[Differentiation of prostate cancer from benign prostatic disease by total prostate specific antigen dynamic profiles after transrectal prostate biopsy].

OBJECTIVE

To investigate the possibility of differentiating prostate cancer (PCa) from benign prostatic disease by total prostate specific antigen (T-PSA) dynamic profiles following transrectal prostate biopsy, and to determine the cutoff value of the T-PSA ratio between pre- and post-biopsy.

METHODS

A total of 36 men at the mean age of 69.89 years with increased serum PSA underwent prostate biopsy guided by transrectal ultrasound, followed by measurement of T-PSA at 10, 30, 60 and 90 min, plotting of T-PSA dynamic profiles and calculation of the pre- and post-biopsy T-PSA ratio at different time points. The patients were divided into a PCa and a non-PCa group according to the pathological results and compared for the difference in T-PSA ratios. The cutoff value of the pre- and post-biopsy T-PSA ratio was determined for the differentiation of PCa from benign prostatic diseases.

RESULTS

The post-biopsy T-PSA ratio was obviously higher in the non-PCa than in the PCa group (P < 0.05). With the ROC curve applied, the cutoff value of the T-PSA ratio was 1.5 and the best time for blood sampling was 30 minutes after the biopsy, with a 75% sensitivity and a 93% specificity.

CONCLUSION

Evaluation of the T-PSA ratio 30 minutes after biopsy might help screen the high-risk PCa population. Biopsy should be repeated for those with a lower T-PSA ratio in spite of initial benign results. The results are to be further supported by more prospective studies.