[Carcinoembryonic antigen in ascites and pleural effusions]

Area of Science:

• Oncology
• Biochemistry
• Diagnostic Medicine

Background:

• Effusion fluid analysis is critical for diagnosing various conditions, including cancer.
• Carcinoembryonic antigen (CEA) is a tumor marker with potential diagnostic value in effusions.
• Distinguishing malignant from benign effusions requires accurate diagnostic methods.

Purpose of the Study:

• To assess the utility of carcinoembryonic antigen (CEA) assays in effusion fluids for cancer diagnosis.
• To compare the diagnostic performance of CEA assays with cytology in effusion samples.
• To investigate the correlation between serum and effusion CEA levels.

Main Methods:

• Prospective study involving 63 patients and 67 effusions (ascites and pleural).
• Analysis of malignant cells (cytology) and CEA concentrations in effusion fluids.
• Defined malignancy threshold for effusion CEA as 4 times the upper limit of normal.

Main Results:

• CEA assays showed 100% specificity with cytology in cirrhotic ascites.
• CEA concentrations were highly significant (p<0.001) for adenocarcinoma effusions.
• CEA assays were not useful for non-adenocarcinoma cancers; cytology was superior.
• Malignant cells were absent in 4/8 adenocarcinoma patients with peritoneal extension but had high effusion CEA.

Conclusions:

• CEA assays are valuable for diagnosing adenocarcinoma in effusion fluids.
• Cytology remains the primary diagnostic tool for non-adenocarcinoma malignant effusions.
• High effusion CEA without malignant cells may indicate localized adenocarcinoma spread via lymphatics.