Free and total prostate-specific antigen levels in saliva and the comparison with serum levels in men

Objective: We investigated free and total prostate-specific antigen (PSA) l evels and free/total (f/t) ratio in the fasting saliva and compared them wi th the serum levels in normal individuals, in patients with benign prostati c hyperplasia (BPH) and prostate cancer. Our aim waste determine free and t otal PSA and f/t ratio in saliva and to improve and simplify the differenti ation between BPH and prostate cancer by using saliva as an alternative to serum. Methods: Serum and fasting saliva concentrations of free and total PSA were measured in 35 men with BPH, 16 men with stage D prostate cancer, and 25 h ealthy men. Serum and fasting saliva samples were collected at the same tim e and were analyzed on the same day at our laboratory with microparticle en zyme immunoassay technology. Results: For the total of 76 men, there was a significant correlation betwe en free and total PSA levels in each sample (r = 0.97 for serum and r = 0.4 4 for saliva, p<0.001). Although there was a significant difference between three groups for serum-free and total PSA levels and serum f/t ratios, no significant difference was determined between groups for salivary free and total PSA levels and salivary f/t ratios. No correlations were found betwee n patient age and salivary PSA levels. Conclusions: Fasting salivary free and total PSA levels are not effected by high serum levels of prostatic origin. Although there was a significant di fference between mean serum and salivary levels of free and total PSA in ea ch group, the f/t ratio of saliva was very close to the serum ratio of norm al subjects. Determination of free and total PSA in saliva to improve and s implify the differentiation between prostate cancer and BPH is not suitable for use as alternative measurement of serum. Copyright (C) 2000 S. Karger AG, Basel.