.

METHOD AND RESULTS

A total of 370 patients were evaluated for K7 expression by immunohistochemistry using a tissue microarray technique. K7 expression was scored semiquantitatively as either focal (<10%), moderate (10-50%) or extensive (>50%). In all, 32 (9%) tumours were immunoreactive for K7, with five cases showing extensive, four moderate and 23 focal expression, respectively. K7 expression was associated with poor tumour differentiation (P = 0.005) and the extent of tumour budding (P = 0.02). In whole sections, K7 immunoreactivity prevailed in single cells and small clusters of cells at the invasion front. Analysis of serial sections showed that K7-positive cells colocalized with keratin 20, whereas they lacked immunoreactivity for E-cadherin, MUC2 and MIB-1. Disease progression occurred in 52% of patients with K7-positive tumours and 41% with K7-negative tumours (P = 0.19); 48% of patients with K7-positive tumours but only 33% with K7-negative tumours died of disease (P = 0.06).

CONCLUSIONS

Aberrant expression of K7 in budding cancer cells represents a modification of the epithelial phenotype ('epithelial-epithelial transition': EET) which may be linked to gains in motility and invasive potential.

Gastric cancer following total proctocolectomy for colon cancer associated with ulcerative colitis

Here we report a case of advanced gastric cancer seen after total proctocolectomy for an early colon cancer associated with ulcerative colitis (UC). A 42-year-old man, diagnosed with UC at the age of 21, had undergone total proctocolectomy at the age of 38 for an early ascending colon cancer. Three years later the patient developed tarry stools and epigastric discomfort. Laboratory data showed anemia together with elevated serum p53 antibody. Gastric endoscopy showed thickening folds around a lesion in the stomach body. The pathological diagnosis was poorly differentiated adenocarcinoma with signet-ring cell carcinoma. Total gastrectomy was performed and the resected specimens showed a diffuse infiltrating tumor (scirrhous gastric carcinoma), 11 × 15 cm in size, with multiple lymph node metastases. Histopathological examination revealed diffuse infiltration of cancer cells throughout the gastric wall and invasion of the serosa. Results of cytology on abdominal lavage were positive for cancer cells. Likewise, immunohistochemical staining showed gastric mucin phenotype cancer cells positive for p53. In conclusion, it is important to bear in mind that patients with UC, especially chronically active pancolitis, potentially bear the risk of upper gastrointestinal complications.

[Polypoid dysplasia in inflammatory bowel disease: differential diagnosis and further diagnostic and therapeutic approaches]

Polypoid dysplasia in inflammatory bowel disease (IBD) is categorized as DALM (dysplasia associated lesion or mass) or ALM (adenoma-like mass). DALMs are etiologically related to the underlying inflammatory disease, have a high risk of cancer and remain an indication for colectomy. Sporadic adenomas occur coincidentally according to the adenoma-carcinoma sequence. They are adequately treated by polypectomy. More recently, a special group of lesions has been termed as "adenoma-like DALM" which shows a morphological overlap with sporadic adenomas in spite of arising against the background of chronic IBD. Adenoma-like DALMs may possess a lower risk of malignancy in contrast to non-adenoma-like DALMs. They may be treated adequately by polypectomy and continued monitoring if the lesion has been excised completely and there is no evidence of flat dysplasia elsewhere in the colon.

Filiform serrated adenomatous polyposis arising in a diverted rectum of an inflammatory bowel disease patient

A 54-year-old man, previously colectomized for inflammatory bowel disease, developed carcinoma in the inflamed rectum stump. The malignant growth was surrounded by a filiform polyposis, grossly considered as pseudopolyps. The histology disclosed, however, a morphology corresponding to the recently described filiform subset of serrated adenoma (FSA). The clustering of the FSA amounted to a filiform serrated adenomatous polyposis, a hitherto unreported observation. It is speculated that neoplastic transformation of pre-existing pseudopolyps and prolaps-related events lead to this peculiar morphology. Minor zones with a villous structure were admixed as were small areas of traditional serrated adenoma and patches of flat dysplasia. Although a combined gastric and intestinal (positivity for MUC5AC, MUC2, MUC6, CDX2) immunoprofile characterized the adenomatous component, a downregulation of the gastric mucin along with a loss of the serrated attribute accompanied the malignant transformation. An added dynamic shift during the adenoma carcinoma sequence included the acquisition of CK7 expression in the malignant portion. Gastric mucin may play a role in the initial step of the neoplastic evolution and CK7 may denote neoplastic progression. This case confirms the notion of a widely variegated morphology of precursor lesions of colorectal carcinoma arising in a chronically inflamed bowel as opposed to the generally more monotonous appearance of adenomas in a sporadic context.

The interaction of large bowel microflora with the colonic mucus barrier

The colonic mucus barrier is the first line of defence that the underlying mucosa has against the wide range of potentially damaging agents of microbial, endogenous, and dietary origin that occur within the colonic lumen. The functional component of mucus is the secreted, polymeric glycoprotein mucin. The mucus barrier can either act as an energy source or a support medium for growth to the intestinal microflora. The mucus barrier appears to effectively partition the vast number of microbial cells from the underlying epithelium. The normal functionality and biochemistry of this mucus barrier appears to be lost in diseases of the colorectal mucosa. Germ-free animal studies have highlighted the necessity of the presence of the colonic microflora to drive the maturation of the colonic mucosa and normal mucus production. A number of by-products of the microflora have been suggested to be key luminal drivers of colonic mucus secretion.

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.

Flat adenoma-carcinoma sequence with high-malignancy potential as demonstrated by CD10 and beta-catenin expression: a different pathway from the polypoid adenoma-carcinoma sequence

AIMS

CD10+ colorectal carcinomas have a high risk of giving rise to liver metastasis. The aim was to examine phenotypic expression in colorectal neoplasia and to elucidate changes in such expression through the adenoma-carcinoma sequence.

METHODS AND RESULTS

We examined the expression of various proteins immunohistochemically in 111 flat [non-polypoid growth (NPG)] colorectal neoplasms, categorized into 28 low-grade (NPG-LGN), 44 high-grades (NPG-HGN) and 39 cases of invasive neoplasia (NPG-IN), as well as in 96 polypoid [polypoid growth (PG)] neoplasms, categorized into 26 PG-LGN, 39 PG-HGN and 31 PG-IN according to the Vienna classification. CD10 was more frequently expressed in NPG than in PG neoplasia. MUC2 and MUC5AC were more frequently expressed in PG than in NPG neoplasias. Nuclear beta-catenin was more frequently expressed in NPG-LGN than in PG-LGN. No difference in p53 expression was found between NPG and PG neoplasia.

CONCLUSIONS

From the viewpoint of the expression of CD10 and beta-catenin, it would appear that NPG-LGN differs significantly from PG-LGN, thereby indicating that NPG-LGN is a precursor of CD10+ carcinoma. It is important to ensure that NPG neoplasia is not overlooked if cases of CD10+ carcinoma are to be detected at an early stage.

Altered expression of CK7 and CK20 in preneoplastic and neoplastic lesions in ulcerative colitis

This study is based on all patients with ulcerative colitis from a defined catchment area in Northern Sweden in a still ongoing colonoscopy surveillance programme, which started in 1977. From this material we selected tissue from eight groups of patients consisting of normal control biopsies (5), inactive colitis (10), active colitis (10), findings of low-grade dysplasia (10), high-grade dysplasia (6), aneuploidy (without dysplasia and with subsequent dysplasia) (10), and ulcerative colitis-associated cancers (5). The samples were evaluated according to immunohistochemical expression of CK7 and CK20. Colonic mucosa from normal controls and inactive colitis was found to be completely negative for CK7. In 9 out of 10 patients with active colitis, CK7 was sparsely expressed in a patchy manner and connected with active epithelial inflammatory areas. 7 out of 10 patients with low-grade dysplasia and 3 out of 6 with high-grade dysplasia were positive for CK7. Samples with aneuploidy without dysplasia were completely negative, while 2 out of 6 showing subsequent dysplasia were positive. Of the five cancers, two were positive for CK7. CK20 was expressed in nearly all samples but relatively more in the lower part of the crypts in neoplasia-associated lesions. Our results indicate a possible relationship between expression of CK7 and CK20 and neoplastic development of colorectal mucosa in patients with ulcerative colitis. Further studies are needed to elucidate whether these findings have clinical significance.

Aberrant gastric apomucin expression in ulcerative colitis and associated neoplasia

AIM

To evaluated the presence of gastric metaplasia in colonic mucosa of patients with ulcerative colitis and its relationship with dysplasia/neoplasia.

MATERIAL AND METHODS

Ninety patients with UC were selected. The duration and the extent of disease were registered in all the cases. Biopsies were histologically and immunohistochemically assessed. Crypt distortion, goblet cell depletion, Paneth cell metaplasia and inflammatory activity were graded, as well as dysplasia and invasive neoplasia (absent or present). Monoclonal antibodies against the gastric apomucins MUC5AC (foveolar) and MUC6 (mucopeptic) were used.

RESULTS

Neoplasia was observed in 16 patients, 8 non-invasive (dysplasia) and 8 invasive (adenocarcinoma). MUC5AC and MUC6 were detected in 63 and 16 out the 90 cases, 70.0% and 17.8%, respectively. The staining was patchy for both antibodies, affecting groups of cells more often than isolated cells. The presence of MUC5AC correlated positively with inflammatory activity and goblet cell depletion (R=0.231, p=0.03 and R=0.211, p=0.048, respectively). The expression of MUC6 correlated positively with age (R=0.297, p=0.005), duration of disease (R=0.287, p=0.008), extent of disease (R=0.342, p=0.001), crypt distortion (R=0.276, p=0.01) and the presence of neoplasia (R=0.483, p<0.00). There was no correlation between Paneth cell metaplasia and apomucin expression.

CONCLUSIONS

Our study demonstrates the aberrant expression of gastric apomucins in UC and suggests that MUC5AC is associated with inflammation while MUC6 is related to the presence of neoplasia. The demonstration of metaplastic cell lineages preceding dysplasia supports the biological link between inflammation and neoplasia, MUC6 emerging as a putative biomarker of dysplasia in ulcerative colitis patients.

Chromosomal analysis of Barrett's cells: demonstration of instability and detection of the metaplastic lineage involved

Barrett's esophagus is lined by columnar and goblets cells with gastric and intestinal characteristics. Despite the association between goblet elements and malignancy, it was not demonstrated that other columnar cells lineages are not related to neoplasia. Chromosomal abnormalities were described in metaplasia adjacent to Barrett's neoplasia, but it is unknown which metaplastic lineages are involved. This work assessed the frequency and the type of chromosomal abnormalities in Barrett's esophagus without neoplasia and performed the identification of the metaplastic cells carrying chromosomal gains. Barrett's esophagus biopsies were collected and processed for short-term cell culture and cytogenetic analysis. Combined immunofluorescence/fluorescence in situ hybridization was performed in cases exhibiting chromosomal gains by using antisera against intestinal (MUC2) and gastric (MUC5AC and MUC6) apomucins and chromosome pericentromeric alpha satellite DNA probes for the chromosomes involved. Each case was scored for the number of spots (0, 1, 2, >2) in 200 nonoverlapping nuclei. Columnar and goblet cells were separately assessed. Short-term cell cultures were achieved in 40/60 cases (67%). There were clonal abnormalities in 27/40 cases (68%) and tetraploid (4n) clones in 10/40 (25%). Structural alterations were detected in 14/40 (35%) with recurrent breakpoints at 1q21, 15q15 and 15q22. Numerical changes (trisomies 7 and 18 and loss of Y) occurred in 16/40 (40%). Gains of chromosomes 7 and 18 were more frequent in columnar than in goblet cells (9.8% vs 0.7% (P<0.05)) and (7.9 vs 1.9% (P<0.05)) respectively. These alterations were detected in cells exhibiting gastric as well as intestinal features and were more frequent in cells without apomucin production.

CONCLUSIONS

(1) chromosomal instability is a common finding in Barrett's esophagus without neoplasia. (2) The two metaplastic populations are committed, chromosomal gains being more frequent in columnar nongoblet than in goblet cells. (3) The two metaplastic phenotypes, gastric and intestinal, are equally involved.