Carcinoembryonic antigen in the assessment of lung cancer.

Carcinoembryonic antigen (CEA) was measured in the plasma by radioimmunoassay in 80 patients who were referred because of an apparently resectable lung cancer. There was no correlation between the initial CEA level and survival in patient whose tumours were found to be inoperable or had metastasized, with only 2 of 37 patients surviving longer than 2 years. Following a curative resection, the median survival for patients with initial CEA greater than 40 micrograms l-1 was 6 months compared to 14 months for those with CEA in the range 20-40 micrograms l-1, while 56 per cent of those with CEA less than 20 micrograms l-1 are still alive at 2 years. This trend was found to be highly significant (P < 0.005). Twenty-five per cent of all patients had an initial CEA greater than 40 micrograms l-1 and this was associated with a poor prognosis, despite complete surgical removal of the primary tumour. Such elevations, if discovered in the preoperative assessment, indicate a need for a thorough search for metastases.