The Clinical Significance of Increased Prostate Specific Antigen Concentration in Routine Check-Up

Abstract

Background : As prostate cancer in men is increasing in Korea, the need for early detection by mass screening has become an important issue. Screening tests for early detection of prostate cancer are digital rectal examination, transrectal ultrasonography (TRUS) and prostate specific antigen (PSA) test. PSA test has been mainly used for prostate cancer screening in health promotion centers. However, PSA has a high sensitivity but low specificity. Therefore, PSA concentration can be increased not only in prostate cancer, but also in several benign prostate diseases such as benign prostate hyperplasia (BPH), prostatitis, and prostate ischemia. Also, PSA concentration can increase in the elderly. Therefore, we investigated the results of follow-up PSA tests, in the cases of increased PSA concentration on screening.

Methods : In 538 cases, the PSA concentration were increased over 2.5 ng/ml among total 17,302 males checked up on screening test at Ajou University Hospital from January 1999 to December 2001. Two hundred and four cases followed up with TRUS or prostate biopsy were chosen. We investigated 89 cases who performed follow- up PSA test. On the basis of the results of biopsy or TRUS, the subjects were classified into non-disease group, benign prostate disease group and prostate cancer group (possible or confirmed prostate cancer group).

Results : The mean age of non-disease group was 35.5 5.9 years, which was significantly lower than that of benign prostate disease group and prostate cancer group (P＜0.05). Compared to the mean age of prostate cancer group (60.6 10.4 years) and non-prostate cancer group (53.1 12.3 years), prostate cancer group was significantly older than non prostate cancer group (P=0.005). When the lower limit of age was set to 40 years (mean-2SD), confirmed prostate cancer group was significantly older than other groups (p＜0.001). The PSA concentration of confirmed prostate cancer group (11.33 7.58 ng/ml) was significantly higher than that of non-prostate disease group (4.35 2.22 ng/ml) and possible prostate cancer group (4.44 2.29 ng/ml) (P＜0.05). The follow-up PSA level of confirmed prostate cancer group (10.13 6.13 ng/ml) was significantly higher than that of non-prostate disease group (2.55 0.97 ng/ml), BPH group (4.33 3.80 ng/ml), prostatitis group (3.61 2.17 ng/ml), prostate cyst group (3.00 1.86 ng/ml) and possible prostate cancer group (3.81 2.82 ng/ml) (P＜0.05).

Conclusion : It is recommended that screening test for prostate cancer be performed after the age of 40. While follow-up PSA test is needed when the PSA is increased up to less than 10 ng/ml, prostate biopsy may be desired in the PSA value of 10.0 ng/ml or greater.