Long-term follow-up of colorectal carcinoma patients by repeated CEA radioimmunoassay

Abstract

One of the major practical applications of carcinoembryonic antigen (CEA) assay is the monitoring of colorectal carcinoma patients after complete tumor resection. During the last 5 years, we have followed by repeated CEA assays 66 patients with histologically confirmed colon or rectum adenocarcinoma. Among 19 patients who developed a tumor recurrence, 17 had increased CEA levels preceding the clinical diagnosis by 2 to 26 months. Among the 47 patients who did not show any clinical evidence of tumor recurrence, 35 had CEA values remaining below the limit of 5 ng/ml, whereas 12 had moderate elevations of CEA level fluctuating around this limit. The majority of patients in this last group were heavy smokers or had liver enlargement, but in a few of them we did not find a satisfactory explanation for their moderately increased CEA levels. While our results confirm that repeated CEA assays can predict tumor recurrence with a lead time of several months over clinical diagnosis, they also give a word of warning concerning the interpretation of moderate elevations of CEA level. A moderate increase of CEA level can be the result of early distant metastases, local recurrence or exacerbation of an inflammatory disease. We feel that the decision of second look operations based on CEA results should be made only if increasing CEA values have been observed on three different blood samples taken within a period of 3 months and if no nonmalignant diseases known to increase CEA level are present. Ultimately only randomized clinical studies will determine if second look operations motivated by elevated CEA levels can improve the quality and length of survival of patients with colorectal carcinoma.

A genome wide association study of genetic loci that influence tumour biomarkers cancer antigen 19-9, carcinoembryonic antigen and α fetoprotein and their associations with cancer risk

“…Evaluation of CEA levels has become a useful complement to methods of detecting and staging tumours, following-up for recurrence or metastases, determining response to therapy and assessing prognosis in cancer patients 30 31. We found significant associations between ABO genotypes and plasma CEA levels.…”

Physikalisch-chemische Aspekte immunologischer und anderer reversibler Assoziations-Reaktionen

“…Furthermore, interference can be caused by an unspecific binding of the conjugate to the solid phase, or by certain plasma proteins or transport proteins which compete with the antibody. In the substrate-labeled fluorescent immunoassäy, interference occurred in a few cases, presumably due to the presence of fluorescing compounds in the sample (42).…”

“…The antibodies of various commercial assays for quantitative determinations show a relatively high specificity (2). However, considerable differences in specificity have been observed, for example, among various commercial immunoassays for determination of theophylline (42).…”

“…For this reason only creatine kinase-B RIAs (assaying BB and MB) or creatine kinase-M RIAs (assaying MM and MB) are available (24,(40)(41)(42)(43)(44). The possibilities of interference in a radioimmunological creatine kinase-MB determination in human seruni are thus already predetermined: the creatine kinase-M RIA is generally unsuitable due to its cross reaction with the creatine kinase-MM which occurs in a concentration about 10 times greater; the creatine kinase-B RIA ( fig.…”

Role of carcinoembryonic antigen in detection of asymptomatic disseminated disease in colorectal carcinoma.

“…Their symptoms developed seven to nine weeks after beginning Maloprim, and the mortality (three deaths) agrees with that reported for dapsone. 2 We assume that the agranulocytosis was due to the dapsone in Maloprim, as a weekly dose of 175 mg reportedly causes agranulocytosis,2 and all seven of these patients were taking 200 mg a week. In vitro data show a dose dependent toxic effect on the granulopoiesis promoted by hydrogen peroxide and mediated by a metabolite of dapsone.5 The manufacturer's recommended dose of one tablet of Maloprim a week does not appear to have been associated with agranulocytosis; nevertheless, the low dose of pyrimethamine per tablet and the short half life of dapsone might suggest that two doses a week would be necessary for effective prophyraxis.…”