Further investigations of immunoreactive carcinoembryonic antigen (CEA) in colorectal cancer patients--with particular emphasis on the correlation between immunoreactive CEA levels in tissue, feces and blood

Tumor Cytosol Carcinoembryonic Antigen as Prognostic Parameter in Non-small Cell Lung Cancer

Aims and Background

Carcinoembryonic antigen (CEA) belongs to a family of cell surface glycoproteins. Its level in serum has a significant value for the follow-up and treatment of patients with malignancies. The aim of this study was to correlate the concentration of tumor cytosol CEA (cCEA) with tumor size, patient age and sex, clinical stage, lymph node metastases, and overall survival rate in primary non-small cell lung carcinoma (NSCLC).

Methods and Study Design

The cCEA levels were determined in 76 NSCLC patients by luminescence assay (LIA) and radioimmunoassay (RIA).

Results

A strong correlation between LIA and RIA assay results was found (r = 0.992). No correlation was observed between serum CEA and cCEA levels. Tumors smaller than 3 cm had significantly higher cCEA levels than larger tumors, but when a logistic modeling process was applied this difference was not significant (P = 0.038). Histologically well-differentiated tumors also showed a significantly higher expression of cCEA (P <0.05). In addition, patients without lymph node involvement had higher cCEA levels than patients with tumor-positive lymph nodes (P <0.05). Univariate statistical analysis revealed that the risk of lymph node metastases was 1.8-fold higher in patients with low cCEA levels than in patients with higher levels, taking the median value as cutoff (P = 0.04, Kruskal-Wallis test).

Conclusions

According to the results of our study, patients with overexpression of cCEA may have a better prognosis than those with low cCEA expression. cCEA might therefore be considered a good prognostic parameter as well as a prognostic factor independent of the traditional parameters for lymph node metastases.

Carcinoembryonic antigen (CEA) measurement during follow-up for rectal carcinoma is useful even if normal levels exist before surgery. A retrospective study of CEA values in the TME trial

BACKGROUND

Carcinoembryonic antigen (CEA) as a marker in the follow-up after curative resection of colorectal carcinoma (CRC) is often omitted from follow-up despite guideline recommendations. One reason is the assumption that when a normal CEA value exists before curative resection of CRC, it will neither rise during follow-up. This study investigates this relationship.

METHOD

Data were derived from a study initiated to evaluate treatment regimes for rectal carcinoma (Dutch TME trial, n=1861) from which 954 were eligible for analysis. Recurrent disease occurred in 272 of these patients (29.5%). The pre-operative CEA value was compared to CEA values during follow-up, using threshold values of 2.5 and 5.0 ng/ml.

RESULTS

Normal pre-operative CEA values were present in 63% (CEA<5.0) and 39% (CEA<2.5) of patients with recurrent disease. Patients with a normal pre-operative CEA and recurrent disease had elevated CEA values during follow-up in 41% (CEA<5.0), 50% (CEA<2.5) and in 60% with both threshold values when the last measurement was done within 3 months before recurrent disease was diagnosed.

CONCLUSION

A normal pre-operative CEA is common in patients with rectal carcinoma. CEA does rise due to recurrent disease in at least 50% of patients with normal pre-operative values. Serial post-operative CEA testing cannot be discarded based on a normal pre-operative serum CEA.

Proliferative activity and malignancy in human gastric cancers. Significance of the proliferation rate and its clinical application

The authors sought useful indicators for predicting the proliferative activity of human gastric cancer and attempted to evaluate its clinical significance. One hundred seventy-two patients with gastric cancer were entered in this study. All patients received bromodeoxyuridine at 200 to 1000 mg/body before laparotomy. Cell kinetics studies using the migration chase method were done for 56 patients, and the DNA synthesis time (Ts) was found to be prolonged in tumors, especially in aneuploid tumors, compared with normal mucosae. Ts correlated with bromodeoxyuridine (BrdUrd) labeling indices (LI) (r = 0.453, P less than 0.0005) and DNA indices (DI) (r = 0.534, P less than 0.0005). Thus, the DNA synthesis time was significantly prolonged in the tumors having a high S-phase fraction or DNA aneuploidy. The result of multivariate analysis indicated that LI/DI was the most potent indicator for predicting the proliferation rate (PR), which was calculated by the formula LI/Ts, and correlated significantly with PR (r = 0.863, P less than 0.0001). As was clear from the result of Cox's proportional hazard model, the predicted proliferation rate (pPR) was the most notable factor for the prognosis because pPR correlated clinically with metastasis, such as that to liver and lymph nodes. The patients with a high pPR (greater than 10%) had a worse prognosis (4-year survival rate: 16.3%) than did those with a low value (less than 10%) (4-year survival rate: 85.1%). In vitro pPR obtained by in vitro BrdUrd labeling of the specimens obtained at biopsy correlated significantly with the in vivo pPR (r = 0.960, P less than 0.0001). The authors concluded that the proliferation rate was the most important factor in judging the malignancy of human gastric cancers and that this rate should be most helpful in determining the treatment and evaluating the prognosis of individual patients.

Contents of tissue CEA and CA19-9 in colonic polyp and colorectal cancer, and their clinical significance

In precancerous states or early cancer, the serum levels of tumor markers are almost not detectable. Therefore, the tissue contents of CEA and CA19-9 were measured in 48 colonic polyps, 8 colorectal cancers and 5 normal colonic mucosa. These tissue specimens were obtained by endoscopic polypectomy, surgery or autopsy, and homogenated in normal saline (10 ml/wet g of tissue). After centrifugation, the supernatant was assayed by enzyme or radioimmunoassay. There was no correlation between serum levels and tissue contents of CEA or CA19-9 in colonic adenomas and colorectal cancers. The mean contents of tissue CEA and CA19-9 in colonic polyp and colorectal cancer were significantly higher than normal colonic mucosa, and the highest contents of CEA and CA19-9 were found in colorectal cancer. The contents of tissue CEA and CA19-9 in cancerous regions were markedly increased as compared with noncancerous regions. In adenomas, there was a relationship between the degree of histological dysplasia and the tissue content of CEA. Relationships were also found between macroscopic findings and tissue tumor markers in adenomas. These results suggest the possibility that the measurement of tissue tumor markers may be useful for borderline colonic lesions.

Role of the spleen on immunosuppression in esophageal and gastric cancer

To elucidate the role of the spleen on immunosuppression of gastric and esophageal cancer, suppressor cell activities of spleen cells (SCs), splenic vein lymphocytes (SVLs) and peripheral blood lymphocytes (PBLs) were investigated. Concanavalin-A induced suppressor cell (Con-AS) activity of SCs was significantly higher in patients with gastric cancer than in those with benign diseases. Higher Con-AS activity of SCs was observed in esophageal cancer patients with tumors located in the lower portion of the esophagus. In comparison with suppressor activities of SCs and SVLs, the decrease of the predominance of suppressor precursors in SCs and the increase of the spontaneously activated suppressor cells in SVLs were noted with the advance of the tumors. Culture supernatants from splenic adherent cells significantly induced suppressor cell activities as well as did sera from splenic venous blood. From these results, it is concluded that the generation of suppressor precursors in the spleen is dependent on the location of tumors and that the maturation of suppressor cells occurs in the spleen by factors released from splenic adherent cells, then migrates into the peripheral blood.