Abstract
Carcinoembryonic antigen (CEA) testing is a valuable adjunct in the overall management of patients who have non-small-cell lung cancer, especially when selecting surgical candidates for curative lung resection and in cases where the diagnosis is in doubt. Carcinoembryonic antigen levels above 50 strongly suggest advanced-stage cancer and should discourage lung resections in otherwise suitable cases. Carcinoembryonic antigen testing can enhance problem solving in difficult cases and help prevent needless invasive interventions.