Diagnostic accuracy of combination of assays for immunosuppressive acidic protein and carcinoembryonic antigen in detection of recurrence of gastric cancer

Significance of serum and tissue carcinoembryonic antigen for the prognosis of gastric carcinoma patients

BACKGROUND AND OBJECTIVES

Carcinoembryonic antigen (CEA) has been widely accepted as a tumor marker useful in the diagnosis and management of colorectal carcinoma. When CEA levels are positive in patients with gastric carcinoma, they could be useful prognostic indicators. The value of CEA as a tumor marker for gastric carcinoma, however, remains a matter of controversy. The purpose of this study was to determine whether preoperative serum CEA value and tissue CEA staining are useful prognostic indicators for gastric carcinoma.

METHODS

We measured preoperative serum CEA levels by radioimmunoassay and stained tissue CEA production by tumor cells from gastric carcinomas using immunohistochemical staining in patients with gastric carcinoma.

RESULTS

The patients with preoperative serum CEA levels >10.0 ng/mL had a more prominent serosal invasion, much more lymph node involvement, more advanced stage and more poorly differentiated than did the patients with preoperative serum CEA levels <5.0 ng/mL. The survival rate of patients with serum CEA levels >10.0 ng/mL was poorer than those of patients with serum CEA levels between 5.0 and 10.0 ng/mL, and those of patients with serum CEA levels <5.0 ng/mL (P < 0.05). The preoperative serum CEA levels and tumor CEA-positivity were correlated (P < 0.05). In patients with lymph node metastases, the CEA-positivity (78.0%) was higher than in patients without lymph node metastasis (63.2%) (P < 0.05). A correlation was also found between the depth of tumor invasion and tissue CEA-positivity (P < 0.001). The postoperative survival rate was significantly better in the CEA-negative staining group (78.0%) than in the CEA-positive staining group (60.0%).

CONCLUSIONS

These data suggest that preoperative serum CEA levels and staining for CEA in gastric carcinoma tissue sections may have a predictive value in determining prognostic information for patients with resectable gastric carcinoma.

Establishment and analysis of biological characteristics of a human duodenal carcinoma cell line, WDC-1

BACKGROUND

Duodenal carcinoma is very rare and its culture cell lines have rarely been established.

METHODS

Tumor cells separated from a surgically resected primary tumor of duodenal carcinoma were put into culture. The patient was an 81-year-old female and had metastatic lymph nodes. We investigated the biological characteristics of the culture cells including in vitro cell kinetics, karyotype, expression of tumor markers and integrins and tumorigenicity and histology in nude mice.

RESULTS

A new cell line, designated WDC-1, was established. This duodenal carcinoma cell line proliferated in a monolayered sheet with a doubling time of 50 h. The histological findings of the xenograft in nude mice were similar to those of the primary tumor. WDC-1 cells produced carcinoembryonic antigen and expressed 1 integrin and very late antigen (VLA)-4d in vitro.

CONCLUSIONS

A duodenal carcinoma cell line was established, which is rare and may contribute to progress in understanding the biological features of duodenal cancer.

Prognostic role of immunosuppressive acidic protein in advanced ovarian cancer

OBJECTIVE

Our purpose was to investigate immunosuppressive acidic protein in the prognostic characterization of advanced ovarian cancer.

STUDY DESIGN

Serum levels of immunosuppressive protein were prospectively measured in 80 patients with untreated ovarian carcinoma. To evaluate the prognostic significance of immunosuppressive acidic protein levels, cutoff points were studied every 50 micrograms/ml between 450 and 1350 micrograms/ml.

RESULTS

Pretreatment immunosuppressive acidic protein levels were not significantly associated with stage, histotype, grade of differentiation, postoperative residual tumor, and response to chemotherapy. The most significant association with survival was observed at a cutoff value of 1100 micrograms/ml (p = 0.0089). In the univariate analysis for overall survival, International Federation of Gynecology and Obstetrics stage and immunosuppressive acidic protein status were found to have a role in predicting ovarian cancer prognosis. In the multivariate analysis only immunosuppressive acidic protein status was significantly associated with survival. A statistical correlation was found between serum levels and overall survival (p = 0.0104, chi 2 6.56), including immunosuppressive acidic protein as a continuous variable.

CONCLUSION

Our data suggest that immunosuppressive acidic protein assay is a potentially useful tool in the prognostic characterization of advanced ovarian cancer.

Clinical significance of quantitative analysis of carcinoembryonic antigen assessed by flow cytometry in fresh human gastric cancer cells

The expression of carcinoembryonic antigen(CEA) on tumor cells freshly excised from 51 patients with gastric cancer was studied using flow cytometry. The expression of CEA by flow cytometry was more quantitative than that by immunohistochemical staining. There was no relationship between the fluorescence intensity assessed by flow cytometry and serum CEA levels, except for patients with a high titer of serum CEA. The patients with high grade CEA expression on tumor cells by flow cytometry had poor prognoses, compared to patients with low CEA expression in undifferentiated gastric cancer. Thus, it is suggested that the quantitative CEA expression on tumor cells by flow cytometry could be a useful prognostic marker in postoperative gastric cancer patients.

Expression of carcinoembryonic antigen in fresh human gastric cancer cells assessed by flow cytometry

The expression of carcinoembryonic antigen (CEA) by tumor cells from freshly excised human gastric cancers was investigated using flow cytometry (FCM). Highly purified fresh human cancer cells were obtained from solid tumors in 20 patients and from malignant ascites in 6 patients. Thirteen of the 26 tumors were positive for CEA by FCM. CEA expression was more common in well-differentiated tumors than in poorly differentiated tumors. CEA expression was investigated by both FCM and immunohistochemistry in 9 patients, and the two methods agreed in 8 of them. However, quantitative evaluation of CEA expression could only be performed by FCM and not by immunohistochemical staining. FCM could analyze the expression of CEA not only on the cell membrane but also in the cytoplasm, by using gastric cancer cells with or without Triton X-100 treatment. Thus, this study showed that CEA expression can be determined and evaluated quantitatively by FCM.

Natural killer activity and serum immunosuppressive acidic protein levels in esophageal and gastric cancers

The natural killer (NK) activity of peripheral blood mononuclear cells and serum immunosuppressive acidic protein (IAP) levels were examined in patients with esophageal or gastric cancer, before and after surgery. Patients with stage IV esophageal or stage IV gastric cancer had significantly lower NK activity (39.5 +/- 14.8% and 37 +/- 11.6%, respectively), and also higher serum IAP levels (778 +/- 264 micrograms/mL and 633 +/- 156 micrograms/mL, respectively), than the corresponding control values (50 +/- 5.6% and 375 +/- 26 micrograms/mL, respectively). Patients with esophageal or gastric cancer who underwent curative resection had high NK activity (54.8 +/- 11.6% and 54.8 +/- 8.0%, respectively), and low IAP levels (471 +/- 116 micrograms/mL and 490 +/- 42 micrograms/mL, respectively), compared with those who underwent non-curative resection. Patients who underwent non-curative resection had lower NK activity and higher serum IAP levels than those who underwent curative resection, even 1 month after surgery. Mononuclear cells in the regional lymph nodes and tumor specimens showed significantly lower NK activity than those in the peripheral blood and spleen. Thus, NK activity and the IAP level reflected the immunocompetence, clinical course, and surgical curability of those patients. NK cells appeared not to have any significant antitumor activity in the regional lymph nodes or in the tumor itself, although they were still active in the peripheral blood.

CA72-4 compared with carcinoembryonic antigen as a tumour marker for gastric cancer

Serum levels of a newly identified, tumour-associated antigen, CA72-4, were measured in 86 patients with histologically proven gastric carcinoma. Preoperative levels of CA72-4 in serum tended to be higher with increased dissemination of the cancer. Elevated levels of CA72-4 (above 5.0 U/ml) were significantly more frequent than those of carcinoembryonic antigen (CEA) (above 5.6 ng/ml) in patients with stage III or IV (P less than 0.01) carcinoma, in patients with Borrmann type 4 (P less than 0.01), and in patients with peritoneal metastasis (P less than 0.01). No correlation was seen between serum levels of CA72-4 and those of CEA. Serum levels of CA72-4 were lower 1 month after gastrectomy in 25 of 39 patients with resected cancers. In each of 4 patients with recurrence, lower levels of CA72-4 after gastrectomy were replaced by elevated levels on detection of the recurrence of cancer. These results indicate that CA72-4 is highly specific to gastric cancer and may be more reliable as a tumour marker than CEA for gastric cancer.