Urinary carcinoembryonic antigen (CEA)-like molecules and urothelial malignancy: a clinical appraisal

Trends in urine biomarker discovery for urothelial bladder cancer: DNA, RNA, or protein?

Urothelial bladder cancer is a complex disease displaying a landscape of heterogenous molecular subtypes, mutation profiles and clinical presentations. Diagnosis and surveillance rely on flexible cystoscopy which has high accuracy, albeit accompanied by a high-cost burden for healthcare providers and discomfort for patients. Advances in "omic" technologies and computational biology have provided insights into the molecular pathogenesis of bladder cancer and provided powerful tools to identify markers for disease detection, risk stratification, and predicting responses to therapy. To date, numerous attempts have been made to discover and validate diagnostic biomarkers that could be deployed as an adjunct to the cystoscopic diagnosis and long-term surveillance of bladder cancer. We report a comprehensive literature analysis using PubMed to assess the changing trends in investigating DNA, RNA, or proteins as diagnostic urinary biomarkers over a period of 5 decades: 1970-2020. A gradual shift has been observed in research away from protein biomarkers to nucleic acids including different classes of RNA, and DNA methylation and mutation markers. Until 2000, publications involving protein biomarker discovery constituted 87% of the total number of research articles with DNA comprising 6% and RNA 7%. Since 2000 the proportion of protein biomarker articles has fallen to 40%, and DNA and RNA studies increased to 32% and 28%, respectively. Clearly research focus, perhaps driven by technological innovation, has shifted from proteins to nucleic acids. We optimistically hypothesise that, following thorough validation, a clinically useful detection test for bladder cancer based on a panel of DNA or RNA markers could become reality within 5-10 years.

Association of Therapeutic Radiation with Golgi Complex Hypertrophy in Human Urinary Bladder Carcinomas: Quantitative Electron Microscopy Studies

The volume (Vv) and surface area (surface density; Sv) of the Golgi complex were measured by electron microscopy stereologic techniques in 17 patients with urinary bladder transitional cell carcinomas. Seven patients were irradiated prior to surgical removal, 4 had recurrent carcinomas that arose from previously irradiated bladder urothelium, and the remaining 6 patients had bladder carcinoma but no prior history of therapeutic irradiation. There were significant differences in the Vv and Sv of Golgi complexes per unit of cytoplasmic volume in carcinomas from irradiated and nonirradiated patients (p < 0.01). In carcinomas obtained from irradiated urinary bladders, the Vv was 3.45 +/- 0.24% (mean +/- SE). In contrast, the Vv was 0.98 +/- 0.15% for tumors in the nonirradiated group. Sv values were 1.51 +/- 0.09 microm2/microm3 in carcinomas from irradiated bladders, and in the nonirradiated group, the mean Sv was 0.76 +/- 0.07 microm2/microm3. These results support the hypothesis that therapeutic irradiation to the urinary bladder induces hyperplasia of Golgi complexes.

Urine carcinoembryonic antigen levels are more useful than serum levels for early detection of Bilharzial and non-Bilharzial urinary bladder carcinoma: observations of 43 Egyptian cases

Background

Both urinary bilharziasis and urothelial neoplasia are associated with increased production of tissue carcinoembryonic antigen (CEA).

Patients and methods

Urine and serum CEA were determined in 43 patients with urinary bladder carcinoma including 22 post bilharzial and 21 nonbiharzial cases, in addition to 10 normal control cases.

Results

A significant increase was detected in both urine and serum CEA levels with bladder carcinoma compared to control cases. Urinary CEA was significantly elevated in 86% of bilharzial, versus 62% in nonbilharzial bladder carcinoma. Only 10.5% of control cases had urinary CEA elevation. The mean urinary CEA in bilharzial, was higher than that of nonbilharzial carcinoma, but the difference was not statistically significant. There was a definite relationship between urine CEA and the stage of malignancy; the higher the stage, the higher the level of urine CEA. No relationship could be detected between the stage of malignancy and serum CEA, or between the grades of malignancy and urine or serum CEA levels.

Conclusion

Urinary CEA is more useful than serum CEA in the early detection of urotherlial carcinoma particularly if provoked by bilharziasis. Its level is also correlated with the tumor stage.

Immunohistochemical demonstration of tumor-associated antigens with the aid of monoclonal and polyclonal antisera in carcinoma of the bladder

Keratin was identified with the aid of polyclonal antisera in the cytoplasm in over 90% of the transitional cell carcinomas investigated. The intensity of staining increased with the degree of dedifferentiation. Detection of cytokeratin with monoclonal antibodies was successful in over 80% of samples. All squamous cell carcinomas of the bladder were strongly positive for keratin and cytokeratin. CEA was found in 20% of the G1 and 40% of the G2 and G3 carcinomas of the bladder. Both the prostatic epithelium markers PSA and PAP and the monoclonal antibody Ca1 were negative in all cases.

Carcinoembryonic antigen in cytological specimens of urothelial carcinoma

A peroxidase-antiperoxidase (PAP) technique was developed for the detection of carcinoembryonic antigen (CEA) in urothelial transitional cells of 52 bladder cancer patients. The percentage of CEA-containing malignant cells varied from 10% to 100%. As a mean, 65% of the malignant cells stained for CEA, while the corresponding figure for benign-looking cells was 24%. The results were compared with cytological evaluations, flow cytophotometric results, and immunofluorescent (IF) staining for CEA. With increasing malignancy, more CEA was detected with the PAP technique, whereas the IF technique failed to show this trend. 18 of 20 malignant-tumors had an aneuploid DNA pattern. The two diploid cases were moderately well differentiated. Samples from bladders with heavy inflammation should be avoided in the PAP technique, since the unspecific staining of granulocytes disturbed a correct evaluation of the transitional cells. The PAP technique used on cytological material is recommended for antigen determinations, since good morphology is obtained.

Urinary carcinoembryogenic antigen (CEA) in the diagnosis and follow-up of bladder carcinoma

The level of urinary carcinoembryogenic antigen (CEA) was evaluated in the diagnosis and follow-up of urothelial carcinoma of the bladder. Urinary CEA concentration, cystoscopic findings and the histopathology of an eventually resected bladder tumour were correlated in 177 cases. The sensitivity proved to be 34%, the specificity 82%. Possible correlations with sex, infection, primary tumour or recurrence, differentiation and invasion of an eventually resected tumour and influence of adjuvant therapy were also evaluated. A comparison was made with the results of other authors and different factors which may influence urinary CEA levels are discussed.

Immunohistochemical demonstration of carcinoembryonic antigen (CEA) and its correlation with grading and staging on tissue sections of urinary bladder carcinomas

In 150 transitional cell carcinomas (TCC) of the urinary bladder, 50 each of Grades 1, 2, and 3, the content of carcinoembryonic antigen (CEA) was examined immunocytochemically and correlated to grading and staging. Fifty-seven percent of the TCC contained CEA-positive tumor cells. Their distribution in tumor tissue is described. They were found in 24% of Grade 1 cases, in 72% of Grade 2 carcinomas, and in 76% of Grade 3 tumors. None of the Grade 1 cases contained more than 10% CEA-positive cells, whereas 34% and 40% of the Grade 2 and 3 tumors, respectively, revealed more than 10% CEA-positive tumor cells. According to the correlation found between grading and staging, the percentage of TCC containing CEA-positive tumor cells was 34% in pTA, 59% in pT1, and 80% in pT2/3 tumors. The results show a correlation between CEA content of tumor tissue and histopathologic malignancy in TCC of urinary bladder.

Urinary CEA for prediction of survival time and recurrence in bladder cancer

The prognostic information from carcinoembryonic antigen was evaluated in bacteria-free urines of patients with bladder carcinoma. Patients with elevated (greater than or equal to 30 ng/ml) U-CEA had a poorer relative and symptom-free survival than patients with initial U-CEA below 30 ng/ml. Patients in whom U-CEA decreased from before to after radiation treatment had a better survival rate than patients with increasing U-CEA. These findings were most significant in cases with large (T3 + T4) tumors or with tumors of a lower differentiation (G3). U-CEA appeared to be an independent variable for prognostic evaluation of survival, since these differences were also true within the subgroups of known variables such as classes or grades. All but one of the patients, in whom short-term local control was obtained, had a posttreatment U-CEA below 50 ng/ml. In oncology units, where the more malignant bladder tumors are treated, U-CEA determinations may indicate which patients require intensified monitoring or treatment.

Assessment of serial CEA determinations in urine of patients with bladder carcinoma

Carcinoembryonic antigen (CEA) levels in urine and serum from 294 patients with bladder cancer in varying stages have been clinically evaluated. All urine samples were obtained from patients with intact renal function and without bacterial infection in the bladder. The samples were collected before, during, and at follow-up examination after radiotherapy. They were perchloric acid extracted before being assayed in a double-antibody radioimmunoassay. The geometric mean of urine CEA levels for patients with primary tumors of Stage T1 or T2 was significantly lower than that for those with Stage T3 or T4 disease. The urine CEA levels for patients with tumors of various histologic grades did not differ. The urine CEA levels decreased from before to after radiation treatment of the primary tumor. Patients with recurrence within six months after undergoing primary treatment had higher initial mean urine CEA levels than did those without evidence of recurrence. The prognostic information for recurrence was limited to the more advanced tumors. Differences were also found between the means of samples taken before recurrence and after treatment of recurrent tumors; with regression of the tumor, a lower mean urine CEA level was found; with progression, a higher value. Urine CEA levels before any treatment were higher when the patients had a short survival time. Serum CEA levels were not related to stage or grade of the primary bladder tumor but levels were slightly elevated with metastases. The determination of urine CEA levels seems to be useful in the follow-up of patients with bladder carcinoma because when initially high, it adds to the information of the T classification and predicts early recurrence, and the monitoring of individual patients after primary treatment is useful for detecting recurrence.

Carcinoembryonic antigen-like activity in gastric juice and plasma in patients with gastric disorders

Carcinoembryonic antigen (CEA)-like activity in gastric juice and plasma was examined in patients with gastric disease. There was no statistical difference in plasma CEA in normal subjects and in patients with benign gastric cancer. However, four patients with advanced gastric cancer, one with stage III and three with stage IV disease had a very high plasma CEA level. There was significant differences in CEA-like activity in gastric juice in patients with benign gastric disease and early gastric cancer (p less than 0.01) and patients wih benign and advanced gastric cancer (p less than 0.001). These results suggest that measurement of CEA-like activity in gastric juice is a useful adjunct to the diagnosis of early malignant changes in the stomach.

Cellular content of carcinoembryonic antigen in urothelial carcinoma

CEA containing cells can be demonstrated in 25--60% of urothelial carcinomas. No staining was seen with benign urothelial cells. Using microfluorometry of single cells, mean fluorescence intensity with anti-CEA antisera was 3--6 times that of preparations stained in parallel with nonimmune sera. A comparison of the IF results with RIA implies a possibility to detect less than 1 pg CEA/cell in unfixed specimens. The cells which stained with anti-CEA antisera did not have any apparent morphologic properties differentiating them from neighboring nonstained cells but it was mainly in the cell populations from well- and moderately well-differentiated tumors that CEA containing cells were seen. Therefore quantitative measurements of CEA amount/cell may be a parameter, in addition to morphologic differentiation, to study new properties of tumor cell populations.

Carcinoembryonic antigen in serum, urine and cells of patients with bladder carcinoma

A raised level of CEA-like substance has been demonstrated by radioimmunoassay in the urine of patients with bladder carcinoma, in concentrations which increase with a more advanced stage, and in serum of patients with advanced disease. In a 2-year follow-up of patients receiving chemotherapy, a correlation of raised urinary CEA to local recurrence was seen, as well as rising and high serum values with metastases. In the patients who responded to treatment, CEA values became normal. CEA was also located in carcinoma cells from bladder washings in 24--61% of the cases. Combined studies of CEA in serum, urine and cells may be used to study the biology of the tumour and perhpas also in the monitoring of patients with urothelial carcinoma.

Isolation of CEA-like material from urinary bladder carcinoma

Carcinoembryonic antigen (CEA)-like material from urinary bladder carcinoma was purified and compared with the immunological and physico-chemical properties of CEA isolated from colon cancer. After immunoadsorbent purification, the final step in a purification procedure similar to that adopted for colon cancer CEA, two main molecular species were identified: 1) Material identical with colon cancer CEA with respect to molecular size, PCA solubility, ability to bind to Con A, and most important the ability to bind to specific monkey anti-CEA serum. 2) Material with the same chromatographic and immunological properties as NCA.

Immunoperoxidase staining of carcinoembryonic antigen in urinary bladder cancer

An immunoperoxidase study of the presence of carcinoembryonic antigen (CEA) in primary cancers of the urinary bladder, metastases to the bladder, non-malignant diseased bladder, and normal bladder tissues revealed that approximately 10 percent of the urothelial carcinomas (transitional cell and squamous cell types) contained detectable quantities of this antigen. The other tissues were devoid of stainable CEA. It thus appears that the incidence of positive CEA by immunoperoxidase staining of formalin-fixed, paraffin-embedded tumour tissue sections is much less than the frequency of blood or urinary CEA elevations in patients with urothelial cancer.

The clinical value of urinary carcinoembryonic antigen-like substances in urothelial cancer

Although there is a positive correlation between the concentration of urinary carcinoembryonic antigen-like substances and urothelial cancer the clinical value of this association is in doubt. Urinary carcinoembryonic antigen values have been determined in large numbers of specimens from patients with a variety of urologic diseases but most studies have recorded only single measurements at the time of diagnosis. We examined the role of carcinoembryonic antigen in urothelial malignancies by comparing serial carcinoembryonic antigen, and cytologic and histologic analyses done on simultaneously collected urine and tissue specimens. We were particularly interested in the value of carcinoembryonic antigen as a diagnostic adjunct to cytology in low grade carcinoma and dysplasia, and the role of serial measurements of this substance in followup. The results of 102 analyses in 48 patients during a 15-month period indicate that urinary carcinoembryonic antigen measurements have little value in the diagnosis of bladder cancer, are of limited usefulness in combination with cytologic studies and are poorly correlated with simultaneously determined cytologic and histologic findings. Although the initial results were not promising serial measurements may be useful in followup.

Characterization of urothelial carcinoma with respect to the content of carcinoembryonic antigen in exfoliated cells

A sutstance immunologically similar to carcinoembryonic antigen (CEA) was demonstrated in urothelial bladder carcinoma cells. When indirect immunofluorescence with specific anti-CEA antisera was used, CEA-containing cells were seen in 18 out of 40 cases in 5% to 30% of the cells. Among patients with tumor cells of well differentiated morphology, 61% had CEA-containing cells, compared with only 24% of patients with a poorly differentiated tumor. Microfluorometry of single cells was performed in six cases to estimate the range of CEA content. The mean fluorescence intensity with anti-CEA antiserum was three to six times that of the same tumor cell population stained with non-immune rabbit sera. This fluorescence was decreased when the anti-CEA anti-sera were incubated with CEA but not with nonspecific cross-reactive antigen. The results show a wide range of CEA antigen content in exofoliated bladder tumor cells. In addition to proliferative status and differentiation, quantitative CEA measurements give further possibilities to study characteristics of tumor cell populations.

The clinical diagnostic value of the carcinoembryonic antigen (CEA) in haematuria

Plasma and urinary CEA levels in patients presenting with haematuria have been studied to assess whether they facilitate the differentiation between benign and malignant urothelial conditions. Plasma CEA is of no diagnostic value although, if raised, it may suggest an invasive tumour. Urinary CEA levels are only of value in the absence of urinary infection; even then, only 37% of the cases with overt urothelial tumours had raised titres. A knowledge of the urinary CEA level, therefore, would seem to contribute little to the diagnosis of patients presenting with haematuria and all patients must still be investigated by the conventional techniques of urinary bacteriology, cytology, intravenous pyelography and cystourethroscopy.

Clinical significance of urinary carcino-embryonic antigen estimations during the follow-up of patients with bladder carcinoma or previous bladder carcinoma. Clinical evaluation of carcino-embryonic antigen, III

Urinary carcino-embryonic antigen (CEA) was measured in a follow-up study of 101 bladder carcinoma patients. Urinary CEA estimation during follow-up appears to be of clinical value. Negative results can be interpreted only in relation to previously increased values. Positive results are of value in retrospect when combined with negative data, e.g. in evaluation of suspicious bladder changes and as an early indication of renewed tumour growth. Increased CEA levels in urines from patients with urinary infection rapidly decline once the infection is cured.

Carcino-embryonic antigen activity in urine of patients with bladder carcinoma. Clinical evaluation of carcino-embryonic antigen. II

This paper deals with the study of CEA levels in urine from healthy control subjects, of patients with bladder carcinoma or previous bladder carcinoma, and other groups of patients. In 53% of the patients with bladder carcinoma and without urinary infection, urinary CEA was increased. There were no false positive results. It is concluded that urinary CEA is a valuable aid in the detection of malignant tumour growth in the bladder. The results are compared with several tumour parameters, e.g. tumour size, stage of disease and histological parameters. Evidence is presented that CEA in infected urine is not produced by bacteria and that, like soluble vaginal excretory products, this substance has antigenic groupings in common with CEA from bladder tumours.

Carcinoembryonic antigen: clinical application

Carcinoembryionic antigen (CEA) a glycoprotein extracted from colonic cancer tissue (beta-globulin electrophoretic mobility, sedimentation coefficient 7 to 8S, and mol wt approximately 200,000) can be detected and measured by radioimmunoassay. Clinical evaluations of CEA determination have given the following results: In health: (1) Serum CEA level is not influenced by sex, age, blood type, time of blood sampling, or family history of cancer; (2) serum CEA level is influenced by a history of smoking or inflammatory disease of the bowel, lung, pancreas, and other organs (occasionally, a CEA level as high as 10 ng/ml is noted); and (3) currently, CEA positivity is defined as greater than 2.5 ng/ml, however, 5 ng/ml may be more realistic. In cancer: (1) CEA level may be increased in primary cancer of the gastrointestinal (GI) tract as well as in non-GI neoplasia; (2) the CEA test is not recommended for screening to detect early cancer; (3) serum CEA level depends on the stage of the neoplasia and usually is not influenced by the grade of differentiation; and (4) markedly increased (greater than 25 ng/ml serum CEA values are highly suggestive of metastatic cancer, particularly hepatic metastasis. In biological fluid: The CEA or CEA-like activity can be measured in gastrointestinal secretions. Quantitative studies of CEA levels in such fluids may yield more information than is obtainable from studies of serum. However, this possibility needs more study at present. Therefore, the currently available CEA tests cannot replace any of the now standard diagnostic methods for cancer detection. This use for assessment of therapy in selected patients or for following those known to be a high risk for cancer appears promising in preliminary studies, but clinical value, if any, remains to be determined.

Human tumour-associated and tumour-specific antigens: some concepts in relation to clinical oncology

The concept of tumour-specific antigens is constantly undergoing reappraisal with the development of more sensitive methods for their detection. This has resulted in the finding that the many 'new' antigens produced by human tumours or materials immunologically closely related to them are also present in non-neoplastic tissues, albeit in small amounts. However, other antigens still appear to exist almost entirely in or on tumour cells so that the antigens of human tumours may be subdivided into either tumour-associated macromolecules or tumour-specific antigens. The elucidation of the chemical nature of the tumour-specific antigens may result in important advances in cancer diagnosis and therapy. As many are organ specific, it should be possible to evolve test systems which will enable tumours to be diagnosed and located before they become apparent clinically. On the other hand the tumour-associated macromolecules, of which the oncofetal antigens are the principal examples, are found in elevated amounts in some non-neoplastic disorders. It is now clear that serial estimation of the levels of these macromolecules is of considerably more diagnostic value than single random measurements. Current work is establishing their value in the detection of recurrent and metastatic tumours before they become apparent by other methods, which is probably their most important role, and also their value as aids to monitor therapeutic efficacy. The future use of both types of antigen may unfold a new era in cancer detection and therapy but many basic chemical and immunological studies are needed before their clinical use can be fully defined.