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

Immunohistochemical panel for distinguishing esophageal adenocarcinoma from squamous cell carcinoma: a combination of p63, cytokeratin 5/6, MUC5AC, and anterior gradient homolog 2 allows optimal subtyping

Distinguishing adenocarcinoma and squamous cell carcinoma of the esophagus is often based on morphological criteria and can be difficult in small biopsies. We analyzed commonly used immunohistochemical markers (p63, cytokeratin 5/6, cytokeratin 7, CDX2, MUC2, and MUC5AC) and 2 new markers, anterior gradient homolog 2 and SOX2, in esophageal carcinomas to establish the best panel to distinguish these tumors. Tissue microarrays with 69 esophageal adenocarcinomas and 41 whole sections of esophageal squamous cell carcinomas were stained for these markers and semiquantitatively scored. Sensitivities and specificities were calculated for individual markers and select combinations using the morphological diagnosis as a gold standard. All squamous cell carcinomas expressed p63 with 38 of 41 demonstrating reactivity in more than 75% of tumor cells. Cytokeratin 5/6 expression was seen in 40 of 41 squamous cell carcinomas with 39 of 41 demonstrating reactivity in more than 75% of tumor cells. SOX2 expression was present in 35 of 41 of squamous cell carcinomas but also in 24 of 69 of adenocarcinomas, frequently demonstrating extensive reactivity in adenocarcinomas. Anterior gradient homolog 2 was highly sensitive for adenocarcinoma and present in 68 of 69 of cases, but anterior gradient homolog 2 reactivity was also identified in 15 of 41 of squamous cell carcinomas, typically demonstrating focal reactivity in squamous cell carcinoma. MUC5AC expression was seen almost exclusively in adenocarcinomas with only a single squamous cell carcinoma demonstrating focal MUC5AC staining. Overall, the dual expression of both p63 and cytokeratin 5/6 was 99% specific and 98% sensitive for squamous cell carcinoma. In addition, anterior gradient homolog 2 and MUC5AC are useful positive markers of adenocarcinoma in the setting of absent or diminished p63 and cytokeratin 5/6 staining.

Evaluation of Barrett's esophagus with CK7, CK20, p53, Ki67, and COX2 expressions using chromoendoscopical examination

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease and can be diagnosed when there is an endoscopically irregular Z-line and intestinal metaplasia (IM) in a biopsy obtained lower esophagus. It is still not clear whether IM in the gastric cardia or columnar mucosa without IM in the lower esophagus have any significance as BE, which is considered as preneoplastic. The aim of the study was to determine the immunohistochemical features of BE and columnar mucosa in the distal esophagus and also to evaluate the value of chromoendoscopy in the diagnosis of BE in a prospective manner. A total of 12 chromoendoscopic biopsies (six from normal-looking unstained esophagus and six from esophageal mucosa stained with methyl blue suspicious of BE) were taken from 111 cases who underwent endoscopy because of a variety of upper gastrointestinal symptoms. Immunohistochemical analysis was performed using CK7, CK20, p53, Ki67, and cyclooxygenase 2 (COX2). Of the 111 cases, 19 cases with carcinoma (nine adeno, six squamous, four undifferentiated carcinomas) and 17 cases with normal squamous epithelium were excluded, while 75 cases showing columnar epithelium, including 46 (61.3%) with IM and 29 (38,7%) without IM, were further evaluated immunohistochemically. CK7 was observed in surface, crypt, and glandular epithelium, whereas CK20 was expressed in surface and superficial crypt epithelium. No significant difference was observed between the Barrett and non-Barrett type of CK7/20 staining pattern (P > 0,05). Expression of p53 did not show any difference between BE and columnar mucosa without IM, whereas COX2 expression was significantly increased in BE (P < 0.05) in comparison with columnar mucosa without IM. Ki67 expression was significiantly higher both in upper and lower crypts in BE (P < 0.05). The present study showed that a Barrett pattern does not seem to exist; however, the analysis of COX2 expression and the Ki67 proliferation fraction by immunohistochemistry can be used to separate BE from non-Barrett's metaplasia of the distal esophagus. In our point of view, the immunohistochemical detection of p53 expression in Barrett's metaplasia stage is useless as a marker for early detection of high-risk patients.

[Pathology and pathobiology of the gastric carcinoma]

Recent epidemiological studies in Serbia revealed that gastric carcinoma is the third and the fifth main cause of cancer morbidity in men and women, respectively. Despite the declining incidence of gastric cancer, it remains the second most common cause of cancer-related deaths as it is worldwide. A well-defined carcinogenic inflammation-metaplasia-dysplasia-cancer sequence typically precedes the development of most gastric adenocarcinomas. Alterations such as gastric mucosal atrophy and intestinal metaplasia are merely markers of increased risk, while gastric epithelial dysplasia (GED) represent a direct precursor of cancer. DNA damage and increased mucosal proliferation secondary to H pylori infection, combined with a suitable host susceptibility phenotype (eg, genetic polymorphisms in interleukin IL-1B, IL-1RN, and tumor necrosis factor a TNF-alpha genes), are important factors in this progression pathway. However, only a small minority of patients infected with H. pylori eventually develops gastric cancer, and eradication of H pylori in these patients does not seem to eliminate the risk of cancer completely. It has been shown that atrophy may be a better indicator of risk of cancer than intestinal metaplasia, and remains to be validated in routine clinical practice according to recent proposal for new quantitative methods. It is often associated with pseudopyloric gland metaplasia in the gastric corpus mucosa, which expresses a type of trefoil peptide, the spasmolytic polypeptide (termed spasmolytic polypeptide-expressing metaplasia or SPEM) and has been shown to be linked more closely to gastric cancer than intestinal metaplasia. Better histological characterization of adenomatous (or type I), hyperplastic (foveolar or type II) and tubule-neck (mucocellular or type III) GED, two-tiered grading system (low and high grade dysplasia) as well as the introduction of Padova and Vienna international classifications of dysplasia seem to be more helpful in GED surveillance and comparative studies. A combination of histopathological features, serum markers such as pepsinogen I, and molecular tests that analyze host susceptibility polymorphisms and bacterial virulence factors, may allow development of strategies for early detection of cancer in the future. At present, pathobiology of gastric cancerogenesis is far from known, despite the progressive knowledge on predisposing environmental conditions and genetic and epigenetic abnormalities, including tumour suppressor genes, oncogenes, microsatellite instability and hypermethylation or the significance of E-cadherin mutational status association with hereditary diffuse gastric cancer syndrome. Recent evidence regarding the importance of several histopathologically derived prognostic factors, such as resection margin status and lymph node metastases and their implications have also been discussed. We aim to review these aspects, with special relevance to gastric cancer specimen reporting.

Pathology and pathobiology of the oesophageal carcinoma

Carcinoma of the oesophagus including carcinoma of gastro-oesophageal junction are rapidly increasing in incidence. During recent years there have been changes in the knowledge surrounding biology of the disease progression. Identification of dysplasia in mucosal biopsies is the most reliable pathologic indicator of an increased risk of development of squamous cell carcinoma and passes through the sequence of chronic esophagitis, low-grade and high-grade dysplasia and invasive carcinoma. Although Barrett's esophagus is a precursor to esophageal adenocarcinoma and have a well described sequence of carcinogenesis: the Barrett's metaplasia-dysplasia-adenocarcinoma sequence, not all patients with this disorder require intensive surveillance. The natural history of dysplasia is poorly understood, particularly in low-risk regions, and prospective follow-up studies are needed. Adjunctive methods to improve reproducibility, such as immunostaining for alpha-methylacyl-coenzyme A racemase (AMACR), show promise, but require confirmation in larger studies. In addition, several controversial methods such as detection of p16, p53, and DNA content abnormalities may help identify patients at particularly high risk for progression to cancer, but these techniques are not yet widely available for routine clinical application. More studies are needed to define other early nonmorphologic biomarkers for risk of squamous cell carcinoma. Recent evidence regarding the importance of several histopathologically derived prognostic factors, such as circumferential resection margin status and lymph node metastases are evaluated, including lymph node micrometastases and the sentinel node concept. With the rising use of multimodal treatments for oesophageal cancer it is important that the response of the tumour to this therapy can be carefully documented by histopathology.

Differences in the molecular biology of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

Adenocarcinoma of the distal esophagus, gastric cardia, and upper gastric third are grouped in type I-III by the Siewert classification. This classification is based on the endoscopic localisation of the tumor center, and is the most important diagnostic tool to group these tumors. On a molecular level, there is currently no marker that would allow to differentiate the three different types. Furthermore, the Siewert classification was not uniformly used in the recent literature, making interpretation and generalization of these results difficult. However, several potential targets have been identified that may help to separate these tumors by molecular markers, and are summarized in this chapter.

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.

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.