Carcinoembryonic antigen in amniotic fluid

Carcinoembryonic antigen (CEA), a substance which is known to occur in high amounts in the fetal gut and also in certain tumors of the gastrointestinal tract, has been demonstrated in amniotic fluids from different stages of pregnancy. Radioimmunoassays of CEA in amniotic fluids of 91 normal pregnancies showed a decrease from a mean of 53 ng/ml at 19 weeks to 25 ng/ml at the end of gestation. The CEA activity in amniotic fluid was eluted in the same volume as a standard 125I-CEA on a Sephadex G200 column. Amniotic fluid therefore contains CEA similar in molecular weight to the CEA purified from liver metastases of colonic cancer. Among 17 cases of abnormal pregnancies, CEA elevations were observed in five with anomalous fetuses.

Placental alkaline phosphatase, alphafetoprotein and carcinoembryonic antigen in testicular tumors. Tissue typing by means of cytologic smears

Indirect immunofluorescence and radioimmunoassay with specific rabbit antisera demonstrated the occurrence of alphafetoprotein (AFP), carcinoembryonic antigen (CEA) and placental alkaline phosphatase (PLAP) in primary testicular tumor cells. Embryonal carcinomas had AFP- and CEA-containing cells, sometimes PLAP. PLAP and sometimes CEA were found in seminoma cells. Sera from patients with advanced non-seminomatous tumors could contain any of these antigens or any combination of them. Sera from patients with seminomas had raised PLAP or CEA. PLAP appears to be a new marker for seminoma.

Carcinoembryonic antigen and other tumor markers in tissue and serum or plasma of patients with primary mammary carcinoma

50 patients with primary breast cancer were studied to determine the CEA and HCG contents in their tumor cells before any treatment was initiated. Tumor cells were obtained by needle biopsy and each tumor cell population was stained by immunofluorescence. In 21 of the 50 patients, CEA containing cells were found in a frequency ranging from 5 to 80% of the tumor cell population. The results were confirmed by radioimmunoassay of tumor extracts. No apparent relation was seen to cytologic type or grade of differentiation. HCG was detected by IF in 4 tumors with an apocrine cytologic cell type. The level of CEA in plasma was determined before treatment and followed for 2-6 months in 72 patients. CEA was the only measured serum parameter that correlated initially with size and extent of the localized tumor. It was too low to be of use for monitoring primary disease, but should be of value in early detection of metastasis. Posttreatment a low or decreased plasma CEA was seen more often in patients who had had curative treatment than in those given palliative radiation. No raised serum HCG levels were found. Raised serum liver enzymes did not predict the extent of the primary tumor but may be an indication of distant spread. Tumor CEA content and CEA plasma concentration were correlated, although not very strongly. This means that CEA, although present in the tumor, is not always released in measurable amounts.

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.