Detection of malignant pleural effusions by tumor marker evaluation

Area of Science:

• Oncology
• Biochemistry
• Medical Diagnostics

Background:

• Distinguishing malignant pleural effusions from benign causes is crucial for patient management.
• Cytologic examination of pleural fluid has limitations in diagnosing malignancy.
• Tumor markers in pleural fluid may offer additional diagnostic value.

Purpose of the Study:

• To evaluate the diagnostic utility of various tumor markers in pleural fluid for detecting neoplastic effusions.
• To assess the individual and combined performance of Carcinoembryonic Antigen (CEA) and beta-human chorionic gonadotropin (beta-HCG) in differentiating malignant pleural effusions.

Main Methods:

• Cytologic examination and measurement of multiple tumor markers (including CEA and beta-HCG) in pleural fluid and serum from 70 patients.
• Patients were categorized into neoplastic, benign inflammatory, and congestive effusion groups.
• Statistical analysis of sensitivity, specificity, and efficiency for individual and combined markers.

Main Results:

• CEA and beta-HCG were the most informative markers for identifying malignant effusions.
• Individually, CEA (6 ng/ml cutoff) showed 57.1% sensitivity and 92.8% specificity; beta-HCG (10 mIU/ml cutoff) showed 45.2% sensitivity and 92.8% specificity.
• Combined use of CEA and beta-HCG increased sensitivity to 73.8% and efficiency to 0.78, correctly identifying 19 out of 20 malignant effusions, particularly those with negative cytology.

Conclusions:

• CEA and beta-HCG are valuable, highly specific markers for evaluating pleural effusions of uncertain origin.
• Their combined measurement can significantly improve the detection of malignant pleural effusions, especially when cytology is inconclusive.
• While useful for identifying malignancy, these markers alone cannot determine the primary site of cancer.