Cerebrospinal fluid bombesin and calcitonin in patients with central nervous system metastases from small-cell lung cancer.

To determine whether levels of mammalian bombesin (MB) or calcitonin would be useful in detecting CNS metastases in patients with small-cell lung cancer (SCLC), we measured their concentrations in the CSF of 94 patients who underwent lumbar puncture for suspected CNS involvement. The MB concentration was significantly elevated in the 51 patients with definite CNS metastases as compared with the 30 patients without apparent CNS involvement (P less than .01). This significance was due to increased levels of MB in 18 patients with meningeal carcinomatosis. Whereas CSF MB was detectable (greater than 10 fmol/mL) in only 7% of patients without apparent CNS involvement, CSF MB was detectable in 21% with parenchymal CNS metastases and in 78% of those with meningeal carcinomatosis. Interestingly, 93% of patients having MB concentrations above 20 fmol/mL had meningeal metastases. The calcitonin concentration was significantly elevated in 42 patients with CNS metastases as compared with 27 patients without CNS involvement (P less than .01). Both the 15 patients with meningeal carcinomatosis and the 27 patients with only parenchymal metastases had significantly elevated levels of CSF calcitonin as compared with those without CNS metastases. Fifty-three percent of patients with meningeal carcinomatosis and 48% with parenchymal metastases had a CSF calcitonin level above 18 fmol/mL, whereas only 7% without apparent CNS metastases exceeded this level. Sixty-seven percent of all patients with CNS metastases had increased CSF levels of one of the two hormonal markers. Thus, in SCLC patients, an elevated CSF calcitonin strongly suggested CNS metastases and an elevated MB was very suggestive of the presence of meningeal carcinomatosis. However, only the latter observation seems of clinical importance due to the difficulties in establishing this diagnosis with current diagnostic measures.

Altered neuropeptide concentrations in cerebrospinal fluid of psychiatric patients.

Immunoreactive somatostatin, bombesin, and cholecystokinin were measured in cerebrospinal fluid of normal subjects and patients with anorexia nervosa, depression, mania, and schizophrenia. Somatostatin-like immunoreactivity was decreased in anorexic and depressed patients. Bombesin-like immunoreactivity tended to be decreased in schizophrenics. Cholecystokinin-like immunoreactivity did not differ between groups. These data suggest a possible function for neuropeptides in regulation of human behavior.

Cerebrospinal fluid cholecystokinin, bombesin and somatostatin in schizophrenia and normals.

Cerebrospinal fluid from 31 normals and two groups of phenomenologically similar schizophrenics (n = 72) were collected by identical methods. Radioimmunoassay of CSF was carried out for somatostatin, bombesin, and cholecystokinin. One group of schizophrenics had increased baseline somatostatin and cholecystokinin, and decreased bombesin. No CSF gradient effect was found for the peptides nor were their levels affected by probenecid or pimozide treatment. An inverse correlation was found between bombesin and psychosis rating. Intercorrelation between the peptides and HVA, 5-HIAA, and MHPG were not significant.