Carcinoembryonic antigen in gastric juice as an aid in diagnosis of early gastric cancer

Comprehensive Analysis to Identify MAGEA3 Expression Correlated With Immune Infiltrates and Lymph Node Metastasis in Gastric Cancer

Gastric cancer (GC) is an aggressive malignant tumor and causes a significant number of deaths every year. With the coming of the age of cancer immunotherapy, search for a new target in gastric cancer may benefit more advanced patients. Melanoma-associated antigen-A3 (MAGEA3), one of the members of the cancer-testis antigen (CTA) family, was considered an important part of cancer immunotherapy. We evaluate the potential role of MAGEA3 in GC through the TCGA database. The result revealed that MAGEA3 is upregulated in GC and linked to poor OS and lymph node metastasis. MAGEA3 was also correlated with immune checkpoints, TMB, and affected the tumor immune microenvironment and the prognosis of GC through CIBERSORT, TIMER, and Kaplan-Meier plotter database analysis. In addition, GSEA-identified MAGEA3 is involved in the immune regulation of GC. Moreover, the protein-protein interaction (PPI) networks of MAGEA3 were constructed through STRING database and MAGEA3-correlated miRNAs were screened based on the joint analysis of multiple databases. In terms of experimental verification, we constructed pET21a (+)/MAGEA3 restructuring plasmids and transformed to Escherichia coli Rosetta. MAGEA3 protein was used as an antigen after being expressed and purified and can effectively detect the specific IgG in 93 GC patients' serum specimens with 44.08% sensitivity and 92.54% specificity. Through further analysis, the positive rate of MAGEA3 was related to the stage and transfer number of lymph nodes. These results indicated that MAGEA3 is a novel biomarker and correlated with lymph node metastasis and immune infiltrates in GC, which could be a new target for immunotherapy.

A novel strategy to identify candidate diagnostic and prognostic biomarkers for gastric cancer

Background

Gastric cancer (GC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of GC. The aim of the present study was to screen candidate biomarkers associated with the pathogenesis and prognosis of GC by a novel strategy.

Methods

The expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as “positive”, and the top 5% genes with “positive rate” were filtered out as candidate diagnostic biomarkers in three Gene Expression Omnibus (GEO) datasets. Further, a prognostic risk model was constructed by multivariate Cox regression analysis in GEO dataset and validated in The Cancer Genome Atlas (TCGA). The expression level of candidate biomarkers was determined in serum and serum-derived exosomes of GC patients. Moreover, the effect of biomarkers in exosomes on migration of GC cells was analyzed by transwell assay.

Results

Ten candidate biomarkers (AGT, SERPINH1, WNT2, LIPG, PLAU, COL1A1, MMP7, MXRA5, CXCL1 and COL11A1) were identified with efficient diagnostic value in GC. A prognostic gene signature consisted of AGT, SERPINH1 and MMP7 was constructed and showed a good performance in predicting overall survivals in TCGA. Consistently, serum levels of the three biomarkers also showed high sensitivity and specificity in distinguishing GC patients from controls. In addition, the expression level of the three biomarkers were associated with malignant degree and decreased after surgery in GC patients. Moreover, the expression level of AGT and MMP7 in exosomes correlated positively with serum level. The exosomes derived from serum of GC patients can promote migration of SGC‐7901 cells. After neutralized the expression level of three proteins in exosomes with antibodies, the migration of GC cells was obviously suppressed.

Conclusions

Our findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that the three-gene signature was a candidate diagnostic and prognostic biomarker for patients with GC.

Prognostic Biomarkers for Gastric Cancer: An Umbrella Review of the Evidence

Introduction: Biomarkers are biological molecules entirely or partially participating in cancerous processes that function as measurable indicators of abnormal changes in the human body microenvironment. Aiming to provide an overview of associations between prognostic biomarkers and gastric cancer (GC), we performed this umbrella review analyzing currently available meta-analyses and grading the evidence depending on the credibility of their associations. Methods: A systematic literature search was conducted by two independent investigators of the PubMed, Embase, Web of Science, and Cochrane Databases to identify meta-analyses investigating associations between prognostic biomarkers and GC. The strength of evidence for prognostic biomarkers for GC were categorized into four grades: strong, highly suggestive, suggestive, and weak. Results: Among 120 associations between prognostic biomarkers and GC survival outcomes, only one association, namely the association between platelet count and GC OS, was supported by strong evidence. Associations between FITC, CEA, NLR, foxp3+ Treg lymphocytes (both 1- and 3-year OS), CA 19-9, or VEGF and GC OS were supported by highly suggestive evidence. Four associations were considered suggestive and the remaining 108 associations were supported by weak or not suggestive evidence. Discussion: The association between platelet count and GC OS was supported by strong evidence. Associations between FITC, CEA, NLR, foxp3+ Treg lymphocytes (both 1- and 3-year OS), CA 19-9, or VEGF and GC OS were supported by highly suggestive evidence, however, the results should be interpreted cautiously due to inadequate methodological quality as deemed by AMSTAR 2.0.

Significant function and research progress of biomarkers in gastric cancer

Gastric cancer is one of the most common gastrointestinal tumor types, and the incidence and mortality rates are higher in men compared with women. Various studies have revealed that gastric cancer is a spectrum of tumor types, which have biological and genetic diversity. It has proven to be difficult to improve the overall survival and disease-free survival of patients with gastric cancer through the use of traditional surgery and chemoradiation, as gastric cancer is usually identified at an advanced stage. In consequence, the outcome is frequently poor. Thus, novel biomarkers and anticancer targets are required to improve the outcome. As the identification of biomarkers has increased due to advances in research and the greater availability of bioinformatics and functional genomics, the potential therapeutic regimens available have also increased concurrently. These advances have also improved the ability to predict responses to chemotherapy, targeted therapy and immunotherapy, whilst other biomarkers predict post-treatment survival and recurrence based on their expression. This review focuses closely on the important functions of biomarkers in the timely diagnosis and treatment of gastric cancer, in addition to the advances in the study of certain novel markers in gastric cancer.

Current and future molecular diagnostics of gastric cancer

Introduction: Gastric cancer (GC) is the fifth most common cancer and confers the second-highest mortality among other cancers. Improving the survival rates of GC patients requires prompt and accurate diagnosis and effective treatment which is often preceded by the poorly understood pathogenic mechanisms. Area covered: This literature review aims to summarize current understanding of genetic and molecular alterations that promote carcinogenesis including (1) activation of oncogenes, (2) overexpression of growth factors, receptors and matrix metalloproteinases, (3) inactivation of tumor suppressor genes, DNA repair genes, and cell adhesion molecules and (4) alterations of cell-cycle regulators that regulate biological characteristics of cancer cells. Moreover, the significance of molecular biomarkers such as micro-RNAs (miRNAs) and long non-coding RNAs (lncRNAs) and advanced molecular techniques including droplet digital polymerase chain reaction (ddPCR), quantitative PCR (qPCR) and next-generation sequencing (NGS) are also discussed. Expert opinion: A GC-specific panel of biomarkers based on the NGS or ddPCR has the potential for diagnosis, prognosis, and monitoring treatment response in GC patients. Despite the requirements for validation in larger population in clinical studies, race-specific differences in the gene panel have also to be examined by performing the clinical trials in subjects with different races.

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.

Gold Nanoparticle Based Platforms for Circulating Cancer Marker Detection

Detection of cancer-related circulating biomarkers in body fluids has become a cutting-edge technology that has the potential to noninvasively screen cancer, diagnose cancer at early stage, monitor tumor progression, and evaluate therapy responses. Traditional molecular and cellular detection methods are either insensitive for early cancer intervention or technically costly and complicated making them impractical for typical clinical settings. Due to their exceptional structural and functional properties that are not available from bulk materials or discrete molecules, nanotechnology is opening new horizons for low cost, rapid, highly sensitive, and highly specific detection of circulating cancer markers. Gold nanoparticles have emerged as a unique nanoplatform for circulating biomarker detection owning to their advantages of easy synthesis, facile surface chemistry, excellent biocompatibility, and remarkable structure and environment sensitive optical properties. In this review, we introduce current gold nanoparticle-based technology platforms for the detection of four major classes of circulating cancer markers - circulating tumor cells, vesicles, nucleic acids, and proteins. The techniques will be summarized in terms of signal detection strategies. Distinctive examples are provided to highlight the state-of-the-art technologies that significantly advance basic and clinical cancer research.

Analyzing Gastric Lavage of Gastric Cancer Patients: A Prospective Observational Study on Cytopathology and Determination of Intragastric CEA, CA 19.9, CA 72.4, and CA 50

OBJECTIVES

To investigate gastric lavage (GL) cytopathology and immunometric analysis as novel clinicopathologic and prognostic parameters for gastric cancer (GC).

STUDY DESIGN

In 38 patients with gastric adenocarcinoma, we performed a cytopathologic analysis and an immunometric assay of GL using four tumor markers (CEA, CA 19.9, CA 72.4, and CA 50). The intragastric tumor marker levels were compared with a control group consisting of 41 non-GC patients to determine a statistically significant cutoff value.

RESULTS

GL cytopathology demonstrated the presence of cancer cells in 13 (34.2%) of the 38 GC patients: such a finding correlated to the parameters pT and pN with a statistically significant validity (p < 0.0267 and p < 0.0306, respectively). Measurement of intragastric CA 19.9 and CA 50 attained a statistically significant cutoff value (p < 0.002 and p < 0.0096, respectively), which was invalidated by the low sensitivity of the ROC curve analysis.

CONCLUSIONS

In contrast to determination of its tumor markers, GL cytopathology correlated well with pT and pN staging parameters. Should this and other features be corroborated by future studies, the GL cytology test could be routinely used to detect aggressive types of GC even at early stages and result in important progress in the knowledge, staging, prediction, as well as management and follow-up of this inauspicious type of cancer.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

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.

The prognostic significance of gastric juice CA 19-9 and CEA levels in gastric carcinoma patients

AIM

The usefulness of gastric juice CA 19-9 and carcinoembryonic antigen (CEA) levels in the diagnosis of gastric carcinoma is controversial. There is only one study related with their prognostic value. In this study the clinical significance of gastric juice CA 19-9 and CEA levels in patients with gastric carcinoma was investigated.

METHODS

Preoperative serum and gastric juice CA 19-9 and CEA concentrations were measured in 139 patients with gastric carcinoma, 54 patients with benign gastroduodenal disease and as the 'healthy' control group 46 patients with inguinal hernia and with no other pathology.

RESULTS

In all groups the mean gastric juice levels of CA 19-9 and CEA were significantly higher than the serum levels. The gastric juice CA 19-9 levels were not different between groups. Gastric juice CEA levels of the gastric carcinoma group were significantly higher than those of the benign gastroduodenal disease group (P=0.007) and had a tendency to increase when compared to those of the control group (P=0.064) whereas there was no significant difference between the benign gastroduodenal disease and the control group. The cut-off values of gastric juice CA 19-9 and CEA were 440U/ml and 320ng/ml and the positivity ratios of these markers in gastric carcinoma patients were 16.5 and 27.3%, respectively. There was no significant relationship between the histopathological features and the gastric juice CA 19-9 or CEA positivities. Neither univariate analysis nor the multivariate Cox proportional hazards model analysis showed prognostic value for gastric juice CA 19-9 and CEA positivities.

CONCLUSIONS

The gastric juice CA 19-9 and CEA levels have no diagnostic and prognostic significance in gastric carcinoma patients.

Biliary carcinoembryonic antigen levels are a marker for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma develops in 5% to 15% of patients with choledochal cysts, sclerosing cholangitis, and intrahepatic stones. The detection of cholangiocarcinoma in patients with premalignant biliary conditions has been difficult. Serum levels of carcinoembryonic antigen (CEA) have been neither sensitive nor specific for the diagnosis of cholangiocarcinoma. However, CEA has been shown to be present in cholangiocarcinomas by immunohistochemical staining. Therefore, we measured the level of CEA excreted in bile in patients with benign strictures, premalignant biliary diseases, and cholangiocarcinoma.

PATIENTS AND METHODS

Bile was obtained from transhepatic stents in patients with benign biliary strictures (34), choledochal cysts (5), primary sclerosing cholangitis (6), intrahepatic cholelithiasis (5), and perihilar cholangiocarcinoma (25). Samples were analyzed for CEA using a solid phase, two-site immunoenzymetric assay.

RESULTS

Biliary CEA levels were significantly elevated (P < 0.01) in patients with cholangiocarcinoma (50.2 +/- 5.8 ng/mL) and intrahepatic cholelithiasis (57.4 +/- 10.4 ng/mL) compared with patients with benign strictures (10.1 +/- 3.9 ng/mL). Patients with sclerosing cholangitis (21.6 +/- 3.9 ng/mL) and choledochal cysts (20.0 +/- 16.5 ng/mL) had intermediate levels. In 5 patients undergoing resection of perihilar cholangiocarcinomas, the mean biliary CEA level decreased from a preoperative level of 46.8 +/- 6.7 ng/mL to a postoperative level of 11.3 +/- 5.6 ng/mL (P < 0.02). In 4 patients with progression of cholangiocarcinoma, biliary CEA increased from a mean of 53.3 +/- 6.9 ng/mL to 98.3 +/- 12.2 ng/mL (P < 0.02) over a mean interval of 9.5 months.

CONCLUSIONS

Increased levels of CEA can be detected in the bile of patients with chlolangiocarcinoma. Monitoring these levels may have a role in the management of cholangiocarcinoma as well as premalignant biliary conditions such as choledochal cysts and sclerosing cholangitis.

Carcinoembryonic antigen (CEA) and CEA-related substances in the bile of patients with biliary diseases

The levels of carcinoembryonic antigen (CEA) in the bile of 10 patients with biliary cancer and 9 patients with cholelithiasis were examined immunochemically by the Western blot analysis. All samples of bile from the patients with biliary cancer showed three bands that corresponded to CEA, nonspecific crossreacting antigen, and biliary glycoprotein 1, respectively. The upper band (CEA) disappeared from the bile of patients who underwent curative operations, but it persisted in the bile of patients who underwent noncurative operations. All samples of bile from the patients with cholelithiasis did not show the upper band (CEA), even in those samples that had high levels of CEA by the conventional enzyme immunoassay. We suggest that, in order to diagnose the presence of tumor, to assess the therapeutic efficacy of surgery, and to detect any residual tumor, not only should the level of bile CEA be measured but also a Western blot analysis of the bile should be performed since it is more reliable.

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.

Early gastric cancer in Korea

We reviewed the 639 cases of early gastric cancer from nation-wide 16 medical centers. The proportion of early gastric cancer among surgically resected gastric carcinoma comprised 6 to 12 percent. Male to female ratio was 1.7 to 1 with male preponderance. Mean ages of the early gastric cancer was 49.0 years and most prevalent ages was 5th decade. Macroscopically type IIc was most prevalent, reaching 59.9 percent. Depressed type lesions was more frequent than elevated type lesions by four folds. The size of lesions less than 4 cm accounted for more than 80 percent. Most frequent site of lesions were lower third by the CMA classification and lesser curvature transectionally. Lymph node metastasis was observed in 10.9 percent of all cases and it was more frequent in large tumor size more than 4 cm, elevated type, and undifferentiated carcinoma. 5-year survival rate was 91.6 percent. Gastrofiberscopic examination was superior to that of radiological examination in the diagnosis of early gastric cancer.

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.

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.

Values of carcinoembryonic antigen, elastase 1, and carbohydrate antigen determinant in aspirated pancreatic cystic fluid in the diagnosis of cysts of the pancreas

The levels of carcinoembryonic antigen (CEA), elastase 1, and carbohydrate antigen determinant (CA 19-9) in the pancreatic cystic fluid and the serum from five patients with cystadenocarcinoma of the pancreas, one patient with retention cyst due to pancreatic carcinoma, three patients with cystadenoma, and eight patients with benign pseudocyst accompanying or following pancreatitis, were determined by immunoassay technique. Fluid from pancreatic cysts was obtained by ultrasonically-guided percutaneous fine-needle aspiration biopsy. The specimens were centrifuged and the supernatant was used for the measurement of CEA, elastase 1, and CA 19-9, while the cell pellet was examined cytologically. The levels of CEA in the aspirated fluid were significantly higher in patients with malignant cysts of the pancreas than in those with benign cystadenomas and pseudocysts. In contrast, the levels of elastase 1 were significantly lower in patients with malignant cysts than in those with benign pancreatic cysts. Although the levels of CA 19-9 were significantly higher in patients with malignant cysts than in those with pseudocysts, the overlap between the values of patients with malignant and benign pancreatic cysts is too great. The serum CA 19-9 was most useful, however, to distinguish an individual patient with malignant cysts of the pancreas from those with benign pancreatic cyst, since there were no significant differences between the levels of serum CEA and elastase 1 in patients with malignant and benign pancreatic cysts. Correct diagnoses were made cytologically in 4 (66.7%) of 6 patients with malignant cysts. In two patients with malignant cyst, in whom no cancer cells were detectable in the aspirated materials, levels of CEA were abnormally high, but high levels of elastase 1 did not occur. Therefore, the combined measurement of CEA and elastase 1 in the aspirated cystic fluid of the pancreas could be used as an aid in diagnosis of malignant cysts of the pancreas.

Values of serum carcinoembryonic antigen and elastase 1 in diagnosis of pancreatic carcinoma

Carcinoembryonic antigen (CEA) and elastase 1 in the serum were determined by enzyme immunoassay and radioimmunoassay, respectively, in 224 healthy subjects, 49 patients with pancreatitis, 53 patients with pancreatic carcinoma and 129 patients with cancer in other organs. The CEA concentrations in the serum were significantly higher in patients with pancreatic carcinoma than in those with pancreatitis, but this concentration was not a satisfactory indicator of pancreatic carcinoma localised to allow irradication by resection as it was raised in only 47% of the patients. High CEA concentrations were also slightly, but not significantly, more frequent in patients with cancer of the pancreatic body or tail, and unresectable cancer or cancer of more than 6.0 cm in longest diameter than in those with cancer of the pancreatic head, resectable cancer or cancer of less than 6.0 cm diameter. Serum elastase 1 was raised in only 42% of the patients with pancreatic carcinoma and could not be used to distinguish patients with pancreatic carcinoma from those with pancreatitis. In contrast with CEA, however, its concentration was abnormally high significantly more frequently in patients with cancer of less than 6.0 cm in longest diameter than in those with larger tumours. It was also raised slightly, but not significantly, more frequently in those with cancer of the pancreatic head and in patients with resectable cancer than in those with unresectable cancer. A combination of these two tests raised the diagnostic rate of pancreatic carcinoma to 77% without a remarkable decrease in the specificity for pancreatic carcinoma. In particular, it raised the diagnostic rates of cases of cancer of the pancreatic head, resectable cancer and cancers of less than 3.0 cm and 3.0-6.0 cm in longest diameter. Therefore, a combination of measurements of CEA and elastase 1 in the serum is very useful for early detection of pancreatic carcinoma.

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

In order to ascertain the role of gastric carcinoembryonic antigen (CEA) determination in detecting patients with a risk for gastric cancer, 69 subjects were studied; 23 were referred for endoscopy because of dyspepsia but without obvious macroscopic lesions, 27 with duodenal ulcer, 11 with benign gastric ulcer, 8 with gastric cancer. The following results were obtained by subdividing the material according to the histologic interpretation of the results of gastric mucosal biopsies: (1) in the presence of minor histologic abnormalities of the gastric mucosa, CEA in gastric juice was under 100 ng/ml in all but five cases; and (2) in moderate or severe chronic atrophic gastritis (associated or otherwise with intestinal metaplasia or dysplasia), and in gastric cancer, gastric CEA ranged between 224 and 3120 ng/ml in all but two cases. Although not diagnostic for gastric cancer, gastric CEA is a promising test in detecting patients at risk, including those with dysplasia of the gastric mucosa.

Carcinoembryonic antigen in the bile in patients with pancreatic and biliary cancer. Correlation with cytology and percutaneous transhepatic cholangiography

The level of carcinoembryonic antigen (CEA) in the bile of 17 patients with benign pancreatic and biliary diseases and 50 patients with pancreatic and biliary cancer were determined by enzyme immunoassay. The bile specimens were obtained at the time of percutaneous transhepatic cholangiography. The bile was centrifuged and the supernatant was used for CEA measurement, while the cell pellet was examined cytologically. High CEA values in the bile were significantly more frequent in patients with pancreatic and biliary cancer than in those with benign pancreatic or biliary diseases; increased CEA concentrations in the bile were observed in 76.0% and 60.0%, respectively, of all the patients and of the patients with localized cancer. The location of the cancer had no influence on the bile CEA level, but the CEA levels in the bile tended to be high when the tumor had distant metastases, or when the biliary tract was completely obstructed. Although patients with pancreatic and biliary cancer had a high CEA value in the bile significantly more frequently, bile CEA measurement is not sufficient to distinguish an individual patient with pancreatic or biliary cancer from those with other disease, since the overlap between the values is too great, and therefore, additional examinations are required. Correct diagnosis of malignancy were made by cytological examination alone, by bile CEA assay alone and visual examination of dye in the biliary tract alone in 72.0, 76.0, and 88.0% respectively, of the patients examined, while the combination of these methods raised the diagnostic rate to 100%.