The carcinoembryonic antigen assay in bronchogenic carcinoma

Pretreatment levels of plasma carcinoembryonic antigen (CEA) were determined for a series of patients with bronchogenic carcinoma and for a series of patients with benign pulmonary disease. These data were analyzed to determine the diagnostic and prognostic value of the CEA radioimmunoassay in bronchogenic carcinoma. CEA plasma values in patients with benign pulmonary disease indicate that the level of discrimination between positive and negative tests for bronchogenic carcinoma should be at least 5.0 ng/ml. Half the patients with bronchogenic carcinoma in this study had CEA plasma values less than 5.0 ng/ml. The data also indicate that the CEA test does not correlate well with patient survival or stage of disease at time of diagnosis, and that the CEA test frequently fails to identify patients with extensive metastatic disease. It is concluded that the pretherapy plasma CEA level will not be of value as a diagnostic or prognostic test in the management of a significant number of patients with bronchogenic carcinoma.