Role of the liver in clearance and excretion of circulating carcinoembryonic antigen (CEA)

Prognostic value of the postoperative carcinoembryonic antigen level in colorectal cancer: A meta-analysis

BACKGROUND

Carcinoembryonic antigen (CEA) is one of the commonly used preoperative biomarkers for colorectal cancer (CRC), but no meta-analysis has evaluated the findings of all recently published studies to determine whether its postoperative level can serve as a prognostic indicator.

METHODS

We conducted a systematic search for eligible literature from the PubMed, EMBASE, and Web of Science databases in October 2023. Studies that investigated the relationship between postoperative serum CEA levels and prognosis in CRC patients were included. Outcome indicators, including overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS)/recurrence-free survival (RFS), were analyzed using a fixed-effects or random-effects model. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used as effective values.

RESULTS

This meta-analysis included 20 eligible studies involving 10,114 CRC patients from the East Asian and Western countries. A comprehensive analysis revealed that elevated postoperative CEA levels were associated with low OS (HR: 2.92, 95% CI: 2.36-3.62, and p < 0.000), DFS (HR: 2.81, 95% CI: 2.01-3.94, and p < 0.000), and RFS/PFS (HR: 2.52, 95% CI: 1.75-3.62, p < 0.000). A subgroup analysis by region, analysis type, distant metastasis, HR obtain method, sample size, postoperative measurement date, and study design demonstrated that the negative correlation observed between high serum CEA levels after surgery and poor prognosis was not significantly different between the subgroups.

CONCLUSION

When CEA levels are found to be elevated during postoperative follow-up, more active intervention measures should be implemented to further improve the patient's survival outcomes.

Progress in the field of noninvasive diagnostics for colorectal cancer: a systematic review for the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions

BACKGROUND

Early detection of pre-cancerous adenomas through screening can reduce colorectal cancer (CRC) incidence. Fecal immunochemical tests are commonly used, but have limited sensitivity for pre-cancerous lesions. Blood-based screening may improve test sensitivity. This systematic review and meta-analysis was conducted to evaluate the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions.

RESEARCH DESIGN AND METHODS

We present the accuracy of blood-based biomarkers for the detection of advanced pre-cancerous lesions. EMBASE, Web of Science and PubMed databases were searched, with study populations limited to adults diagnosed with advanced pre-cancerous lesions at colonoscopy, who had a blood-based biomarker test analyzed with reports of sensitivity and specificity.

RESULTS

69 studies were identified, which assessed 133 unique biomarkers sets. The best performing test was a panel of 6 miRNAs, with a sensitivity of 95% and specificity of 90% for advanced pre-cancerous lesions. Only 6 biomarkers demonstrated sensitivity ≥ 50% and specificity ≥ 90% for the detection of advanced pre-cancerous lesions.

CONCLUSION

Many different blood-based biomarkers have been assessed for detection of advanced pre-cancerous lesions, but few have progressed beyond the discovery stage. While some biomarkers have reported high sensitivity and specificity, larger prospective studies in unbiased intended-use screening populations are required for validation.

Which patients are prone to suffer liver metastasis? A review of risk factors of metachronous liver metastasis of colorectal cancer

Background

In recent years, with the increasing incidence of colorectal cancer (CRC) and its high fatality rate, CRC has seized the attention of the world. And liver metastasis, as the main cause of death of CRC, has become the leading cause of treatment failure in CRC, especially metachronous liver metastasis, have caused patients who underwent bowel resection to experience multiple tortures.

Main body

Metachronous liver metastasis has severely affected the quality of life and prognosis of patients. Therefore, in this review, we discuss risk factors for metachronous liver metastasis of CRC, which is the premise for effective intervention for CRC patients who suffer metachronous liver metastasis after undergoing surgery, as well as the signaling pathways associated with CRC.

Conclusion

The occurrence of metachronous liver metastasis is closely related to histology-based prognostic biomarkers, serum-based biomarkers, tumor microenvironment, pre-metastatic niche, liquid biopsy and tissue-based biomarkers. Further research is required to explore the risk factors associated with liver metastasis of CRC.

Serum carcinoembryonic antigen elevation in benign lung diseases

Carcinoembryonic antigen (CEA) is not only used to aid the diagnosis of lung cancer, but also help monitor recurrence and determine the prognosis of lung cancer as well as evaluate the therapeutic efficacy for lung cancer. However, studies have also shown that CEA is present at low levels in the serum of patients with benign lung diseases (BLD), which will interfere with the accurate judgment of the disease. Due to difference in sample size, detection methods, cutoff values and sources of BLD, the positive rate of CEA in BLD is different with different literature. Therefore, it is necessary to define CEA levels in patients of different BLD in a large sample study. 4796 patients with BLD were included in this study. The results showed that the CEA levels of 3.1% (149/4796) patients with BLD were elevated, with three cases exceeds 20 ng/mL (0.06%, 3/4796). The results from the literature showed that BLD had a mean positive rate of 5.99% (53/885) and only two cases had CEA above 20 ng/mL. The CEA elevations mainly distributed in chronic obstructive pulmonary disease (COPD), pneumonitis and interstitial lung disease and significantly correlated with age of patients (OR 2.69, 95% CI 1.94–3.73, p < 0.001). Pulmonary tuberculosis (7/1311, 0.53%) had the lowest positive rate of CEA elevations while pulmonary alveolar proteinosis (6/27, 22.22%) had the highest positive rate. The majority of patients with abnormally elevated CEA levels had multiple underlying diseases, mainly diseases of the circulatory system (42.28% [63/149]), endocrine diseases (26.85% [40/149]), and respiratory or heart failure (24.16% [36/149]. In endocrine diseases, 87.5% (35/40) of patients had diabetes. In conclusion, CEA is present at a low positive rate in the serum of patients with BLD, but few exceed 20 ng/mL. For lung disease patients, if CEA levels rise, we should carry out comprehensive analysis of types of lung diseases, age of patients, and comorbid diseases.

Inappropriate practice in tumor marker requests at a university hospital in Western Saudi Arabia: A 3-year retrospective study

OBJECTIVES

This study assessed the level of appropriateness of tumor marker requests in a teaching hospital and estimated the financial cost associated with inappropriate use.

METHODS

A retrospective review of patients' electronic records was conducted over a 3-year period (2015-2017) for tumor marker requests, including carcinoembryonic antigen, alpha-fetoprotein, cancer antigen (CA)15-3, CA125, CA19-9, and total and free prostate-specific antigen (PSA and fPSA), along with the associated clinical data that motivated the requests. Inappropriate use was defined as tumor marker requests without any relevant clinical picture. Costs due to inappropriate tumor marker requests were estimated based on the unit costs applied in the institution.

RESULTS

A total of 7128 patients had at least one tumor marker request between 2015 and 2017. The clinical picture that motivated tumor marker requests was absent in 71.5%, while 12.9% of the requests were associated with a malignancy. The most frequent prescribing pattern was total prostate-specific antigen alone (2128; 29.9%), followed by alpha-fetoprotein alone (1185; 16.6%), and carcinoembryonic antigen alone (506; 7.1%). Year-over-year analysis revealed an increasing tendency in requesting carcinoembryonic antigen and CA15-3. The rate of inappropriate use varied by tumor marker and ranged between 56.4% for fPSA and 86.8% for total prostate-specific antigen. The overall costs due to inappropriate tumor marker requests were estimated at $2,785,493 over the 3 years, representing an average of $0.93 million per year.

CONCLUSION

Inappropriate use of tumor marker requests is a major issue regarding its high prevalence and the considerable associated costs. The role of laboratories in the management of tumor marker requests should be emphasized.

Prognostic value of postoperative serum carcinoembryonic antigen levels in colorectal cancer patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) can increase serum carcinoembryonic antigen (CEA) levels. We thus aimed to evaluate the impact of CKD on CEA prognostic accuracy in colorectal cancer.

METHODS

Altogether, 429 patients who underwent curative resection for stages I-III colorectal adenocarcinoma were grouped according to postoperative CEA levels and history of CKD.

RESULTS

Three-year disease-free survival (DFS) was higher in patients with normal postoperative CEA (group A, 83.4%) than in those with elevated postoperative CEA (group B, 64.3%) (p < 0.001). CKD patients had higher postoperative CEA levels than non-CKD patients (odds ratio 3.27, 95% confidence interval 1.78-5.99, p < 0.001). In multivariable analysis, postoperative CEA level was an independent prognostic factor for DFS in non-CKD, but not CKD, patients.

CONCLUSIONS

CKD can increase postoperative CEA levels in colorectal cancer patients. Elevated postoperative CEA levels were associated with shorter DFS in non-CKD, but not CKD, patients.

Tumor Markers, Liver Function Tests and Symptoms in 115 Patients with Isolated Colorectal Liver Metastases

Development of the hybridoma technique has made the identification of several new tumor antigens possible. Although it was hoped that they would be more tumor-specific, none of these markers are found exclusively in tumor or in serum of tumor patients. Compared with carcinoembryionic antigen (CEA) and liver function tests, the roles of these markers (CA 19-9, CA 125, CA 15-3) were prospectively evaluated in 115 patients with colorectal liver metastases. Patients were classified according to tumor volume (T1 <25%, T2 25-75%, T3 >75%), and the extension of infiltration (solitary/multiple/diffuse; unilateral, bilateral). Patients with benign liver or biliary disease served as a control group (n=63). Overall sensitivity was 87% for *1 , 50% for *2 and 38% for *3 , with a significant correlation with tumor size. CEA serum levels were elevated in 88% of all patients. CA 19-9 was less sensitive: positive in 59%. Because of some complementary elevations, the combined use of CEA, CA 19-9 and CA 125 raised sensitivity to 94%. CA 19-9 and LDH could be useful for confirmation because of their higher specificity; however, the specificity of CEA rose to 93% on using a cut-off of 10 ng/ml instead of 3 ng/ml. The results indicate that CEA and CA 19-9 as well as liver function tests are helpful for preoperative staging in conjunction with imaging procedures before liver resection or regional chemotherapy.

Evaluation of the Behavior of Carcinoembryonic Antigen in Cirrhotic Patients

Benign liver diseases are a cause of increased serum levels of CEA. We studied the behavior of CEA in 86 patients with liver cirrhosis who underwent extensive clinical and laboratory evaluation. We found abnormal CEA levels in 38.4% of the patients (28.6% Child's grade A, 40.6% Child's B, and 42.4% Child's C) with a mean of 4.75 ng/ml. Significant differences were found between patients and controls. There was a trend towards higher levels of CEA in more severe cirrhosis according to Child's classification, although this was not significant. We found significant correlations between CEA and some liver tests, including glycocholic acid (r = 0.264., p = 0.012), a marker of severity in liver diseases. The increase of CEA in these patients is probably due to alterations in its metabolic processing caused by hepatocellular dysfunction. Moderate elevations of serum CEA can be expected in cirrhotic patients independently of malignancy.

Enhanced colorectal cancer metastases in the alcohol-injured liver

Metastatic liver disease is a major cause of mortality in colorectal cancer (CRC) patients. Alcohol consumption is a noted risk factor for secondary cancers yet the role of alcoholic liver disease (ALD) in colorectal liver metastases (CRLM) is not defined. This work evaluated tumor cell colonization in the alcoholic host liver using a novel preclinical model of human CRC liver metastases. Immunocompromised Rag1-deficient mice were fed either ethanol (E) or isocaloric control (C) diets for 4 weeks prior to intrasplenic injection of LS174T human CRC cells. ALD and CRLM were evaluated 3 or 5 weeks post-LS174T cell injection with continued C/E diet administration. ALD was confirmed by increased serum transaminases, hepatic steatosis and expression of cytochrome P4502E1, a major ethanol-metabolizing enzyme. Alcohol-mediated liver dysfunction was validated by impaired endocytosis of asialoorosomucoid and carcinoembryonic antigen (CEA), indicators of hepatocellular injury and progressive CRC disease, respectively. Strikingly, the rate and burden of CRLM was distinctly enhanced in alcoholic livers with metastases observed earlier and more severely in E-fed mice. Further, alcohol-related increases (1.5-3.0 fold) were observed in the expression of hepatic cytokines (TNF-α, IL-1 beta, IL-6, IL-10) and other factors noted to be involved in the colonization of CRC cells including ICAM-1, CCL-2, CCL-7, MMP-2, and MMP-9. Also, alcoholic liver injury was associated with altered hepatic localization as well as increased circulating levels of CEA released from CRC cells. Altogether, these findings indicate that the alcoholic liver provides a permissive environment for the establishment of CRLM, possibly through CEA-related inflammatory mechanisms.

Avoiding hepatic metastasis naturally: Lessons from the cotton top tamarin (Saguinus oedipus)

Much has been written about hepatic metastasis and animal models abound. In terms of the human experience, progress in treating this final common pathway, a terminal event of many human malignancies has been relatively slow. The current thinking is that primary prevention is best served by early detection of cancer and eradication of early stage cancers by screening. Some cancers spread early in their course and the role of screening may be limited. Until relatively recently there has not been a pathfinder model that makes the evasion of this unfortunate event a reality. This review discusses such an animal model and attempts to relate it to human disease in terms of intervention. Concrete proposals are also offered on how scientists may be able to intervene to prevent this deadly progression of the cancer process.

Physiology of cholangiocytes

Cholangiocytes are epithelial cells that line the intra- and extrahepatic ducts of the biliary tree. The main physiologic function of cholangiocytes is modification of hepatocyte-derived bile, an intricate process regulated by hormones, peptides, nucleotides, neurotransmitters, and other molecules through intracellular signaling pathways and cascades. The mechanisms and regulation of bile modification are reviewed herein.

Tumor marker requests in a general teaching Turkish hospital

Serum tumor markers may be requested inappropriately by clinicians. In this retrospective study, we aimed to investigate the appropriateness of TM requests in our hospital. Patients in the study were identified from the TM requests for 3 months between June-August 2004, using the laboratory database. A total of 2249 patients (1351 men, 898 women) were included in the study and there were 6570 TM requests. The number of requests were 1050 (16%) for Carbohydrate Antigen 19-9, 993 (15.1%) for Cancer Antigen 125, 941 (14.3%) for Prostate Specific Antigen, 921 (14%) for free PSA, 925 (14.1%) for Cancer Antigen 15-3, 788 (12%) for Alphafetoprotein, 730 (11.1%) for Carcinoembryonic Antigen and 222 (3.4%) for AFP/Human Chorionic Gonadotrophin. Our findings support the idea that for the evidence-based use of TM requests the education of clinical staff is required. Clear clinical guidelines including recommendations about the appropriate use of TM can be useful for this education process. Careful audit studies are also useful to determine the impact of these guidelines on the practice of evidence-based laboratory medicine.

Hexapeptide fragment of carcinoembryonic antigen which acts as an agonist of heterogeneous ribonucleoprotein M

Colorectal cancers with metastatic potential secrete the glycoprotein carcinoembryonic antigen (CEA). CEA has been implicated in colorectal cancer metastasis by inducing Kupffer cells to produce inflammatory cytokines which, in turn, make the hepatic micro-environment ideal for tumor cell implantation. CEA binds to the heterogeneous ribonucleoprotein M (hnRNP M) which acts as a cell surface receptor in Kupffer cells. The amino acid sequence in CEA, which binds the hnRNP M receptor, is Tyr-Pro-Glu-Leu-Pro-Lys. In this study, the structure of Ac-Tyr-Pro-Glu-Leu-Pro-Lys-NH₂ (YPELPK) was investigated using electronic circular dichroism, vibrational circular dichroism, and molecular dynamics simulations. The binding of the peptide to hnRNP M was also investigated using molecular docking calculations. The biological activity of YPELPK was studied using differentiated human THP-1 cells, which express hnRNP M on their surface and secrete IL-6 when stimulated by CEA. YPELPK forms a stable polyproline-II helix and stimulates IL-6 production of THP-1 cells at micromolar concentrations.

Regulation of carcinoembryonic antigen release from colorectal cancer cells

Clinical and experimental evidence suggest that circulating carcinoembryonic antigen (CEA) released from tumor cells has an instrumental role in colorectal cancer-liver metastasis. However, the precise mechanism of the regulation of the CEA release from cancer cells is not known. We investigated if the rate of CEA and another GPI-anchored protein, alkaline phosphatase (AP) release is correlated with cellular glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) expression. We also evaluated the effects of phosphatidic acid (PA), a compound known to inhibit GPI-PLD activity, on the CEA and AP release from colon cancer cells. The expression of CEA, GPI-PLD, and AP in five colon carcinoma cells (LS180, Caco2, SW742, SW1116, and HT29/219) was verified by immunoblot and real-time RT-PCR analysis. The amounts of CEA and AP released into cell culture media were determined using ELISA and a colorimetric assay, respectively. We examined the effects of PA (20-100 μM) on CEA and AP release from LS180 cells. All five cancer cell lines analyzed expressed GPI-PLD protein. While there was a positive relationship between AP release and the levels of GPI-PLD transcript expression, we found no direct correlation between CEA released from cancer cells and the GPI-PLD mRNA expression level. However, the rate of CEA release was positively associated with the level of CEA transcript expression. In comparison to controls, the release of GPI-anchored CEA and AP, but not CA19-9 was inhibited significantly by both crude and pure phosphatidic acid (by 56 and 54.5%, respectively). Using PA for inhibiting CEA release from cancer cells may have therapeutic application in preventing CRC-liver metastasis.

Relationship between peripheral and mesenteric serum levels of CEA and CA 242 with staging and histopathological variables in colorectal adenocarcinoma

PURPOSE

To compare histopathological variables and staging in colorectal adenocarcinoma cases with CEA and CA 242 in peripheral and mesenteric blood.

METHODS

In 169 individuals underwent surgery for colorectal cancer, CEA and CA 242 were analyzed and compared to mesenteric and peripheral blood and correlated with macroscopic tumor's morphology and size, degree of cell differentiation, venous, neural and lymphatic involvement and TNM classification.

RESULTS

There was a difference between the mesenteric (M) and peripheral (P) serum levels of CEA (p=0.020). Higher levels of markers were correlated with venous invasion CEA (P) p=0.013, CEA (M) p=0.05, CA 242 (M) p=0.005 and CA 242 (P) p=0.038; with advanced staging CEA (P) < CEA (M) (p < 0.05); CA 242 (P) < CA 242 (M) (p < 0.05); and with greater dimensions CEA (P) < CEA (M) (p < 0.001); CA 242 (P) < CA 242 (M) (p < 0.001). CA 242 became higher with neural invasion (P): p=0.014, (M): p=0.003).

CONCLUSIONS

There were higher mesenteric than peripheral levels of CEA. Both mesenteric and peripheral levels of CEA and CA 242 were higher in neoplasm with venous involvement, greater diameter and advanced stages. There was a correlation between CA 242 and neural invasion.

An audit of tumour marker utilization in Greece

INTRODUCTION

Several international organizations have published guidelines for the correct use of tumour markers in clinical practice. However, there are reports that clinicians do not adhere to these guidelines in clinical practice. The present study constitutes an audit of TM use in a major hospital in Northern Greece. Purpose of our study is to quantify the magnitude of inappropriate TM requests as well as the corresponding financial cost.

METHODS

We examined retrospectively all TM requests between 10/2006 and 07/2007 in the department of biochemistry of our hospital. The tumour markers included in our study were: CA 19-9, CA 125, CA 15-3, AFP, NSE, CYFRA 21-1 and CEA.

RESULTS

We found 9782 inappropriate TM orders. For five of them - namely CA 125, AFP, CA 19-9, CYFRA 21-1 and NSE - the proper requests were below 10%. There were 5.6 TM requests per patient. The total cost for inappropriate TM reached 239,748 euro, which corresponds to a monthly cost of 23,974euro.

CONCLUSIONS

There is considerable inappropriateness in the utilization of TM in Greece which corresponds to significant financial cost. Various measures should be applied in order to increase the cost-effectiveness of TM use.

Normalisation of high CA 19-9 values in autoimmune hepatitis after steroidal treatment

Carbohydrate 19-9 antigen (CA 19-9) is considered a specific marker of pancreatobiliary adenocarcinomas, but slight increase of its levels can be found in several non-malignant diseases of the liver, such as autoimmune hepatitis. We describe a case of marked CA 19-9 elevation (up to 898.0 U/ml) in a patient with autoimmune hepatitis. Laboratory and instrumental examinations excluded malignant diseases. Immunohistochemical analysis for CA 19-9 and MIB-1, performed on liver biopsy, showed reactivity in inflammatory areas, in particular in bile ductule cells and hepatocytes in ductular metaplasia, suggesting that these cells could be involved in CA 19-9 serum levels increase. After steroids, the clinical picture improved and all the laboratory parameters normalised.

Determination of carcinoembryonic antigen levels in peripheral and draining venous blood in patients with colorectal carcinoma

BACKGROUND: The problem of the relationship between blood carcinoembryonic antigen (CEA) levels and tissue CEA content in colorectal carcinoma, and the mechanisms for CEA release from tumor cells in tissue adjacent to the neoplasm is important to understanding the biology of colorectal carcinoma. It has not been adequately explained whether CEA in the peripheral blood is drained mainly by portal system blood or by the lymphatic system, or indeed by both systems. AIM: To study the behavior of CEA levels in peripheral blood (CEA-p) and venous effluent blood (CEA-d) among patients with colorectal tumors, who underwent curative operation. METHOD: A total of 28 patients were studied (12 male [42.9%] and 16 female [57.1%], mean age 66.1 years [range: 43 - 84]). Immediately after laparotomy, peripheral venous blood was extracted by antecubital venous puncture and venous effluent blood was collected from the main drainage vein of the lesions. Values of CEA-p, CEA-d and the gradient between CEA-d and CEA-p that were less than 5.0 ng/mL were considered normal. RESULTS: Eight (28.6%) patients were stage A in Duke's classification, nine (32.1%) stage B and 11 (39.3%) stage C. The neoplasm was located in the rectum of 14 patients (50.0%), in the transverse colon in five (17.9%), in the sigmoid in four (14.3%), in the cecum and/or ascending colon in three (10.7%), and in the descending colon in two (7.1%). The histopathological examination revealed well-differentiated adenocarcinoma in all the patients. Only one patient (3.6%), Duke's classification stage C, presented neoplasm with venous invasion. The gradient between the CEA-p and CEA-d levels were normal in 25 patients (88.3%) and high in three (10.7%). The mean value for CEA-p was 3.8 ± 4.1 ng/mL (0.1-21.1 ng/mL) and for the drained CEA (CEA-d) it was 4.5 ± 4.3 ng/mL (0.3-20.2 ng/mL), without significant difference between these values. There was a significant difference between the mean value for CEA-p and CEA-d levels greater than 5 ng/mL. CONCLUSION: The CEA-p and CEA-d levels in the colorectal carcinoma patients were not shown to be different. The results from this study suggest that, in colorectal neoplasm without venous invasion, there may not be notable CEA drainage from the tumor by the portal vein effluent blood.

Differences in plasma gastrin, CEA, and CA 19-9 concentration in patients with proximal and distal colorectal cancer

AIM

We investigated whether there are differences in plasma gastrin, as compared with carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 between patients with proximal and distal colorectal cancer. Gastrin concentration has also been analyzed, dependent on the tumor stage, in order to evaluate the possible prognostic role of this measurement.

METHODS

In 50 patients with colon cancer-fasting gastrin, CA 19-9 and CEA levels were evaluated.

RESULTS

Mean plasma-gastrin level in patients with distal tumor yielded 105.31 +/- 12.5 microU/L and was significantly higher than in patients with the proximal tumor site (42.2 +/- 3.1 microU/L) as well as in controls (p < 0.001). No significant difference was observed between mean plasma gastrin in patients with proximal tumors and the control group. The mean CEA plasma level was significantly higher (p < 0.01) in patients with distal tumors (9.1 +/- 1.1 ng/mL) than in those with proximal tumors (1.48 +/- 0.1 ng/mL). Similarly, the mean CA 19-9 plasma level was significantly higher (p < 0.01) in patients with distal tumor (19.9 +/- 2.1 U/mL) than in those with proximal tumor: 1.8 +/- 0.2 U/mL. The mean gastrin plasma, CA 19-9, and CEA level was significantly higher in group of Duke's stage C and D as compared to A and B.

CONCLUSION

We speculate that observed differences in gastrin concentration in patients with distal and proximal tumors may contribute to the distinct pathogenesis and biological properties of those cancers. The significance of gastrin as a marker for diagnostic or prognostic purposes in colorectal cancer requires further study.

Matrix metalloproteinase-2 and -9 in bile as a marker of liver metastasis in colorectal cancer

Matrix metallproteinases (MMP)-2 and -9 are associated with cancer invasion and metastasis. MMP-2 and MMP-9 activities have never been assayed in bile. In the present study we investigated whether MMP-2 and -9 activities in the bile could be a marker for evaluation of liver metastasis in colorectal cancer. Fifty-three patients underwent colorectal resection for histologically verified adenocarcinoma. Twenty-six patients had colorectal cancer without liver metastasis and 27 patients had metastatic liver tumor. Six patients were studied as carcinoma-free control. MMP-2 and MMP-9 activities were assayed in bile using gelatin zymography and quantitated. Active MMP-2 activity of colorectal cancer with liver metastasis group (24.1 +/- 2.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (11.4 +/- 1.3 pixel count) (P < 0.001) or of control group (6.4 +/- 1.0 pixel count) (P < 0.001). Active MMP-9 was not detected in bile. ProMMP-9 activity of colorectal cancer with liver metastasis group (530.3 +/- 127.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (213.9 +/- 33.2 pixel count) (P = 0.008). This is the first report showing that the levels of active MMP-2 and proMMP-9 in bile were significantly higher in liver metastasis of colorectal cancer than in metastasis-free colorectal cancer. The results suggest that activities of active MMP-2 and proMMP-9 in the bile may be useful markers for predicting liver metastasis in colorectal cancer.

Value of CEA level determination in gallbladder bile in the diagnosis of liver metastases secondary to colorectal adenocarcinoma

CONTEXT

The relevance of colorectal adenocarcinoma lies in its high incidence, with the liver being the organ most frequently affected by distant metastases. Liver metastases occur in 40 to 50% of patients with colorectal adenocarcinoma, accounting for approximately 80% of deaths in the first three postoperative years. Nevertheless, despite this, they are occasionally susceptible to curative treatment.

OBJECTIVE

The present investigation focused on the relationship between the level of carcinoembryonic antigen (CEA) in gallbladder bile and the presence of liver metastases secondary to colorectal adenocarcinoma.

DESIGN

Diagnostic test study.

SETTING

Surgical Gastroenterology Discipline at the São Paulo Hospital, São Paulo, Brazil.

SAMPLE

Forty-five patients with colorectal adenocarcinoma were studied, 30 without liver metastases (group I), and 15 with liver metastases (group II). Diagnosis of liver metastases was made through computed tomography, magnetic resonance imaging and computed tomography during arterial portography. Samples of peripheral blood, portal system blood, and gallbladder bile were collected from patients during the surgical procedure. A control group composed of 18 organ donors underwent the same material collection procedures. CEA level determination was made through fluoroimmunoassay.

RESULTS

Mean CEA value in peripheral serum was 2.0 ng/ml (range: 0.7 to 3.8 ng/ml) in the control group, 11.4 ng/ml (range: 0.5 to 110.3 ng/ml) in group I, and 66.0 ng/ml (range: 2.1 to 670 ng/ml) in group II. In the portal system, serum mean values found were 1.9 ng/ml (range: 0.4 to 5.0 ng/ml) in the control group, 15.3 ng/ml (range: 0.8 to 133.3 ng/ml) in group I, and 70.8 ng/ml (range: 1.8 to 725 ng/ml) in group II. Mean values found in gallbladder bile were 4.1 ng/ml (range: 1.0 to 8.6 ng/ml) in the control group, 14.3 ng/ml (range: zero to 93.0 ng/ml) in group I, and 154.8 ng/ml (range: 14.0 to 534.7 ng/ml) in group II.

CONCLUSIONS

The CEA level in gallbladder bile is elevated in patients with liver metastases. Determination of CEA both in peripheral serum and in gallbladder bile enabled patients with liver metastases to be distinguished from those without such lesions. The level of CEA in gallbladder bile, however, seems to lead to a more accurate diagnosis of liver metastases secondary to colorectal adenocarcinoma.

Hierarchy of post-translational modifications involved in the circulatory longevity of glycoproteins. Demonstration of concerted contributions of glycan sialylation and subunit assembly to the pharmacokinetic behavior of bovine acetylcholinesterase

The tetrameric form of native serum-derived bovine acetylcholinesterase is retained in the circulation for much longer periods (mean residence time, MRT = 1390 min) than recombinant bovine acetylcholinesterase (rBoAChE) produced in the HEK-293 cell system (MRT = 57 min). Extensive matrix-assisted laser desorption ionization-time of flight analyses established that the basic structures of the N-glycans associated with the native and recombinant enzymes are similar (the major species (50-60%) are of the biantennary fucosylated type and 20-30% are of the triantennary type), yet the glycan termini of the native enzyme are mostly capped with sialic acid (82%) and alpha-galactose (12%), whereas glycans of the recombinant enzyme exhibit a high level of exposed beta-galactose residues (50%) and a lack of alpha-galactose. Glycan termini of both fetal bovine serum and rBoAChE were altered in vitro using exoglycosidases and sialyltransferase or in vivo by a HEK-293 cell line developed specifically to allow efficient sialic acid capping of beta-galactose-exposed termini. In addition, the dimeric and monomeric forms of rBoAChE were quantitatively converted to tetramers by complexation with a synthetic peptide representing the human ColQ-derived proline-rich attachment domain. Thus by controlling both the level and nature of N-glycan capping and subunit assembly, we generated and characterized 9 distinct bovine AChE glycoforms displaying a 400-fold difference in their circulatory lifetimes (MRT = 3.5-1390 min). This revealed some general rules and a hierarchy of post-translation factors determining the circulatory profile of glycoproteins. Accordingly, an rBoAChE was generated that displayed a circulatory profile indistinguishable from the native form.

Carbohydrate 19-9 antigen as a marker of non-malignant hepatocytic ductular transformation in patients with acute liver failure. A comparison with alpha-fetoprotein and carcinoembryonic antigen

BACKGROUND

We have observed increased serum tumor markers, especially carbohydrate antigen 19-9 (CA 19-9) levels, in patients with acute liver failure (ALF) being evaluated for liver transplantation, raising the question of potential malignancy. In chronic liver disease increased serum alpha-fetoprotein (AFP) may be a sign of liver regeneration, but little is known of these markers in ALF. The aim of this study was to evaluate the causes of overexpression of tumor markers in patients with non-malignant ALF.

METHODS

The serum AFP, carcinoembryonic antigen (CEA), and CA 19-9 levels were compared with the liver function tests in 33 patients with acute liver failure and in 78 patients with chronic non-malignant liver disease being evaluated for liver transplantation. Immunohistochemical stainings of the tumor markers were performed on explanted liver specimens.

RESULTS

The AFP (1-218 U/ml) and CA 19-9 (10-6520 U/ml) levels were significantly higher in the patients with ALF than in the patients with chronic liver disease (P < 0.01). The AFP and CA 19-9 values also correlated with the total serum bilirubin level. In the patients with ALF the immunohistochemical staining for CA 19-9 was highly positive in periportal transformed ductular hepatocytes and correlated positively with the serum CA 19-9 values (P < 0.001). The stainings for AFP or CEA showed no or only slight positivity in the patients with increased serum values of the tumor markers.

CONCLUSIONS

In patients with ALF increased serum levels of CA 19-9 reflect the amount of transformed ductular hepatocytes without any evidence of malignancy. Increased CA 19-9 values should not be the cause of delay when an ALF patient needs an urgent liver transplantation.

A predictive value of carcinoembryonic antigen in draining venous blood for colorectal cancer patients with postoperative hematogenous metastases

Correlations between carcinoembryonic antigen (CEA) levels of peripheral (p) and draining (d) venous blood and postoperative hematogenous metastases (HM) were examined in 76 advanced (T2-4) colorectal adenocarcinoma patients, to clarify a predictive value of dCEA and the gradient (d-pCEA) between d- and pCEA levels in patients with HM. HM were found in 19 patients (HM group), but not found in 57 patients (non-HM group). The mean value (27.4 ng/ml) of dCEA and positive rates (100 and 89.5%) of d- and d-pCEA levels were significantly higher than those (9.8 ng/ml and 57.9%) of pCEA in the HM group, though no significant difference was found among p-, d-, and d-pCEA values and positive rates in the non-HM group. Significant linear correlations, Y (log dCEA, ng/ml) = -0.039X (month) + 2.016 and Y (log d-pCEA, ng/ml) = -0.039X (month) + 1.823, were found between d- and d-pCEA levels and HM-diagnostic period. These results suggest that colorectal cancer patients with HM are more effectively predicted by the determination of d- and d-pCEA levels than of pCEA levels and that they are patients with positive d- and d-pCEA levels. These patients seem to have a high possibility of early HM.

Endocytosis in rat intrahepatic bile duct epithelial cells of horseradish peroxidase injected into the common bile duct or the portal vein

While recent data in intrahepatic bile duct epithelial cells (IBDECs) isolated from normal rat liver have established their ability to undergo endocytosis, few studies have assessed endocytosis in IBDECs in situ. Thus, to clarify the activity of IBDECs in situ on macro-molecules in bile and blood, we injected horseradish peroxidase (HRP) into either the common bile duct or the portal vein, and determined its intracellular distribution by electron microscopic cytochemistry. Successful retrograde injection into the common bile duct was achieved by resection of the liver surface so as to avoid HRP leakage from the bile duct on injection. IBDECs internalized HRP through both the apical and basolateral plasma membranes. By quantitative analysis, counting the number of HRP-positive vesicles in the cells, apical endocytosis was found more active than basolateral. HRP internalized through the apical membrane was either routed to the acid phosphatase-positive lysosomes for degradation or to extracellular space for transcytosis. HRP through the basolateral membrane was transferred to the organelles having lipid inclusion, which were expected to be lysosomes negative for acid phosphatase. Our results suggest that IBDECs in situ are actively engaged in endocytosis for degradation of macromolecules in bile and blood, and possibly engaged in the excretion of macromolecules into extracellular space.

Identification of carcinoembryonic antigen-producing cells circulating in the blood of patients with colorectal carcinoma by reverse transcriptase polymerase chain reaction

BACKGROUND

Application of the reverse transcriptase polymerase chain reaction (RT-PCR) to identification of circulating tumour cells in colorectal cancer.

AIMS

To assess whether circulating malignant cells in patients with colorectal liver metastasis could be identified by RT-PCR recognition of mRNA coding for the tumour marker carcinoembryonic antigen (CEA).

PATIENTS

A total of 31 with colorectal liver metastases and 22 no-cancer controls.

METHODS

Specific cDNA primers for CEA transcripts were used to apply RT-PCR to tissue biopsy specimens, colon carcinoma cell lines, and peripheral blood samples from patients with colorectal liver metastases. A strongly CEA-expressive HT115 colorectal carcinoma cell line was used to spike blood samples from no-cancer control subjects.

RESULTS

The limit for detection of CEA cDNA by Southern blotting using HT115 cells was 50 cells per 14 ml of spiked blood. There was a significant difference (p = 0.007) in RT-PCR positive expression between patients with liver metastasis (26/31) compared with controls (5/22). There was no significant relation between the prevalence of CEA cDNA amplification and serum CEA level or metastasis volume in patients with liver metastasis.

CONCLUSIONS

This is the first study to suggest that identification of circulating colorectal cancer cells using RT-PCR for detection of CEA cDNA is feasible.

Differences in serum tumor markers between colon and rectal cancer. Comparison of CA 242 and carcinoembryonic antigen

PURPOSE

We investigated whether there are differences in serum levels of CA 242 and carcinoembryonic antigen (CEA) between patients with colon and rectal cancer.

METHODS

Preoperative serum levels of CA 242 and CEA were determined in 153 patients with colon cancer and in 107 patients with rectal cancer.

RESULTS

At the recommended cut-off levels for CA 242 and CEA, the overall sensitivity of CA 242 was 39 percent for both colon and rectal cancer, whereas the sensitivity of CEA was 40 percent for colon and 47 percent for rectal cancer. A combination of CA 242 and CEA increased overall sensitivity to 57 percent in colon cancer and to 62 percent in rectal cancer, whereas specificity decreased by 10 percent, compared with CEA alone. In colon cancer either or both markers were elevated in 38, 46, 56, and 84 percent of patients with Dukes Stages A, B, C, and D, respectively. Corresponding figures for rectal cancer were 52, 46, 71, and 87 percent, respectively.

CONCLUSIONS

CA 242 showed equal sensitivity for colon and rectal cancer. In Stages A, C, and D, sensitivity of CEA and of a combination of CEA and CA 242 was higher in rectal than in colon cancer, but the difference was not significant. Concomitant use of markers increased sensitivity sharply compared with use of a single marker both in colon and rectal cancer.

Involvement of oligomerization, N-glycosylation and sialylation in the clearance of cholinesterases from the circulation

The possible role of post-translational modifications such as subunit oligomerization, protein glycosylation and oligosaccharide processing on the circulatory life-time of proteins was studied using recombinant human acetylcholinesterase (rHuAChE). Different preparations of rHuAChE containing various amounts of tetramers, dimers and monomers are cleared at similar rates from the circulation, suggesting that oligomerization does not play an important role in determining the rate of clearance. An engineered rHuAChE mutant containing only one N-glycosylation site was cleared from the circulation more rapidly than the wild-type triglycosylated enzyme. On the other hand, hyperglycosylated mutants containing either four or five occupied N-glycosylation sites, analagous to those present on the slowly cleared fetal bovine serum acetylcholinesterase (FBS-AChE), were also cleared more rapidly from the bloodstream than the wild-type species. Furthermore, the two different tetraglycosylated mutants were cleared at different rates while the pentaglycosylated mutant exhibited the most rapid clearance profile. These results imply that though the number of N-glycosylation sites plays a role in the circulatory life-time of the enzyme, the number of N-glycan units in itself does not determine the rate of clearance. When saturating amounts of asialofetuin were administered together with rHuAChE, the circulatory half-life of the enzyme was dramatically increased (from 80 min to 19 h) and was found to be similar to that displayed by plasma-derived cholinesterases while desialylation of these enzymes caused a sharp decrease in the circulatory half-life to approximately 3-5 min. Determination of the average number of sialic acid residues per enzyme subunit of the five different N-glycosylation species generated, revealed that the rate of clearance is not a function of the absolute number of appended sialic acid moieties but rather of the number of unoccupied sialic acid attachment sites per enzyme molecule. Specifically, we demonstrate an inverse-linear relationship between the number of vacant sialic acid attachment sites and the values of the enzyme residence time within the bloodstream.

Diagnostic pitfall; interpretation of CA 19-9 concentrations in the presence of hepatic dysfunction

A 50 year old man is described with hepatic dysfunction and chronic pancreatitis in whom greatly increased concentrations of the pancreatic tumour marker CA 19-9 combined with an abnormal appearance at endoscopic retrograde cholangiopancreatography lead to the false suspicion of pancreatic carcinoma. CA 19-9 concentrations should be interpreted with caution in patients with intrinsic liver disease or biliary obstruction.

Pre- and postoperative carcinoembryonic antigen determinations in hepatic resection for colorectal metastases. Predictive value and implications for adjuvant treatment based on multivariate analysis

OBJECTIVE

The object of this study was to evaluate the prognostic significance of pre- and postoperative serum carcinoembryonic antigen (CEA) levels in the resectional treatment of colorectal hepatic metastases. The main question was whether postoperative CEA levels correlated with survival and the time to recurrence.

SUMMARY BACKGROUND DATA

Despite numerous investigations on prognostic factors in colorectal cancer, only sparse data are available to estimate the patient's individual risk for tumor recurrence postoperatively. It is controversial whether preoperative CEA values are of prognostic significance, and after observing the kinetics of CEA decline, elevated CEA levels postoperatively were found to be an ominous sign. CEA therefore could indicate the presence of a tumor burden after resection.

METHODS

One hundred sixty-six patients undergoing hepatic resection for colorectal metastases with curative intent were prospectively documented and underwent multivariate analysis for indicators of prognosis.

RESULTS

Abnormal preoperative CEA levels were not of prognostic significance compared with values within the normal range (survival, 36 vs. 30 months; p = 0.12; disease-free survival, 12 vs. 10 months; p = 0.82). The postoperative serum CEA level, however, was the most predictive factor with regard to survival and the disease-free interval. Patients in whom CEA levels were abnormal before surgery and returned into the normal range after resection had significantly better survival times (37 vs. 23 months, p = 0.0001) and disease-free survival times (12 vs. 6.2 months, p = 0.0001) compared with patients with persistently abnormal values.

CONCLUSIONS

Pre- and postoperative determination of the serum CEA level is mandatory to judge whether a curative resection has been performed and whether tumor has been left behind after the operation. Postoperative CEA levels also should be used as a stratification criterion in adjuvant treatment studies after hepatic resection to indicate patients with a high risk of tumor recurrence.

The influence of cholestasis on CA 50 and CA 242 in pancreatic cancer and benign biliopancreatic diseases

The tumour markers CA 50 and CA 242 were determined in serum from 70 cholestatic patients--35 with pancreatic cancer and 35 with benign biliopancreatic diseases. Both markers correlated (r = 0.37) with serum bilirubin in all patients. When the patients were subdivided into groups, the only correlation apparent was between CA 50 and bilirubin in patients with benign diseases (r = 0.40). The serum concentrations of both markers were much higher in patients with pancreatic cancer. Serial sampling before and after decompression of the cholestasis showed reduction of CA 50 and CA 242 concurrently with bilirubin and alkaline phosphatases in nine patients with benign disease but unchanged levels in six cancer patients. When the two markers were compared, sensitivity was superior for CA 50 (94% versus 73%), whereas specificity was better for CA 242 (65% versus 34%), as was positive prediction (76% versus 59%), whereas negative prediction was higher for CA 50 (86% versus 61%). Higher cut-off levels yielded better specificity for CA 50 but not for CA 242. Both markers indicate pancreatic cancer irrespective of cholestasis, but moderate elevations occur in some patients with benign disorders.

Extra-hepatic cholestasis determines a reversible increase of glycoproteic tumour markers in benign and malignant diseases

This study was performed in order to assess the relative role of cholestasis in increasing some serum glycoproteic markers of malignancy (CA 19-9, TPA, CEA). 30 Patients with benign and 16 with malignant extra-hepatic cholestasis were studied on admission (stage A) and after the operative or spontaneous resolution of the cholestatic picture (stage B). CA 19-9 and TPA were found to be lower in stage B than in stage A benign diseases. A similar behaviour was found in malignant diseases, although findings were significant only for CA 19-9. In neither of the patient groups was CEA found to present a significant trend. Extra-hepatic cholestasis appears able to increase per se serum glycoproteic markers in benign diseases, with variations proportional to the severity of the clinical picture. The same considerations can apply to malignancies, even if in these situations the production of tumour markers by the neoplastic growth should also be considered. We should therefore be cautious in assessing the diagnostic usefulness of new tumour markers when cholestasis is present.

Carcinoembryonic antigen levels of peripheral and draining venous blood in patients with colorectal cancer. Correlation with survival

Correlations between preoperative carcinoembryonic antigen (CEA) levels of peripheral (p-CEA) and draining blood (d-CEA), the CEA gradient between d-CEA and p-CEA (d-p CEA gradient) levels, and survival after resection of cancer lesions were examined in 94 patients with colorectal cancer. Survival rates of patients with normal p-CEA and d-CEA levels and d-p CEA gradient levels (less than 5 ng/ml) were significantly better than those of patients with abnormal levels (greater than or equal to 5 ng/ml), and the 5-year survival rates were, respectively, 62%, 69%, and 72% in the former and 42%, 41%, and 35% in the latter. The differences in the 5-year survival rates between patients with normal and abnormal d-p CEA gradient, d-CEA, and p-CEA levels were 37%, 28%, and 20%, respectively. Furthermore, the positive rates of d-CEA levels (64%) and d-p CEA gradient levels (48%) were higher than that of p-CEA levels (36%). However, some significant differences in background variables also were found between the respective groups of patients with normal and abnormal p-CEA and d-CEA levels and d-p CEA gradient levels. These results suggest that patients with poor prognoses are examined more effectively by determining their d-p CEA gradient and d-CEA levels than their p-CEA levels, and that CEA may be expressed as a quantitative sum total of various pathophysiologic variables of patients with colorectal cancer but not as an independent prognostic variable.

Metastatic potential of human colon cancer cell lines: relationship to cellular differentiation and carcinoembryonic antigen production

The relationship between cellular differentiation and carcinoembryonic antigen (CEA) production by human colorectal tumor cells and their ability to form hepatic metastases was studied. Eight human colon cancer cell lines were injected into athymic mice using different routes of administration to characterize their metastatic potential. The four poorly differentiated, non or low CEA producing cell lines were poorly metastatic to the liver after intrasplenic injection. After intraperitoneal implantation the same cell lines were highly tumorigenic, and subsequently metastatic to the liver. In contrast, the four moderate to well-differentiated cell lines that produced moderate to high levels of CEA were highly metastatic to the liver following intrasplenic injection. After intraperitoneal implantation they were less tumorigenic, and metastatic to the liver. We conclude that in this system poorly differentiated non or low CEA producing colorectal cell lines have a lower metastatic capacity compared to the well-differentiated high CEA producing colorectal cell lines. These data correlate directly with the pattern of metastatic spread and clinical course observed in patients with these tumors, suggesting that degree of differentiation and level of CEA production may play a role in development of site-specific metastases.

Breast cancer-associated antigen CA 15.3 in liver cirrhosis

The tumor marker CA 15.3 was studied in 85 patients with liver cirrhosis. Nine patients (10.6%) had abnormal levels of CA 15.3 with the highest values in cases of Child's C patients. However, Child's classes were not significantly associated with the level of the antigen. We found significant correlations with some laboratory tests, especially IgA. All patients with an elevated CA 15.3 value also had abnormal levels of IgA, and multivariate analysis showed that IgA was the only independent factor associated with CA 15.3. Although IgA is a marker of alcoholic liver disease, other markers of alcoholism were not associated with CA 15.3. Cytolysis and cholestasis were not significantly associated with the CA 15.3 level, but liver dysfunction seemed to be involved. Liver disease does not substantially limit the usefulness of CA 15.3 in the cancer patient who also has liver cirrhosis, since both the percentage of abnormal values and the elevation of the serum levels are moderate in cirrhotic patients.

Serum CA 19-9 and alpha-fetoprotein levels in primary hepatocellular carcinoma and liver cirrhosis

Serum CA 19-9 and alpha-fetoprotein (AFP) levels were determined in 211 patients with liver cirrhosis and 27 with primary hepatocellular carcinoma (HCC) associated with liver cirrhosis. This was done to determine the usefulness of CA 19-9 level with respect to AFP level in distinguishing between these two illnesses, and to assess the influence of some clinical and biochemical variables on these tests in patients with liver cirrhosis with or without primary HCC. Pathologic AFP values were found in 23 of 27 (sensitivity, 85%) patients with HCC; CA 19-9 levels increased in only 12 of 27 (sensitivity, 44%) HCC patients, the values being comparable with those of patients with liver cirrhosis. In liver cirrhosis a substantial number of false-positive values was found for both markers, although they were higher for CA 19-9 (50 of 211 versus 39 of 211). In liver cirrhosis correlations were found between AFP level and alanine amino-transferase level; and between CA 19-9 level and (1) total bilirubin value, (2) alkaline phosphatase level, and (3) pseudocholinesterase level. The authors conclude that CA 19-9 level is a poor biochemical marker, inferior to AFP level, in the detection of a carcinomatous transformation of liver cirrhosis. The finding of false-positive AFP values in liver cirrhosis seems mainly attributable to cellular proliferation and necrosis. Cholestasis seems to greatly affect serum CA 19-9 level variations, probably by reducing its liver metabolism.

Colorectal cancer patients with high risk of hematogenous metastasis: correlation with CEA levels in peripheral and draining venous blood during the period of operation

Correlations between carcinoembryonic antigen (CEA) levels of peripheral (p) and draining (d) venous blood during the period of operation, and pre- and post-operatively detected hematogenous metastases were examined in 78 patients with colorectal cancer. The metastases were found in 28 patients (HM group), but not found in the other 50 patients (non-HM group). The mean values (43 and 198 ng/ml) and positive rates (61 and 96%) greater than 5 ng/ml of p- and d-CEA levels in the HM group were significantly higher than those (6 and 14 ng/ml, and 22 and 48%, respectively) in the non-HM group. The differences (mean 184 ng/ml and positive rate 49%) of d-CEA levels between both groups were more significant than those (39 ng/ml and 30%) of p-CEA levels. The mean value (155 ng/ml) and positive rate (82%) greater than 5 ng/ml of the gradient between d- and p-CEA levels (d-p CEA gradient) in the HM group were significantly higher than those (8 ng/ml and 34%) in the non-HM group. These results suggest that patients with a high risk of hematogenous metastases are more effectively checked by the determination of d-CEA levels and d-p CEA gradient than of p-CEA levels, and that they are patients with positive d-CEA and d-p CEA gradient levels.

Axillary versus peripheral blood levels of sialic acid, ferritin, and CEA in patients with breast cancer

Serum levels of total sialic acid, carcinoembryonic antigen (CEA), ferritin, lactate dehydrogenase, and creatine phosphokinase were measured both in tumor drainage blood (axillary vein) and in peripheral blood obtained from 121 breast cancer patients during surgery. No significant differences between mean values in peripheral and tumor draining blood, between cancer patients and healthy controls, or between patients with or without axillary lymph node metastases were found for any of the markers. Both ferritin and CEA levels were higher in axillary and peripheral blood from patients with central breast cancer versus other sites but the difference was significant only for CEA (p less than 0.05). CEA levels were significantly higher (p less than 0.01) in patients with greater than 2 cm diameter carcinomas versus T1 stage patients in axillary but not in peripheral blood. When the cephalic vein was clamped before the axillary sample was taken, ferritin showed a significant increase (p less than 0.05). We conclude that measurement of sialic acid, CEA, and ferritin in axillary venous blood in breast cancer patients is not of clinical benefit, although further data are needed to clarify whether other advantages can be derived.

Induction of carcinoembryonic-antigen-gene expression in human colorectal carcinoma by sodium butyrate

The effect of sodium butyrate on the expression of the carcinoembryonic-antigen (CEA) gene was studied in two poorly differentiated colorectal-carcinoma cell lines (Clone-A and MIP-101) and in one well-differentiated cell line (LS-174T); A.T.C.C. no. CCL 188). Northern-blot and dot-blot analyses indicated a steady increase in CEA mRNA from day 4 to a maximal level by day 14 after these cells were exposed to 2 mM-sodium butyrate. Studies using nuclear run-off assays followed by dot-blot hybridization to a partial CEA cDNA clone demonstrated that specific increases in gene transcription rates (3-fold in MIP-101, 4-fold in LS-174T and 6-fold in Clone-A) are not sufficient to account for the observed increases in CEA mRNA abundance. Further studies showed that CEA-specific transcripts have a half-life of about 60-80 min, and treatment with sodium butyrate increased the stability of CEA-specific transcripts to about 340 min in LS-174T cells and to about 500 min in Clone-A cells. We conclude that the induction of the CEA-gene expression by sodium butyrate in colorectal-cancer cells is mediated by both transcriptional and post-transcriptional mechanisms, with CEA mRNA stability as one of the major check-points.

A carcinoembryonic antigen (CEA) binding protein from ascites influences CEA uptake by macrophages

A variant of CEA which is less readily endocytosed by macrophages has been isolated from malignant ascites. In vivo, CEA is cleared more slowly by the liver (t1/2 = 15.1 minutes) than CEAs isolated from hepatic metastases (t1/2 = 3.1 minutes). In vitro, rat and human Kupffer cells and rat alveolar macrophages endocytose this CEA less effectively. This slow clearing form of CEA is associated with a smaller (45kD) acidic glycoprotein (CORA) with which it forms a stable complex. CORA can be visualized on reducing gels but not on non reducing gels or by HPLC run under non reducing conditions. This suggests a non-covalent complex between the two glycoproteins. Analysis of protein conformation by circular dichroism revealed changes in the ascites CEA consistent with binding of CORA to the molecule. Western blot showed that CORA crossreacts with antisera to alpha 1-acid glycoprotein and double immunodiffusion demonstrated cross-reactivity but not identify. Sequencing of CNBr peptides showed sequence homology with alpha 1-acid glycoprotein but areas of unique sequence were also found. It is suggested that binding of CORA to CEA blocks the macrophage receptor binding of CEA.

Relationship between colorectal liver metastases and CEA levels in gallbladder bile

While computerized tomographic (CT) scanning and intraoperative exploration are both considered accurate measures of liver involvement with metastatic disease, 10% to 30% of colorectal liver metastases remain undetected. Attempting to improve current methods for detecting colorectal liver metastases, CEA levels in gallbladder bile and serum from patients with known liver metastases were determined. One hundred per cent of patients with single and multiple metastases of various dimensions were observed to have gallbladder bile CEA levels strikingly higher than serum values (4.7 to 259 times greater, p = 0.0009). Linear regression analysis of estimated tumor volume and surface area versus gallbladder bile CEA levels predicted that very small tumors (less than or equal to 1 cm3 in volume) might produce detectable levels (9 to 41 ng/mL) of biliary CEA. For this reason, patients who lack clinical and radiologic evidence of distant metastases at the time of primary colorectal resection but who do have elevated gallbladder bile CEA levels (greater than or equal to 10 ng/mL) are being followed for the appearance of occult hepatic metastases.

Carcinoembryonic antigen levels of portal blood in gastric cancer patients

Correlation between carcinoembryonic antigen (CEA) levels of peripheral venous and portal blood and six histopathologic and immunohistochemical variables was examined in 53 gastric cancer patients and in 8 patients with benign diseases, in order to clarify the elevation mechanism of CEA in the peripheral blood. Immunohistochemically, CEA was localized in 48 (90.6%) of the 53 cancer lesions. CEA levels of portal blood (with a mean of 136.5 ng/ml and positive rates greater than 5 ng/ml, 58.3%) were significantly higher than those (30.3 ng/ml and 22.9%) of peripheral blood in 48 patients with CEA localized cancer. However, CEA levels of portal blood were as low as 5 ng/ml and were not different from those of peripheral blood in all of the CEA nonlocalized cancer and benign diseases. Elevation of CEA in portal blood and also peripheral blood was most highly correlated with venous invasion, although CEA levels in portal blood were significantly associated with three other variables including tumor size, lymphatic invasion, and node metastasis. These variables relating to CEA elevation in the blood were significantly related to venous invasion, whereas a relationship between venous invasion and tumor differentiation and the CEA distributed pattern was not found. These results suggest that CEA may be mainly drained by the hematogenous portal system via the draining vein from CEA localized cancer cells in the invaded veins of gastric cancer lesions, and, additionally, that histopathologic CEA elevation-relating variables may secondarily affect the CEA elevation in the blood in association with the venous invasion.

Assessment of serial carcinoembryonic antigen: determinations to monitor the therapeutic progress and prognosis of metastatic liver disease treated by regional chemotherapy

It is difficult, time-consuming, and expensive to evaluate the therapeutic efficacy of regional chemotherapy of metastatic liver disease by means of imaging procedures. Therefore it was the aim of this study to find out whether serial carcinoembryonic antigen (CEA) determinations yield reliable data on the therapeutic progress and the individual prognosis of these patients. Since there exists no generally accepted modality to assess CEA curves of patients receiving chemotherapy, we developed our own criterion and tested it in a group of 35 patients. For each patient an individual reference level (CEA-means) was fixed which was obtained as the arithmetical mean of serial CEA values taken during the first three courses of chemotherapy (reference time). On the basis of CEA-means the marker curves of the 35 patients could be divided into two groups. After the reference time the CEA values of group 1 (12 patients) never decreased below CEA-means. Survival of these patients was significantly (P = 0.00001) shorter than that of the 23 patients (group 2) who showed a decrease in their CEA curves below CEA-means after the reference time. Beyond this it could be observed that the improvement in survival was significantly greater in those patients who showed a CEA decrease below CEA-means for a prolonged period (3 months). This difference in prognosis is not an artefact due to different pretherapeutic conditions but is a sign of different responses to therapy. The decrease in CEA values below the individual reference level (CEA-means) is a certain sign of the efficacy of the chosen chemotherapy. A continuous rise of the CEA curve above CEA-means signifies an ineffective intrahepatic chemotherapy or extrahepatic tumor manifestation. In this case an intensive diagnostic workup of the patient and possibly a modification of the therapy are indicated.

Alpha-fetoprotein, tissue polypeptide antigen and ferritin in diagnosing primary hepatocellular carcinoma in patients with liver cirrhosis

This study was undertaken in order to compare the usefulness of three indices of tumour proliferation in detecting primary hepatocellular carcinoma (HCC) and in differentiating this neoplasm from liver cirrhosis. In 10 patients with HCC and in 63 with liver cirrhosis serum alpha-fetoprotein (AFP), tissue polypeptide antigen (TPA) and ferritin were assayed. Increased levels of AFP but not of TPA and ferritin were observed in HCC as compared to liver/cirrhosis. The receiver-operating characteristic curves demonstrated that AFP is more discriminating between HCC and liver cirrhosis than the other two markers. Correlations between liver function tests and serum markers were observed in liver cirrhosis but no in HCC. We can conclude that AFP is more useful than TPA and ferritin in detecting HCC in patients with liver cirrhosis, owing to the high frequency of false positive results of the latter two indices in liver cirrhosis. Liver dysfunction is probably involved in increasing all these markers of malignancy, thus reducing the specificity of these tests.

Carcinoembryonic antigen and carbohydrate antigen 19-9 levels of peripheral and draining venous blood in colorectal cancer patients. Correlation with histopathologic and immunohistochemical variables

Correlation between carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels of peripheral and draining venous blood, and 11 histopathologic and immunohistochemical variables was examined in 83 patients with colorectal cancer. CEA levels of draining blood (mean 34.5 ng/ml and positive rate greater than 5 ng/ml, 60.2%) were significantly higher than those (13.0 ng/ml and 28.9%) of peripheral blood. However, CA19-9 levels (mean 576.1 U/ml and positive rate greater than 37 U/ml, 29.5%) of draining blood were not different from those (568.0 U/ml and 29.5%) of peripheral blood. Immunohistochemically, CEA was observed in all of the 83 specimens and distributed in most of all cancer cells, whereas CA19-9 was found in 52 (62.5%) of the 83 specimens and sporadically distributed in some parts of cancer lesions in general. Elevation of CEA levels in draining and peripheral blood was most highly correlated with venous invasion, although the levels were related to four other histopathologic variables including liver metastasis, invasive layer of colorectal wall, lymphatic invasion, and Dukes' classification. Significant correlation between the CEA localized pattern of cancer cells was not found. Patients with CA19-9 nonlocalized cancer showed no elevation of the antigen levels in both peripheral and draining blood. The elevation of CA19-9 levels in peripheral blood of patients with CA19-9 localized cancer was most highly associated with lymphatic invasion, although the levels were correlated with five other variables consisting of liver metastasis, tumor differentiation, invasive layer of colorectal wall, venous invasion, and Dukes' classification out of 11 histopathologic and immunohistochemical variables. CEA levels of draining blood rose from 18.2 ng/ml and 40.3% to 30.1 ng/ml and 72.6%, respectively, after operative stimuli to cancer lesions, whereas the change of CA19-9 levels in draining blood of patients with CA19-9 localized cancer was not found during the time of operation. These results suggest that CEA may be drained mainly by the hematogenous portal system by the draining vein from the cancer cells in the invasive veins and that CA19-9 may be drained by the thoracic duct of the lymphatic system. It is also suggested that the CEA and CA19-9 elevation-relating variables may secondarily affect the CEA and CA19-9 elevation in the blood in association with the venous and lymphatic invasion of cancer lesions, respectively.

Hepatic clearance and metabolism in the rat of a human breast cancer associated glycoprotein (GCDFP-15)

Gross Cystic Disease Fluid Protein (GCDFP-15) is a 60,000 dalton glycoprotein isolated from human breast cyst fluid, composed of four 15,000 dalton monomers. Carbohydrate analysis indicates that each monomer has a single carbohydrate chain of the complex type. GCDFP-15 intravenously injected into rats showed a rapid circulatory clearance, the rate of clearance being faster in female animals [t1/2 = 12.8 (+/- 2.0) min. females, and 16.7 (+/- 2.6) min. males]. The major organs of clearance were the liver (70%) and kidneys (15%). Immunoperoxidase staining showed localization in Kupffer cells and the proximal convoluted tubules of the kidney. Removal of sialic acid from GCDFP-15 resulted in a more rapid clearance (t1/2 = 2.2 min) by the liver (85%). This clearance was inhibited by coinjection of asialo alpha 1 acid glycoprotein. About 3% of GCDFP-15 was excreted in bile with a transit time through the liver of 38 min. Examination of the uptake of GCDFP-15 by isolated rat Kupffer cells showed that yeast mannan, fucosylated BSA, and carcinoembryonic antigen (CEA) failed to inhibit uptake, though the binding of GCDFP-15 was clearly saturable. This suggests that a novel receptor system on the rat Kupffer cell may be responsible for GCDFP-15 clearance.