Immunohistochemical evaluation of nonspecific cross reactive antigen and carcinoembryonic antigen (CEA) in urinary bladder carcinoma

The immunohistochemical expression of CEA in formalin-fixed paraffin sections in urinary bladder carcinomas was compared to the use of polyclonal anti-CEA antiserum (P-CEA), NCA-absorbed anti-CEA (NCA-aCEA) and monoclonal antibody to CEA (M-CEA). The urinary bladder carcinomas examined consisted of 19 cases of transitional cell carcinoma (TCC) and 7 cases of squamous cell carcinoma (SCC). Both TCC and SCC were positive for CEA with the use of P-CEA and NCA-aCEA, and the degree of staining was markedly dependent on the grade of malignancy in TCC. However, the reaction to M-CEA was generally very weak or negative in TCC and SCC. In SCC, the staining reaction was confined to keratinized foci and not found in all malignant tumour cells when polyclonal CEA antiserum was used. These findings indicate that positive reactions seen with conventional CEA antibodies (P-CEA and NCA-aCEA) are possibly related to NCA and that urinary bladder carcinoma may contain relatively more NCA than true CEA.     

Immunohistochemical localization of carcinoembryonic antigen (CEA), CEA-S, and nonspecific cross-reacting antigen (NCA) in carcinomas of lung

Antisera to carcinoembryonic antigen (CEA), to a physicochemical subset of CEA, namely CEA-S, and to nonspecific cross-reacting antigen (NCA) were used for the immunohistochemical localization of these antigens in human bronchogenic carcinomas using a triple layer immunoperoxidase technique. The study is based on an analysis of tumors from 130 patients. CEA, CEA-S, and NCA were all identified in the membrane and/or cytoplasm of neoplastic cells, and a good correlation between the antigens was observed in a majority of tumors. The presence or absence of these tumor-associated glycoproteins appeared to be correlated with the histologic type of the tumors, especially in small cell anaplastic carcinoma and adenocarcinoma, and the degree of histologic differentiation of adenocarcinomas correlated positively with these tumor-associated antigens. Data from this group of patients suggest that analysis of tissue CEA at the time of biopsy or surgical resection may facilitate a more objective interpretation of serial plasma CEA assays.     

Evaluation of plasma carcinoembryonic antigen (CEA) in patients with head and neck cancer: correlation with tissue CEA staining

Forty-five patients with head and neck cancer were the subjects of the study. In most cases, plasma CEA was low and could not provide a significant clinical monitor. Two patients with poorly differentiated epidermoid carcinoma had low plasma CEA levels at the pretreatment stage, but after treatment, the levels tended to be higher because of distant metastasis. Tow other cases exhibiting undifferentiated carcinoma of the maxillary sinus at the pretreatment stage had abnormally high plasma CEA levels of 160 ng/ml and 46 ng/ml. These two patients proved the value of the correlation with cancer therapy and recurrence.     

Immunohistochemical demonstration of tumor-associated antigens in urinary bladder carcinomas using mono- and polyclonal antisera

Keratin was found in more than 90% of transitional cell carcinomas of the bladder in the cytoplasma with polyclonal antibodies. Intensity increased with dedifferentiation. Cytokeratin was detected with monoclonal antibodies in more than 80%. Squamous cell carcinoma of the urinary bladder was always strongly positive for keratin and cytokeratin. CEA was found in 20% of G1 and 40% of G2 and G3 carcinomas of the urinary bladder. The prostatic epithelium markers PSA and PAP were always negative also Ca1.     

Immunohistochemical localization and molecular characteristics of three monoclonal antibody-defined epitopes detectable on carcinoembryonic antigen (CEA)

Three murine monoclonal antibodies (MAbs) reactive to different epitopes on CEA were selected according to their ability to bind to various human tissue sections. The most selective MAb, BW 431/31, bound to the majority of colon carcinomas but only faintly to normal colon mucosa. In addition to the tissues stained by MAb BW 431/31, MAb BW 250/183 reacted with granulocytes, colon mucosa and faintly with pancreatic ducts. The third MAb, BW 374/14, reacted with granulocytes, colon mucosa, strongly with pancreatic ducts and with alveolar and bronchial epithelium. The antigenic determinants recognized by the 3 MAbs in human tissue sections were resistant to formaldehyde fixation and paraffin embedding as well as to periodic acid oxidation and neuraminidase treatment. The last two treatments suggest that the epitopes are protein in nature. Using MAb affinity chromatography, 3 antigen preparations were isolated from a human colon carcinoma xenograft with an approximate molecular weight of 180 kd. These preparations were shown to bear the epitopes from each of the MAbs and from a polyclonal antiserum specific for purified CEA. Furthermore, the ability of MAb BW 431/31 to localize its antigenic determinant in vivo on a human colon carcinoma xenograft is evaluated and its possible application in the patient is suggested.     

Clinical use of carcinoembryonic antigen (CEA) determination]

The carcinoembryonic antigen (CEA) is a tumor marker defined by specific heterologous antisera. Elevated levels of circulating CEA have been detected by radioimmunoassay in 20-90 per cent of cases of colorectal carcinomas depending on the degree of tumor spread. The fact that elevation of CEA level can also be observed in other types of carcinomas and in several non malignant conditions greatly limit the value of the CEA test for the early diagnosis of colorectal carcinoma. Thus, the CEA assay should not be used as a screening test for cancer. Repeated CEA measurements, however, appear to be of importance for the evaluation of tumor resection and the detection of tumor recurrence. The only localized tumors known to produce elevation of CEA above the levels observed in non malignant diseases are carcinomas of the large bowel and the pancreas. In carcinomas derived from other organs a marked increase of CEA level is always associated with the presence of distant metastasis. Therefore at the present time the clinical applications of the CEA radioimmunoassay should be limited to the differential diagnosis of patients with suspicion of primary colorectal or pancreatic carcinoma, to the detection of distant metastasis in other types of carcinomas and to the post operative follow up of patients who had elevated levels of CEA before surgery. Well-controlled studies are still needed to determine if therapeutic decisions based on CEA results can lead to improved survival.     

The correlation between the productive capacity of carcinoembryonic antigen (CEA) and prognosis in gastric cancer

In 130 resected specimens of gastric cancer, CEA was stained by the enzyme labeled antibody method. The positive rate of CEA stain was 74.6% and higher in well differentiated adenocarcinoma, mucinous adenocarcinoma, and signet ring cell carcinoma. The positive rate was lower in poorly differentiated adenocarcinoma. The 5-year survival rate was higher in the CEA (-) group in stage II, and higher in the CEA (+) group in stage III (p less than 0.05) and stage IV. This suggests that the correlation of the CEA stain and the prognosis varies with the stage of cancer.     

Expression of carcinoembryonic antigen (CEA) and nonspecific crossreacting antigen (NCA) in gastrointestinal cancer; the correlation with degree of differentiation.

In spite of its reputation as a tumour marker, little is known about the function of carcinoembryonic antigen (CEA). We examined the mRNA expression of CEA and NCA in 26 gastric and 14 colorectal cancers together with adjacent morphologically normal mucosae. There was no significant difference between the CEA mRNA levels of colorectal cancer and adjacent mucosa, whereas the CEA mRNA levels were significantly elevated in gastric cancer compared with normal gastric mucosa. The expression of NCA, on the other hand, was more cancer-specific and was significantly up-regulated in both gastric and colorectal cancers compared with the corresponding normal mucosae. No correlation was found between the mRNA level and plasma CEA value. No significant up-regulation was recognised in the node positive cancer, cancer with distant metastasis, or the metastatic tissues themselves. Marked diversity in the degree of differentiation in gastric cancer tissues, however, resulted in varied expression of the CEA gene family, compared with the constantly high expression found in colorectal cancer. Further analysis revealed significant up-regulation of NCA in well and moderately differentiated gastric cancers over poorly differentiated cancers, suggesting that NCA might have roles in differentiation.     

Portal blood level of carcinoembryonic antigen (CEA) in colorectal cancer: correlation between tumor CEA content and immunohistochemical staining

From tumors obtained from 87 patients with colorectal cancer during operation, portal blood levels of carcinoembryonic antigen (CEA) in drainage vein were measured and evaluated, according to the disease stage and histology, in comparison with cancerous tissue CEA in the extracts of surgical specimens and immunohistochemical analyses graded according to localization patterns and immunoreactivity; thereby trying to clarify a mechanism for the elevation of peripheral CEA levels. Mean value of portal CEA was higher than that of peripheral CEA at each stage of diseases, with a marked elevation by operative procedures. Although no significant correlation was observed between CEA contents of cancerous tissue (ng/g wet weight) and peripheral CEA levels, a close correlation was observed between portal CEA levels and cancerous CEA contents. A high CEA value was noted in moderately differentiated adenocarcinoma, according to cell differentiation (p less than 0.05). High portal CEA level was recognized in those with stain of cytoplasm and stroma, besides cancerous tissue CEA content, by means of immunopathochemical localization pattern, but a more significantly elevated CEA level was observed in those with the cancer pathologically infiltrating over muscle layers. The present study suggests that the route of CEA transfer from tumor to portal blood can be an important contributing factor to the control of peripheral CEA level.     

Faecal carcinoembryonic antigen (CEA) in patients with large bowel cancer

The possibility that faecal CEA may be a more useful measurement than serum CEA for the detection of large bowel cancer has received very little attention. For this reason faecal CEA was measured before and after tumour resection in colorectal cancer patients and in a variety of control subjects. CEA was extracted from faeces by a new method with 3M KCl and assayed by an EIA technique utilising two monoclonal antibodies. Mean +/- SE faecal CEA in 32 cancer patients was 4.15 +/- 1.17 micrograms/g preoperatively. Values were not related to either stage of disease or serum CEA and they fell to 0.83 +/- 0.34 micrograms/g (n = 20) following tumour resection (P less than 0.05). Mean +/- SE faecal CEA in 34 control patients with no known colorectal disease was 0.94 +/- 0.49 micrograms/g which was significantly lower than in the cancer patients (P less than 0.05). Furthermore faecal CEA in 25 patients with non malignant colorectal disease was 1.44 +/- 0.63 micrograms/g which again was significantly lower than that in the cancer patients. It is concluded that as CEA is present in the faeces of the majority of colorectal cancer patients even at early stages of the disease its measurement here may be more useful for the detection of large bowel cancer than that in serum.     

Epitopes of carcinoembryonic antigen (CEA) defined by monoclonal antibodies

Of 15 anti-CEA monoclonal antibodies, the first 8 were reactive only with CEA, while the remaining 7 antibodies reacted with epitopes commonly expressed on CEA and the normal cross-reacting antigen, NCA. Separate and distinct, conformation-dependent (i.e. susceptible to reduction and alkylation), CEA-associated epitopes were identified using antibodies 1, 2 and 3. Antibodies 4 to 7 defined a series of conformation-independent epitopes which were topographically closely related on the CEA molecule. Antibody number 8 reacted with a separate determinant found on CEA but not NCA, and this also was resistant to reduction and alkylation. Antibody number 9 defined an epitope which was commonly expressed on CEA and NCA. This epitope was conformation-dependent and was the most sensitive to NaIO4. The remaining antibodies, 10 to 15, which also reacted with CEA and NCA, defined an immunodominant region of these molecules since the 6 epitopes were clearly closely related, but not necessarily identical. The findings presented establish a rational basis for the selection of combinations of anti-CEA antibodies for diagnostic and therapeutic purposes.     

Clinical application of carcinoembryonic antigen (CEA) monoclonal antibodies (McAbs)

CEA McAbs, recognizing three different epitopes on CEA molecules, were used to measure serum CEA level in cancer patients by enzyme-immunoassay (EIA). The results, as compared with those using polyclonal antibodies, indicated that the positive rate was higher while the false positivity was lower. Immunohistochemistry of tumour sections showed that the CEA McAbs are bonded to 80-90% of gastrointestinal cancers. Although the normal colon epithelium occasionally reacted with CEA McAbs, other normal tissues did not. After in vivo administration of radio-labeled CEA McAbs to nude mice xenograft with human colon cancer, the radio-isotope was found to be concentrated preferentially in the tumour. The ratio of tumour and normal tissue was 3.6-11.8 after 48 hours following administration. Thus, the CEA McAbs can be used clinically not only for serum CEA determination but also for diagnostic imaging.     

Immunological study of carcinoembryonic antigen (CEA) and a related glycoprotein

A comparison has been made of the immunological properties of CEA (carcinoembryonic antigen) and another perchloric acid-soluble macromolecule which occurs in colonic and certain other carcinomata and which is here termed CEX. By using a variety of antisera it was shown that the two substances share common antigenic groups as well as having characteristic ones of their own. These latter groups have enabled the preparation of (a) antisera which give a gel diffusion line only with CEA and (b) and antiserum which gives a line only with CEX. No immunological difference could be found between CEX and the NGP of Mach or the NCA of von Kleist and Burtin. CEX was found in foetal gut, in plasma and associated with CEA in virtually all the tissues and fluids in which the latter occurs; the two appear to go hand-in-hand and no proof was found that CEX is either less or more cancer specific than CEA—it is merely found in greater quantity; neither substance showed absolute cancer specificity. The usefulness of a radioimmunoassay for CEX is discussed, and also the possibility of interference by CEX in the radioimmunoassay for CEA. Evidence of two molecular species of CEA has been found.     

Immunohistochemical study of carcinoembryonic antigen (CEA) in gastric tumors: correlation with preoperative serum levels, histologic type, and grade of anaplasia of the tumor

The occurrence of carcinoembryonic antigen (CEA) was studied in 45 cases of gastric tumors by the immunoperoxidase technique. CEA-positive staining was found in 48.8% of tumors. A correlation was found between preoperative CEA values and tumor CEA staining. All patients with serum CEA values below 2.5 ng/ml showed CEA-negative staining of tumor. In patients with serum CEA values between 2.6 and 10 ng/ml, the tumors showed a minority of CEA-positive cells; but in patients with serum CEA values above 10 ng/ml, the tumors contained a majority of CEA-positive cells. CEA-positive staining was found in 34.4% of tumors of the diffuse type, and in 75% of tumors of the intestinal type. A high percentage of CEA positivity was seen in well-differentiated tumors (87.7%) compared to the moderately differentiated (69.2%), and to the undifferentiated (28.7%). A faint CEA-positivity was observed in intestinal metaplasia, while normal gastric mucosa was CEA-negative.