CSF carcinoembryonic antigen in meningeal carcinomatosis from breast cancer.

Levels of CSF carcinoembryonic antigen (CEA) were determined in 23 patients with breast cancer and meningeal carcinomatosis. Levels greater than 1.5 ng/mL were observed in 16 patients; seven patients had undetectable levels. The meningeal disease of seven patients with elevated CSF CEA levels completely responded to treatment, and their CSF CEA levels concurrently decreased. Two patients whose meningeal disease responded poorly to treatment had persistently elevated levels of CSF CEA. In two other patients, a rising CSF CEA level was detected before there was any other evidence of meningeal relapse. Serial measurement of CSF CEA may play an important role in the clinical management of meningeal carcinomatosis in patients with breast cancer.