Serum level of clusterin and its density in men with prostate cancer as novel biomarkers reflecting disease extension.

OBJECTIVES

To assess whether the serum level of clusterin and its density could be used as novel biomarkers of prostate cancer.

METHODS

Sera were obtained from 380 patients with prostate cancer and 120 with benign prostatic hyperplasia. Serum clusterin level was measured by a sandwich enzyme immunoassay, and clusterin density, which was determined by dividing the serum clusterin level by the prostate volume, was also calculated. These findings were analyzed with respect to several clinicopathologic factors.

RESULTS

The mean serum level of clusterin in prostate cancer patients was significantly higher than that in the benign prostatic hyperplasia group. Both the serum clusterin level and clusterin density in prostate cancer patients were significantly associated with major prognostic factors other than biopsy Gleason score. Of the 380 prostate cancer patients, 162 underwent radical prostatectomy and pelvic lymphadenectomy, and 104 and 58 were diagnosed as having organ-confined and extraprostatic diseases, respectively. The clusterin density in patients with organ-confined disease was significantly higher than that in patients with extraprostatic disease; however, there was no significant difference in the serum clusterin level between these 2 groups. Furthermore, biochemical recurrence-free survival in patients with elevated clusterin density was significantly lower than that in patients with normal density.

CONCLUSIONS

These findings suggest that serum clusterin level and its density could serve as a useful practical adjuncts to conventional parameters for estimating the extension of prostate cancer.