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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The circulating levels of four tumor- or trophoblast-associated antigens were measured by specific radioimmunoassays in 11 patients with gestational choriocarcinoma. The estimations were carried out at the time when the urinary gonadotropin (hCG) excretion was low or negligible. Gonadotropin, measured as the hCG beta-subunit, was detected in serum of three patients, one of whom also showed a slightly raised level of carcinoembryonic antigen (CEA). All patients had normal serum alpha-fetoprotein (AFP) levels and no trace of human placental lactogen could be demonstrated. Repeat estimation after treatment of patients with raised levels showed a disappearance or a marked decrease of the circulating hCG levels and a return to normal of the elevated serum CEA level. The results show that although CEA levels may occasionally be elevated new information can hardly be expected from markers other than hCG when one is monitoring response to treatment, but AFP may have potential significance in the distinction between pregnancy and a trophoblastic disease. The circulating levels of hCG are of vital importance in the monitoring of choriocarcinoma patients who appear to be in remission by the conventional analysis of urinary hCG excretion.
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PMID:Choriocarcinoma: expression of tumor- and trophoblast-associated antigens in patients with low chorionic gonadotropin excretion. 6 10

Pleural and peritoneal fluids from humans with pathological diseases were examined for the presence of carcinoembryonic antigen-like substances (CEA-LS). Among eight samples tested by a solid phase radioimmunoassay, two pleural fluids and one peritoneal fluid showed significantly elevated CEA-activity. The substances responsible for the CEA-activity were isolated by perchloric acid-extraction followed by two successive Sephadex G-200 chromatography into two pools, Pool I (PI) and Pool II (PII). According to their sedimentation properties, PII was slightly smaller than CEA from tumor tissue-extract (CEA-TTE), while PI was larger than CEA-TTE and approximately twice the size of PII. Micro-double diffusion and antibody binding studies showed that CEA-LS possessed identical antigenic determinants as CEA-TTE, which did not cross-react with normal colon antigen (NCA).
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PMID:Carcinoembryonic antigen-like substances in human cavity fluids. 6 11

Five tumor markers were measured simultaneously in serum by radioimmunoassay: carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), human chorionic gonadotrophin (HGC), the beta subunit of HCG, and Kappa casein. In a population of 935 normal subjects these antigens were undetectable or found within precise limits. In patients with tumors of various origins the rate of pathologically elevated levels was 72% at the beginning of the clinical course (194 cases). This high rate was primarily due to the simultaneous measurement of CEA, betaHCG, HCG, and casein. AFP was of little importance. The simultaneous measurement of these tumor markers may be one biochemical element of diagnosis of carcinoma, although this criterion is neither absolute nor specific, as 14.7% of patients with non-neoplastic disorders (234 cases) were positive for one antigen. In the presence of metastases (112 cases) the rate of pathologic levels of at least one antigen was increased: 86% due to CEA and casein assay at the same time as their absolute levels were increased. Surgical removal reduces the rate of positivity of these antigens to 37%. As was shown in patients with breast cancer, the rate was 10% when the tumor had been removed at Stage N- and 54% when it was removed at Stage N+. Thus, the persistence of pathologic levels could be correlated with the capacity for recurrence or metastases. Finally chemotherapy, radiotherapy, or both, do not decrease the rate of positivity of the tumor markers.
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PMID:Simultaneous assays of cancer-associated antigens in various neoplastic disorders. 6 15

Germinal cell tumors of the testis were studied for the presence of several tumor-associated antigens. Antisera were produced by immunizing rabbits with the purified antigens of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and hepatoma ferritin. Indirect immunofluorescence on embryonal carcinoma with or without teratoma components demonstrated that their staining range was 1--60 per cent with antiserum against AFP, 0--16 per cent with anti-serum against ferritin, and 0-40% with antiserum against CEA. Ferritin-like substances have not been described previously in germinal tumors of the testis. No staining was seen with seminoma cells or benign testicular tissues. Raised serum levels of AFP and the ferritin-like substance were related both to the presence of tumor and to dissemination of the disease. CEA occurred transiently in serum. Eleven patients with primary tumors had no antigen in their sera and have all survived, but the median survival time for 8 patients with either antigen in preoperative sera was 12 months. Five patients with advanced tumor in whom neither AFP nor ferritin was detected had a much longer median survival time (58 mo) than did 13 patients with high levels of serum AFP or ferritin (12 mo). The presence of either AFP or ferritin in sera of patients with primary or advanced disease, therefore, seemed to indicate a poor prognosis. The determination of both substances in serum may be useful in the follow-up of patients with certain types of testicular tumors. The proportion of cells containing each antigen varied in the different tumors. Similarly, each antigen could occur independently in serum. This suggested that certain germ cell tumors contained subpopulations of cells, which differed in their production and release of the antigens studied.
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PMID:Multiple antigens as marker substances in germinal tumors of the testis. 6 76

Three human lung tumor-associated antigens (TAA's) have been identified in soluble and membrane-solubilized extracts of human squamous cell lung carcinoma with the use of antisera raised in rabbits. The antigens were identified and partially characterized by means of an agarose adsorption technique. These antigens, termed lung TAA's 1,2, and 3, are all soluble in 50% ammonium sulfate, are antigenically distinct, and do not cross-react with carcinoembryonic antigen or alpha-fetoprotein. Lung TAA's 1 and 2 are oncofetal antigens demonstrable in soluble extracts from 24-week-old but not from 26-week-old fetal lungs. Rabbit antibodies to these lung TAA's were not adsorbed by types A, B, and O human red blood cells, serum proteins as well as soluble or insoluble lung preparations. Of several commercial antisera to human proteins, none cross-reacted with lung TTA 1, but anti-human liver ferritin cross-reacted with lung TAA 2, and anti-human lactoferrin cross-reacted with lung TAA 3. Lung TAA 1 was partially adsorbed and cross-reacted with certain normal serum or plasma preparations used and appears to be a normal serum protein in Cohn Fraction IV-4. Lung TAA 2 and 3 appear only in lung tumor-soluble extracts, whereas the lung TAA 1 was demonstrable in soluble extracts of breast, colon, cervical and head and neck carcinoma. All may be tumor markers of value in immunodiagnosis.
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PMID:Isolation and identification of human lung tumor-associated antigens. 6 79

Determinations of carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), and alpha-fetoprotein (AFP) were done by use of frozen serum samples antedating the diagnosis of cancer for 9 pancreatic and 8 gastric carcinoma patients from the Framingham Heart Study. The longest intervals for elevated antigens before cancer diagnosis were 10 months for CEA and 26 months for HCG. (The single elevated AFP was found in a sample 10 days before clinical diagnosis.) Samples from 31 controls matched with the cancer subjects by age, sex, vital capacity, and smoking status showed over 20% "false" positive CEA elevations (all smokers with low vital capacities) and over 20% borderline false positive HCG elevations in postmenopausal females. Although 10-26 months' lead time could infer some potential for use of these tumor-associated antigens to help detect malignant neoplasms at an earlier stage, a serious problem of frequent false positives prevents CEA and HCG levels from being useful as cancer-screening tests at this time.
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PMID:Tumor-associated antigen levels (carcinoembryonic antigen, human chorionic gonadotropin, and alpha-fetoprotein) antedating the diagnosis of cancer in the Framingham study. 6 18

A wide variety of malignancies have associated tumor antigens. Two which have proven useful in the clinical detection and management of cancer are alphafetoprotein (AFP) and the carcinoembryonic antigen (CEA). These materials have been determined both by radioimmunoassay and by a newer technique employing enzymes to replace radioisotopea as markers. The interpretation of these immune assay results and the factors governing the shape of the standard curve are discussed. The advantages of 57Co over 22Na as a volume marker in radioimmunoassay are presented.
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PMID:Detection of circulating tumor antigens. 6 86

A membrane-associated glycoprotein fraction, referred to a CEA-M was isolated from human colonic tumor tissue by sodium dodecyl sulfate extraction of membrane fragments followed by wheat germ agglutinin affinity chromatography, Bio-Gel A-1.5 gel filtration and preparative slab gel electrophoresis. With a m.w. of approximately 200,000, isoelectric point of about 4.2 and carbohydrate:protein ratio of 2:1, this glycoprotein has physiocochemical and antigenic similarities to carcinoembryonic antigen, CEA. Immunochemical studies have shown that antiserum developed for this glycoprotein possesses relative specificity for human colonic carcinomas. Chemical cleavage of this glycoprotein by 2-nitro-5-thiocyanobenzoic acid resulted in three major Coomassie Blue and two periodic acid Schiff stainable fragments (one of which stains with both). It was found that one of the glycopeptides, labeled as TA, isolated by affinity and covalent chromatography, contained 77% carbohydrates and possessed antigenic determinants recognized by at least 70% of the antibody population raised against the total glycoprotein fraction; purified antibodies to this region of the molecule seem promising for the development of a specific assay for gastrointestinal tumors.
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PMID:Colonic tumor membrane-associated glycoprotein: isolation of antigenically-active peptides after chemical cleavage. 6 65

The biologic and clinical significance of the oncofetal antigens carcinoembryonic antigen (CEA) and alpha1-fetoprotein (AFP) are discussed. Although the current assays for these molecules are not tumor-specific, measurement of these molecules in the circulation of cancer patients is useful either for tumor diagnosis or for management of the cancer patient in the postoperative or post-chemotherapy state. An approach to increasing the specificity of the CEA radioimmunoassay is described.
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PMID:Oncofetal antigens. Increasing the specificity of the CEA radioimmunoassay. 7 1

Various biochemical markers of cancer were investigated in two men aged 26 and 45 years with primary mediastinal choriocarcinoma. The daily excretion of urinary human chorionic gonadotropin (HCG) and the serum concentration of the beta-subunit of HCG were elevated in both patients, but carcinoembryonic antigen, Regan isoenzyme, alpha1-fetoprotein, serum pregnancy-associated globulin and human chorionic somatomammotropin were not detectable. Comparison of the results of the investigation of biochemical markers of this rare neoplasm in these two men with those published previously illustrates the discordance in the expression of biochemical markers of primary mediastinal choriocarcinoma.
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PMID:Tumour antigens associated with primary mediastinal choriocarcinoma. 7 6


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