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

Needle stochastic sensors for on-site fast recognition and quantification of biomarkers for gastric cancer in biological samples

N-Doped graphenes recognised CA19-9, CEA, and p53 in biological samples.

Detection of cancer cells and tumor markers in gastric lavage of patients with gastric cancer: Do these findings have a clinicopathological significance and oncological implication?

Although decreasing in the incidence over the last years, currently gastric adenocarcinoma represents the second cause of cancer related-death worldwide. Further knowledge and novel therapies are desperately needed in order to make the prognosis of these patients more acceptable. Infact, even though in recent years numerous staging parameters have been largely studied and unanimously recognized for their clinical and prognostic value, today too many shadows still exist around the capacity to predict exactly the natural history or post-treatment behavior of this cancer even among patients of the same stage. This study has identified the presence of isolated cancer cells as well as tumor markers (CEA, Ca 19.9, Ca 72.4 and Ca 50) from the gastric lavage of patients affected by gastric adenocarcinoma. Such findings led to the hypothesis that endoluminal exfoliation of neoplastic cells and the release of their products (tumor markers) into the gastric juice might be an expression of neoplastic behavior as well as aggressive malignancy. Should this hypothesis become a reality, some important progress could be made in the knowledge, staging, prediction as well as management and follow-up of this inauspicious type of cancer.

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.

Detection of serum gastric cancer-associated MG7-Ag from gastric cancer patients using a sensitive and convenient ELISA method

PURPOSE

To seek a high sensitive and convenient method for early diagnosis of gastric cancer by testing MG7-Ag in serum of gastric cancer patients and some other control groups using a convenient ELISA method.

EXPERIMENT DESIGN

The expression of serum MG7-Ag was detected in 116 preoperative gastric cancer patients, 63 postoperative gastric cancer patients, 78 precancerous lesion patients, 50 healthy blood donors and patients of other cancers by a convenient ELISA method. For comparison, serum CEA, CA 50, CA 19-9 and TAG-72 were also detected in preoperative gastric cancer patients. Meanwhile, the expression of MG7-Ag was detected by immunohistochemical analysis in the groups of patients with gastric cancer or precancerous lesion mentioned above.

RESULTS

The positive rate of Mg7-Ag determined by ELISA was 83. 6% of preoperative gastric cancer patients, 54.8% of lung cancer patients, 45.5% of rectal cancer patients, 17.6% of colonic cancer patients, 14.2% of breast cancer patients, 47.6% of postoperative gastric cancer patients, 12.8% of precancerous lesions patients and 0% of healthy blood donors, respectively. The sensitivity of ELISA (83.6%) was found to be similar with that of immunohistochemistry (94%, p > 0. 01), while the false positive rate was lower (12.8% vs. 51.3%). MG7-Ag expression level in gastric cancer was correlated with tumor differentiation (p < 0. 01) and pathological stage (p < 0. 01).

CONCLUSION

This ELISA method may be a non-invasive candidate method for screening of large population with high risk of gastric cancer.

Intracellular Helicobacter pylori in gastric epithelial progenitors

Helicobacter pylori is generally viewed as an extracellular pathogen. We have analyzed the tropism of H. pylori clinical isolates in a gnotobiotic transgenic mouse model of human chronic atrophic gastritis, a preneoplastic condition. These mice lack acid-producing parietal cells and have an amplified population of dividing gastric epithelial progenitors (GEPs) that express NeuAc alpha 2,3Gal beta 1,4-glycans recognized by H. pylori adhesins. Scanning confocal and transmission electron microscopic studies of stomachs that had been colonized for 1 month or 1 year revealed intracellular bacterial collections (IBCs) in a small subset of multi- and oligopotential epithelial progenitors. Transmission electron microscopic and multilabel immunohistochemical analyses disclosed bacteria with several morphotypes, including spiral-shaped, in the cytoplasm and endosomes. Several stages in IBC evolution were documented, from a few solitary bacteria to consolidated populations in dividing and nondividing GEPs, to microorganisms traversing breaches in the GEP plasma cell membrane. IBC formation was not a unique feature of H. pylori strains isolated from patients with chronic atrophic gastritis. The notion that adult mammalian epithelial progenitors can function as a repository for H. pylori broadens the view of host habitats available to this and perhaps other pathogens.

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.

Glycans as legislators of host-microbial interactions: spanning the spectrum from symbiosis to pathogenicity

The number of microbes associated with our gut likely exceeds our total number of somatic and germ cells. Despite their numbers, almost nothing is known about the molecular mechanisms that determine whether the interaction between a microbial species and its host will be beneficial. Recent results obtained from in vivo models have revealed critical roles for glycoconjugates in helping define the outcome of two such host-microbial relationships. In one case, attachment of Helicobacter pylori to fucosylated or sialylated glycans produced by various gastric epithelial lineages and their progenitors skews the destiny of colonization toward pathogenicity. In the second case, a molecular dissection of how Bacteroides thetaiotaomicron, a normal inhabitant of the distal small intestine, is able to communicate with intestinal epithelial cells has revealed a novel role for host fucosylated glycans in forging a mutually beneficial relationship. These observations lend support to the hypothesis that the capacity to synthesize diverse carbohydrate structures may have arisen in part from our need to both evade pathogenic relationships and to coevolve symbiotic relationships with our nonpathogenic resident microbes.

Helicobacter pylori adhesins: review and perspectives

It is highly unlikely that chronic infection with H. pylori could occur in the absence of adhesin-host cell interactions. Also, there is no evidence that any of the serious outcomes of H. pylori infection such as gastric and duodenal ulcers, gastric cancer or mucosa-associated lymphoid tissue (MALT) lymphoma could occur without prior colonization of the gastric epithelium mediated by H. pylori adhesins. H. pylori is highly adaptable, as evidenced by the fact that it can occupy a single host for decades. An important facet of this adaptability is its ability to physically interact with various types of host cells and also with host mucins and extracellular matrix proteins using a number of different adhesins displaying a variety of unique receptor specificities. Thus it is highly unlikely that any one particular H. pylori adhesin will ever be proven responsible for a particular outcome such as duodenal ulcer, MALT lymphoma, or adenocarcinoma. Also, while the search for additional H. pylori adhesins should and certainly will continue, we suggest that the scope of this effort should be expanded to include investigations into the patterns of expression and interaction between individual outer membrane proteins. Which of the numerous H. pylori outer membrane proteins (OMPs) actually function as adhesins (i.e., have receptor-binding sites) and which OMPs are simply necessary for optimal display of the adhesive OMPs? There are many other important questions about H. pylori adhesins waiting to be answered. For example, which adhesins are responsible for loose adherence to host cells and which adhesins are responsible for intimate, or membrane-to-membrane, adherence, and do these adhesins normally work in concert or in a sequential fashion? Also, is a specific type of adhesin necessary for type IV protein translocation into host cells and, if so, is adhesin expression coregulated with the effector protein export?

Theoretical and experimental approaches for studying factors defining the Helicobacter pylori-host relationship

Mathematical modeling has helped develop hypotheses about the role of microbial and host parameters in the initial and subsequent phases of Helicobacter pylori colonization. Transgenic mice have been used to test the hypothesis that the outcome of colonization is influenced by whether bacteria can adhere to available epithelial cell receptors. Complementary use of modeling and experimental approaches should facilitate studies of H. pylori pathogenesis.

Helicobacter pylori attaches to NeuAc alpha 2,3Gal beta 1,4 glycoconjugates produced in the stomach of transgenic mice lacking parietal cells

Helicobacter pylori infection of the human stomach is associated with altered acid secretion, loss of acid-producing parietal cells, and, in some hosts, adenocarcinoma. We have used a transgenic mouse model to study the effects of parietal cell ablation on H. pylori pathogenesis. Ablation results in amplification of the presumptive gastric epithelial stem cell and its immediate committed daughters. The amplified cells produce sialylated oncofetal carbohydrate antigens that function as receptors for H. pylori adhesins. Attachment results in enhanced cellular and humoral immune responses. NeuAc alpha 2,3Gal beta 1,4 glycoconjugates may not only facilitate persistent H. pylori infection in a changing gastric ecosystem, but by promoting interactions with lineage progenitors and/or initiated cells contribute to tumorigenesis in patients with chronic atrophic gastritis.

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.

New cancer markers

In recent years many new and improved cancer markers have become available. From a clinical point of view, the most useful of the new markers include CA 19-9 for pancreatic adenocarcinoma, CA 125 for epithelial ovarian cancer, CA 15-3 for breast cancer, prostate specific antigen for prostatic adenocarcinoma, placental alkaline phosphatase for testicular seminomas and neuron-specific enolase for small cell carcinoma of lung. None of these new markers are specific for cancer. Furthermore, none are organ specific, except prostate specific antigen for prostatic tissue. The main application of these markers is in monitoring patients with the specific malignancies indicated. Whether routine use of any of these new markers leads to higher quality of life or enhanced survival remains to be determined.