Prostate Specific Antigen Velocity in Healthy Men with Initial PSA Levels of 4.0ng/ml or Less

Kim, Jong Gu; Cho, In Rae; Park, Seok San

Abstract

PURPOSE: We evaluated the relative long-term longitudinal changes in the levels of serial prostate specific antigen in healthy men without urinary tract infection and initial PSA of 4.0ng/ml or less.
MATERIALS AND METHODS
Between February 1996 and June 2000, the rate of PSA change (PSAV) in 1,132 healthy men with an initial PSA of 4.0ng/ml or less who were clinically free of urinary tract infection and known prostate disease were analyzed. In all cases, a minimum of 2 PSA levels were measured at intervals of at least 12month. The influence of age, initial PSA and interval between measurements were assessed.
RESULTS
The mean age, initial PSA, interval between measurements, change in PSA and PSAV were 45.2 (24-80) years, 1.05 (0.04-4.0)ng/ml, 19.2 (12-39) month, 0.13 ( 1.0-3.1)ng/ml and 0.08 ( 0.8-1.22)ng/ml/year. A cumulative frequency plot of PSAV demonstrated that 50%, 95% and 97% of subjects had PSAV 0.06ng/ml/year, 0.55 ng/ml/year and 0.60ng/ml/year or less, respectively. PSAV was correlated with age (r=0.090, p=0.002) and initial PSA (r=0.331, p <0.001) but not with interval between measurements (r=0.046, p=0.132). Age was directly correlated with initial PSA (r=0.118, p<0.05). However, age was not correlated with PSAV (r=0.052, p>0.05) when adjusted by the initial PSA level. Percentage of the men with PSAV of great than 0.75ng/ml/year was 1.8% (20/1,132); 0.6% (4/708) for those whose initial PSA were less than 1.0ng/ml, 1.7% (6/358) for 1.1-2.0ng/ml and 15.1% (10/66) for 2.1-4.0ng/ml.
CONCLUSIONS
Among men with normal PSA whose PSA is sampled over relatively long-term interval, PSAV is directly correlated with initial PSA but not with age and interval between measurements. Men with a PSA of 2.0ng/ml or less are at low risk for abnormal PSAV and annual PSA monitoring may not be necessary, but the annual longitudinal monitoring may be clinically useful in men with an initial PSA of 2.1-4.0ng/ml. Large prospective studies are required to assess the precise cut-off point of PSAV for Korean men in the early detection of prostate cancer.