High expression of tumor‐associated antigen RCAS1 in pancreatic ductal adenocarcinoma is an unfavorable prognostic marker

Abstract

RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is a recently identified human tumor-associated antigen expressed on various cancer cells. It is thought that tumor cells evade immune surveillance by expression of RCAS1, which induces apoptotic cell death in receptor-positive immune cells. The purpose of our study was to investigate the relation between RCAS1 expression and the clinicopathological variables and clinical outcome in patients with pancreatic adenocarcinoma. Immunohistochemical analysis for RCAS1 was performed on paraffin-embedded specimens of 80 patients (mean age, 62 years) who underwent surgical resection for pancreatic adenocarcinoma. Of the 80 specimens, 77 (96%) were positive for RCAS1. No significant correlation was found between RCAS1 expression and age, gender, depth of invasion, tumor diameter, surgical margin, lymphatic invasion, venous invasion or histopathological grading. Borderline correlations between RCAS1 expression were noted for lymph node metastasis and stage (p ‫؍‬ 0.0608 and 0.0934, respectively). RCAS1 expression was very frequently observed and the survival of patients with high RCAS1 expression was significantly shorter than that of those with low expression (p ‫؍‬ 0.0012). Multivariate analysis using the Cox regression model indicated that high RCAS1 expression was an independent prognostic factor (risk ratio, 3.090; p ‫؍‬ 0.0090). These results suggested that RCAS1 might be a significant tumor marker for pancreatic adenocarcinoma and an unfavorable predictor for prognosis of patients who have undergone surgical resection. © 2002 Wiley-Liss, Inc. Key words: RCAS 1; tumor-associated antigen; pancreatic carcinoma; immunohistochemical analysis; prognostic factorPancreatic cancer has a very poor prognosis and is one of the most common malignancies. 1 Tumor resection is performed in 9 -36% of patients and the 5-year survival rate of patients who have undergone resection is 19 -24%. 2,3 Many attempts have been made to improve the outcome of patients' survival. Recently, significant improvements in survival have been reported compared to the survival expected from series in the 1980s. 4 -9 The mechanisms responsible for the aggressiveness of this disease are not completely understood, therefore, it is very important to find novel molecular markers that are expressed frequently and predominantly in pancreatic cancer. Furthermore, the identification of factors that significantly correlate with clinicopathological features or poor prognosis is of importance in selecting patients who would benefit from radical treatment and to understand the biological characteristics of the disease.A number of biologic markers that specifically predict the progression and prognosis of pancreatic cancer have been reported, including the K-ras oncogene, 10 -12 tumor suppressor DPC4, [13][14][15][16] and vascular endothelial growth factor (VEGF). 17 Recently, the human tumor-associated antigen RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) has been recognized as another ...

Diagnostic Markers of Ovarian Cancer by High-Throughput Antigen Cloning and Detection on Arrays

“…Using two-dimensional followed by mass spectrometry, autoantibodies against eIF-5A were detected in sera from patients having lung adenocarcinoma (45). RCAS1 is overexpressed in many cancers, such as uterine, breast, and pancreatic cancers (35,46,47). As indicated by the broad overexpression of RCAS1 in human cancers, some of the antigens we have identified may not be specific to ovarian cancer.…”

Expression of Tumor-Associated Membrane Antigen, RCAS1, in Human Colorectal Carcinomas and Possible Role in Apoptosis of Tumor-Infiltrating Lymphocytes

“…Expression of RCAS1 correlates with invasion or progression in several carcinomas (2,9,10). In addition, RCAS1 expression is associated with poor prognosis in uterine, lung, gallbladder, pancreas, and esophageal carcinoma (11)(12)(13)(14)(15). Although previous studies suggested that RCAS1 is also expressed in colorectal carcinoma cells, the relationship between RCAS1 expression and prognosis in colorectal carcinomas is not known at present.…”

Tumor-Associated Antigen Recognized by the 22-1-1 Monoclonal Antibody Encourages Colorectal Cancer Progression under the Scanty CD8+ T Cells

“…Cell surface staining with monoclonal antibody 22-1-1 and the presence of CD8 + T cells are both reported to be prognostic factors in a variety of cancers (9,10,12,23). In human colorectal cancer, the infiltration of CD8 + T cells into the cancer cell nest is a reliable positive prognostic indicator (21).…”

“…Immunohistochemistry revealed positive cell surface staining with 22-1-1 in a large number of different tumor tissues. In some tumor entities, 22-1-1 staining correlated with poor clinical prognosis (9,10). The physiologic molecular function of RCAS1 in humans, however, remains controversial.…”