The utility of cytokeratin subsets in distinguishing Barrett's-related oesophageal adenocarcinoma from gastric adenocarcinoma

Adenocarcinoma arising from heterotopic gastric mucosa in the cervical esophagus and upper thoracic esophagus: two case reports and literature review

Primary adenocarcinoma arising from heterotopic gastric mucosa (HGM) is rare and the clinicopathological characteristics are not well known. We present two cases of esophageal adenocarcinoma arising from HGM with a review of a case series. Case 1 was a 78-year-old woman who underwent a periodic medical examination without complaining of any symptoms. Preoperative evaluation suggested esophageal adenocarcinoma arising from the HGM. The patient was treated with endoscopic submucosal dissection. Definitive pathological diagnosis confirmed adenocarcinoma arising from the HGM. Case 2 was a 70-year-old man who underwent a medical examination after complaining of dysphagia. Preoperative diagnosis suggested esophageal adenocarcinoma; however, its origin was unclear. The patient was treated with surgical resection. Definitive pathological diagnosis revealed adenocarcinoma arising from the HGM. In this article, the authors report the clinicopathological features of esophageal adenocarcinoma arising from HGM that were collected from a literature review and our cases.

Tropomyosin-4 correlates with higher SBR grades and tubular differentiation in infiltrating ductal breast carcinomas: an immunohistochemical and proteomics-based study

The aim of this study is to evaluate tropomyosin-4 (TM4) expression in infiltrating ductal breast carcinomas (IDCAs), as well as its prognostic significance. Using a 2-DE/MALDI-TOF mass spectrometry investigation coupled with an immunohistochemical approach, we have assessed the expression of TM4 in IDCAs, as well as in other types of breast tumors. Proteomic analyses revealed an increased expression of tropomyosin-4 in IDCA tumors. Using immunohistochemistry, overexpression of tropomyosin-4 was confirmed in 51 additional tumor specimens. Statistical analyses revealed, however, no significant correlations between tropomyosin-4 expression and clinicopathological parameters of the disease including tumor stage, patient age, estrogen and progesterone receptor status, and lymph node metastasis occurrence. A significant association was found, however, with a high Scarf-Bloom-Richardson (SBR) grade, a known marker of tumor severity. Additionally, the SBR component showing a correlation with TM4 expression was the tubular differentiation status. This study demonstrates the upregulation of tropomyosin-4 in IDCA tissues, which may highlight its involvement in breast cancer development. Our findings also support a link between tropomyosin-4 expression and aggressiveness of IDCA tumors.

Contribution of proteomics to the study of the role of cytokeratins in disease and physiopathology

Cytokeratins (CKs), the most abundant group of cytoskeletal intermediate filaments, and proteomics are strongly connected. On the one hand, proteomics has been extremely useful to uncover new features and functions of CKs, on the other, the highly abundant CKs serve as an exceptional tool to test new technological developments in proteomics. As a result, proteomics has contributed to finding valuable associations of CKs with diseases as diverse as cancer, cystic fibrosis, steatohepatitis, viral and bacterial infection, keratoconus, vitreoretinopathy, preeclampsia or the chronic fatigue syndrome, as well as to characterizing their participation in a number of physiopathological processes, including drug resistance, response to toxicants, inflammation, stem cell differentiation, embryo development, and tissue repair. In some cases, like in cystic fibrosis, CKs have been described as potential therapeutic targets. The development of a specific field of proteomics where CKs become the main subject of research aims and hypotheses is suggested.

Cytokeratin expression profiling in gastric carcinoma: clinicopathologic significance and comparison with tumor-associated molecules

OBJECTIVE

The expressions of cytokeratin (CK) 7 and 20 have been studied in various primary and metastatic carcinomas, and their determination may help distinguish the site of origin of metastatic carcinomas. However, little is known about the molecular basis that determines variations in CK patterns in gastric cancers (GCs). The aim of the present study was to analyze the CK expression patterns in a large number of GCs and to investigate how the CK patterns correlate with clinicopathologic parameters, histology, mucin phenotype or several tumor-related molecules.

METHODS AND RESULTS

We immunohistochemically examined the CK7/CK20 patterns, mucin expression profiles (MUC5AC, MUC6, MUC2 and CD10), and the cancer-related molecules (CDX2, p53, EGFR and β-catenin), using a tissue microarray with 870 GCs. The GCs were divided into four patterns; 17% of CK7+/CK20+, 57% of CK7+/CK20-, 9% of CK7-/CK20+ and 17% of CK7-/CK20. GCs with the CK7-/CK20- pattern demonstrated a close relation to undifferentiated adenocarcinoma. CK7 expression was significantly correlated with the expression of MUC5AC and MUC6, while CK20 expression was correlated with MUC2 and CDX2. There were statistically significant associations between CK expression patterns and mucin phenotypes.

CONCLUSION

These results indicate that the CK7/CK20 expression patterns in GCs demonstrated different clinicopathologic features and molecular signatures.

Phenotypic differences between esophageal and gastric intestinal metaplasia

Intestinal metaplasia is a cancer precursor in the esophagus and the stomach. Marked differences exist between the carcinogenic processes in the two locations in terms of natural history and clinical significance. We investigated biopsies from 52 patients with Barrett's esophagus and from 50 patients with gastric intestinal metaplasia in an attempt to throw light on their pathogenic processes. Morphologic characteristics, presence of Helicobacter pylori (H. pylori), and markers of differentiation, inflammation, and proliferation were evaluated by histochemical and immunohistochemical techniques. The area covered by incomplete type of intestinal metaplasia and the proportion of sulfomucins were significantly higher in the esophagus than in the stomach. Immunoreactivity with MUC1, MUC2, MUC5AC, Das-1, cytokeratins 7 and 20, inducible nitric oxide synthase and cyclooxygenase-2 antibodies was also significantly greater in Barrett's esophagus than in gastric intestinal metaplasia. In gastric intestinal metaplasia, the presence of MUC1, MUC5AC, Das-1 and cytokeratin 7 was restricted to areas with the incomplete type of metaplasia. Cell proliferation (Ki-67) was significantly higher in Barrett's esophagus than in gastric intestinal metaplasia. H. pylori was absent in all of the patients with Barrett's esophagus, while it was present in 70% of the patients with gastric intestinal metaplasia. Our observations made clear that Barrett's esophagus shares some phenotypic characteristics with gastric intestinal metaplasia, leading us to suggest that both could arise in response to injuries with eventual carcinogenic potential. However, the progression to more advanced lesions could be modulated by the nature of the carcinogenic insult.

Application of immunohistochemistry to gynecologic pathology

CONTEXT

A large variety of tumors and lesions arise in the female genital tract. Although the majority of these can be correctly recognized on routine hematoxylin-eosin-stained slides, occasional cases present a diagnostic challenge. Immunohistochemical stains are extremely useful in resolving many of these problematic cases. As the knowledge in this area is constantly expanding, it is useful to have this updated information in a review form for easy access.

OBJECTIVE

To present our current knowledge of immunohistochemistry of the lesions of the female genital tract in a readily accessible form.

DATA SOURCES

The review is based on previously published articles on this topic.

CONCLUSIONS

Immunohistochemical stains help in reaching a conclusive diagnosis in a variety of problematic lesions seen in gynecologic pathology. As in any other system, immunohistochemical findings need to be interpreted in light of the clinical history and morphologic findings.

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.

MODIFIED CLASSIFICATION FOR ADENOCARCINOMA OF THE GASTRO-OESOPHAGEAL JUNCTION

BACKGROUND

Incidence of the gastro-oesophageal junction adenocarcinoma is increasing. Siewert's classification subdivides junctional adenocarcinomas anatomically. Cytokeratin (CK) 7 and 20 immunophenotypes differentiate Barrett's intestinal metaplasia (IM) from gastric IM. Comparing CK immunostaining with Siewert's classification may establish tumour origin and influence surgical choice.

METHODS

In this experimental study, 57 patients with gastro-oesophageal junction adenocarcinoma were subdivided endoscopically into 15 type 1, 26 type 2 and 16 type 3 adenocarcinomas. Representative biopsies were immunostained for CK7 and CK20.

RESULTS

Intestinal metaplasia was associated with type 1 adenocarcinoma in 12 of 15 patients, 80%; with type 2 in 13 of 26 patients, 50% and type 3 in 6 of 16 patients, 37.5%. All type 1 patients showed Barrett's CK7/CK20 phenotype within IM; type 2 a mixture: 69% (n=9) Barrett's CK7/CK20 and 31% (n=4) gastric CK7/CK20 whereas type 3 patients had a gastric CK7/CK20 pattern in 83% (n=5). Immunostaining within the adenocarcinoma was variable.

CONCLUSION

Siewert's type 1 adenocarcinomas express Barrett's CK7/CK20 pattern, type 3 a gastric CK7/CK20 pattern and type 2 tumours a mixture of Barrett's and gastric CK7/CK20 patterns within associated IM. CK immunostaining may refine Siewert's classification into oesophageal type 1 or gastric type 2 adenocarcinoma with IM.

The use of cytokeratin stain to distinguish Barrett's esophagus from contiguous tissues: a systematic review

Our objective was to systematically review the existing literature regarding the use of cytokeratin (CK) stain in differentiating Barrett's esophagus (BE) from tissues of the gastric cardia, corpus, or antrum, with or without intestinal metaplasia (IM). Pubmed was searched for full publications in English (1983-2005) addressing the use of CK for differentiation of BE from contiguous tissues. Information was collected on the study sample, blinding, the methods used for CK staining, and for defining and applying the gold standard tests. Test characteristics were obtained or calculated. Sixteen studies (containing 46 comparisons) met the inclusion and exclusion criteria. Immunostaining for CK 7 and 20 was generally highly specific in distinguishing long-segment BE from antrum IM, fundus IM, or noncardiac gastric IM; 27 comparisons showed statistically significant differences. However, only 8 of 15 comparisons (6 of 12 studies) reported significant differences in CK staining patterns between BE and gastric cardia IM with a high sensitivity (89%-100%) and specificity (83%-100%) for long-segment BE and lower estimates for short-segment BE, while the other seven comparisons showed no significant differences and a very low sensitivity. Examination by a blinded pathologist was reported in five of six positive studies and in only one of six of the negative studies. In addition, variation in the patient populations, use of surgical resection versus endoscopic biopsies, and biopsy sampling technique in endoscopic studies may have accounted for these differences. Finally, two studies did not find significant differences in CK staining patterns between BE and normal cardiac mucosa. In conclusions, CK immunostaining has not performed well in differentiating BE, especially short-segment BE, from cardia IM. There seems to be a spectrum bias where the accuracy varies with different tested populations. CK immunostaining distinguished well between BE and IM in noncardiac segments of the stomach; however, these comparisons are not clinically relevant.

Immunopathological Patterns of the Stomach in Adenocarcinoma of the Esophagus, Cardia, and Gastric Antrum: Gastric Profiles in Siewert Type I and II Tumors

BACKGROUND

The morphologic and immunohistochemical profiles of gastric mucosa and of the tumor were assessed in Siewert type I, type II, and gastric antrum adenocarcinomas.

METHODS

Sixty-two patients, prospectively operated upon, were included in the study: 37 type II, 15 type I, and 10 antrum adenocarcinoma. Samples of the tumor, the surrounding area, and the gastric corpus and antrum were analyzed histologically, and immunostained for cytokeratins (CK)7/20 (staining positive for cells labeled > or = 50%).

RESULTS

Among the 37 type II adenocarcinomas were the following: (1) 13 of 37 (35%) had intestinal metaplasia (IM) in the stomach; (2) 24 of 37 (65%) did not show IM at any level; (3) 34 of 37 (92%) had Helicobacter pylori (HP) infection; (4) 13 of 37(35%) had CK7/20 expression of "Barrett's type" (CK7+/20-); 24 of 37 (65%) had a "no Barrett's type" profile (10 of 37 with CK7-/CK20+ and 14 of 37 with CK7+/CK20+); (5) 100% showed the same CK immunoprofile, both in IM and adenocarcinoma (measure of agreement k = 1, p = 0.000). Type I adenocarcinomas showed the following: (1) 87.5% CK Barrett's type, both in the tumor, and in the surrounding IM; (2) 100% gastric samples devoid of both IM and HP infection. Comparison between CK immunoprofiles in type I and type II tumors showed a difference within the two groups (p = 0.002). One hundred percent of antrum adenocarcinomas showed a no Barrett's type CK profile, both in the tumor and in the IM of the entire stomach.

CONCLUSIONS

Data suggest that type II adenocarcinoma cannot be always considered a gastroesophageal reflux disease-related tumor; other pathogenetic pathways should be taken into consideration.

Metastatic esophageal carcinoma masquerading as inflammatory breast carcinoma

A 50-year-old Caucasian woman with a history of esophageal adenocarcinoma presented with a 3-week history of right breast swelling and progressive erythema. Twenty-two months prior to presentation, she had been diagnosed with adenocarcinoma of the esophagus (T3,N1,M1a) and underwent neoadjuvant chemoradiotherapy followed by surgical resection. On physical examination, the right breast was red, swollen (40% larger than the contralateral breast), tender to palpation, and warm to the touch (Fig. 1). No mass was palpable. On the basis of the clinical findings, inflammatory breast carcinoma was suspected. A punch biopsy revealed a poorly differentiated adenocarcinoma with extensive involvement of dermal lymphatics (Fig. 2). The clinical and histologic differential diagnosis included inflammatory breast carcinoma vs. metastatic esophageal adenocarcinoma to the skin of the breast. To resolve this question, immunohistochemical stains for estrogen and progesterone receptors and CDX-2 (BioGenex, San Ramon, CA, USA) were performed. CDX-2 is an intestinal homeobox gene expressed in gastrointestinal epithelium and gastrointestinal tumors. The tumor nuclei were positive for CDX-2 but negative for both steroid receptors (Fig. 3), confirming the diagnosis of metastatic esophageal adenocarcinoma.

Treatment of the Adenocarcinoma of the Esophagogastric Junction at a Single Institution in Mexico

BACKGROUND

Adenocarcinoma of the esophagogastric junction (EGJ) is rapidly increasing in the west. Our aim is to define the prognostic factors and treatment of EGJ carcinoma in Mexico, particularly the location after the Siewert's classification.

METHODS

A retrospective cohort of patients suffering from EGJ adenocarcinoma treated from 1987 to 2000. The Kaplan-Meier and the Cox's models were used to define prognostic factors.

RESULTS

Two hundred and thirty-four patients were included, 90 females and 144 males. Surgical resection was possible in 68 cases only (29%). Significant prognostic factors were tumor node metastasis (TNM) stage [stages I-II: risk ratio (RR) is 1; stage III RR is 1.3, 95% confidence interval (CI) 0.75-2.4; stage IV RR, 2.04, 95% CI 1.1-3.7], gender (male RR = 1.47, 95% CI 1.05-2.05), metastatic lymph node ratio (no resection: RR = 1; ratio 0.2-1 RR=0.67, 95% CI 0.39-1.14; ratio 0-0.19 RR = 0.42, 95% CI 0.23-0.76) and seralbumin (3 mg/dL or less RR = 2.05 95% CI 1.3-3.2; 3.1-3.4 mg/dL RR = 1.9 95% CI 1.2-3.03; 3.5-3.8 mg/dL RR = 1.3 95% CI 0.8-1.9; 3.9 mg/dL or more: RR = 1) (model P = 0.0001).

CONCLUSIONS

EGJ adenocarcinoma is a highly lethal neoplasia and the location after the Siewert' classification is not a prognostic factor. In Mexico, TNM clinical stage, serum albumin, gender, surgical resection and metastatic lymph node ratio are significant prognostic factors. Curative treatment is infrequent but radical resection is associated to longer survival. Consequently, the management must consider quality of life and surgical morbidity.

Cytokeratin expression patterns of gastric carcinomas according to Lauren and Goseki classification

The Goseki system is a new gastric carcinoma classification system that classifies gastric carcinomas as grade I (intestinal type), grade II (mucinous type), grade III (mucin-poor, diffuse infiltrating type), and grade IV (signet ring cell type). The main advantage of the Goseki classification may be to separate these distinct entities into different groups. CK7 is not observed in normal gastric mucosa but can be detected in chronically inflamed gastric mucosa and coexists with incomplete intestinal metaplasia. CK20 can be observed in the superficial foveolar epithelium and mature goblet cells. The aim of this study was to examine the cytokeratin expression profiles in gastric carcinomas that are classified according to both the Goseki and Lauren systems. CK7, CK8, CK19, and CK20 were applied to the paraffin sections of 66 gastric carcinoma cases. The cytokeratin expression patterns were grouped as CK20+/CK7+, CK20+/CK7-, CK20-/CK7+, or CK20-/CK7-. The results were examined statistically. CK20 immunoreactivity was observed in 18%, 24%, and 31% of grade I, III, and IV cases, respectively. The CK20+/CK7- pattern was observed in 20% of the grade IV and 66.7% of the grade II carcinomas and was not observed in grade I or grade III tumors (P<0.0001). Goseki grade III and IV carcinomas originate from superficial gastric mucosa, but grade III carcinomas are poorly differentiated. Goseki grade II carcinomas have a specific immunophenotype other than intestinal-type gastric tumors. The Goseki classification seems to be superior in identifying poorly and well-differentiated forms of diffuse infiltrating carcinomas and mucinous carcinomas.

Prospective analysis of patients with adenocarcinoma of the gastric cardia and lymph node metastasis in the proximal field of the chest

BACKGROUND

The extent to which adenocarcinoma of the cardia with lymph node metastasis in the upper mediastinum is amenable to cure by radical surgery is open to debate. It remains unclear whether these relatively distant metastases have an effect on long-term survival. The aim of this study was to identify the incidence of such positive nodes and evaluate their prognostic significance.

METHODS

Some 50 patients with adenocarcinoma of the gastric cardia and substantial invasion of the oesophagus (junctional type II), who underwent an extended transthoracic oesophagectomy as part of a prospective randomized trial between 1994 and 2000, were studied.

RESULTS

Eleven patients (22 per cent) had lymph node metastasis in the proximal field of the chest. These patients had more positive nodes overall (P = 0.020) and a shorter median survival (P = 0.009) than those without such metastasis. Multivariate analysis identified positive nodes in the proximal field as an independent predictor of poor survival.

CONCLUSION

Lymph node metastasis in the proximal field of the chest is common and is an indicator of poor prognosis in patients with adenocarcinoma of the cardia.

Cytokeratin phenotyping does not help in distinguishing oesophageal adenocarcinoma from cancer of the gastric cardia

BACKGROUND

It is sometimes difficult to distinguish between cardia cancer and oesophageal cancer.

AIMS

To evaluate whether cytokeratin (CK) expression of the tumour can be of value in differentiating between the two tumour types.

METHODS

Consecutive patients with a malignant tumour in the oesophagus or stomach were recruited. Biopsy specimens were taken for routine haematoxylin and eosin staining. One tissue block with representative tissue was selected for immunohistochemical staining (CK7 and CK20).

RESULTS

Endoscopically located adenocarcinoma of the oesophagus was present in 84 patients (64 men, 20 women; mean age, 68 years; range, 44-91). Cancer located primarily in the gastric cardia was present in 63 patients (42 men, 21 women; mean age, 68 years; range, 42-88). The histological diagnosis was metastasis from a primary tumour outside the oesophagus or stomach in 19 patients. The patients were divided into three groups for the immunohistochemical analysis. Patients in group A had definite oesophageal cancer, group B patients had a definite carcinoma located in the gastric cardia, and group C patients had an obstructing tumour distal in the oesophagus at the level of the diaphragm, which could not be passed with the endoscope. Paraffin wax embedded material was available from 122 patients for immunostaining and CK analysis. There was no significant difference in expression or distribution of CK7 or CK20 in the three groups of patients.

CONCLUSION

CK phenotyping cannot distinguish between cancer arising from a Barrett's oesophagus and carcinoma originating in the gastric cardia.

Expression of cytokeratins 7 and 20 in serrated adenoma and related diseases

The entity of serrated adenoma of the colorectum was first proposed in 1990, and it was characterized as epithelial neoplasia combining the architectural features of a hyperplastic polyp with the cytological features of an adenoma. Over the past few years, various clinicopathological studies on serrated adenoma have been reported, but its histogenesis remains unclear. Recently the existence of a "serrated neoplasia pathway" leading to malignancy, which is different from the so-called adenoma-carcinoma sequence, has been discussed. Yao et al. reported that hyperplastic polyps and serrated adenomas share a common cell lineage with gastric differentiation. To clarify the existence of the serrated neoplasia pathway, we performed immunohistochemical staining of cytokeratin 7 (CK7) and cytokeratin 20 (CK20), which are commonly used to determine the primary site of a metastatic lesion, and we examined the pattern of CK7/CK20 expression in various colorectal lesions including 44 serrated adenomas, 25 hyperplastic polyps, 20 traditional adenomas, and 48 carcinomas. An obvious difference existed in the pattern of CK7/CK20 expression between the serrated lesions (hyperplastic polyps and serrated adenomas) and others. The majority of serrated adenomas and hyperplastic polyps presented a CK7+/CK20+ pattern, whereas most conventional adenomas and adenocarcinomas expressed CK7-/CK20+. Adenocarcinoma developing in serrated adenoma also presented a CK7+/CK20+ pattern. There are several reports that CK7 is a possible marker of transient dedifferentiation in the gastric carcinogenesis process. Taken together with the present results, a distinct pathway of colorectal carcinogenesis must exist, which is different from the adenoma-carcinoma sequence. CK7 is a possible marker for the serrated neoplasia pathway of colorectal carcinogenesis.

Hepatocyte paraffin 1 immunoexpression in esophageal brush samples

BACKGROUND

Intestinal metaplasia (IM) is often a component of Barrett esophagus (BE) and is characterized by a distinctive type of epithelium. Because IM has the potential to progress to dysplasia or adenocarcinoma, an accurate identification of its presence is important clinically. A cytopathologic diagnosis of IM on esophageal brushings by morphology alone can be difficult. The authors investigated the role of hepatocyte paraffin 1 (Heppar-1) immunostaining as a possible marker of IM in cytologic samples of BE.

METHODS

Eleven samples each of BE with and without IM diagnosed on esophageal brushings were retrieved from the cytopathology files of The Johns Hopkins Hospital over an 8-year period (1993-2001). All 22 specimens were confirmed histologically on subsequent tissue biopsies. Slides initially were prepared by cytospin and stained with Papanicolaou stain. After destaining, the slides were immunostained with hepatocyte paraffin 1 (Heppar-1) antibody at 1:100 dilution employing conventional methodology.

RESULTS

Among the samples of BE with IM, 9 of 11 samples (82%) were immunoreactive for Heppar-1, compared with 0 of 11 specimens of BE with only cardiac-type metaplasia. The immunoexpression was cytoplasmic and granular and was seen only focally in the glandular fragments.

CONCLUSIONS

Heppar-1 was a moderately sensitive (82%) and highly specific (100%) immunomarker for IM in BE. It was easy to use in limited cytologic samples that originally were stained with Papanicolaou stain and is recommended for inclusion in morphologically difficult samples of BE with questionable IM. The immunostaining pattern predominantly was focal, necessitating a careful evaluation of positive reactions on cytologic samples.

Expression of cytokeratins 7 and 20 in Helicobacter pylori-associated chronic gastritis in children

Helicobacter pylori gastric infection induces structural changes in the gastric epithelium. Among them, variations in the expression of cytokeratins have been reported in adult patients. In the present study, we describe the expression of CK7 and CK20 in gastric samples taken from the antrum in three groups of pediatric patients: (A) Helicobacter pylori-associated chronic gastritis (mean age: 11.4 years); (B) previous H. pylori chronic gastritis patients (mean age: 9.4 years); and (C) controls (mean age: 8.8 years). In all, the presence of sulfomucins was assessed with Alcian blue-periodic acid-Schiff pH 1.0. Immunoreactivity was graded as absent (0), weak (1+), moderate (2+), or intense (3+), in accordance with the intensity of the staining, and its distribution as focal or diffuse. CK7 reactivity was 2+ either focal or diffuse in all group A biopsies. The reactivity was more evident in the cells at the neck of the glands, in the areas with more inflammatory infiltrates, decorating long vertical segments of epithelium. In groups B and C, CK7 reactivity was also focal and 1+ at the cells of the necks of the glands. However, group B presented longer vertical segments of positive cells as compared to group C, and shorter than those of group A. The deeper glandular structures were focally 1+ in both groups. CK20 expression was comparable in all three groups, depicting a 2+ diffuse reactivity at the surface epithelium and interposed pits with absence or focal reactivity at the neck and coiled gland areas. Ki-67 immunostaining paralleled that of the CK7. Staining for sulfated mucosubstances was positive in two of five cases of groups A and B, and in none of the cases of group C. We conclude that: (1) the long segments of CK7-positive glandular necks in H. pylori cases most probably indicate intense regenerative activity during active inflammation; (2) eradication of H. pylori does not warrant ad integrum restitution since long segments of Ki-67+, CK7+ cells at the germinative compartment of the glands (as well as cells with sulfomucins) were still recognizable in ex- H. pylori patients; (3) finally, differing from what happens in adults, children somehow manage to maintain fully differentiated CK20+ superficial epithelium while the H. pylori is in action.

Identical cytokeratin expression pattern CK7+/CK20- in esophageal and cardiac cancer: etiopathological and clinical implications

Surgical treatment and prognosis is different in esophageal, cardiac and distal gastric adenocarcinomas. Determination of the origin, in particular of adenocarcinomas situated at the gastroesophageal junction, may be difficult. It has been suggested that esophageal adenocarcinomas are characterized by a specific cytokeratin pattern, namely the CK7+/CK20- pattern. According to the same authors, this cytokeratin pattern is absent in gastric adenocarcinomas. The aim of our study is to evaluate if this cytokeratin pattern CK7+/CK20- is absent in cardiac and distal gastric adenocarcinomas. Therefore, we evaluated the combined immunohistochemical expression of CK7 and CK20 on paraffin-embedded material of 214 resection specimens for adenocarcinoma, comprising 66 esophageal, 73 cardiac and 75 distal gastric adenocarcinomas (UICC-classification). The adenocarcinomas were subtyped into intestinal- and diffuse-type according to the Lauren classification. The immunohistochemical staining was considered as positive if 50% or more of the tumor cells were stained. Statistical analysis has been performed applying the chi2-test. The tumors situated at the gastroesophageal junction, esophageal as well as cardiac adenocarcinomas, showed predominantly a CK7+/CK20- expression pattern (67 vs 68%), whereas this cytokeratin pattern is rather uncommon in distal gastric adenocarcinomas (31%, P<4 x 10(-5)). Independent of their localization, intestinal- as well as diffuse-type adenocarcinomas have a similar cytokeratin pattern. Our data show that the combined expression of CK7 and CK20 is different for the adenocarcinomas situated on both sides of the gastroesophageal junction compared to the distal gastric adenocarcinomas. However, in contrast to data in the literature, the combined expression of CK7 and CK20 has a low specificity in the distinction between esophageal and cardiac adenocarcinomas. This may suggest a similar origin (cell lineage) and thus may have an impact on therapeutic strategies.

Cytokeratin 7/20 and mucin expression patterns in oesophageal, cardia and distal gastric adenocarcinomas

AIMS

The current study examined cytokeratin (CK)7 and 20 as well as MUC1-6 immunoprofiles in oesophageal, gastric and gastro-oesophageal junction (GOJ) adenocarcinomas. The aim was to compare expression patterns in these locations as aids to accurate classification of these morphologically similar carcinomas which all may involve the GOJ.

METHODS AND RESULTS

Tissue microarrays were constructed using tissue from 14 oesophageal, 78 gastric and 39 GOJ adenocarcinomas. Sections were immunostained with CK7, CK20, MUC1, MUC2, MUC5AC and MUC6. The results of this study showed no differences in CK7 and CK20 expression patterns in the three locations. MUC2 expression was higher proximally (43% of oesophageal, 28% of GOJ and 17% of gastric carcinomas) and MUC6 expression was higher distally (7% of oesophageal, 28% of GOJ and 15% of gastric carcinomas). MUC1 expression was associated with higher pTNM-stage.

CONCLUSIONS

CK 7/20 profiles have no role in distinguishing tumours of the three locations. Mucin expression patterns differed in oesophageal and gastric adenocarcinomas, although not sufficiently to classify individual cases. GOJ adenocarcinomas showed a mucin expression pattern that was partly 'gastric', and partly 'oesophageal'. MUC1 expression was associated with a higher pTNM stage.

Adenocarcinoma in situ arising from the submucosal oesophageal mucous glands

The incidence of adenocarcinoma of the oesophagus is increasing; this type of carcinoma commonly arises on Barrett's oesophagus. We report a case of in-situ adenocarcinoma of the lower oesophagus arising in submucosal oesophageal mucous glands without intestinal metaplasia. We describe the histological findings, discuss the difficulties of differentiating this from invasive disease and review the current literature regarding this rare condition.

Immunoreactivity of cytokeratins (CK7, CK20) and mucin peptide core antigens (MUC1, MUC2, MUC5AC) in adenocarcinomas, normal and metaplastic tissues of the distal oesophagus, oesophago-gastric junction and proximal stomach

AIMS

Adenocarcinomas of the distal oesophagus and especially the oesophago-gastric junction have shown an increasing incidence during the last decade. Definition of subgroups according to different sites of development, histogenesis or aetiology may prove to be valuable for clinical diagnosis and treatment. Previous studies have shown differences in cytokeratin patterns between Barrett's metaplasia of the oesophagus and intestinal metaplasia in the stomach. The aim of our study was to investigate whether the expression of certain cytokeratins (CK7, CK20) and mucins (MUC1, MUC2, MUC5AC) exhibit clear-cut patterns, thus allowing a subclassification of adenocarcinomas of the oesophago-gastric junction. The possibility of a relationship between antigen expression and the presence or absence of Barrett's metaplastic epithelium was also studied.

METHODS AND RESULTS

CK7, CK20, MUC1, MUC2 and MUC5AC were visualized in six adenocarcinomas of the distal oesophagus, 29 adenocarcinomas of the oesophago-gastric junction and eight adenocarcinomas of the proximal stomach. CK7, CK20 and MUC1 were strongly expressed in the great majority of all neoplasms under study, whereas MUC2 and MUC5AC were absent or only faintly detectable. CK20 exhibited a significantly stronger expression in poorly differentiated tumours (G3) and MUC1 immunoreactivity correlated with tubular and papillary versus signet-ring cell histopathology. Other statistically significant correlations between antigens and histopathological features (pTNM stage, grading, histopathological subtype, presence/absence of Barrett's epithelium) were not observed.

CONCLUSIONS

According to our results, most adenocarcinomas of the oesophago-gastric junction show a CK7+, CK20+, MUC1+ phenotype irrespective of the presence or absence of Barrett's epithelium. The immunohistochemical data suggest a similar histogenesis of these tumours.

Hepatocyte antigen as a marker of intestinal metaplasia

Intestinal metaplasia is a histologic hallmark of Barrett's esophagus and chronic gastritis. Intestinal metaplasia may progress to dysplasia or carcinomas without proper treatment. Most cases of intestinal metaplasia are easily recognized on hematoxylin and eosin-stained sections. However, some cases of intestinal metaplasia may be hard to recognize if they lack the characteristic mucin-producing cells and Paneth cells, or if they are small in size. Recently, keratin 7, keratin 20, and MUC2 expression patterns were reported to be useful in confirming the diagnosis of intestinal metaplasia. We studied hepatocyte (Hep) antigen (a hepatocellular antigen mainly expressing in normal and neoplastic hepatic tissues) in 33 cases of Barrett's esophagus (9 cases associated with esophageal adenocarcinoma) and 13 cases of chronic gastritis associated with intestinal metaplasia and gastric adenocarcinoma. Hep monoclonal antibody recognizes intestinal metaplasia in all cases. We also compared expression of Hep with that of keratin 7, keratin 20, and MUC2 in intestinal metaplasia. The specificity and sensitivity of Hep for intestinal metaplasia were higher than that of keratin 7 and keratin 20, or MUC2. We conclude that Hep may be used as a single diagnostic marker for intestinal metaplasia.

Intestinal metaplasia at the gastroesophageal junction: Barrett's, bacteria, and biomarkers

For patients found to have intestinal metaplasia at the gastroesophageal junction, technical problems can make it difficult to distinguish short-segment Barrett's esophagus from intestinal metaplasia of the gastric cardia. Whereas the risk of malignancy for the former condition seems to be higher than that for the latter, the distinction between these conditions can have practical clinical implications. Immunostaining for cytokeratins has been proposed as a means to distinguish intestinal metaplasia of esophageal and gastric origins. We review recent data on this issue, and conclude that immunostaining for cytokeratins has no clear advantages over other biomarkers that have been proposed for identifying Barrett's esophagus (e.g., mucin histochemistry, mAb Das-1 immunoreactivity). Presently, the importance of intestinal metaplasia at the gastroesophageal junction remains unclear, and the clinical utility of biomarkers in distinguishing short-segment Barrett's esophagus from intestinal metaplasia of the gastric cardia has not yet been established.

Expression of cytokeratins 7 and 20 in primary carcinomas of the stomach and colorectum and their value in the differential diagnosis of metastatic carcinomas to the ovary

The expressions of cytokeratin (CK) 7 and 20 have been studied in various primary and metastatic carcinomas, and their determination may help distinguish the site of origin of metastatic carcinomas. However, little is known about the factors that determine variations in their expression patterns in primary gastric and colorectal carcinomas. We investigated the expressions of CK7 and CK20 in 289 cases of gastric carcinoma and 225 cases of colorectal carcinoma using a tissue microarray. To evaluate CK7 and CK20 expression patterns of ovarian metastases from gastric or colorectal carcinomas, 54 cases of metastatic carcinomas to the ovary were examined. It was found that 71% (207 of 289) of the gastric carcinomas stained positively for CK7, whereas only 9% (21 of 225) of the colorectal carcinomas proved to be CK7 positive, and that 41% (117 of 289) of the gastric carcinomas and 73% (165 of 225) of the colorectal carcinomas were CK20 positive. The proportion of CK7+/CK20- was highest in the gastric carcinomas at 46% (132 of 289), and was independent of the histologic classification of Lauren (46% of the intestinal type, 45% of the diffuse type). The CK7 and CK20 expression patterns were different in colorectal carcinomas according to histologic grade and location of the tumor. CK7-/CK20+ had the greatest proportion (68%) in colorectal carcinomas, and this was dependent on the tumor's histologic grade (75% of low-grade versus 52% of high-grade) and location (46% of right-sided versus 76% of left-sided). Moreover, 42% (18 of 43) of gastric carcinomas metastatic to the ovary were CK7+/CK20-, whereas 19% (8 of 43) were CK7-/CK20+. All colorectal cancers metastatic to the ovary were CK7-/CK20+, except 1 case that was CK7-/CK20-. In conclusion, the CK7 and CK20 expression patterns in primary gastric carcinomas vary considerably, and those in colorectal carcinomas are associated with histologic grade and tumor location. The CK7-/CK20+ expression pattern is specific for metastatic colorectal carcinomas to the ovary, but has low predictability for colorectal origin in metastatic ovarian carcinoma.

Cytokeratin expression in adenocarcinomas of the esophagogastric junction: a comparative study of adenocarcinomas of the distal esophagus and of the proximal stomach

Adenocarcinomas of the esophagogastric junction form a heterogeneous group of tumors. We aimed to evaluate the value of the expression pattern of cytokeratins 7, 19, and 20 for their diagnosis and classification. A total of 85 cases of adenocarcinoma of the distal esophagus and 67 cases of adenocarcinoma of the proximal stomach, defined on strict topographical criteria, were investigated. About 90% of the adenocarcinomas of distal esophagus were positive for cytokeratins 7 and 19, in contrast to <45% of the adenocarcinomas of proximal stomach (p <0.01); 17.6% of the adenocarcinomas of the distal esophagus and 55.2% of the adenocarcinomas of the proximal stomach expressed cytokeratin 20 (p <0.01); and 74.1% of the adenocarcinomas of the distal esophagus and 23.8% of the adenocarcinomas of the proximal stomach had a CK7+/CK20- immunophenotype (p <0.01). In intestinal-type tumors a CK7+/CK20- immunophenotype had a sensitivity of 76.5%, a specificity of 84.5%, and a predictive positive value of 87.3% for the diagnosis of adenocarcinoma of the distal esophagus. Cytokeratin patterns are different in adenocarcinomas of the distal esophagus and in adenocarcinomas of the proximal stomach. A CK7+/CK20- pattern is highly suggestive of an esophageal origin and may be helpful for the correct classification of esophagogastric adenocarcinomas.

Keratin expression in human tissues and neoplasms

Keratin expression in human tissues and neoplasms Keratin filaments constitute type I and type II intermediate filaments (IFs), with at least 20 subtypes named keratin 1-20. Since certain keratin subtypes are only expressed in some normal human tissues but not others, and vice versa, various tissues have been subclassified according to the pattern of keratin staining. Simple epithelia generally express the simple epithelial keratins 7, 18, 19, and 20, while complex epithelia express complex epithelial keratins 5/6, 10, 14, and 15. When an epithelium undergoes malignant transformation, its keratin profile usually remains constant. The constitution and expression patterns of keratin filaments in human epithelial neoplasms are complex and often distinctive. In this article, we first briefly review the molecular and cell biology of keratin filaments. We then focus on the expression patterns of keratin filaments in various human neoplasms.

Transcriptional analyses of Barrett's metaplasia and normal upper GI mucosae

Over the last two decades, the incidence of esophageal adenocarcinoma (EA) has increased dramatically in the US and Western Europe. It has been shown that EAs evolve from premalignant Barrett's esophagus (BE) tissue by a process of clonal expansion and evolution. However, the molecular phenotype of the premalignant metaplasia, and its relationship to those of the normal upper gastrointestinal (GI) mucosae, including gastric, duodenal, and squamous epithelium of the esophagus, has not been systematically characterized. Therefore, we used oligonucleotide-based microarrays to characterize gene expression profiles in each of these tissues. The similarity of BE to each of the normal tissues was compared using a series of computational approaches. Our analyses included esophageal squamous epithelium, which is present at the same anatomic site and exposed to similar conditions as Barrett's epithelium, duodenum that shares morphologic similarity to Barrett's epithelium, and adjacent gastric epithelium. There was a clear distinction among the expression profiles of gastric, duodenal, and squamous epithelium whereas the BE profiles showed considerable overlap with normal tissues. Furthermore, we identified clusters of genes that are specific to each of the tissues, to the Barrett's metaplastic epithelia, and a cluster of genes that was distinct between squamous and non-squamous epithelia.

Cytokeratin expression patterns in noncardia, intestinal metaplasia-associated gastric adenocarcinoma: implication for the evaluation of intestinal metaplasia and tumors at the esophagogastric junction

BACKGROUND

Barrett esophagus (BE)/Barrett adenocarcinoma and distal gastric intestinal metaplasia (IM)/adenocarcinoma are similar histologically, but they differ in their clinical presentation, epidemiology, and pathogenesis. Differentiating BE from gastric IM and Barrett adenocarcinoma from gastric adenocarcinoma is difficult, especially when IM is short or tumors are large and involve both sides of the esophagogastric junction. Previously, the authors identified unique cytokeratin (CK) immunoreactivity patterns that were associated strongly with BE and Barrett adenocarcinoma. The specificity of CK7 and CK20 (CK7/20) expression patterns in patients with IM-associated gastric adenocarcinoma, which is distinct epidemiologically from BE/Barrett adenocarcinoma, has not been evaluated. The objective of the current study was to evaluate the CK7/20 expression patterns in noncardia, IM-associated gastric adenocarcinoma in a Chinese population with a low risk for BE and esophageal adenocarcinoma and a high risk for Helicobacter pylori infection and gastric carcinoma.

METHODS

Endoscopic biopsy specimens of gastric IM and adjacent tumor from 50 consecutive patients with advanced noncardia gastric carcinoma were immunostained for CK7 and CK20. Clinical and endoscopic features and H. pylori status were documented. Two gastrointestinal pathologists, blinded to clinical and endoscopic data, independently assessed CK7/20 immunohistochemistry.

RESULTS

H. pylori infection was present in 43 of 50 patients (86%). In the area of IM, patchy CK7 staining was seen in 9 patients (18%), and diffuse CK20 staining was seen in all 50 patients (100%). The BE CK7/20 pattern characterized by CK7 staining in superficial and deep glands and the CK20 staining in surface epithelium was not seen in any of the 50 patients. Only one patient (2%) demonstrated a CK7 positive/CK20 negative immunophenotype characteristic of Barrett adenocarcinoma. The remaining 49 patients (98%) showed non-Barrett adenocarcinoma patterns of CK7/20 staining, i.e., a CK7 positive/CK20 positive pattern was seen in 33 patients (66%), a CK7 negative/CK20 positive pattern was seen in 12 patients (24%), and a CK7 negative/CK20 negative pattern was seen in 4 patients (8%).

CONCLUSIONS

In a patient population without risk factors for the development of BE/esophageal adenocarcinoma, the CK7/20 pattern characteristic of BE was not present in gastric IM adjacent to adenocarcinoma, and the CK7/20 pattern characteristic of Barrett adenocarcinoma also was extremely rare. These results support the hypothesis that, despite the presence of intestinalized mucosa in both disorders, BE/Barrett adenocarcinoma and gastric IM/adenocarcinoma are two distinct clinical entities with unique demographic, clinical, and CK immunophenotypic findings. These results may have application to the evaluation of patients with IM and adenocarcinoma arising at the esophagogastric junction.