Carcinoembryonic antigen gradients between plasma and malignant ascites: use in detecting peritoneal and liver metastases.

In the study of 19 patients with malignant ascites and elevated plasma carcinoembryonic antigen (CEA) (greater than 2.5 ng/ml) and/or ascites CEA (greater than 10 ng/ml), two patients emerged: 1) The 10 patients with higher ascitic fluid than plasma CEA levels (medians: 230 and 10.6 ng/ml, respectively) had exudates and intraperitoneal cancer but usually had no hepatic metastases. 2) The 9 patients with lower ascitic fluid than plasma CEA levels (medians: 29 and 140 ng/ml, respectively) had transudates and negative cytology examinations but did have demonstrable liver metastases. Determination of ascitic fluid and plasma CEA gradients in patients with malignant ascites may help localize, with potentially therapeutic importance, the site of metastases.

The disparity of indirect and direct zirconyl-gel assays for carcinoembryonic antigen.

Experience with the zirconyl phosphate gel (Z-gel) radioimmunoassays for plasma CEA levels below 20 ng/ml (the indirect method) and for levels greater than 20 ng/ml (the direct method) has shown that a disparity of values exists, caused by shifting from one assay to the other. This disparity is at least partially due to PCA-labile proteins reacting in the direct assay. It may be constant for individual patients but varies among patients. The magnitude of this disparity is independent of the CEA level (above 15 ng/ml).

Transient carcinoembryonic antigen (CEA) elevations following resection of colorectal cancer: a limitation in the use of serial CEA levels as an indicator for second-look surgery.

In a previous study, other investigators recommended second-look surgery for colorectal cancer primarily on the basis of plasma carcinoembryonic antigen (CEA) rises and prepared a nomogram for ready recognition of these "significant" increases. We found 25 patients whose CEA levels met the recommended criteria for significance; however, in 9 of these patients the rises were transient. Eight had no clinical evidence of recurrent cancer and they might have had negative second-look surgery had this been done because of CEA rises alone. The use of the CEA nomogram merely eliminated laboratory variation as a cause of the CEA rise. It did not, however, rule out biologic causes of CEA rises, other than that of cancer, especially benign liver disease. We were unable to differentiate benign from malignant rises on the basis of CEA changes alone. Preoperative CEA values helped to separate the two rises. Transient rises usually began earlier. Malignant CEA rises were more likely to be exponential. The rate of rise alone did not discriminate between the two rises. Thus, although serial CEA levels were helpful in making the decision for reexploration, they did not substitute for complete clinical assessment.

Carcinoembryonic antigen assay of ascites and detection of malignancy.

Levels of carcinoembryonic antigen (CEA) activity were measured in 105 unselected samples of ascitic fluid submitted for routine cytologic analysis to ascertain whether this assay was useful in the detection of malignancy. The highest CEA level found in the 70 specimens of "benign" ascites was 10 ng/ml. Using values greater than 10 ng/ml as indicating a cancerous effusion, CEA assay successfully detected 14 of the 29 malignant ascites studied. Cytology, on the other hand, detected only 12 of these fluids. Combining the two methods increased the yield to 20. The CEA assay alone thus detected more than one fourth of these malignant fluids. The assay was particularly useful in detecting malignant transudates, nearly half of which had elevated CEA levels despite negative cytologic findings. The CEA assay of ascites thus showed promise as an adjunct to cytology in the detection of malignant ascites when used as part of a complete clinical and laboratory assessment.

Carcinoembryonic antigen levels in benign and malignant pleural effusions.

One hundred ninety-one unselected fluid specimens submitted routinely for cytologic examination were assayed to determine whether the measurement of carcinoembryonic antigen (CEA) levels in pleural effusions is useful in detecting malignancy. The mean +/- SD CEA level of 103 benign effusions was 4.1 +/- 2.9 ng/ml. Only one benign effusion had a level greater than 12 ng/ml (18 ng/ml). Benign inflammatory effusions (pneumonia, empyema) had a higher mean CEA activity (6.2 +/- 3.4) than effusions caused by congestive heart failure (2.9 +/- 1.5) (p less than 0.001). Twenty-four (34%) of 70 malignant effusions had a CEA level greater than 12 ng/ml, and 28 (40%) were "positive" by cytologic study. Thirty-eight (54%) were detected by one or both methods. Ten malignant effusions were positive by CEA (greater than 12 ng/ml) alone. These data suggest that the determination of CEA activity levels, when used in conjunction with other clinical findings, may be useful in detecting malignant pleural effusions.