The radioimmunoassay of circulating carcinoembryonic antigen of the human digestive system

Diagnostic and therapeutic use of monoclonal antibodies to human tumor antigens

Monoclonal antibodies have been obtained to various differentiation antigens that are more strongly expressed on tumor cells than on normal cells from the adult host, some of these antigens are relatively specific for tumors of a given type, e.g. melanoma. Monoclonal anti-tumor antibodies offer strong promise for clinical use, initially for tumor diagnosis and, ultimately, also for therapy.

Serum CEA testing in the post-operative surveillance of colorectal carcinoma

Six hundred and sixty-three patients were followed with serial serum CEA measurements in addition to routine clinical surveillance after radical resection of colorectal carcinoma. Of 626 available for analysis, 366 (58.4%) remained clinically free of recurrence and had a normal CEA (less than 20 ng ml-1) throughout and 89 (14.2%) had a temporary non-progressive rise in CEA with no evidence of secondary disease. Of 171 patients who developed proven or suggestive recurrence, 114 had a preceding rise in the serum CEA and in further 21 the CEA rose simultaneously with recurrence. In 36 patients secondary disease was detected while the CEA was still within normal limits. CEA was more effective as an early index of distant metastasis, thus in 76% of those patients with a preceding rise in CEA, the secondary disease was disseminated, whereas only 20% had localised recurrence. The pattern of rise in CEA was of no practical value in distinguishing localised from distant recurrence.

The prognostic significance of preoperative carcinoembryonic antigen levels in colorectal cancer. Results from NSABP (National Surgical Adjuvant Breast and Bowel Project) clinical trials

This analysis explores the prognostic significance of preoperative carcinoembryonic antigen (CEA) levels in patients with colorectal cancer. The data were derived from 945 patients entered into two randomized prospective clinical trials of the National Surgical Adjuvant Breast and Bowel Project. A strong correlation was evident between preoperative CEA level and Dukes class. The mean CEA progressively increased with each Dukes category and the mean value for each of the four classes was significantly different. This relationship was prevalent whether the data were analyzed for all colorectal lesions regardless of location or specifically for right-sided colon tumors. The prognostic function of preoperative CEA level was independent of the number of positive histologic nodes. Preoperative CEA level correlated with the degree of lumen encirclement by tumor. Tumors that did not encircle more than one half the lumen were associated with significantly lower preoperative CEA levels than those that did. The presence or absence of lumen obstruction was unrelated to the preoperative CEA level. The relative risk of developing a treatment failure was associated with preoperative CEA, in both Dukes B and C patients, demonstrating that the prognostic significance of preoperative CEA was independent of Dukes class.

Carcinoembryonic antigen in high risk pregnancies

The significance of carcinoembryonic antigen (CEA) measurement was evaluated in 25 pregnant women with diabetes mellitus, 15 Rh negative sensitized and nine prolonged pregnancies. Another 114 women with normal pregnancy served as controls. Values in maternal and umbilical cord serum and in amniotic fluid did not change appreciably through 24-42 weeks' gestation. No significant difference in maternal serum, cord serum and amniotic fluid CEA values was found between diabetic, Rh negative sensitized and normal pregnancies at the corresponding weeks. Similar findings were obtained in prolonged pregnancies, except the values in amniotic fluid which were significantly higher than in normal pregnancies due to the presence of meconium. These results suggest that the measurement of CEA in high risk pregnancies is not useful in predicting fetal condition.

Comparison of CA 19-9 and carcinoembryonic antigen (CEA) levels in the serum of patients with colorectal diseases

The serum levels of CA 19-9 and carcinoembryonic antigen (CEA) were determined in 37 patients with benign colorectal diseases and in 111 patients with newly discovered colorectal carcinomas or clinically verified relapses. In cancer patients, the CA 19-9 level ranged from normal (0-37 U ml-1) to 77,500 U ml-1 whereas all samples but one from patients with benign colorectal diseases had a normal value. CA 19-9 was increased in 46% and 45% of patients with an advanced (Dukes C or D) carcinoma or a verified recidive, respectively. Only one out of 26 patients (4%) with a localized (Dukes A or B) carcinoma displayed an elevated CA 19-9 level (greater than 37 U ml-1). No clear correlation was found between the CA 19-9 and CEA levels. The sensitivity of the CA 19-9 test (36%) was poorer than that of the CEA assay (69%), but the new test was markedly more specific (97% vs 70%) than the CEA assay.

Localization of CEA, beta-HCG, SP1, and keratin in the tissue of lung carcinomas. An immunohistochemical study

One hundred and twenty seven cases of lung tumors were studied by the immunoperoxidase technique for the presence of CEA and beta-HCG. Twenty-nine of these tumors were additionally stained for keratin and SP1, CEA and SP1 could be demonstrated in 80% of the studied cases, while beta-HCG was found in only 9%. SP1 revealed an almost identical staining pattern to CEA and keratin was found only in squamous cell carcinomas. The tissue positivity of none of these three markers correlated with tumor size, lymphnodal involvement or histological type.

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.

Acute-phase reactant proteins and carcinoembryonic antigen in cancer of the colon and rectum

One hundred and twenty-eight patients bearing primary malignancies of the large bowel were studied to ascertain the value of acute-phase reactant proteins (serum protein hexose, ceruloplasmin, transferrin, alpha-1-antitrypsin, seromucoid and haptoglobin) either alone or in conjunction with carcinoembryonic antigen to accurately reflect the disease status of patients both before and after resection of their large bowel malignancy. The results indicate that acute-phase reactant proteins have a higher diagnostic rate for the presence of malignancy than does CEA. Estimation of the serum protein hexose alone is of greater diagnostic value than a combination of acute-phase reactant proteins. Furthermore, serum protein hexose and CEA are complementary and when combined will reflect the presence of malignancy in a greater number of patients than either one alone. Following resection of primary large bowel cancer, acute-phase reactant proteins are as accurate as CEA in evaluating the disease-free status of patients and furthermore when combined with CEA increased the predictive value for the detection of patients with recurrent disease.

The detection and evaluation of human tumor metastases

Many biochemical indices are purported to have clinical utility in the detection and management of neoplasia. Experience gained during the past decade tends to indicate their having a more important role in the detection and monitoring of metastases than of the primary lesion. From this present review of some of the commoner human tumours, it is concluded that such marker substances are important adjuncts in the management of germ cell and certain endocrine and endocrine-related tumours. The carcinoembryonic antigen (CEA) provides a marker for many gastrointestinal cancers, but there are no presently available substances with clinical usefulness for either breast or lung neoplasms. Alternative approaches to the detection of metastases are also presented. The particular use of antibody probes at an immunohistochemical level has been claimed to be able to detect micrometastastic disease in bone marrow or tumour-related monoclonal antibody probes may have application to other cancers in the future.

Immunoglobulins reactive to carcinoembryonic antigen and their relationship to the antigen in malignant ascitic fluid of ovarian carcinoma

Samples of malignant ascitic fluid from 30 patients with advanced ovarian carcinoma were examined for the presence of IgM antibodies to CEA and PEG-precipitable proteins binding to 125I-CEA. The IgM antibodies to CEA were measured by a solid-phase radioimmunoassay using ovarian CEA. There was no correlation between the level of IgM antibodies to CEA and that of total IgM in the fluid. In 11 of 30 (37%) samples tested, significant amounts of IgM antibodies to CEA were found. The CEA-binding proteins were measured by the ability of ascitic fluid to incorporate 125I-colonic-CEA into PEG-precipitable complexes. In 9 of 39 (30%) samples, the precipitation was significant. There was no association between antibodies to the ABO and Lewis blood group factors and these antibodies to CEA. An inverse relationship was observed between the level of CEA and that of CEA-binding proteins shown by the two assays. When 125I-CEA was incubated with these "positive" samples, a high molecular weight fraction was demonstrated by chromatography. By contrast, in the "negative" samples, there was no incorporation of 125I-CEA. These findings would indicate the presence of CEA-reactive proteins possibly existing as immune-complex-like material in ascitic fluid of some patients.

Ultrastructural localization of carcinoembryonic antigen in normal intestine and colon cancer: abnormal distribution of CEA on the surfaces of colon cancer cells

The distribution of carcinoembryonic antigen (CEA) in normal small intestine, normal colon, and colon cancer of humans was determined immunocytochemically by the peroxidase-labeled antibody method at the light and electron microscopic levels. In the small intestine, CEA was found in protein synthetic organelles, in the mucus, on the microvilli of goblet cells, and on some microvilli of columnar cells adjacent to goblet cells. In the normal colon, CEA was found in protein synthetic organelles of the fully differentiated columnar cells and goblet cells, as well as on the microvilli of the cells. In two well-differentiated colon cancers, the normal preferential surface expression of CEA on the microvilli was maintained, but in six poorly differentiated cancers, CEA was distributed equally over the entire cell surface. We conclude that CEA is a product of goblet cells in the small intestine, columnar and goblet cells in the colon, and colonic cancer cells. CEA on the surfaces of the normal epithelial cells is expressed in a polar manner. This polarity is lacking in undifferentiated neoplastic colon cells, which suggests that failure to establish or maintain the polar expression of normal cell-surface glycoproteins is a characteristic of the neoplastic cells.

Extracorporeal immunoadsorption of plasma from a metastatic colon carcinoma patient by protein A-containing nonviable Staphylococcus aureus: clinical, biochemical, serologic, and histologic evaluation of the patient's response

A patient with a metastatic colon carcinoma was treated by immunoadsorption (IA) therapy using heat-killed, formalin-stabilized protein A-containing Staphylococcus aureus Cowan I as the immunoadsorbent. The patient experienced both subjective and objective positive clinical response without undue morbidity. The patient's response correlated well with laboratory findings of decreased concentrations of carcinoembryonic antigen (CEA), immunoglobulin G (IgG), immune complexes (IC) and histopathologic data. The patient underwent surgery following 15 IA treatments; she lived for eighteen months, post-treatment.

Kinetics of the reactivity of subpopulations of spleen cells of mice bearing virus-induced mammary tumors to syngeneic antigenic extracts in vitro. Supportive and suppressive effects of macrophages

This study was designed to investigate the nature of lymphocyte reactivity to soluble tumor antigens with respect to the kinetics of the reactivity, the responding cell type, and the role of accessory cells, within a syngeneic system. BALB/c mice were inoculated with 1 X 10(6) viable cells of syngeneic MTV-induced mammary tumors. Assessment of proliferative activity of spleen cells of these animals by DNA synthesis (3H-thymidine incorporation in vitro) indicated a biphasic response to stimulation by 200 micrograms of a syngeneic perchloric acid (PCA)-soluble extract (AMMT) of the tumor over a 25-day period, with peak activities at days 13 and 19 post inoculation. The response was predominantly T-cell-mediated. Splenic macrophage population rose from less than 2% of total spleen cells by day 25 without any appreciable change in the T or B cell population. Depletion of spleen cells of macrophages abolished the first peak activity (at day 13) but significantly enhanced the second (at day 19). Reconstitution of the depleted cells with macrophages prepared from peritoneal exudates of tumor-bearing or normal mice restored the responses to undepleted values, thus indicating an accessory role for macrophages in these responses. These results provide new data which should contribute to a better understanding of the tumor-host relationship.

[The value of poly-C-specific serum ribonuclease and CEA in the diagnosis of pancreatic carcinoma (author's transl)]

The possible role of poly(C)RNase serum activity and CEA serum level for early detection and differentiation of pancreatic carcinoma and its specificity and valuability were critically analyzed: Serum RNase (median, min-max) with polycytidin as substrate was determined in 13 "normal" patients (14.6 E/ml, 4.3--29.8 E/ml), 16 patients with pancreatic cancer (T3 or metastases) (17.6 E/ml, 6--49-9 E/ml), 15 patients with chronic pancreatitis (9.5 E/ml, 4.9--26.5 E/ml), 7 patients with acute pancreatitis (14.2 E/ml, 5.5--67.3 ng/ml), and 13 patients with other types of malignomas (15 E/ml, 4.3--42.5 E/ml). Serum CEA level was evaluated in 18 "normal" patients (1.15 ng/ml, 0--4.3 ng/ml), 12 patients with pancreatic carcinoma (T3 or metastases) (6.5 mg/ml, 2--456.5 ng/ml), 13 patients with chronic pancreatitis (2.3 ng/ml, 0--8.5 ng/ml), 8 patients with acute pancreatitis (2.7 ng/ml, 0.1--4.6 ng/ml) and 5 patients without operative verification of suspected pancreatic carcinoma (0.9 ng/ml, 0--1.7 ng/ml). The serum RNase activity in pancreatic cancer patients did not show any significant increase in comparison to the other groups, and these patients could not be distinguished from those with the other diseases when excluding other factors influencing serum RNase level such as: Renal insufficiency, nutrition, age, sex. Their CEA level was significantly higher in comparison to the other groups (p less than 0.05). Using 2.5 ng/ml as the limit, the sensitivity was found to be 80% (10/12 of pancreatic carcinomas positive) and the specificity being 70.5% (31/44 of other groups without malignant diseases negative). The presented study and data in the literature show that poly (C) RNase measurement is not useful in early detection of pancreatic carcinoma, but the CEA test could be helpful in the differential diagnosis of pancreatic diseases due to its specificity (70.5%) and seems to be valuable in detection of residual and in monitoring for recurrent pancreatic carcinoma in view of its sensitivity and correlation with the stage of cancer.

A comparison of tube leukocyte adherence inhibition assay and standard physical methods for diagnosing colorectal cancer

In vitro antitumor immunity, measured by means of a tube leukocyte adherence inhibition (LAI) assay, was able to demonstrate early colorectal cancer in cases yet undiagnosed. Testing 106 patients attending a colonoscopy clinic, we found that nine of 15 (60%) patients with colorectal cancer were LAI-positive. The nine included: five of six with Dukes' A and B; one of two with Dukes' C; and three of seven with Dukes' D lesions. Of 58 patients without colon neoplasia, one had a positive test. By contrast, barium enema results were diagnostic for 13 of 15 (87%) cases and colonoscopy for 11 of 15 (73%). There were 32 colon polyps discovered by means of barium enema and colonoscopy. Of 13 adenomas removed, four had stimulated positive LAI responses. Of another 19 polyps not removed two incited positive LAI responses. Two patients with histories of recurrent adenomas were LAI-positive, though only one had a new polyp that could be detected by means of barium enema. For a procedure to be of diagnostic value for a given disease, sensitivity and specificity must be at least 1.0. If this sum is 2.0, the test is ideal. The sum of sensitivity and specificity for the tube LAI assay, barium enema, and colonoscopy were 1.58, 1.87, and 1.73, respectively, for colorectal cancer; 1.81, 2.0, and 2.0, respectively, for early colorectal cancer; and 1.42, 1.77, and 1.55 respectively, for advanced colorectal cancer. In this limited series of patients, the barium enema seems to be superior to the tube LAI assay for diagnosing colorectal cancer, but the difference in sensitivity and specificity is not statistically valid by the paired chi square test. The results of this study shows conclusively, that the tube LAI is of diagnostic value and suggest its use for evaluating suspected cases, especially early ones, of colorectal cancer.

A scanning electron microscopy study of ultrastructural changes in the colonic mucosa of patients with large bowel tumours

Scanning electron microscopy (SEM) has been used to compare the appearances of the colonic mucosal surface and overlying mucus layer of patients with normal colons, adenomatous polyps and colorectal carcinoma. The normal colonic mucosa had a characteristic orderly arrangement of crypts and was completely covered by an intact mucus layer. Epithelial and cryptal irregularities were seen on the surface of both polyps and carcinomas, and, in addition, the mucus layer was fragmented, leaving areas of the underlying epithelium exposed. These changes were more marked in colorectal cancers than in polyps and were present to a lesser degree in the apparently normal mucosa adjacent to tumours. The findings indicate that SEM can detect minor subtle irregularities on the surface of the colon and so may be useful in detecting pre-neoplastic and early neoplastic changes.

Value of serial carcinoembryonic antigen determinations for early detection of recurrent cancer

Carcinoembryonic antigen (CEA) has been monitored at intervals of approximately three months in patients who had undergone potentially curative surgery for breast cancer, head and neck cancer, lung cancer, and colorectal cancer, but who were considered to be at high risk of recurrence. Monitoring of CEA in patients' serum was of no value for the early detection of tumour recurrence in either breast or head and neck cancer patients. It was of value for the early detection of lung cancer recurrence, but these patients were always beyond the scope of cure. In colorectal cancer patients, two-thirds of recurrences were heralded by a rising CEA, but only one of 15 patients had disease confined to local tissues which could be totally excised, although a further three patients had liver metastases which were apparently localized to one lobe of the liver. For colorectal cancer patients, serial CEA estimations are an effective method for the early diagnosis of recurrence, although this seldom translates into improved patient benefit.

A statistical evaluation of baseline and follow-up carcinoembryonic antigen in patients with resectable colorectal carcinoma

A long-term CEA follow-up was evaluated statistically for a series of 74 patients with primary colorectal carcinoma who underwent resections for cure. Thirty-three recurrences and 29 deaths were reported among this population after a median follow-up interval of 55 months. Preoperative CEA levels correlated with the Dukes' classification. However, the preoperative level adds significant information to Dukes' classification in the prediction of recurrence. Postoperative CEA assays taken later in the clinical evaluation process carry the most prognostic information for subsequent recurrence. Using matched-pairs techniques, the authors noted that CEA often rose in anticipation of recurrence, sometimes as early as one year before recurrence. The following four follow-up CEA events were evaluated: 1) three consecutive rising CEA's 2) CEA rises 5.0 ng/ml; 3) CEA exceeds 5.0 ng/ml; 4) CEA exceeds 5.0 ng/ml two consecutive times. The follow-up CEA events examined were characterized by false positive rates ranging from 17% to 66% and true positive rates ranging from 43% to 56% in the prediction of recurrence. From follow-up CEA evaluations, further clinical investigation appeared most warranted when CEA exceeds 5.0 ng/ml at two consecutive follow-up evaluations, but the chances of finding any subsequent recurrent disease was near 50%. Among patients experiencing recurrences, although forewarned by CEA elevations, there was no subsequent time when patients were most likely to have recurrence of disease.

Immunoperoxidase staining for carcinoembryonic antigen in colonic carcinoma, osteosarcoma, and chordoma

An indirect immunoperoxidase method was used in an attempt to detect carcinoembryonic antigen (CEA) in 17 well-differentiated colonic adenocarcinomas, five osteosarcomas, and four chordomas. Fifteen of the adenocarcinomas were positive, and five of them had been fixed and embedded in 1952 and one in 1942. Two other adenocarcinomas from 1942 were not positive. CEA was not demonstrated in any of the osteosarcomas or chordomas.

Quantitative analysis of melanoma-associated antigen p97 in normal and neoplastic tissues

We have used two highly sensitive assays to quantitate p97, a protein associated with human melanoma, in cultured cells and normal adult, fetal, and neoplastic tissues. To measure p97 at the surface of intact cells, radiolabeled Fab fragments of a monoclonal antibody specific for p97 were used in a binding assay. To measure p97 in detergent-solubilized membrane preparations, we used a novel double-determinant immunoassay that uses two monoclonal antibodies to two distinct antigenic determinants of p97. These assays revealed that although p97 is present in small amounts in normal adult tissues, it is present in much larger amounts in most melanomas, in some other tumors (both benign and malignant), and in certain fetal tissues. We conclude that monoclonal antibodies to p97 may prove to be of value for the diagnosis and therapy of melanoma.

Specific and aspecific immune responsiveness in lung cancer patients: cutaneous delayed hypersensitivity reactions to a lung cancer-associated antigen

The ability of a lung cancer-associated antigen (LCAA) to provoke specific cutaneous delayed-hypersensitivity reactions has been studied on a group of 59 lung cancer patients. Biological activity of LCAA, monitored by skin testing, was demonstrated in 32% (17 of 53) of lung cancer patients, in 48.0% with limited disease, and in 17.2% with extensive disease. All the responders were in the group of normal reactors to standard recall antigens, if three antigens were used (PPDSK-SD, candida). No correlation was found between biological activity of LCAA and level of immunocompetence evaluated by lymphocyte-blastic transformation with PHA and count of rosette E-forming cells. These studies on the capacity to evoke specific DTH reactions in lung-cancer patients will be extended to the use of assays in vitro in the perspective of a more significant evaluation of immunocompetence levels.

Value of serial CEA determinations in a surgical adjuvant trial of colorectal and gastric carcinoma

At the Cross Cancer Institute in Edmonton, a concurrently controlled, randomized, prospective surgical adjuvant trial involving Dukes' B2 and C colorectal carcinoma and gastric carcinoma (T1-4, No-2, Mo) has been activated for the last two years. To date, a total of 150 patients have been entered into the three arms of the trial (namely control, immunotherapy, and chemoimmunotherapy). Of these, 127 cases are colorectal carcinoma and 28 are gastric cancer. As part of the protocol, serial CEA determinations are obtained in all patients on a regular three-monthly basis. So far, 28 patients have confirmed recurrence (colorectal 20, gastric 8) demonstrated clinically or radiologically. Out of these 28 patients, 25 (89.2%) had CEA greater than 2.5 ng/ml months before actual demonstration of recurrence. However, if one uses a cutoff of 5.0 ng/ml as significant, that is, one standard deviation from the usual accepted value, then 21 out of 28 (75%) had persistent, elevated CEA's months before the recurrence manifested itself clinically or radiologically. The CEA profiles of three representative cases from each arm of the adjuvant trial are included. It is suggested that serial CEA determinations will be an invaluable adjunctive test in following patients in an adjuvant trial setting.

Products of gynaecological neoplasms: clinical and pathological applications

Alphafetoprotein is at present the only 'antigen' of proved clinical value in gynaecological neoplasia. Its synthesis and release by a particular type of germ cell tumour (yolk sac, endodermal sinus tumour) present alone or as part of a teratoma approaches many of the essential criteria of a utopian tumour marker. Unfortunately, none of the other recognised 'antigens' expressed and/or released by gynaecological tumours and which have been adequately assessed in the clinical situation, seem to represent laboratory adjuncts essential for adequate patient care at present. Further research is needed to define other factors if this approach to improving diagnosis and management is to succeed.

Role of serum carcinoembryonic antigen in preoperative diagnosis of cancer in patients with thyroid nodules

Serum carcinoembryonic antigen (CEA) was measured by double antibody radioimmunoassay technique in 95 normal subjects and in 258 patients with thyroid nodules. All the normal subjects and the patients with benign nodules had normal CEA values. Increased serum CEA levels (above 50 ng/ml) were found in all medullary and undifferentiated (giant cell) carcinomas. After surgery, the CEA fell within the normal range in the patients with medullary carcinoma. High levels of CEA were also present in 26% of differentiated carcinomas. A relationship between high CEA values and the presence of metastatic disease was not found. Measurement of serum carciniembryonic antigen may be useful in the preoperative diagnosis of cancer in patients with thyroid nodules.

Serial CEA levels in colorectal carcinoma on adjuvant immuno(chemo)therapy--further follow-up. Modulation of adjuvant treatment

Serial plasma CEA levels have been studied preoperatively (testing A); one day after surgery (B); 10--15 days after surgery (C); 4 (D), 8 (E), 12 (F), 16--18 (G), and 22--24 (H) months after surgery in a series of 45 patients affected by colorectal carcinoma who started soon after surgery a protocol of adjuvant immuno(chemo)therapy with Levamisole and BCG. Postoperative follow-up was from one to 26 months, with 28 patients followed for at least one year. Fourteen patients had recurrences: two of these had false-negative CEA tests, three had persistent high CEA levels after surgery, nine had increasing levels 9--12 months before clinical recurrence; and nine of these 14 patients showed frankly pathologic preoperative plasma CEA levels. Six patients who did not have a recurrence but (both at clinical and instrumental evaluation) who had two consecutive high plasma CEA levels, were put on prophylactic polichemotherapy. The prognostic importance of CEA levels both pre- and postoperatively, the possibility of "modulating" postoperative adjuvant treatments on the basis of CEA levels, and the problem of unexplained fluctuations of plasma CEA levels with the putative metabolic linkages are discussed.

The use of carcinoembryonic antigen in the clinical management of colorectal cancer

Measurement of plasma levels of carcinoembryonic antigen, though not infrequently helpful in the mangement of patients with colorectal cancer, has serious limitations in terms of specificity and sensitivity. Many benign conditions may cause elevations of carcinoembryonic antigen, and even far advanced metastatic large bowel cancer may be associated with normal levels. Major treatment decisions should rarely, if ever, be based on plasma levels of carcinoembryonic antigen alone. Studies are currently underway to assess the value of serial levels of carcinoembryonic antigen in the early detection of recurrent disease with the hope of identifying patients who might be cured by secondary resections.

The value of serial carcinoembryonic antigen (CEA) in predicting response rate and survival of patients with gastrointestinal cancer treated with chemotherapy

Elevated serum levels of carcinoembryonic antigen (CEA) were found in 70% of 141 patients with advanced gastrointestinal (GI) cancers. Serial CEA measurements were performed on 70 patients before and during chemotherapy. The majority were treated with 5-FU and Methyl-CCNU (33 patients), 5-FU (19 patients), or 5-FU and mitomycin-C (8 patients). In 49 patients with colorectal carcinoma who had elevated serum CEA prior to chemotherapy, 18 had objective partial tumor remission, 16/18 (89%) showed definite decrease in CEA level, one had no change, and one had an increase CEA titer. Thirty-one patients had either stable disease (10 patients) or increasing disease (21 patients) while on chemotherapy. Of these patients four showed decrease in CEA, eight had no change, and 19 had increase in CEA levels as compared to pretreatment value. The survival of patients with a decrease in CEA during chemotherapy was statistically significant (p = .03) as compared to survival of those with no change or increasing CEA levels. In 21 patients with other GI cancers, the correlation between the clinical response and change in CEA level observed was not as definite as in patients with colorectal carcinoma.

The value of carcinoembryonic antigen in patients with carcinoma of the lung

Carcinoembryonic antigen levels in 682 lung cancer patients have been studied in order to assess their value in the screening of high-risk populations, monitoring total surgical ablation and projecting the effectiveness of therapy. The initial values are shown to be related to the histology of the tumor and to the extent of the disease. All histologic types of lung cancer produce elevated CEA but adenocarcinoma characteristically produces higher values than small, large or squamous cell carcinomas. CEA has its most precise value in distinguishing at an early date cured patients subsequent to surgical resection from those patients who will eventually fail because of recurrent disease.

Immunoreactive carcinoembryonic antigen [CEA] levels in feces from colorectal cancer patients

Immunoreactive CEA (IR-CEA) in feces or sera from 20 volunteers and 20 patients with colorectal cancer were measured before and at various intervals after surgery by a radioimmunoassay utilizing a "one step sandwich method." Elevated fecal IR-CEA level was observed in 17 of 20 patients with colorectal cancer; elevated serum CEA levels were observed in only 7 of all patients. There could not be found any correlation between fecal IR-CEA levels and Dukes' classification; there was but a little correlation between serum and fecal IR-CEA levels. In 8 of 14 patients treated by surgery, fecal IR-CEA levels obviously dropped, but in 2 patients with hepatic metastasis they were found rising in spite of colon tumor removal. It was speculated from these data that high values of fecal CEA depend on mass production of CEA by cancer cells. From these observations, it appears that fecal IR-CEA level presents a more ideal diagnostic competency in colorectal cancer than serum CEA level.

Tube leukocyte adherence inhibition (LAI) assay in gastrointestinal (GIT) cancer

Tumor-specific immunity to carcinoma of the colon, pancreas and stomach was assayed by tube LAI. Cancers of the colon, pancreas and stomach, were shown to possess organ-type specific neoantigens. In 115 patients with colon cancer, 100%, 75%, 61% with Dukes' A, B and C cancer were LAI positive, respectively. Even a microfocus of in situ cancer in a colon adenoma was sufficient to stimulate measurable tumor-specific immunity in the host. In Dukes' D cancer, 25% of patients with widespread metastasis were positive, whereas 100% with solitary lesions were positive. Reactive leukocytes from patients with colon cancer did not react to extracts of normal bowel mucosa or villous adenoma from LAI-negative patients. Leukocytes from 19% (3 of 16) of patients with colon adenomas reacted to the extract of colon cancer but not normal colon mucosa. Moreover, the LAI-positive response of the patients with colon adenomas or colon cancer is directed to a colon cancer TSA which is linked to beta2-microglobulin. These studies suggest that some colon adenomas express TSA before morphological evidence of cancer. It is not known if the acquisition of a cell surface TSA is an irreversible step toward unrestrained growth and metastasis. In pancreatic cancer, 100% of patients with cancers less than 5 cm and without metastasis were LAI positive, whereas 29% were positive when the cancer was greater than 5 cm or had metastasized. In Patients with stomach cancer, 100% with Stage II and 46% with Stage III and IV cancer were LAI-positive. Leukocytes from patients with other GIT cancers and from patients with inflammatory bowel disease or pancreatitis did not react with extracts of colon, stomach or pancreatic cancer. Leukocytes from patients with metastatic cancer, usually did not react in the tube LAI assay because their surfaces were coated in vivo with TSA. LAI reactivity was present when CEA was not detectable and when CEA levels were elevated LAI activity was often absent. The present study suggests that the automated tube LAI shows sufficient promise to warrant studies to determine its efficacy for the diagnosis of GIT cancers.

A reappraisal of the value of carcinoembryonic antigen in the management of patients with various neoplasms

Eight hundred and eight patients with histologically proved malignant disease had carcinoembryonic antigen (CEA) estimations performed at the time of tissue diagnosis. An elevated level was found in 384 of 518 patients with gastrointestinal neoplasms (74 per cent) and in 162 of 290 patients with other neoplasms (56 per cent). No correlation was found between CEA elevations and tumour differentiation. There was a good correlation between tumour staging and CEA levels for patients with colorectal cancer; the more advanced the tumour, the higher the CEA. Several illustrative cases are presented and the role of CEA assay in the diagnosis and management of neoplasia is discussed. CEA assay is a poor screening test for neoplastic disease, but serial CEA monitoring is valuable in the detection of residual or recurrent cancer.

Carcinoembryonic antigen in urine in patients with urothelial carcinoma. An expression for the extent of inflammatory reaction of the urinary tract

The concentration of carcinoembryonic antigen (CEA) in urine and serum was determined repeatedly during one year in 213 patients followed because of previously treated urothelial carcinoma of the bladder. The findings were correlated to grade and stage of previously treated tumour, given therapy, recurrence and the cytological evaluation of a midstream urine specimen. During the period of follow up 43 recurrences were clinically observed. With the exception for the content of inflammatory cells no correlation was found between the CEA levels in urine or blood and the parameters studied. Thus CEA in urine and/or serum cannot substitute for cystourethroscopy, urography and exfoliative cytology in the follow-up of patients previously treated for urothelial carcinoma.

Carcinoembryonic antigen (CEA) in the gastric mucosa after partial gastrectomy

Carcinoembryonic antigen (CEA) was studied by the three-layer bridge immunoperoxidase technique in gastric biopsy specimens taken from 49 patients, 13--20 years after partial gastrectomy. Routine histological examination revealed various degrees of chronic atrophic gastritis in all patients. A positive CEA reaction was found in 6 out of 9 with malignant or premalignant mucosal changes and in 4 out of 40 without these changes. In two cases of carcinoma the biopsies revealed a positive CEA reaction. In 4 patients with carcinoma diagnosed 1--2 years after the first examination the initial nonmalignant biopsies were CEA-positive in one case. All biopsies from mucosa with severe dysplasia and adenomatous polyps were CEA-positive. Four patients without malignant or premalignant changes in the gastric mucosa had CEA-positive biopsies. No carcinoma has been found in these patients at re-examinations after 1 year. The results indicate that the occurrence of immunohistochemically detectable CEA may be associated with malignant transformation of the gastric mucosa. The value of this method in screening patients at increased risk of gastric carcinoma will be further explored.

Carcinoembryonic antigen concentrations in undiagnosed patients

Serum carcinoembryonic antigen (C.E.A.) levels were measured in 381 undiagnosed patients who presented with clinical problems commonly associated with gastrointestinal malignancy. The results were compared with the final diagnosis after follow-up for up to 5 years to see whether C.E.A.-testing added any useful information. Of 307 patients presenting with upper gastrointestinal symptoms, lower gastrointestinal symptoms, or irom deficiency anaemia, C.E.A. levels greater than 20 ng/ml indicated malignancy in 5 but in 3 of these malignancy was also diagnosed after routine investigation. Of 74 patients presenting with obstructive jaundice, hepatomegaly, or abnormal liver function, malignancy was diagnosed in 38. In 9 of these patients the diagnosis of malignancy could otherwise have been reached only by laparotomy. The serum-C.E.A. thus reached only by laparotomy. The serum-C.E.A. thus seems to be of value in the assessment of liver disease but not in patients with gastric or colonic symptoms or iron-deficiency anaemia.

The natural history of antitumour immunity in human breast cancer assayed by tube leucocyte adherence inhibition

The specificity of the tube LAI in breast cancer was examined in a study with coded samples of PBL. In addition, 64 patients with breast cancer had their LAI reactivity monitored and correlated with their clinical status for up to 3 years after mastectomy. When patients were assayed by tube LAI, 83, 72, and 29% with Stage I, and II and III breast cancer respectively were positive. In Stage IV brest cancer, 88% of those with local recurrence and 15% of those with disseminated cancer were positive. By contrast, 3% of control subjects were LAI+. A select group of patients admitted to hospital with suspicious breast lumps that histopathologically proved to be benign breast disease (BBD) had a higher incidence of LAI+ (12%), whereas of outpatients with BBD only 2% were LAI+. Most breast cancer patients LAI reactivity became negative 2--4 months after mastectomy, even when some harboured micrometastases. LAI reactivity remained absent in those patients who remained clinically "cancer-free". In the follow-up patients, LAI activity returned about 4 months before local recurrence. LAI reactivity was observed in 7/8 patients in the coded study and 14/15 patients in the follow-up study preceding and/or at the time of local recurrence. A few patients (15%) progressed to widespread cancer without preceding positive LAI activity. The results suggest that tumour-specific immunity rapidly fades after surgery and may play no role in the rejection of micrometastases by 6 months after surgery. In addition, the present study has shown that the human hose manifests tumour-specific immunity when the cancer is small, and suggests that the early detection of human cancer would depend upon reliable methods to measure the tumour-specific immune response.

Carcinoembryonic antigen in patients with breast or colon cancer

The rationale and results of clinical use of carcinoembryonic antigen (CEA) tests in patients with carcinoma of the breast and colon deserve review. Plasma CEA levels have been found to correlate with the extent of tumor invasion and site of metastatic spread, and CEA titers have diagnostic and prognostic value. Although postresectional serial CEA testing is not as useful in cases of breast carcinoma, in cases of carcinoma of the colon it may indicate recurrence or progression of the lesion. However, there are limitations and CEA results should be interpreted in conjunction with other clinical information.