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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of carcinoembryonic antigen (CEA) to monitor patients after intentionally curative colon cancer resection can have advantages (improved life expectancy as a result of early detection of recurrences) as well as disadvantages (false-positive CEA rises and early detection of incurable recurrences in asymptomatic patients). This study estimated how the favorable and unfavorable effects of CEA monitoring affect life expectancy and quality of life of colon cancer patients. These effects were simulated using a Markov analysis for which the variables had been defined on the basis of data found in literature. The influence of CEA monitoring on quality adjusted life expectancy appears to be modest and varies, according to the data used, from an average increase of +7 days (+0.3%) to an average decrease of -5 days (-0.09%). This value is dependent, among other things, on patient related variables; the adverse effects especially dominate in older patients with a favorable Dukes' stage of the primary tumor and if operative mortality exceeds 2%. The total cost of CEA monitoring, including diagnosis and therapy performed as a result of true- or false-positive CEA rise, is considerable. High cost and low return leads to a high marginal cost-effectiveness ratio, which varies from $22,963 to $4,888,208 per quality adjusted life year saved. It is concluded that CEA monitoring should not be used for routine following of colon cancer patients, as its advantages have so far been demonstrated insufficiently.
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PMID:Utility and cost of carcinoembryonic antigen monitoring in colon cancer follow-up evaluation. A Markov analysis. 233 75

Recurrence of colon cancer at a stapled colotomy site separate from the anastomosis was discovered through a rising carcinoembryonic antigen (CEA). Resection resulted in cure. Exfoliation and implantation of cancer cells is discussed.
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PMID:Cancer recurrent at stapled colon incision. 235 57

The synthesis and release of the tumor marker carcinoembryonic antigen (CEA) from the colon cancer cell line LS180 has previously been reported to be enhanced during the later stages of in vitro culture after growth has stopped. It has been suggested that CEA expression was inversely related to the growth rate for these cells (Kahan, B.D.; Rutzky, L.P.; Legrue, S.J.; Tom, B.H. Methods Cancer Res. 18:197-275; 1979 and Shi, Z.R.; Tsao, D.; Kim, Y.S. Cancer Res. 43:4045-4049; 1983). Our studies indicate, however, that while certain environmental perturbations that halt growth (e.g., glucose starvation and elevated temperatures) do indeed stimulate CEA expression and release; other growth-arresting conditions, such as oxygen starvation, have no effect. Replacement of spent or conditioned medium with fresh medium during the later culture stages resulted in a 10-fold decrease in CEA release, indicating that either depleted nutrients or accumulating cellular products (such as lactate or ammonium) trigger enhanced CEA production.
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PMID:The effects of adverse growth conditions on the shedding of carcinoembryonic antigen from cultured LS180 colon cancer cells. 237 72

One of the problems of in vivo diagnosis and therapy of tumors with monoclonal antibodies is their heterogeneity with respect to antigen expression, with some cells expressing no antigen and others being weakly or strongly positive. Selected mixtures of antibodies to different antigens are therefore likely to react with more cells than single antibodies and be more effective for imaging and therapy. With this in mind, we have examined a new human colon cancer cell line (LIM1899) which has a heterogeneous expression of several cell surface molecules: by flow cytometry 38% were carcinoembryonic antigen positive; 64%, human milk fat globule positive, and 73%, CD46 positive; 87% of tumor cells bound a mixture of all three antibodies in vitro. Some blocking of the binding of anti-human milk fat globule antibody by the anti-CD46 antibody was noted. LIM1899 was established as a xenograft in nude mice and in vivo biodistribution studies performed using antibodies alone or in combination. Mixtures of antibodies clearly showed a higher percentage of injected dose of antibody in the tumor than did single antibodies: one antibody gave 10%; two together, 17 to 21%; and all three together gave 29% of the injected dose in the tumor. Tumor:blood ratios were also superior for combinations of antibodies, provided that low doses of the antibodies were used; at higher doses the effect was lost. The study demonstrates that combinations of antibodies are better than single antibodies for localization, provided that the dose used is carefully selected.
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PMID:Tumor localization by combinations of monoclonal antibodies in a new human colon carcinoma cell line (LIM1899). 238 31

Ca2 and Ca3 are new monoclonal antibodies of IgG1 class, directed against the Ca antigen, a mucus-type glycoprotein expressed on the surface of a wide range of malignant human cells and certain specialized normal epithelia. These antibodies were produced by immunization with purified preparations of the Ca antigen. They were tested to assess their value in the diagnosis of malignant effusions. Immuno-alkaline-phosphatase staining was used. Smears of pleural and peritoneal effusions were chosen to show: undoubted malignant cells of various types; and mesothelial cells in effusions from cases in which cancer was not in question. The Ca2 antibody, at 1 in 20 dilution of the culture supernatant, was the most specific, giving no reactions with benign mesothelial cells from any of the 35 cases tested. Malignant cells were clearly stained in 35 of 40 cases of carcinoma or mesothelioma. The staining was negative in two cases of oat cell bronchial carcinoma, and in three of four cases of carcinoma of the colon. Ca3 gave similar, but somewhat stronger, reactions with carcinoma cells, but was less specific, reacting weakly with mesothelial cells in 8 of 35 benign effusions. Because the false-negative reactions given by the Ca series of antibodies are to some extent complementary to those given by monoclonal antibodies directed against the carcinoembryonic antigen (CEA), a combination of Ca2 and anti-CEA is recommended as a most useful addition to the normal cytologic examination of effusions.
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PMID:Ca2 and Ca3. New monoclonal antibodies evaluated as tumor markers in serous effusions. 240 23

Immunoradiometric assay (IRMA) using monoclonal antibody for colon cancer cell surface antigen (CA19-9) was compared with carcinoembryonic antigen (CEA) with regard to sensitivity and specificity in 730 patients. In the 341 patients who had no evidence of malignant disease, CA19-9 levels ranged between less than 1.5 to 49 U/ml. Specificity of CA19-9 at a cutoff of 20 U/ml was similar to that of CEA at a cutoff of 5.0 ng/ml; CA19-9 was more sensitive than CEA in pancreatic cancer, whereas CEA was more sensitive than CA19-9 in breast, colon, and gastric cancer. Of 17 patients with pancreatic cancer, 13 had elevated levels of CA19-9 (sensitivity, 76%), whereas only 8 had elevated levels of CEA (sensitivity, 47%) and 15 had elevated levels of either CEA or CA19-9 (sensitivity, 88%). These findings suggest that, like CEA, CA19-9 is detectable in nonmalignant diseases and is not specific for gastrointestinal tumors, and has higher sensitivity than CEA only in pancreatic cancer. However, further prospective studies are required to verify its value in the diagnosis and management of pancreatic cancer.
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PMID:Measurement of a monoclonal-antibody-defined antigen (CA19-9) in the sera of patients with malignant and nonmalignant diseases. Comparison with carcinoembryonic antigen. 240 29

Sixteen tumor markers are reviewed, and measured to the ideal: produced by the tumor cell alone absent in health and in benign disease present in all patients with a given malignancy level in the blood representative of tumor mass detectable in occult disease. The only marker that approaches the ideal is human chorionic gonadotropin (HCG) in gestational trophoblastic tumors. In this malignancy, the HCG level suggests the diagnosis and stage, confirms response to therapy, and predicts relapse. The three most widely used and intensely studied tumor markers are carcinoembryonic antigen (CEA), alphafetoprotein (AFP), and HCG. CEA cannot be used in screening for cancer, but in carcinoma of the colon its elevation preoperatively increases the likelihood of advanced disease and postoperative recurrence. Postoperatively, elevated titers are often but not invariably associated with recurrent disease. AFP and HCG are useful in the management of nonseminomatous germ cell testicular tumors. Like CEA, they cannot be used for screening. They are more likely to be increased with advancing stage, and after therapy rising levels almost always mean recurrent disease. Some markers are valuable in specific circumstances, such as calcitonin in screening for familial medullary carcinoma of the thyroid. In multiple myeloma, immunoglobulins are useful in determining the tumor mass and response to therapy. In neuroblastoma, catecholamine metabolites are useful primarily in making the diagnosis. In some malignancies, the absence of effective therapy lowers the value of the marker, as for AFP in hepatoma. The remaining markers are too unreliable or too little studied to be useful in the management of an individual patient with cancer. The purpose of this paper is to provide the clinician with an understanding of the limitations of the present tumor markers that will lead to wiser use of the tests, and to provide standards to which future tumor markers should be measured.
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PMID:Tumor markers: value and limitations in the management of cancer patients. 241 41

The role of cyclic adenosine 3':5'-monophosphate (cAMP) in the regulation of the synthesis and release of glycoproteins and of carcinoembryonic antigen by colon cancer cells was studied using LS174T cells in vitro. Adenylate cyclase and cAMP phosphodiesterase activities were assessed by measuring cellular cAMP in response to forskolin and cholera toxin (adenylate cyclase activators) and to 3-isobutyl-1-methylxanthine (a phosphodiesterase inhibitor). Each agent increased cAMP levels significantly. Dibutyryl-cAMP (1 mM) stimulated glycoprotein synthesis and release when [3H]fucose was used as a precursor. The synthesis and release of carcinoembryonic antigen, a membrane-associated glycoprotein antigen, was also significantly increased by these test agents. A close dose-response relationship existed for forskolin and for cholera toxin between cAMP generation and carcinoembryonic antigen release. cAMP may play a role in regulating the synthesis and release of glycoprotein antigens by colon cancer cells.
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PMID:Effects of cyclic adenosine 3':5'-monophosphate upon glycoprotein and carcinoembryonic antigen synthesis and release by human colon cancer cells. 242 31

Monoclonal antibodies against human alpha-fetoprotein (AFP) or carcinoembryonic antigen (CEA) were conjugated to liposomes containing adriamycin (ADM), and the therapeutic effects of the conjugates were experimentally studied in vitro and in vivo. The liposomes were prepared from a lipid mixture of egg phosphatidyl choline, cholesterol and dipalmitoylphosphatidyl ethanolamine, and were covalently coupled with anti-AFP monoclonal antibody (19-F-12) or anti-CEA monoclonal antibody (1-C-11) after activation of antibody with the N-hydroxysuccinimidyl 8-(2-pyridyldithio) propionate and dithiothreitol. The selective binding of the 19-F-12 conjugated liposomes to AFP-positive human hepatoma cell line PLC and the 1-C-11 conjugated liposomes to CEA-positive colon cancer cell line C-1 as demonstrated using fluorescent liposomes. In vitro studies with PLC and C-1 clearly indicated that monoclonal antibody-conjugated liposomes containing ADM exerted much more effects than unconjugated liposomes containing ADM on target cells in the inhibition assay of [3H]-thymidine incorporation. The therapeutic effects of the conjugates were tested in vivo on AFP-positive human hepatoma xenograft, Li-7, and CEA-positive human colon cancer xenograft, Co-4, maintained in BALB/c nu/nu mice. The antitumor effect of the antibody-conjugated liposomes containing ADM was far greater than that of unconjugated liposomes containing ADM or that of ADM alone as assessed by tumor weight and histological findings.
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PMID:[Antitumor effect of adriamycin entrapped in liposomes conjugated with anti-human alpha-fetoprotein or anti-carcinoembryonic antigen monoclonal antibodies]. 242 62

Established human colon cancer cells with distinct degrees of differentiation (LoVo, well-differentiated; SW620, intermediate differentiation; and SW1116, poorly differentiated) were used to produce monoclonal antibodies (MoAbs) by standard hybridoma techniques. Specificity was tested by an enzyme-linked immunosorbent assay against human foreskin cells, 7 established human colon cancer lines, a panel of 17 established human tumor lines of different histological origins, purified carcinoembryonic antigen, panels of red blood cells, and a suspension of lymphocytes obtained from 30 random normal donors. MoAb LoVo-F4 3E4/1A1/2E10 (MoAb F4/2E10) reacted with five colon cancer lines and only slightly with MCF-7 cells (estrogen receptor positive breast carcinoma). MoAb LoVo-F4 3E4/1A1/5C10 also reacted with the previous five colon cancer lines and with two gastric cancer lines. A MoAb obtained with a LoVo 3 M KCl membrane extract reacted exclusively with LoVo cells. MoAb SW620-F1 4E5/1A3 reacted with only three colon cancer cell lines and an estrogen receptor negative breast cancer line. MoAb SW1116-F2 1E3/1A1 reacted with four colon carcinoma cell lines, one gastric cancer line, MCF-7 cells, and a lung cancer line. MoAb SW1116-F2 1F3/1B1 reacted intensely with purified carcinoembryonic antigen and with every carcinoembryonic antigen-producing cell line available in our laboratory. Further studies concentrated on the immunoglobulin G1 MoAb F4/2E10. We demonstrated that the purified MoAb did not inhibit binding of MoAb CA19-9 to any colon Ca lines and reacted with fresh human colon carcinoma specimens regardless of whether they were processed by cryostat or paraffin embedding after fixation in formalin for 24 through 96 h. Using the peroxidase-antiperoxidase technique, MoAb F4/2E10 did not react with 23 normal adult and 18 fetal (less than 3 months old) human tissue specimens. When tested on 312 specimens of diverse histological origins and diseases, the MoAb was positive in 57 of 62 colorectal cancers, in 12 of 19 villous adenomas, in 5 of 7 adenomatous polyps, and in 10 of 12 cases of ulcerative colitis. With the exception of 2 of 15 cases of Crohn's disease that were slightly positive, all tissues from nonmalignant diseases (regardless of histological origin) were consistently negative. There was only weak reactivity in 2 of 18 breast cancers, 7 of 21 squamous cell carcinomas, 4 of 27 lung tumors, 1 of 13 kidney carcinomas and in 7 miscellaneous tumors.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:New monoclonal antibodies against colon cancer-associated antigens. 242 73


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