The Relationship Between High Serum Prostate Specific Antigen Levels And Prostate Disease

Objective: To investigate the relationship between high level of serum prostate-specific antigen(PSA) (>4ng/ml) and prostate diseases. To study the detection of prostate cancer (PCa) in different PSA level and evaluate the importance of PSA density (PSAD) and the diagnostic values of repeat transrectal ultrasound guided biopsy in PCa.Methods: From July 2007 to December 2009, 464 cases underwent transrectal ultrasound (TRUS) guided 10 cores prostate biopsy due to elevated PSA level (>4ng/ml). After biopsy, serum PSA was measured and TRUS examination was performed at 3-monthly intervals in patients with negative biopsy. The mean (range) follow-up was 20.6 (11-33) months. 27 patients subsequently underwent transurethral resection of prostate (TURP). 69 patients with persistently raised total PSA levels or prostatic intraepithelial neoplasm (PIN) had repeat biopsy. We investigated the detection rate of PCa in Chinese men according to different PSA levels and tried to explain the reason of high serum PSA by the correlation analysis among serum PSA, age, PV and PSAD and comparing with different prostatic histopathological disease. Receiver-operating characteristic (ROC) curves were constructed to evaluate the diagnostic value of PSAD in detecting PCa. Age, PSA, PV and PSAD between the group of PCa and benign prostate disease in repeat biopsy were compared, and the differences in age, PSA, PSAD and Gleason score between patients with positive results on initial and repeat biopsies were also compared.Results: In all 464 patients, PCa 117(25.2%), BPH 201(43.3%), BPH asscoicated with prostatitis 146(31.5%). Among 117 cases of PCa, 111 were diagnosed in the initial biopsy and 6 were indentified after repeat biopsy. The detection rate of PCa in the PSA ranges of 4.1-10.0ng/ml, 10.1-20.0ng/ml, >20.0ng/ml was 17.7%, 33.4% and 60.8% respectively. Age, PSA and PSAD in patients with PCa were higher than that in patients with benign prostate diseases(P<0.01). There were no significant correlation among age, PSA, and PV in PCa group. There were no statistically significant difference between BPH group and BPH with prostatitis group in age, PSA, PV and PSAD. PSA correlated positively with age and PV (the correlation coefficient 0.161, 0.278, P<0.05, 0.01 respectively) in BPH group. For BPH with prostatitis group, there was significant inverse correlation between PSA and age(the correlation coefficient 0.249, P<0.01), but there was not significant correlation between PSA and PV. In the PSA ranges of 4.1-20.0ng/ml, there was significant differences between PCa group and PSAD in PCA group was significantly higher than BPH group and prostatitis group respectively (p<0.05 and p<0.01, respectively). The area under the curve (AUC) of PSAD (0.661) was greater than that of PSA (0.616). The sensitivity, specificity, positive predictive value and avoided biopsy rate of PSAD at a cutoff of 0.24 was 53.9%, 65.4%, 29.6% and 51.4%, respectively. For 69 patients underwent repeat biopsy, there were no significant difference in age and PSA between patients with positive and negative biopsy, but there was significant statistical difference in PSAD. When PSA in the same ranges of 4.1-20.0ng/ml, there were no significant difference in patient age, PSA, PSAD and Gleason score between initial and repeat biopsy with positive resultsConclusions: Men with high serum PSA level may result in BPH, BPH with prostatitis or PCa. The level of serum PSA is not affected by age and PV in PCa group. For patients with PSA at 4.1-20.0ng/ml, PSAD (≥0.24) will play an important role to improve cancer detection rate. Despite an initial negative biopsy, repeat biopsy should be carried out to exclude PCa in high risk population, and elevated PSA and PSAD may be used to avoid unnecessary biopsies with an acceptable decrease in sensitively.