Comparative analysis of cancer-associated antigen CA-195, CA 19-9 and carcinoembryonic antigen in diagnosis, follow-up and monitoring of response to chemotherapy in patients with gastrointestinal cancer

The Protective Role of Urtica dioica Seed Extract Against Azoxymethane-Induced Colon Carcinogenesis in Rats

The aim of this study was to investigate the protective role of Urtica dioica seed (UDS) extract against azoxymethane (AOM)-induced colon carcinogenesis in rats. Thirty-two male Wistar albino rats were divided into four groups: Control, AOM, AOM + UDS, and UDS. The AOM and AOM + UDS groups were induced by AOM (15 mg/kg body weight) subcutaneously once a week for 10 weeks. AOM + UDS and UDS groups additionally received fed with pellets included 30 ml/kg UDS extract. At the end of the trial, blood and colon tissue samples were taken from the rats following necropsy. The gross and histopathological findings revealed that the administration of UDS extract significantly decreased lesions including aberrant cript foci, adenoma, and adenocarcinoma formation both numerically and dimensionally. Immunohistochemically, slight CEA and COX-2, strong Caspase-3 immune-expressions were detected in the group AOM + UDS compared to AOM group. Biochemical examinations indicated that a markedly increase in the malondialdehyde and fluctuated antioxidant defense system constituents levels such as reduced glutathione, glutathione s-transferase, glutathione peroxidase, superoxide dismutase were restored in AOM + UDS group. These results reveal that the UDS may act as a chemopreventive dietary agent, inducing apoptosis, resulting in a significant reduction of colon carcinogenesis.

The sensitivity and specificity of serum glycan-based biomarkers for cancer detection

Most of clinically used serum biomarkers for cancer detection were established in early 1980s when the Nobel Prize in physiology or medicine was awarded for the "discovery of the principle for the production of monoclonal antibodies." Using this "Nobel" technology, various monoclonal antibodies were obtained when different types of cancer cells were injected into mice and the ligands on the cancer cell surface were characterized. Both aberrant glycan structures and aberrant glycan-associated glycoproteins were revealed as a common feature of cancer cell surfaces through the specific interactions with the monoclonal antibodies. These results indicate that the biosynthesis of the environment-sensitive glycan structures goes awry in cancer cells, which is beyond genetic mutations. Later on, the glycan-related biomarkers were detected in the sera of cancer patients and then developed into serum biomarkers, such as CA125, CA153, CA195, CA199, CA242, CA27.29, CA50, and CA724, which are still in clinical use as of today. During the past 30 years, even with the advancement of different OMICS technologies not limited to genomics, epigenomics, proteomics, glycomics, lipidomics, and metabolomics, very few serum biomarkers have been introduced into clinical practice. The reason is that most of the newly discovered cancer biomarkers are inferior in terms of sensitivity and specificity to these biomarkers. We will summarize the reported sensitivity and specificity of currently used cancer biomarkers, especially the glycan-related biomarkers, in the forms of tables and radar plots and discuss the pros and cons of currently used cancer biomarkers.

Preoperative Carbohydrate Antigen 195 (CA195) and CEA Serum Levels as Prognostic Factors in Patients with Colorectal Cancer

We evaluated in 214 patients with primary colorectal cancer the prognostic value of the preoperative serum levels of CEA and CA195. For CEA these levels were above the cutoff of 6 ng/ml in 31.3% of patients, whereas for CA195 they were higher than 12 U/ml in 35.9% of patients. The simultaneous use of both antigens increased the sensitivity to 49%, which was significantly higher than that of CEA (p<0.001) and CA195 (p<0.01) taken singly. The mean preoperative CEA levels were significantly (p<0.001) correlated with Dukes’ stage only, while there was a significant correlation between preoperative serum levels of CA195 and Dukes’ stage (p<0.001), grade of differentiation (p<0.01) and tumor location (p<0.05).

The results indicated that high preoperative serum levels of CEA and CA195 were associated with a shorter overall survival (p<0.0001). In addition, separate Cox multivariate analysis showed that preoperative CA195 was, after Dukes’ stage, the strongest factor to predict overall survival (p<0.0001).

Cutoff value of carcinoembryonic antigen and carbohydrate antigen 19-9 elevation levels for monitoring recurrence in patients with resectable gastric adenocarcinoma

Background

The aim of this longitudinal study was to try and improve the specificity of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in monitoring tumor recurrence in patients with resectable gastric adenocarcinoma by setting suitable elevation levels.

Methods

One hundred eighty-one patients with resectable gastric adenocarcinoma were considered. Serum samples were obtained preoperatively and every 3 months postoperatively.

Results

Preoperative CEA and CA19-9 positivity rates were 19.9% and 18.2%. The specificity and sensitivity of CEA elevation to monitor recurrence were 92.9% and 23.4% versus 76.5% and 78.9% in CEA-negative versus CEA-positive patients, respectively. For CA19-9 the specificity and sensitivity were 95.0% and 18.8% versus 60.0% and 83.3% in CA19-9-negative versus CA19-9-positive patients, respectively. When we set the elevation level of CEA at 5 ng/mL, the specificity of CEA elevation to monitor recurrence increased to 94.1% for CEA-positive patients. The specificity increased to 93.3% for CA19-9-positive patients when the CA19-9 elevation level was set at 100 U/mL.

Conclusions

For CEA- or CA19-9-positive patients with resectable gastric adenocarcinoma we can increase the specificity of CEA and CA19-9 by setting the elevation level of CEA at 5 ng/mL and CA19-9 at 100 U/mL.

Clinical application of serum tumor abnormal protein from patients with gastric cancer

BACKGROUND

To verify whether serum tumor abnormal protein (TAP) would correlate with the responsiveness of palliative chemotherapy in patients with advanced gastric cancer, and the variation of conventional serum tumor markers e.g., carcinoembryonic antigen (CEA), antigen 125 (CA125),carbohydrate antigen19-9 (CA19-9) of adjuvant chemotherapy in patients with early gastric cancer.

MATERIALS AND METHODS

Patients with histologically confirmed gastric cancer and treated with chemotherapy were enrolled into this study. TAP values of these patients were determined by detecting abnormal sugar chain glycoprotein in serum, combined with the area of agglomerated particles. For patients with advanced gastric cancer, responsiveness of palliative chemotherapy was compared with variation of TAP and the relation between variation of TAP and tumor markers in patients with early gastric cancer was analyzed.

RESULTS

Totally 82 gastric cancer patients were enrolled into this study. The value of TAP is more closely related to responsiveness of palliative chemotherapy for patients with advanced gastric cancer. The correlation between TAP and responsiveness to palliative chemotherapy is stronger than the correlation between several conventional serum tumor markers (CEA, CA125 and CA199) .The variation of TAP was also positively correlated with the trend of CA125 in adjuvant chemotherapy.

CONCLUSIONS

TAP is sensitive in monitoring the responsiveness to palliative chemotherapy in patients with advanced gastric cancer. But this result should be confirmed by randomized clinical trials for patients with gastric cancer.

Preoperative serum tumor marker levels in gastric cancer

OBJECTIVE

Tumor markers have shown little benefit as a method for screening. However, they can be used clinically for the monitoring of tumor recurrence and used as prognostic factors because higher levels have been observed in advanced disease. This study aimed to investigate the relationship between the preoperative tumor marker levels and different clinical aspects of gastric cancer.

METHODS

One hundred and six consecutive patients with confirmed diagnosis of gastric cancer and 106 subjects (age and sex matched) with no malignancy as control group were included prospectively in this study in 3 years. The relationships between tumor markers CEA, CA 19-9 and stage of disease, tumor differentiation, presence of ringlet cell type, presence of peritoneal carcinomatozis were investigated.

RESULTS

The serum CEA and CA 125 levels were found to be significantly elevated in gastric cancer patients than in controls. The serum level of CEA had showed a significant elevation with the presence of distant metastasis. The CA 19-9 and CA 125 levels had showed significant elevations with the presence of peritoneal carcinomatozis. Conclusions : This study showed that there is a limited clinical benefit of preoperative tumor marker measurements in gastric cancer such as estimation of peritoneal dissemination.

Promoter hypermethylation of BCL6B gene is a potential plasma DNA biomarker for gastric cancer

We previously showed that BCL6B acts as a tumor suppressor in gastric cancer and up to 66% gastric cancer patients have promoter hypermethylation in tumor tissues. We aimed to evaluate the feasibility of detecting BCL6B methylation in plasma DNA as a potential biomarker for gastric cancer. Hypermethylation of the CpG islands in BCL6B promoter was detected in 42.5% (17/40) plasma DNA samples from gastric cancer patients, while no methylation was found in the plasma DNA of healthy controls (p < 0.001). BCL6B methylation may serve as a novel potential non-invasive plasma biomarker for the detection of gastric cancer.

The Diagnostic and Prognostic Role of microRNA in Colorectal Cancer - a Comprehensive review

The discovery of microRNA, a group of regulatory short RNA fragments, has added a new dimension to the diagnosis and management of neoplastic diseases. Differential expression of microRNA in a unique pattern in a wide range of tumor types enables researches to develop a microRNA-based assay for source identification of metastatic disease of unknown origin. This is just one example of many microRNA-based cancer diagnostic and prognostic assays in various phases of clinical research.

Since colorectal cancer (CRC) is a phenotypic expression of multiple molecular pathways including chromosomal instability (CIN), micro-satellite instability (MIS) and CpG islands promoter hypermethylation (CIMP), there is no one-unique pattern of microRNA expression expected in this disease and indeed, there are multiple reports published, describing different patterns of microRNA expression in CRC.

The scope of this manuscript is to provide a comprehensive review of the scientific literature describing the dysregulation of and the potential role for microRNA in the management of CRC. A Pubmed search was conducted using the following MeSH terms, "microRNA" and "colorectal cancer". Of the 493 publications screened, there were 57 papers describing dysregulation of microRNA in CRC.

Sensitivity estimates of blood-based tests for colorectal cancer detection: impact of overrepresentation of advanced stage disease

A large number of blood-based markers have been proposed for early detection of colorectal cancer (CRC). Their sensitivity for detecting CRC has mostly been evaluated in clinical settings, and found to be higher in more advanced stages compared with earlier stages of the disease. The aim of this study is to estimate the overall sensitivity of blood-based markers expected in screening settings, where the proportion of advanced stages is typically lower than in clinical settings. A systematic literature review was performed on studies evaluating sensitivity and specificity of blood-based markers for early detection of CRC. For each study, overall sensitivity expected in screening settings was estimated by weighting stage-specific sensitivities according to the stage distribution of CRC expected in the screening setting. The latter was derived from 12,605 CRC cases diagnosed in the German screening colonoscopy program during 2003-2007. Overall, 73 studies evaluating 55 blood-based markers were identified. Adjusted sensitivity was lower than reported sensitivity in 120 (90%) evaluations of different markers. Median absolute reduction in sensitivity after adjustment was 9.0% (interquartile range: 4.0-13.0) units, whereas median relative reduction was 19.5% (interquartile range: 11.3-33.3%). Blood-based markers for CRC detection reported from clinical settings showed higher sensitivities than expected in the screening setting in most cases, mainly due to substantially higher proportions of advanced stage cancers. Adjustment of sensitivity to the stage distribution expected in the screening setting is crucial to obtain realistic and comparable estimates of sensitivities.

Blood markers for early detection of colorectal cancer: a systematic review

BACKGROUND

Despite different available methods for colorectal cancer (CRC) screening and their proven benefits, morbidity, and mortality of this malignancy are still high, partly due to low compliance with screening. Minimally invasive tests based on the analysis of blood specimens may overcome this problem. The purpose of this review was to give an overview of published studies on blood markers aimed at the early detection of CRC and to summarize their performance characteristics.

METHOD

The PUBMED database was searched for relevant studies published until June 2006. Only studies with more than 20 cases and more than 20 controls were included. Information on the markers under study, on the underlying study populations, and on performance characteristics was extracted. Special attention was given to performance characteristics by tumor stage.

RESULTS

Overall, 93 studies evaluating 70 different markers were included. Most studies were done on protein markers, but DNA markers and RNA markers were also investigated. Performance characteristics varied widely between different markers, but also between different studies using the same marker. Promising results were reported for some novel assays, e.g., assays based on SELDI-TOF MS or MALDI-TOF MS, for some proteins (e.g., soluble CD26 and bone sialoprotein) and also for some genetic assays (e.g., L6 mRNA), but evidence thus far is restricted to single studies with limited sample size and without further external validation.

CONCLUSIONS

Larger prospective studies using study populations representing a screening population are needed to verify promising results. In addition, future studies should pay increased attention to the potential of detecting precursor lesions.

Clinical utility of CEA, CA 19-9, and CA 72-4 in the follow-up of patients with resectable gastric cancer

BACKGROUND

The aim of this longitudinal study was to evaluate the effectiveness of the serum tumor markers CEA, CA 19-9, and CA 72-4 in the early diagnosis of recurrence of gastric cancer.

METHODS

One hundred and thirty-three patients who had undergone potentially curative surgery were considered. Serum samples were obtained preoperatively, 1 week after surgery, and at every follow-up examination. Mean follow-up time for the entire patient population was 41 +/- 33 months, and 71 +/- 27 months for patients classified as disease-free.

RESULTS

Preoperative positivity was 16% for CEA, 35% for CA 19-9, and 20% for CA 72-4. Recurrence of disease was found in 75 patients (56%). Marker sensitivity in recurrent cases was 44% for CEA, 56% for CA 19-9, and 51% for CA 72-4; the combined use of the three markers increased sensitivity to 87%, which reached 100% in patients with positive preoperative levels. Marker specificity, evaluated in 58 disease-free patients, was 79% for CEA, 74% for CA 19-9, and 97% for CA 72-4.

CONCLUSIONS

The combined assay of CEA, CA 19-9, and CA 72-4 may be useful for early diagnosis of recurrence of gastric cancer; however, only CA 72-4 positivity should be considered a specific predictor of tumor recurrence.

Plasma sialic acid as a marker of the effect of the treatment on metastatic colorectal cancer

The concentration of total sialic acid (TSA) is increased in the plasma of patients with many types of cancer. The purpose of this study was to assess the usefulness of the TSA marker in predicting the efficacy of the treatment, and to compare TSA with two common markers, carcinoembryonic antigen (CEA) and the carbohydrate antigen 19-9 (CA 19-9). The study was performed on 44 patients treated for advanced colorectal carcinoma by a weekly 8 h continuous infusion of 5-fluorouracil (1300 mg/m2) plus bolus injection of L-folinic acid (100 mg/m2). TSA, CEA and CA 19-9 levels were measured before and after 3 months of treatment and their variations analysed as a function of the response to the treatment. TSA levels of patients with metastatic colorectal carcinoma before treatment (959 +/- 265 mg/l) were significantly higher than those of 32 healthy people (584 +/- 99 mg/l). The percentage of patients with TSA concentration above the cut-off level (782 mg/l) was 73% before treatment and 23% after. All patients who experienced an objective response to the treatment (complete, partial or minor response) (n = 29) had a significant decrease of TSA levels (t = 5.96; P < 0.001). When the disease was considered as stabilised (n = 10), TSA changed slightly, but it increased with progressive disease (4 out of 5 patients). Changes in CEA and CA 19-9 did not correlate as well as TSA to the treatment efficacy. Initial levels of TSA did not permit prediction of the efficacy of the treatment since they were not significantly different between the five response groups. TSA seems to be more likely involved in tumour changes than in tumour volume. Its determination could provide useful information about the spreading and metastatic properties of the tumour. TSA normalisation is an indicator of probable tumour growth arrest and its elevation could be a marker of relapse.

CEA, CA 19-9, and CA-50 in monitoring gastric carcinoma

This study was conducted to investigate the clinical utility of CEA, CA 19-9, and CA-50 in the diagnosis, monitoring, and prognosis of 62 gastric carcinoma patients having either adjuvant or palliative chemotherapy. Patients were divided in two groups: group A included patients treated on an adjuvant basis following a curative resection of gastric cancer, and group B included patients with residual disease post surgery or patients with inoperable tumor or generalized disease. Serum marker levels were measured in a prospective study just before the initiation of chemotherapy and before each course during chemotherapy. In group A, CEA was positive in 2/25 (8%) patients, CA 19-9 in 1/25 (4%), and CA-50 in 1/25 (4%). In group B the sensitivity of CEA was 48.6% (18/37 patients), of CA 19-9 64.9% (27/37 patients), and of CA-50 70.3% (26/37) patients. There was a significant correlation between the CA 19-9 and CA-50 levels in both groups. No correlation was found between the sensitivity or the absolute initial marker levels and the tumor's differentiation or extent of disease. In group A the only patient with initially elevated CA 19-9 and CA-50 values relapsed early while he was on adjuvant chemotherapy. It was also found that the rising final CA 19-9 and CA-50 values at the end of chemotherapy were correlated with an increased incidence of relapse, but not with the disease-free interval. In group B the initially low marker levels showed a trend to predict a favorable outcome of treatment. There was no statistically significant correlation between the marker titers before each course and response to chemotherapy. It is concluded that the comeasurement of CA 19-9 and CA-50, and to some degree of CEA, is justifiable for gastric cancer. The estimation of CA 19-9 and CA-50 may be useful for early detection of recurrence after curative surgery and adjuvant chemotherapy. In advanced or recurrent gastric cancer, the estimation of either CA 19-9 or CA-50 and CEA serum values may help in checking the prognosis, determining the efficacy of palliative treatment modalities, and recognizing recurrences.

A prognostic value of CA 19-9 but not of CEA in patients with gastric cancer

The diagnostic and prognostic value of tumour markers CEA and CA 19-9 was studied in patients with gastric cancer. Pre-operative serum concentrations of CEA and CA 19-9 were determined in 100 gastric cancer patients and in 77 patients with relevant benign diseases. The sensitivity of both CEA (cut-off level 3 ng/ml) and CA 19-9 (cut-off level 37 U/ml) for gastric cancer was 30%. The specificities were 73% and 87%, respectively. There was a significant difference in prognosis, for both CEA (cut-off level 3 ng/ml, P < 0.05) and CA 19-9 (cut-off level 37 U/ml, P < 0.01), between patients with high vs low pre-operative serum levels. The overall 5-year survival was 26% and that of patients with low marker levels was 30% (CEA) and 35% (CA 19-9) compared with 15% (CEA) and 0% (CA 19-9) for patients with high marker levels. To evaluate whether the high vs low serum marker level was an independent prognostic factor, the patients were compared within the same stage of disease. There was still a significant difference in 5-year survival in stages II, III and IV between patients with high vs low pre-operative serum levels for CA 19-9 (P < 0.05), but not for CEA. In stage I, no differences in survival could be found for either marker. In conclusion, high pre-operative serum levels of CEA seem to predict higher stage of disease, whereas CA 19-9 might have an independent prognostic value in patients within the stage of II, III or IV gastric cancer. The diagnostic value of both CEA and CA 19-9 is limited.

Predictive value of preoperative serum sialyl Tn antigen levels in prognosis of patients with gastric cancer

BACKGROUND

Expression of sialyl Tn antigen (STN) or serum STN levels were reported to be the independent prognostic factors of colon and ovarian cancers, respectively. The clinical significance of serum STN was evaluated as a tumor marker in gastric cancer.

METHODS

Preoperative STN levels were examined in 350 patients with gastric cancer, surgically treated in the Department of Surgery II, Kyushu University Hospital, and in the National Kyushu Cancer Center, between April, 1981 and April, 1986. The patients were divided into two groups: a high STN group (n = 304), with over 45 U/ml of STN, and a low STN group (n = 46), with less than or equal to 45 U/ml.

RESULTS

In the high STN group, the patients were older and the tumors were larger, compared to the low STN group. Histologically, tumors in the high STN group were deeply penetrating and the rates of lymphatic involvement, vascular involvement, and lymph node and hepatic metastases were higher. Infiltrative growth patterns dominated. Thus, the tumors were in an advanced stage. The 5-year survival rate for patients in the high STN group was significantly less than that of patients in the low STN group (44.8% +/- 7.9% versus 75.1% +/- 2.6%, P < 0.05).

CONCLUSIONS

Because a high STN level correlates with an advanced tumor stage and a poorer prognosis, close follow-up and aggressive therapy are recommended.

Comparative evaluation of serum CA 195 and carcinoembryonic antigen in metastatic carcinoma

BACKGROUND

Carcinoembryonic antigen (CEA) is a well-described human tumor-associated antigen most useful clinically in colon cancer. However, the clinical usefulness of CEA is limited by the marker's overall poor specificity and low sensitivity in patients with minimal disease. CA 195 is a recently discovered human tumor-associated glycoprotein that can be measured in serum using an immunoradiometric assay. CA 195 is expressed on the membrane of human colon cancer cells and shares an epitope with the Lewis A blood group antigens. The authors initiated a study to compare the clinical utility of serum CA 195 with CEA in patients with advanced cancer. A control population was studied to assess the effects of age, gender, alcohol, and tobacco on the measured levels of serum CA 195.

METHODS

Using a solid-phase two-site immunoradiometric assay, serum CA 195 and CEA levels were measured in 71 control subjects and 167 patients with a prior diagnosis of cancer. The tumor histologic types included breast cancer, 49 patients; colon cancer, 38; prostate cancer, 24; lung cancer, 22; gastrointestinal noncolon cancer, 7; and miscellaneous, 27. Among patients with a history of cancer, 124 (74%) had active metastatic disease, and 43 (26%) were without evidence of active disease. The control population was composed of subjects without a history of malignancy. Clinical data collected from them included age, gender, smoking history, and alcohol consumption.

RESULTS

In this laboratory, the normal ranges established for CA 195 and CEA in the control group were: 0.0-8.3 U/ml and 0.2-4.2 ng/ml, respectively. In the control subjects, the serum CA 195 level, unlike that of CEA, was not affected by age, gender, alcohol consumption, or tobacco use. In the study population, CA 195 had either equivalent or inferior specificity and sensitivity to CEA in all tumor types. A determination of the additive specificity and sensitivity of CA 195 and CEA did not significantly improve its clinical utility compared with CEA alone. However, CA 195 was significantly elevated in three patients with a prior history of colon cancer thought to be without evidence of active disease. Because all three of these patients had a relapse within the next 1-15 months, CA 195 might identify early relapses of colon cancer in some patients.

CONCLUSIONS

Based on these results, it was concluded that CA 195 is not superior to CEA as an indicator of disease activity in advanced colon cancer or other solid tumors. However, studies utilizing CA 195 in the detection of early relapses of colon cancer may be warranted. A review of the English literature revealed that CA 195 might be a useful marker in pancreatic cancer.

Comparative analysis of CA72-4, CA195 and carcinoembryonic antigen in patients with gastrointestinal malignancies

To establish further the clinical significance of the novel quantitative immunoradiometric assay system CA72-4 in patients with gastric and other digestive tract malignancies, the sera of a total of 208 subjects have been analysed and levels of carcinoembryonic antigen (CEA) and another promising new tumour marker, CA195, have been compared. Twenty patients had gastric (GC), 60 colorectal (CC), and 14 pancreatic carcinomas (CC); 94 patients had benign disorders, and 20 were healthy volunteers. CA72-4 elevations above normal (greater than 4 U/ml) were observed in 6 (30%) GC, 17 (28%) CC, and 8 (57%) PC patients. CA195 appeared more sensitive and was increased (greater than 10 U/ml) in 35% GC, 70% CC, and in 100% PC patients; CEA levels above normal (greater than 5 ng/ml) were noted in 35%, 45%, and 66% of patients respectively. CA72-4 had a rather high specificity and was increased in only 6/94 (6%) patients with benign diseases, whereas CA195 had a false positive rate of 23%, and CEA of 33%. Among 20 healthy donors, none had elevated levels of CA72-4 or CA195, but marginal elevations of CEA were noted in 3 smokers. Despite some advantage of the new tumour marker CA72-4 in terms of specificity, its value as a serodiagnostic test in gastrointestinal cancer patients seems inferior to that of CA195 and CEA.