Cerebrospinal fluid prostate specific antigen (CSF PSA) in prostate cancer patients with lower spine metastasis.

ABSTRACT

AIM: In this prospective study, our aim was to investigate the CSF PSA levels and CSF/Serum PSA ratios in patients with prostate cancer with lower spine metastasis. METHODS: The study involved patients with prostate cancer (n = 15), benign prostatic hyperplasia (n = 17) and non-prostatic disease (n = 9). Serum and CSF were obtained prior to spinal anesthesia for urological surgery. Total PSA levels in the serum and CSF were measured by electrochemiluminescence immunoassay. The results were tested statistically using the Mann-Whitney U test. RESULTS: The mean serum PSA levels were 20.36 ng/ml in the prostate cancer patients, 5.37 ng/ml in the BPH patients and 0.76 ng/ml non-prostatic disease. The mean CSF PSA levels in groups were 0.127, 0.051 and 0.027 ng/ml, respectively. The mean CSF PSA/serum PSA ratios in groups were 0.007, 0.018 and 0.042, respectively. This result is statistically significant (P < 0.001). CONCLUSIONS: Although mean serum PSA and CSF PSA levels in the patients with cancer of the prostate and lower spine metastasis are higher than those in the others, the mean CSF PSA/serum PSA ratio is lower. However, clinical usefulness of CSF PSA value and CSF PSA/ Serum PSA ratio can be limited because CSF PSA values are usually very low, and CSF PSA/Serum PSA ratio of 4 prostate cancer patients are as high as 1 BPH patient.