[A case of resected endocrine cell carcinoma in the remnant stomach].

We report a rare case of resected endocrine cell carcinoma in the remnant stomach. A 68-year-old man had undergone laparoscopy-assisted distal gastrectomy for gastric cancer. Eleven months later, postoperative endoscopy survey showed a flat, depressed lesion in the posterior wall of the remnant gastric cardia. After 3 months, endoscopic re-examination indicated that the tumor had grown rapidly and had changed in shape. Endocrine cell carcinoma was diagnosed by biopsy. He then underwent total resection of the remnant stomach with lymph node dissection. Although adjuvant chemotherapy was given, multiple liver metastases and lymph node recurrence were found 13 months after the second surgery. A new regimen of chemotherapy was not effective and he died 18 months after surgery.

A clinical and immunohistochemical study on gastrointestinal mesenchymal tumor (GIMT): RCAS1 as a predictor for recurrence of GIMT.

Gastrointestinal mesenchymal tumors (GIMTs) are the most common mesenchymal tumors of the gastrointestinal tract. RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is a cancer cell-surface antigen and has been identified as a prognostic factor in several cancer types. It is thought that tumor cells escape immune attack by expressing RCAS1, which induces apoptosis in receptor-positive immune cells. The current study was designed to elucidate the histogenesis of these tumors by using various immunohistochemical markers, and identify parameters that will help to establish the criteria of malignancy in the GIMT. We also discuss the clinicopathological significance of RCAS1 expression in the diagnosis and prognosis of GIMTs. A total of 70 cases of GIMTs were reviewed. Immunohistochemistry was performed between 1990 and 2000, with the avidin-biotin-peroxidase complex method on 3 microm-thick sections of formalin-fixed paraffin-embedded specimens of GIMTs. Antibodies to the following antigens were used: KIT (CD117), CD34 alpha-SMA, Desmin, cytokeratin, S-100 protein, p53, and RCAS1. Recurrence-free survival analysis was done with Stat View-J 5.0 statistical packages. Univariate analysis for a recurrence-free prognosis demonstrated that antibody detection of p53 expression (p=0.0333) and expression of RCAS1 (p=0.0008) is correlated with a significantly higher potential of recurrence. On multivariate analysis, tumor size and RCAS1 expression were independently and inversely correlated with recurrence-free survival. The expression of RCAS1 has not previously been reported in GIMT; indeed, our study suggests that the expression of RCAS1 is correlated with recurrence not only in carcinomas, but also in mesenchymal tumors.

Amplification/overexpression of Aurora-A in human gastric carcinoma: potential role in differentiated type gastric carcinogenesis.

Aurora-A encodes a cell cycle regulated serine/threonine kinase that has essential functions for centrosome maturation and chromosome segregation. Aurora-A is amplified and overexpressed in various human carcinomas and is suggested to be a potential oncogene. To clarify the potential role of Aurora-A in human gastric carcinoma, we examined the amplification and expression in both tumor cell lines and primary carcinoma. We examined the amplification and overexpression of Aurora-A in 9 gastric carcinoma cell lines and 88 primary gastric carcinomas using Southern and Northern blot analysis, and confirmed a protein expression by immunohistochemical staining. We also investigated the relationship between Aurora-A overexpression and clinicopathological features of the tumors. Aurora-A amplification and overexpression was observed in 29% and 44.4% of cell lines and 12.5% and 41% of primary carcinomas, respectively. There was discordance between gene amplification and transcript expression, since in a previous study DNA amplification was the main mechanism for Aurora-A activation. Aurora-A overexpression exhibited significant association with increasing age and differentiated type gastric carcinoma. It was also detected in early stage gastric cancer as well as in gastric intestinal metaplasia, which is considered as a common precursor lesion for the differentiated type gastric carcinoma, and severe dysplastic cells showed stronger protein expression. We concluded that Aurora-A overexpression may well be involved in differentiated type gastric carcinogenesis. Further evaluation of the possible roles of Aurora-A and the regulation of Aurora-A expression in malignant cells will be critically important for the development of new strategies aimed at controlling the growth of malignant cells.

The prognostic significance of overexpression of the decoy receptor for Fas ligand (DcR3) in patients with gastric carcinomas.

BACKGROUND: The FasL-Fas system has an important role in mediating immune-cytotoxic killing of cells such as virus-infected or tumor cells. It was recently reported that there is a soluble decoy receptor (DcR3), which binds to FasL and inhibits FasL-induced apoptosis, and certain tumors may escape FasL-dependent immune-cytotoxic attack by expressing a decoy receptor that blocks FasL. We evaluated whether DcR3 has clinical relevance in actual human gastric cancers. METHODS: : The expression of DcR3 was investigated by Northern blot analysis in a series of 84 primary gastric carcinomas and compared with clinicopathological features and prognosis. The DcR3 expression level was analyzed and quantified densitometrically. The location of DcR3 mRNA in gastric carcinoma tissue was detected by in situ hybridization. RESULTS: The frequency of DcR3 overexpression was 26% (22 of 84 surgical specimens). The DcR3 expression level was significantly associated with lymph node metastasis and pathological stage, but did not correlate with tumor size, metastatic status, or histological type. In situ hybridization demonstrated that DcR3 mRNA was expressed in tumor cells. When the patients were followed up for 63 months, DcR3 overexpression was found to be associated with a significantly shortened duration of overall survival compared with findings in patients having normal DcR3 expression. CONCLUSION: The DcR3 decoy receptor for FasL may be involved in the progression of gastric cancer. Further evaluation of these possible roles of DcR3 and the regulation of DcR3 expression in malignant cells will be critically important for the development of new strategies for controlling the growth of malignant cells that escape host immune surveillance.