Carcinoembryonic antigen in gastric juice collected during endoscopy. Value in detecting high-risk patients and gastric cancer

CEA Levels in Gastric Juice in Precancerous Conditions and Cancer

First described in 1965 as a specific antigen for cancer of the colon, CEA is now considered to be an antigen associated with many types of malignant neoplasia, although the CEA-Test's role in clinical routine has yet to be clearly defined.

In the present study CEA levels in gastric juice were measured in subjects with gastric carcinoma (n = 25) and with benign gastric lesions (n = 171). CEA was significantly (p < 0.05) higher in patients with gastric carcinoma (GC) than in subjects with benign gastric lesions, other than chronic atrophic gastritis (CAG) associated with intestinal metaplasia (IM). In this latter condition CEA levels were similar to those in patients with GC.

These results suggest that the assay of CEA in gastric juice could be included in the diagnostic program for gastric cancer and its precursors with the aim of assessing its utility as risk indicator in the management of precancerous conditions and lesion.

Immunohistochemical Detection of Carcinoembryonic Antigen (CEA) in Non-Cancerous and Cancerous Gastric Mucosa

Carcinoembryonic antigen (CEA) was stained by the PAP immunoperoxidase method in cancerous and non-cancerous gastric mucosa of 40 patients (25 non-cancerous dyspeptic patients and 15 patients with gastric carcinoma). The pattern of CEA localization was apical or membranous-cytoplasmic and immuno-reactivity was mild (+), moderate (++) or intensive (+++). No CEA immunoreactivity was detected in normal gastric mucosa whereas it was marked in gastric mucosa of non-cancerous dyspeptic patients with chronic atrophic gastritis and dysplasia (intense). In patients with superficial gastritis and epithelial hyperplasia it was mild or absent. The CEA localization pattern was also apical in non-cancerous dyspeptic patients with microscopic changes, e.g. superficial or chronic atrophic gastritis, epithelial hyperplasia and dysplasia, and in non-cancerous mucosa and cancerous tissue of patients with well (G1) and moderately (G2) differentiated adenocarcinoma.

An endogastric capsule for measuring tumor markers in gastric juice: an evaluation of the safety and efficacy of a new diagnostic tool

BACKGROUND

In gastric juice, high levels of the carcinoembryonic antigen (CEA) and the carbohydrate antigen 19-9 (CA 19-9) have been found to correlate with precancerous lesions and gastric cancer. So far, sampling of gastric juice has required upper endoscopy. In place of this invasive procedure, we investigated a new tool for the quantitation of tumor markers in gastric juice.

MATERIALS AND METHODS

The study population consisted of healthy controls and consecutive subjects with suspected gastric cancer or dyspepsia/epigastric distress. Patients were asked to swallow a small gelatine capsule (14 mm in length and 5 mm in diameter) containing a pierced plastic cover and surrounding a piece of absorbent paper. The capsule was left in the gastric cavity for 60 min to allow saturation of the absorbent paper with gastric juice. A 45-50 cm length of nylon thread connected to the inner capsule was used to remove the device from the gastric cavity. After processing the absorbent paper for radioimmunoassay, CEA and CA 19-9 levels were correlated to the findings of upper endoscopy and biopsies of gastric mucosa or suspected lesions.

RESULTS

The endogastric capsule did not cause any side-effects and 62 participants were fully compliant to the procedure. Assessable gastric juice samples were taken from 23 patients with gastric cancer, 15 patients with intestinal metaplasia or dysplasia, 12 patients with gastritis and 12 controls without gastric diseases. In the 12 samples of gastric juice from control patients, mean values of CEA and CA 19-9 were 1.1 +/- 0.9 ng/ml and 16 +/- 7.5 ng/ml, respectively. The mean levels of both markers were found to increase according to the severity of gastric lesions and in patients with cancer, mean CEA and CA 19-9 levels were 513 +/- 627 ng/ml and 545 +/- 510 ng/ml, respectively. Patients with precancerous lesions and cancer showed higher levels of CEA and CA 19-9 than patients with normal findings or gastritis (P <0.001).

CONCLUSIONS

The endogastric capsule is a simple, non-invasive tool for the measurement of CEA and CA 19-9 levels in gastric juice. These values may discriminate between normal or minor pathologic changes and precancerous lesions or carcinomas. Further investigations are warranted, since this may represent a new method for gastric cancer screening.

CA 50 determination in body fluids: can we screen patients at risk for gastric cancer?

CA 50 (a tumor-associated gangliosidic antigen) levels have been determined by an RIA test in serum, gastric juice and urine of patients undergoing upper gastrointestinal tract endoscopy: 22 control subjects (no macroscopic or microscopic lesions), 29 patients with chronic atrophic gastritis, 20 with epithelial dysplasia and 16 with gastric cancer entered the study. Gastric juices were also tested for pH, protein concentration and specific gravity, urines for protein concentration and osmolarity. Serum and gastric juices were also tested for CEA levels and the results obtained with the two markers compared. In patients with gastric cancer, CA 50 gastric juice levels were statistically higher than in controls; a wide overlap was however present among groups, and sensitivity and specificity were respectively 38% and 85% for serum and 69% and 82% for gastric juice. Sensitivity and specificity were respectively 23% and 89% for CA 50 determination in urines. In this case, no statistically significant difference was observed between gastric cancer and control patients. A trend toward higher median values was observed in advanced with respect to early gastric cancer. A correlation was found between gastric juice and serum CA 50 levels, as well as between serum and urine levels of the marker. A correlation was also observed between CA 50 values and protein concentration in gastric juice and with osmolarity in urines. Overall, CA 50 levels were statistically higher in patients with intestinal metaplasia than in those who did not present the lesion. Increased CA 50 gastric juice levels are also observed in patients with chronic atrophic gastritis and epithelial dysplasia. CA 50 gastric juice and urine levels appear to be dependent, at least in part, on the concentration of the fluid.

Carcinoembryonic antigen measurement in gastric juice. Discovery and elimination of an inhibitory interference

In biological fluids containing mucus an inhibitory interference on CEA measurement was found. The interference could be eliminated.

Tumor marker radioimmunoassays in gastric juice. Methodologic drawbacks due to pH variations

Conflicting data have been reported on tumor marker determination in gastric juice. In the present study the effect of pH variations on both antibody-antigen binding and the immunologic stability of the antigen were evaluated for the radioimmunoassay of carcinoembryonic antigen, CA19-9, tissue polypeptide antigen, and ferritin. A significant inhibition of antibody-antigen binding was constantly found in acidic conditions. Antigen concentration was lower in acidified than in untreated samples, possibly due to the carryover of acidity in the incubation mixture. Neutralization of acidified samples partly improved recovery of carcinoembryonic antigen and CA19-9. Tissue polypeptide antigen and ferritin were not recovered by neutralization in samples with pH less than 4.5, suggesting an irreversible damage of the immunologic characteristics of the two antigens. From the present data we conclude that an accurate validation of methods and a rigorous standardization of sample collection are mandatory for tumor marker determination by radioimmunoassay in gastric juice.

CA 19-9 determination in gastric juice: role in identifying gastric cancer and high risk patients

Gastric juice CA 19-9 levels were determined in 23 patients affected by gastric cancer, in 57 patients affected by chronic atrophic gastritis of different severities and in 55 'healthy' controls, undergoing endoscopy for upper gastrointestinal tract symptoms. Increased CA 19-9 levels were documented in chronic atrophic gastritis patients as well as in gastric cancer patients, the difference with respect to controls being statistically significant. However, there was considerable overlap between different groups. In particular, gastric cancer patients had CA 19-9 levels similar to those detected in moderate and severe chronic atrophic gastritis. CA 19-9 correlated with gastric juice pH and CEA concentration. Its values were not influenced by the patients' age or sex. In our opinion CA 19-9 gastric juice determination, although not useful in singling out patients harboring gastric neoplasia, may be used in identifying patients 'at risk' for gastric cancer and who might then be referred for more accurate investigations.

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.

Early and advanced gastric cancer during follow-up of apparently benign gastric ulcer: significance of the presence of epithelial dysplasia

One hundred and forty-four patients with apparently benign gastric ulcer were endoscopically followed up in order to evaluate the outcome of the lesion. Particular attention was given to: (a) detect possible delay in diagnosing gastric cancer; (b) ascertain the frequency of association with epithelial dysplasia; (c) establish the role of markers, such as serum pepsinogen group I (PGI), and gastric juice CEA in predicting gastric ulcer evolution. Endoscopic and bioptic check-ups were carried out during the first year at 3, 6 and 12 months after endoscopic healing of the ulcer, and then at every symptomatic recurrence. Ten patients (6.9%) were found to present histological evidence of malignancy (within 3 months in six cases, between 6 and 12 months in three cases, and after 41 months in the rest). Four cases were early gastric cancers, and six had shown dysplastic changes of the mucosa at the edge or scar of the ulcer. Serum PGI levels were not significantly different in gastric cancer patients, while gastric juice CEA levels were sharply increased compared to those of gastric ulcer patients: nine out of ten patients had values above normal range. These data suggest that: (a) there may be some delay in diagnosing gastric carcinoma, and gastric ulcer patients should be controlled routinely more than once; (b) the presence of dysplasia indicates the need for prolonged follow-up, because of the high risk of association with or evolution into gastric cancer, and because of the higher number of early gastric cancer detections that this protocol allows; (c) further support in monitoring patients "at risk" may be afforded by gastric juice CEA determination.

Perendoscopic gastric pH determination. Simple method for increasing accuracy in diagnosing chronic atrophic gastritis

The endoscopic diagnosis of chronic atrophic gastritis is often underestimated, and most of the procedures adopted to increase diagnostic accuracy are time consuming and complex. In this study, we evaluated the usefulness of the determination of gastric juice pH by means of litmus paper. Values obtained by this method correlate well with gastric acid secretory capacity as measured by gastric acid analysis (r = -0.64, p less than 0.001) and are not affected by the presence of bile. Gastric juice pH determination increases sensitivity and other diagnostic parameters such as performance index (Youden J test), positive predictive value, and post-test probability difference by 50%. Furthermore, the negative predictive value is very high, the probability of missing a patient with chronic atrophic gastritis with this simple method being 2% for fundic and 15% for antral atrophic change. We conclude that gastric juice pH determination, which substantially increases diagnostic accuracy and is very simple to perform, should be routinely adopted.

Evaluation of gastric carcinoembryonic antigen analysis as an aid during screening for gastric neoplasia in atrophic gastritis

The value of gastric juice and tissue carcinoembryonic antigen (CEA) analysis as an adjunct to endoscopic screening for gastric neoplasia was investigated in 61 patients with atrophic gastritis of whom 41 had other (superimposed) gastric lesions: six adenocarcinoma, four carcinoid, 23 regenerative polyps with or without dysplasia and eight fundic, or antral mucosal dysplasia. The gastric concentration of CEA did not differ between patient groups with different superimposed lesions. In these patients the gastric juice CEA concentrations were significantly increased in comparison with those in patients without superimposed lesions (p = 0.002). Gastric juice CEA concentrations above the upper range (+2SD) of those observed in normal controls were found in 40 (98%) of 41 patients with superimposed lesions and in 13 (65%) of 20 patients without such lesions (p = 0.001). At re-examination of 26 patients without neoplasia initially, after a mean interval of 32 months two (without polyps initially), had developed regenerative polyps, one an adenoma, and one an adenocarcinoma. These four had raised gastric juice CEA concentrations at the initial examination.