Carcinoembryonic antigen estimation in cerebrospinal fluid in patients with metastatic breast cancer.

Cerebrospinal fluid (CSF) and plasma levels of carcinoembryonic antigen (CEA) have been measured in 39 patients with disseminated breast cancer, 22 of whom had metastases involving the central nervous system (CNS). CSF CEA was also measured in 13 patients without cancer who had non-malignant disorders. Thirteen of the 22 patients with CNS metastases had elevated CSF CEA, together with 4 of 17 patients with disseminated breast cancer without neurological involvement. These 4 patients were shown to have extensive dorso-lumbar spine deposits. CSF CEA was not detected in any of the 13 patients without cancer. Estimation of CEA in the cerebrospinal fluid may be a useful adjunct in the diagnosis of disseminated breast cancer involving the CNS, provided that spinal metastases are absent.