Sensitivity and specificity of single and combined tumour markers in the diagnosis of leptomeningeal metastasis from breast cancer.

The clinical efficacy of four laboratory tests in detecting leptomeningeal metastases in 57 patients with breast carcinoma was assessed. The sensitivity and specificity of beta-glucuronidase, beta 2-microglobulin, carcinoembryonic antigen and lactate dehydrogenase in cerebrospinal fluid were determined. As a single test beta-glucuronidase was the most sensitive (93%) and specific (93%) for discriminating between leptomeningeal metastases and other CNS metastases from breast cancer. Lactate dehydrogenase was the next most useful marker. Both beta 2-microglobulin and carcinoembryonic antigen had a sensitivity of 60%. More specific results were achieved by combining beta-glucuronidase and lactate dehydrogenase. CSF beta-glucuronidase may be useful by itself and in combination with lactate dehydrogenase in the detection of leptomeningeal metastases from breast carcinoma.